LTC1563-2/LTC1563-3

Extremely Easy to Use--A Single Resistor Value
Sets the Cutoff Frequency (256Hz < f

< 256kHz)

Extremely Flexible--Different Resistor Values
Allow Arbitrary Transfer Functions with or without
Gain (256Hz < f

< 256kHz)

Supports Cutoff Frequencies Up to 360kHz Using
FilterCAD

LTC1563-2: Unity-Gain Butterworth Response Uses a
Single Resistor Value, Different Resistor Values
Allow Other Responses with or without Gain

LTC1563-3: Unity-Gain Bessel Response Uses a
Single Resistor Value, Different Resistor Values
Allow Other Responses with or without Gain

Rail-to-Rail Input and Output Voltages

Operates from a Single 3V (2.7V Min) to

5V Supply

Low Noise: 36

RMS

for f

= 25.6kHz, 60

RMS

for

= 256kHz

Accuracy <

2% (Typ)

DC Offset < 1mV

Cascadable to Form 8th Order Lowpass Filters

The LTC

1563-2/LTC1563-3 are a family of extremely

easy-to-use, active RC lowpass filters with rail-to-rail
inputs and outputs and low DC offset suitable for systems
with a resolution of up to 16 bits. The LTC1563-2, with a
single resistor value, gives a unity-gain Butterworth
response. The LTC1563-3, with a single resistor value,
gives a unity-gain Bessel response. The proprietary
architecture of these parts allows for a simple resistor
calculation:

R = 10k (256kHz/f

); f

= Cutoff Frequency

where f

is the desired cutoff frequency. For many appli-

cations, this formula is all that is needed to design a filter.
By simply utilizing different valued resistors, gain and
other responses are achieved.

The LTC1563-X features a low power mode, for the lower
frequency applications, where the supply current is re-
duced by an order of magnitude and a near zero power
shutdown mode.

The LTC1563-Xs are available in the narrow SSOP-16
package (SO-8 footprint).

Replaces Discrete RC Active Filters and Modules

Antialiasing Filters

Smoothing or Reconstruction Filters

Linear Phase Filtering for Data Communication

Phase Locked Loops

Single 3.3V, 256Hz to 256kHz Butterworth Lowpass Filter

Active RC, 4th Order

Lowpass Filter Family

, LTC and LT are registered trademarks of Linear Technology Corporation.

0.1

3.3V

OUT

= 256kHz

1563 TA01

LTC1563-2

0.1

INVA

LPA

AGND

LPB

INVB

10k

( )

FREQUENCY (Hz)

10k

100

GAIN (dB)

100k

1563 TA02

R = 10M
f

= 256Hz

R = 10k

= 256kHz

Frequency Response

APPLICATIO S

FEATURES

TYPICAL APPLICATIO

DESCRIPTIO

FilterCAD is trademark of Linear Technology Corporation.

LTC1563-2/LTC1563-3

LTC1563-2CGN
LTC1563-3CGN
LTC1563-2IGN
LTC1563-3IGN

JMAX

= 150

= 135

C/ W

ORDER PART

NUMBER

Total Supply Voltage (V

to V

) ............................... 11V

Maximum Input Voltage at
Any Pin ....................... (V

0.3V)

+ 0.3V)

Power Dissipation .............................................. 500mW
Operating Temperature Range

LTC1563C ............................................... 0

C to 70

LTC1563I ............................................ 40

C to 85

Storage Temperature Range ................. 65

C to 150

Lead Temperature (Soldering, 10 sec).................. 300

(Note 1)

ABSOLUTE

AXI

RATINGS

PACKAGE/ORDER I

FOR

ATIO

ELECTRICAL CHARACTERISTICS

TOP VIEW

GN PACKAGE

16-LEAD PLASTIC SSOP

INVA

LPA

AGND

LPB

INVB

NOTE: PINS LABELED NC ARE NOT CONNECTED
INTERNALLY AND SHOULD BE CONNECTED TO THE
SYSTEM GROUND

The

denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25

= Single 4.75V, EN pin to logic "low," Gain = 1, R

FIL

= R11 = R21 = R31 = R12 = R22 = R32, specifications apply to both the high

speed (HS) and low power (LP) modes unless otherwise noted.

Consult factory for Military grade parts.

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Specifications for Both LTC1563-2 and LTC1563-3

Total Supply Voltage (V

), HS Mode

Total Supply Voltage (V

), LP Mode

2.7

Output Voltage Swing High (LPB Pin)

= 3V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

2.9

2.95

HS Mode

= 4.75V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

4.55

4.7

5V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

4.8

4.9

Output Voltage Swing Low (LPB Pin)

= 3V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

0.015

0.05

HS Mode

= 4.75V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

0.02

0.05

5V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

4.95

4.9

Output Swing High (LPB Pin)

= 2.7V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

2.6

2.65

LP Mode

= 4.75V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

4.55

4.65

5V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

4.8

4.9

Output Swing Low (LPB Pin)

= 2.7V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

0.01

0.05

LP Mode

= 4.75V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

0.015

0.05

5V, f

= 25.6kHz, R

FIL

= 100k, R

= 10k to GND

4.95

4.9

DC Offset Voltage, HS Mode

= 3V, f

= 25.6kHz, R

FIL

= 100k

1.5

(Section A Only)

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

1.0

5V, f

= 25.6kHz, R

FIL

= 100k

1.5

DC Offset Voltage, LP Mode

= 2.7V, f

= 25.6kHz, R

FIL

= 100k

(Section A Only)

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

5V, f

= 25.6kHz, R

FIL

= 100k

DC Offset Voltage, HS Mode

= 3V, f

= 25.6kHz, R

FIL

= 100k

1.5

(Input to Output, Sections A, B Cascaded)

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

1.0

5V, f

= 25.6kHz, R

FIL

= 100k

1.5

DC Offset Voltage, LP Mode

= 2.7V, f

= 25.6kHz, R

FIL

= 100k

(Input to Output, Sections A, B Cascaded)

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

5V, f

= 25.6kHz, R

FIL

= 100k

15632
15633
15632I
15633I

GN PART

MARKING

LTC1563-2/LTC1563-3

ELECTRICAL CHARACTERISTICS

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

DC Offset Voltage Drift, HS Mode

= 3V, f

= 25.6kHz, R

FIL

= 100k

(Input to Output, Sections A, B Cascaded)

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

5V, f

= 25.6kHz, R

FIL

= 100k

DC Offset Voltage Drift, LP Mode

= 2.7V, f

= 25.6kHz, R

FIL

= 100k

(Input to Output, Sections A, B Cascaded)

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

5V, f

= 25.6kHz, R

FIL

= 100k

AGND Voltage

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

2.35

2.375

2.40

Power Supply Current, HS Mode

= 3V, f

= 25.6kHz, R

FIL

= 100k

8.0

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

10.5

5V, f

= 25.6kHz, R

FIL

= 100k

Power Supply Current, LP Mode

= 2.7V, f

= 25.6kHz, R

FIL

= 100k

1.0

1.8

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

1.4

2.5

5V, f

= 25.6kHz, R

FIL

= 100k

2.3

3.5

Shutdown Mode Supply Current

= 4.75V, f

= 25.6kHz, R

FIL

= 100k

EN Input

= 3V

0.8

Logic Low Level

= 4.75V

EN Input

= 3V

2.5

Logic High Level

= 4.75V

4.3

4.4

= 3V

0.8

Logic Low Level

= 4.75V

= 3V

2.5

Logic High Level

= 4.75V

4.3

4.4

LTC1563-2 Transfer Function Characteristics

Cutoff Frequency Range, f

= 3V

0.256

256

kHz

HS Mode

= 4.75V

0.256

256

kHz

(Note 2)

0.256

256

kHz

Cutoff Frequency Range, f

= 2.7V

0.256

25.6

kHz

LP Mode

= 4.75V

0.256

25.6

kHz

(Note 2)

0.256

25.6

kHz

Cutoff Frequency Accuracy, HS Mode

= 3V, R

FIL

= 100k

2.0

1.5

3.5

= 25.6kHz

= 4.75V, R

FIL

= 100k

2.0

1.5

3.5

5V, R

FIL

= 100k

2.0

1.5

3.5

Cutoff Frequency Accuracy, HS Mode

= 3V, R

FIL

= 10k

1.5

= 256kHz

= 4.75V, R

FIL

= 10k

1.5

5V, R

FIL

= 10k

1.5

Cutoff Frequency Accuracy, LP Mode

= 2.7V, R

FIL

= 100k

1.5

= 25.6kHz

= 4.75V, R

FIL

= 100k

1.5

5V, R

FIL

= 100k

1.5

Cutoff Frequency Temperature Coefficient

(Note 3)

ppm/

Passband Gain, HS Mode, f

= 25.6kHz

Test Frequency = 2.56kHz (0.1 · f

)

0.2

= 4.75V, R

FIL

= 100k

Test Frequency = 12.8kHz (0.5 · f

)

0.3

The

denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25

= Single 4.75V, EN pin to logic "low," Gain = 1, R

FIL

= R11 = R21 = R31 = R12 = R22 = R32, specifications apply to both the high

speed (HS) and low power (LP) modes unless otherwise noted.

LTC1563-2/LTC1563-3

ELECTRICAL CHARACTERISTICS

PARAMETER

CONDITIONS

MIN

TYP

MAX

UNITS

Stopband Gain, HS Mode, f

= 25.6kHz

Test Frequency = 51.2kHz (2 · f

)

21.5

d B

= 4.75V, R

FIL

= 100k

Test Frequency = 102.4kHz (4 · f

)

Passband Gain, HS Mode, f

= 256kHz

Test Frequency = 25.6kHz (0.1 · f

)

0.2

= 4.75V, R

FIL

= 10k

Test Frequency = 128kHz (0.5 · f

)

0.5

Stopband Gain, HS Mode, f

= 256kHz

Test Frequency = 400kHz (1.56 · f

)

15.7

13.5

= 4.75V, R

FIL

= 10k

Test Frequency = 500kHz (1.95 · f

)

23.3

21.5

Passband Gain, LP Mode, f

= 25.6kHz

Test Frequency = 2.56kHz (0.1 · f

)

0.25

= 4.75V, R

FIL

= 100k

Test Frequency = 12.8kHz (0.5 · f

)

0.6

0.02

0.6

Stopband Gain, LP Mode, f

= 25.6kHz

Test Frequency = 51.2kHz (2 · f

)

= 4.75V, R

FIL

= 100k

Test Frequency = 102.4kHz (4 · f

)

46.5

LTC1563-3 Transfer Function Characteristics

Cutoff Frequency Range, f

= 3V

0.256

256

kHz

HS Mode

= 4.75V

0.256

256

kHz

(Note 2)

0.256

256

kHz

Cutoff Frequency Range, f

= 2.7V

0.256

25.6

kHz

LP Mode

= 4.75V

0.256

25.6

kHz

(Note 2)

0.256

25.6

kHz

Cutoff Frequency Accuracy, HS Mode

= 3V, R

FIL

= 100k

5.5

= 25.6kHz

= 4.75V, R

FIL

= 100k

5.5

5V, R

FIL

= 100k

5.5

Cutoff Frequency Accuracy, HS Mode

= 3V, R

FIL

= 10k

= 256kHz

= 4.75V, R

FIL

= 10

5V, R

FIL

= 10k

Cutoff Frequency Accuracy, LP Mode

= 2.7V, R

FIL

= 100k

= 25.6kHz

= 4.75V, R

FIL

= 100k

5V, R

FIL

= 100k

Cutoff Frequency Temperature Coefficient

(Note 3)

ppm/

Passband Gain, HS Mode, f

= 25.6kHz

Test Frequency = 2.56kHz (0.1 · f

)

0.2

0.03

0.2

= 4.75V, R

FIL

= 100k

Test Frequency = 12.8kHz (0.5 · f

)

1.0

0.72

0.25

Stopband Gain, HS Mode, f

= 25.6kHz

Test Frequency = 51.2kHz (2 · f

)

13.6

= 4.75V, R

FIL

= 100k

Test Frequency = 102.4kHz (4 · f

)

34.7

Passband Gain, HS Mode, f

= 256kHz

Test Frequency = 25.6kHz (0.1 · f

)

0.2

0.03

0.2

= 4.75V, R

FIL

= 10k

Test Frequency = 128kHz (0.5 · f

)

1.1

0.72

0.5

Stopband Gain, HS Mode, f

= 256kHz

Test Frequency = 400kHz (1.56 · f

)

8.3

= 4.75V, R

FIL

= 10k

Test Frequency = 500kHz (1.95 · f

)

10.5

Passband Gain, LP Mode, f

= 25.6kHz

Test Frequency = 2.56kHz (0.1 · f

)

0.2

0.03

0.2

= 4.75V, R

FIL

= 100k

Test Frequency = 12.8kHz (0.5 · f

)

1.0

0.72

0.25

Stopband Gain, LP Mode, f

= 25.6kHz

Test Frequency = 51.2kHz (2 · f

)

13.6

= 4.75V, R

FIL

= 100k

Test Frequency = 102.4kHz (4 · f

)

34.7

Note 1: Absolute Maximum Ratings are those value beyond which the life
of a device may be impaired.

Note 2: The minimum cutoff frequency of the LTC1563 is arbitrarily listed
as 256Hz. The limit is arrived at by setting the maximum resistor value
limit at 10M

. The LTC1563 can be used with even larger valued resistors.

When using very large values of resistance careful layout and thorough
assembly practices are required. There may also be greater DC offset at
high temperatures when using such large valued resistors.

The

denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25

= Single 4.75V, EN pin to logic "low," Gain = 1, R

FIL

= R11 = R21 = R31 = R12 = R22 = R32, specifications apply to both the high

speed (HS) and low power (LP) modes unless otherwise noted.

Note 3: The cutoff frequency temperature drift at low frequencies is as
listed. At higher cutoff frequencies (approaching 25.6kHz in low power
mode and approaching 256kHz in high speed mode) the internal
amplifier's bandwidth can effect the cutoff frequency. At these limits the
cutoff frequency temperature drift is

15ppm/

LTC1563-2/LTC1563-3

TYPICAL PERFOR A CE CHARACTERISTICS

Output Voltage Swing High vs
Load Resistance

Output Voltage Swing Low vs
Load Resistance

THD + Noise vs Input Voltage

LOAD RESISTANCE--LOAD TO GROUND (

)

100

OUTPUT VOLTAGE (V)

3.4

3.2

3.0

2.8

2.6

2.4

2.2

2.0

10k

100k

1563 G01

= SINGLE 3.3V

LP MODE

HS MODE

LOAD RESISTANCE--LOAD TO GROUND (

)

100

OUTPUT VOLTAGE (V)

5.5

5.0

4.5

4.0

3.5

3.0

2.5

10k

100k

1563 G02

HS MODE

LP MODE

= SINGLE 5V

LOAD RESISTANCE--LOAD TO GROUND (

)

100

OUTPUT VOLTAGE (V)

5.5

5.0

4.5

4.0

3.5

3.0

2.5

10k

100k

1563 G03

HS MODE

LP MODE

LOAD RESISTANCE--LOAD TO GROUND (

)

100

OUTPUT VOLTAGE (V)

0.025

0.020

0.015

0.010

0.005

10k

100k

1563 G04

HS MODE

LP MODE

= SINGLE 3.3V

LOAD RESISTANCE--LOAD TO GROUND (

)

100

OUTPUT VOLTAGE (V)

0.025

0.020

0.015

0.010

0.005

10k

100k

1563 G05

HS MODE

LP MODE

= SINGLE 5V

LOAD RESISTANCE--LOAD TO GROUND (

)

100

OUTPUT VOLTAGE (V)

4.3

4.4

4.5

4.6

4.7

4.8

4.9

5.0

10k

100k

1563 G06

HS MODE

LP MODE

INPUT VOLTAGE (V

P-P

)

0.1

(THD + NOISE)/SIGNAL (dB)

100

1563 G07

3.3V SUPPLY

5V SUPPLY

= 25.6kHz

LOW POWER MODE
f

= 5kHz

INPUT VOLTAGE (V

P-P

)

0.1

(THD + NOISE)/SIGNAL (dB)

100

1563 G08

3.3V SUPPLY

5V SUPPLY

= 25.6kHz

HIGH SPEED MODE
f

= 5kHz

INPUT VOLTAGE (V

P-P

)

0.1

(THD + NOISE)/SIGNAL (dB)

100

1563 G09

3.3V SUPPLY

5V SUPPLY

= 256kHz

HIGH SPEED MODE
f

= 50kHz

LTC1563-2/LTC1563-3

THD + Noise vs Input Frequency

INPUT FREQUENCY (kHz)

(THD + NOISE)/SIGNAL (dB)

1563 G10

100

P-P

= SINGLE 3.3V

LOW POWER MODE
f

= 25.6kHz

INPUT FREQUENCY (kHz)

(THD + NOISE)/SIGNAL (dB)

1563 G11

100

P-P

= SINGLE 3.3V

HIGH SPEED MODE
f

= 25.6kHz

100

INPUT FREQUENCY (kHz)

100

1563 G12

200

(THD + NOISE)/SIGNAL (dB)

P-P

= SINGLE 3V

HIGH SPEED MODE
f

= 256kHz

INPUT FREQUENCY (kHz)

(THD + NOISE)/SIGNAL (dB)

1563 G13

100

P-P

= SINGLE 5V

LOW POWER MODE
f

= 25.6kHz

INPUT FREQUENCY (kHz)

(THD + NOISE)/SIGNAL (dB)

1563 G14

100

P-P

= SINGLE 5V

HIGH SPEED MODE
f

= 25.6kHz

100

INPUT FREQUENCY (kHz)

100

1563 G15

200

(THD + NOISE)/SIGNAL (dB)

P-P

= SINGLE 5V

HIGH SPEED MODE
f

= 256kHz

INPUT FREQUENCY (kHz)

(THD + NOISE)/SIGNAL (dB)

1563 G16

100

P-P

LOW POWER MODE
f

= 25.6kHz

INPUT FREQUENCY (kHz)

(THD + NOISE)/SIGNAL (dB)

1563 G17

100

P-P

HIGH SPEED MODE
f

= 25.6kHz

100

INPUT FREQUENCY (kHz)

100

1563 G18

200

(THD + NOISE)/SIGNAL (dB)

P-P

HIGH SPEED MODE
f

= 256kHz

TYPICAL PERFOR A CE CHARACTERISTICS

LTC1563-2/LTC1563-3

THD + Noise vs Output Load

Output Voltage Noise vs Cutoff
Frequency

THD + Noise vs Output Load

Stopband Gain vs Input Frequency

Crosstalk Rejection vs Frequency

OUTPUT LOAD RESISTANCE--LOAD TO GROUND (k

)

(THD + NOISE)/SIGNAL (dB)

1563 G19

100

LP MODE,
3V

P-P

SIGNAL

LP MODE,
2V

P-P

SIGNAL

HS MODE,
3V

P-P

SIGNAL

HS MODE,
2V

P-P

SIGNAL

= SINGLE 5V

= 25.6kHz

= 5kHz

OUTPUT LOAD RESISTANCE--LOAD TO GROUND (k

)

(THD + NOISE)/SIGNAL (dB)

1563 G20

100

= SINGLE 5V

HIGH SPEED MODE
f

= 256kHz

= 20kHz, 50kHz

P-P

, 20kHz

P-P

, 50kHz

P-P

, 50kHz

P-P

, 20kHz

(Hz)

TOTAL INTEGRATED NOISE (

RMS

)

0.1

100

1000

1563 G21

= 25

HS MODE

LP MODE

OUTPUT LOAD RESISTANCE--LOAD TO GROUND (k

)

(THD + NOISE)/SIGNAL (dB)

1563 G22

100

LP MODE,
5V

P-P

SIGNAL

LP MODE,
2V

P-P

SIGNAL

HS MODE,
5V

P-P

SIGNAL

HS MODE,
2V

P-P

SIGNAL

= 25.6kHz

= 5kHz

100

OUTPUT LOAD RESISTANCE--LOAD TO GROUND (k

)

(THD + NOISE)/SIGNAL (dB)

1563 G23

P-P

, 50kHz

P-P

, 20kHz

P-P

, 20kHz

P-P

, 50kHz

HIGH SPEED MODE
f

= 256kHz

= 20kHz, 50kHz

FREQUENCY (kHz)

CROSSTALK (dB)

100

110

100

1563 G25

DUAL SECOND ORDER
BUTTERWORTH
f

= 25.6kHz

HS OR LP MODE

FREQUENCY (Hz)

10k

100k

1563 G26

CROSSTALK (dB)

100

110

DUAL SECOND ORDER
BUTTERWORTH
f

= 256kHz

HIGH SPEED MODE

FREQUENCY (Hz)

GAIN (dB)

10k

10M

100M

1563 G24

100k

LTC1563-3

LTC1563-2

= 256kHz

TYPICAL PERFOR A CE CHARACTERISTICS

LTC1563-2/LTC1563-3

LP (Pin 1): Low Power. The LTC1563-X has two operating
modes. Most applications use the part's High Speed
operating mode. Some lower frequency, lower gain appli-
cations can take advantage of the Low Power mode. When
placed in the Low Power mode, the supply current is nearly
an order of magnitude lower than the High Speed mode.
Refer to the Applications Information section for more
information on the Low Power mode.

The LTC1563-X is in the High Speed mode when the
LP input is at a logic high level or is open-circuited. A small
pull-up current source at the LP input defaults the
LTC1563-X to the High Speed mode if the pin is left open.
The part is in the Low Power mode when the pin is pulled
to a logic low level or connected to V

SA, SB (Pins 2, 11): Summing Pins. These pins are a
summing point for signals fed forward and backward.
Capacitance on the SA or SB pin will cause excess peaking
of the frequency response near the cutoff frequency. The
three external resistors for each section should be located
as close as possible to the summing pin to minimize this
effect. Refer to the Applications Information section for
more details.

NC (Pins 3, 5, 10, 12, 14): These pins are not connected
internally. For best performance, they should be con-
nected to ground.

INVA, INVB (Pins 4, 13): Inverting Input. Each of the INV
pins is an inverting input of an op amp. Note that the INV
pins are high impedance, sensitive nodes of the filter and
very susceptible to coupling of unintended signals.
Capacitance on the INV nodes will also affect the fre-
quency response of the filter sections. For these reasons,
printed circuit connections to the INV pins must be kept as
short as possible.

CTIO

LPA, LPB (Pins 6, 15): Lowpass Output. These pins are
the rail-to-rail outputs of an op amp. Each output is
designed to drive a nominal net load of 5k

and 20pF.

Refer to the Applications Information section for more
details on output loading effects.

AGND (Pin 7): Analog Ground. The AGND pin is the
midpoint of an internal resistive voltage divider developing
a potential halfway between the V

and V

pins. The

equivalent series resistance is nominally 10k

. This serves

as an internal ground reference. Filter performance will
reflect the quality of the analog signal ground. An analog
ground plane surrounding the package is recommended.
The analog ground plane should be connected to any
digital ground at a single point. Figures 1 and 2 show the
proper connections for dual and single supply operation.

, V

(Pins 8, 16): The V

and V

pins should be

bypassed with 0.1

F capacitors to an adequate analog

ground or ground plane. These capacitors should be
connected as closely as possible to the supply pins. Low
noise linear supplies are recommended. Switching sup-
plies are not recommended as they will decrease the
filter's dynamic range. Refer to Figures 1 and 2 for the
proper connections for dual and single supply operation.

EN (Pin 9): ENABLE. When the EN input goes high or is
open-circuited, the LTC1563-X enters a shutdown state
and only junction leakage currents flow. The AGND pin, the
LPA output and the LPB output assume high impedance
states. If an input signal is applied to a complete filter
circuit while the LTC1563-X is in shutdown, some signal
will normally flow to the output through passive compo-
nents around the inactive part.

A small internal pull-up current source at the EN input
defaults the LTC1563 to the shutdown state if the EN pin
is left floating. Therefore, the user must connect the EN pin
to V

(or a logic low) to enable the part for normal

operation.

LTC1563-2/LTC1563-3

INVA

LPA

AGND

LPB

INVB

0.1

LTC1563-X

ANALOG
GROUND
PLANE

DIGITAL

GROUND PLANE

(IF ANY)

1563 PF01

SINGLE POINT
SYSTEM GROUND

0.1

CTIO

INVA

LPA

AGND

LPB

INVB

0.1

LTC1563-X

ANALOG
GROUND
PLANE

DIGITAL

GROUND PLANE

(IF ANY)

1563 PF02

SINGLE POINT
SYSTEM GROUND

0.1

Dual Supply Power and Ground Connections

Single Supply Power and Ground Connections

BLOCK DIAGRA

SHUTDOWN

SWITCH

SHUTDOWN

SWITCH

20k

AGND

LPA

INVA

R31

R21

R11

C2A

AGND

C1A

LPB

LTC1563-X

PATENT PENDING

1563 BD

INVB

R32

R22

R12

C2B

AGND

OUT

C1B

LTC1563-2/LTC1563-3

APPLICATIO

S I

FOR

ATIO

Functional Description

The LTC1563-2/LTC1563-3 are a family of easy-to-use,
4th order lowpass filters with rail-to-rail operation. The
LTC1563-2, with a single resistor value, gives a unity-gain
filter approximating a Butterworth response. The
LTC1563-3, with a single resistor value, gives a unity-gain
filter approximating a Bessel (linear phase) response. The
proprietary architecture of these parts allows for a simple
unity-gain resistor calculation:

R = 10k(256kHz/f

)

where f

is the desired cutoff frequency. For many appli-

cations, this formula is all that is needed to design a filter.
For example, a 50kHz filter requires a 51.2k resistor. In
practice, a 51.1k resistor would be used as this is the
closest E96, 1% value available.

The LTC1563-X is constructed with two 2nd order sec-
tions. The output of the first section (section A) is simply
fed into the second section (section B). Note that section
A and section B are similar, but not identical. The parts are
designed to be simple and easy to use.

By simply utilizing different valued resistors, gain, other
transfer functions and higher cutoff frequencies are
achieved. For these applications, the resistor value calcu-
lation gets more difficult. The tables of formulas provided
later in this section make this task much easier. For best
results, design these filters using FilterCAD Version 3.0 (or
newer) or contact the Linear Technology Filter Applica-
tions group for assistance.

Cutoff Frequency (f

) and Gain limitations

The LTC563-X has both a maximum f

limit and a mini-

mum f

limit. The maximum f

limit (256kHz in High Speed

mode and 25.6kHz in the Low Power mode) is set by the
speed of the LTC1563-X's op amps. At the maximum f

the gain is also limited to unity.

A minimum f

is dictated by the practical limitation of

reliably obtaining large valued, precision resistors. As the
desired f

decreases, the resistor value required increases.

When f

is 256Hz, the resistors are 10M. Obtaining a

reliable, precise 10M resistance between two points on a
printed circuit board is somewhat difficult. For example, a
10M resistor with only 200M

of stray, layout related

resistance in parallel, yields a net effective resistance of
9.52M and an error of 5%. Note that the gain is also
limited to unity at the minimum f

At intermediate f

, the gain is limited by one of the two

reasons discussed above. For best results, design filters
with gain using FilterCAD Version 3 (or newer) or contact
the Linear Technology Filter Applications Group for assis-
tance.

While the simple formula and the tables in the applications
section deliver good approximations of the transfer func-
tions, a more accurate response is achieved using FilterCAD.
FilterCAD calculates the resistor values using an accurate
and complex algorithm to account for parasitics and op
amp limitations. A design using FilterCAD will always yield
the best possible design. By using the FilterCAD design
tool you can also achieve filters with cutoff frequencies
beyond 256kHz. Cutoff frequencies up to 360kHz are
attainable.

Contact the Linear Technology Filter Applications Group
for a copy the FilterCAD software. FilterCAD can also be
downloaded from our website at www.linear-tech.com.

DC Offset, Noise and Gain Considerations

The LTC1563-X is DC offset trimmed in a 2-step manner.
First, section A is trimmed for minimum DC offset. Next,
section B is trimmed to minimize the total DC offset
(section A

plus section B). This method is used to give the

minimum DC offset in unity gain applications and most
higher gain applications.

For gains greater than unity, the gain should be distributed
such that most of the gain is taken in section A, with
section B at a lower gain (preferably unity). This type of
gain distribution results in the lowest noise and lowest DC
offset. For high gain, low frequency applications, all of the
gain is taken in section A, with section B set for unity-gain.
In this configuration, the noise and DC offset is dominated
by those of section A. At higher frequencies, the op amps'
finite bandwidth limits the amount of gain that section A
can reliably achieve. The gain is more evenly distributed in
this case. The noise and DC offset of section A is now
multiplied by the gain of section B. The result is slightly
higher noise and offset.

LTC1563-2/LTC1563-3

APPLICATIO

S I

FOR

ATIO

Output Loading: Resistive and Capacitive

The op amps of the LTC1563-X have a rail-to-rail output
stage. To obtain maximum performance, the output load-
ing effects must be considered. Output loading issues can
be divided into resistive effects and capacitive effects.

Resistive loading affects the maximum output signal swing
and signal distortion. If the output load is excessive, the
output swing is reduced and distortion is increased. All of
the output voltage swing testing on the LTC1563-X is done
with R22 = 100k and a 10k load resistor. For best undistorted
output swing, the output load resistance should be greater
than 10k.

Capacitive loading on the output reduces the stability of
the op amp. If the capacitive loading is sufficiently high,
the stability margin is decreased to the point of oscillation
at the output. Capacitive loading should be kept below
30pF. Good, tight layout techniques should be maintained
at all times. These parts should not drive long traces and
must never drive a long coaxial cable.

When probing the

LTC1563-X, always use a 10x probe. Never use a 1x probe.
A standard 10x probe has a capacitance of 10pF to 15pF
while a 1x probe's capacitance can be as high as 150pF.
The use of a 1x probe will probably cause oscillation.

For larger capacitive loads, a series isolation resistor can
be used between the part and the capacitive load. If the
load is too great, a buffer must be used.

Layout Precautions

The LTC1563-X is an active RC filter. The response of the
filter is determined by the on-chip capacitors and the
external resistors. Any external, stray capacitance in par-
allel with an on-chip capacitor, or to an AC ground, can
alter the transfer function.

Capacitance to an AC ground is the most likely problem.
Capacitance on the LPA or LPB pins does not affect the
transfer function but does affect the stability of the op
amps. Capacitance on the INVA and INVB pins will affect
the transfer function somewhat and will also affect the
stability of the op amps. Capacitance on the SA and SB
pins alters the transfer function of the filter. These pins are
the most sensitive to stray capacitance. Stray capacitance
on these pins results in peaking of the frequency response

near the cutoff frequency. Poor layout can give 0.5dB to
1dB of excess peaking.

To minimize the effects of parasitic layout capacitance, all
of the resistors for section A should be placed as close as
possible to the SA pin. Place the R31 resistor first so that
it is as close as possible to the SA pin on one end and as
close as possible to the INVA pin on the other end. Use the
same strategy for the layout of section B, keeping all of the
resistors as close as possible to the SB node and first
placing R32 between the SB and INVB pins. It is also best
if the signal routing and resistors are on the same layer as
the part without any vias in the signal path.

Figure 1 illustrates a good layout using the LTC1563-X
with surface mount 0805 size resistors. An even tighter
layout is possible with smaller resistors.

1653 F01

R11

LTC1563-X

R12

R32

R22

R21

R31

OUT

Figure 1. PC Board Layout

Single Pole Sections and Odd Order Filters

The LTC1563 is configured to naturally form even ordered
filters (2nd, 4th, 6th and 8th). With a little bit of work,
single pole sections and odd order filters are easily achieved.
To form a single pole section you simply use the op amp,
the on-chip C1 capacitor and two external resistors as
shown in Figure 2. This gives an inverting section with the
gain set by the R2-R1 ratio and the pole set by the R2-C1
time constant. You can use this pole with a 2nd order
section to form a noninverting gain 3rd order filter or as a
stand alone inverting gain single pole filter.

Figure 3 illustrates another way of making odd order
filters. The R1 input resistor is split into two parts with an
additional capacitor connected to ground in between the
resistors. This "TEE" network forms a single real pole. RB1

LTC1563-2/LTC1563-3

should be much larger than RA1 to minimize the interac-
tion of this pole with the 2nd order section. This circuit is
useful in forming dual 3rd order filters and 5th order filters
with a single LTC1563 part. By cascading two parts, 7th
order and 9th order filters are achieved.

DC GAIN =

LTC1563-2: C1A = 53.9pF, C1B = 39.2pF
LTC1563-3: C1A = 35pF, C1B = 26.8pF

· R2 · C1

1563 F02

INV

1/2 LTC1563

AGND

(OPEN)

OUT

Figure 2

RA1

RB1

RA1

1563 F03

RA1 · RB1

RA1 + RB1

( )

INV

1/2 LTC1563

AGND

(OPEN)

INV

1/2 LTC1563

1563 F04

AGND

You can also use the TEE network in both sections of the
part to make a 6th order filter. This 6th order filter does not
conform exactly to the textbook responses. Textbook
responses (Butterworth, Bessel, Chebyshev etc.) all have
three complex pole pairs. This filter has two complex pole
pairs and two real poles. The textbook response always
has one section with a low Q value between 0.5 and 0.6. By
replacing this low Q section with two real poles (two real
poles are the same mathematically as a complex pole pair
with a Q of 0.5) and tweaking the Q of the other two
complex pole pair sections you end up with a filter that is
indistinguishable from the textbook filter. The Typical
Applications section illustrates a 100kHz, 6th order pseudo-
Butterworth filter. FilterCAD is a valuable tool for custom
filter design and tweaking textbook responses.

Figure 3

What To Do with An Unused Section

If the LTC1563 is used as a 2nd or 3rd order filter, one of
the sections is not used. Do not leave this section uncon-
nected. If the section is left unconnected, the output is left
to float and oscillation may occur. The unused section
should be connected as shown in Figure 4 with the INV pin
connected to the LP pin and the S pin left open.

Figure 4

APPLICATIO

S I

FOR

ATIO

LTC1563-2/LTC1563-3

Figure 5. 4th Order Filter Connections (Power Supply, Ground,
EN and LP Connections Not Shown for Clarity). Table 1 Shows
Resistor Values

INVA

LPA

AGND

LPB

INVB

OUT

LTC1563-2

1563 F03

R31

R32

R22

R21

R11

R12

4th Order Filter Responses Using the LTC1563-2

FREQUENCY (Hz)

0.1

GAIN (dB)

1563 F03a

NORMALIZED TO f

= 1Hz

BUTTERWORTH
0.5dB RIPPLE
CHEBYSHEV

0.1dB RIPPLE
CHEBYSHEV

Figure 5a. Frequency Response

FREQUENCY (Hz)

0.1

GAIN (dB)

1563 F03b

BUTTERWORTH
0.5dB RIPPLE
CHEBYSHEV

0.1dB RIPPLE
CHEBYSHEV

NORMALIZED TO f

= 1Hz

Figure 5b. Passband Frequency Response

TIME (s)

OUTPUT VOLTAGE (V)

1.2

1.0

0.8

0.6

0.4

0.2

1.0

0.5

1.5

2.0

1563 F03C

2.5

3.0

BUTTERWORTH
0.5dB RIPPLE
CHEBYSHEV

0.1dB RIPPLE
CHEBYSHEV

NORMALIZED TO f

= 1Hz

Figure 5c. Step Response

Table 1. Resistor Values, Normalized to 256kHz Cutoff Frequency (f

), Figure 5. The Passband

Gain, of the 4th Order LTC1563-2 Lowpass Filter, Is Set to Unity. (Note 1)

0.1dB RIPPLE

0.5dB RIPPLE

BUTTERWORTH

CHEBYSHEV

LP Mode Max f

25.6kHz

15kHz

13kHz

HS Mode Max f

256kHz

135kHz

113kHz

R11 = R21 =

10k(256kHz/f

)

13.7k(256kHz/f

)

20.5k(256kHz/f

)

R31 =

10k(256kHz/f

)

10.7k(256kHz/f

)

12.4k(256kHz/f

)

R12 = R22 =

10k(256kHz/f

)

10k(256kHz/f

)

12.1k(256kHz/f

)

R32 =

10k(256kHz/f

)

6.81k(256kHz/f

)

6.98k(256kHz/f

)

Example: In HS mode, 0.1dB ripple Chebyshev, 100kHz cutoff frequency, R11 = R21 = 35k

34.8k (1%),

R31 = 27.39k

27.4k (1%), R12 = R22 = 256k

255k (1%), R32 = 17.43k

17.4k (1%)

Note 1: The resistor values listed in this table provide good approximations of the listed transfer functions. For the
optimal resistor values, higher gain or other transfer functions, use FilterCAD Version 3.0 (or newer) or contact the
Linear Technology Filter Applications group for assistance.

APPLICATIO

S I

FOR

ATIO

LTC1563-2/LTC1563-3

Table 2. Resistor Values, Normalized to 256kHz Cutoff Frequency (f

), Figure 6. The Passband

Gain, of the 4th Order LTC1563-3 Lowpass Filter, Is Set to Unity. (Note 1)

TRANSITIONAL

BESSEL

GAUSSIAN TO 6dB

GAUSSIAN TO 12dB

LP Mode Max f

25.6kHz

20kHz

21kHz

HS Mode Max f

256kHz

175kHz

185kHz

R11 = R21 =

10k(256kHz/f

)

17.4k(256kHz/f

)

15k(256kHz/f

)

R31 =

10k(256kHz/f

)

13.3k(256kHz/f

)

11.8k(256kHz/f

)

R12 = R22 =

10k(256kHz/f

)

14.3k(256kHz/f

)

10.5k(256kHz/f

)

R32 =

10k(256kHz/f

)

6.04k(256kHz/f

)

6.19k(256kHz/f

)

INVA

LPA

AGND

LPB

INVB

OUT

LTC1563-3

1563 F04

R31

R32

R22

R21

R11

R12

Figure 6. 4th Order Filter Connections (Power Supply, Ground,
EN and LP Connections Not Shown for Clarity). Table 2 Shows
Resistor Values

FREQUENCY (Hz)

0.1

GAIN (dB)

1563 F04a

NORMALIZED TO f

= 1Hz

BESSEL
TRANSITIONAL
GAUSSIAN TO 12dB

TRANSITIONAL
GAUSSIAN TO 6dB

4th Order Filter Responses Using the LTC1563-3

Figure 6a. Frequency Response

Figure 6b. Step Response

Figure 6c. Step Response--Settling

TIME (s)

OUTPUT VOLTAGE (V)

1.2

1.0

0.8

0.6

0.4

0.2

1.0

0.5

1.5

2.0

1563 F04b

2.5

3.0

BESSEL
TRANSITIONAL
GAUSSIAN TO 12dB

TRANSITIONAL
GAUSSIAN TO 6dB

NORMALIZED TO f

= 1Hz

TIME (s)

OUTPUT VOLTAGE (V)

2.0

1563 F04c

0.5

1.0

1.5

1.05

1.00

0.95

BESSEL
TRANSITIONAL
GAUSSIAN TO 12dB

TRANSITIONAL
GAUSSIAN TO 6dB

NORMALIZED TO f

= 1Hz

APPLICATIO

S I

FOR

ATIO

LTC1563-2/LTC1563-3

INVA

LPA

AGND

LPB

INVB

OUT

ENABLE

1563 TA03

169k

95.3k

162k

274k

162k

0.1

LTC1563-2

0.1

5V, 2.3mA Supply Current, 20kHz, 4th Order,

0.5dB Ripple Chebyshev Lowpass Filter

Frequency Response

INVA

LPA

AGND

LPB

INVB

ENABLE

115k

196k

82.5k

210k

LTC1563-2

137k

115k

0.1

82.5k

INVA

LPA

AGND

LPB

INVB

OUT

3.3V

1563 TA05

75k

100k

158k

210k

158k

0.1

Single 3.3V, 2mA Supply Current, 20kHz 8th Order Butterworth Lowpass Filter

FREQUENCY (kHz)

GAIN (dB)

100

1563 TA06

Frequency Response

FREQUENCY (kHz)

GAIN (dB)

100

1563 TA04

TYPICAL APPLICATIO S

LTC1563-2/LTC1563-3

TYPICAL APPLICATIO S

INVA

LPA

AGND

LPB

INVB

OUT

3.3V

1563 TA09

R31

17.8k

R32

20.5k

R22

28.7k

R21

32.4k

0.1

LTC1563-2

0.1

C12
560pF

C11
560pF

3.16k

25.5k

3.16k

29.4k

FREQUENCY (Hz)

10k

GAIN (dB)

100

100k

1563 TA09a

100kHz, 6th Order Pseudo-Butterworth

Frequency Response

TEXTBOOK BUTTERWORTH

PSEUDO-BUTTERWORTH

1 = 100kHz

Q1 = 1.9319

1 = 100kHz

Q1 = 1.9319

2 = 100kHz

Q2 = 0.7071

2 = 100kHz

Q2 = 0.7358

3 = 100kHz

Q3 = 0.5176

3 = 100kHz

Real Poles

4 = 100kHz

Real Poles

The complex, 2nd order section of the textbook design
with the lowest Q is replaced with two real first order poles.
The Q of another section is slightly altered such that the
final filter's response is indistinguisable from a textbook
Butterworth response.

The f

and Q values listed above can be entered in

FilterCAD's Enhanced Design window as a custom re-
sponse filter. After entering the coefficients, FilterCAD will
produce a schematic of the circuit. The procedure is as
follows:

1. After starting FilterCAD, select the Enhanced Design

window.

2. Select the Custom Response and set the custom F

1Hz.

3. In the Coefficients table, go to the Type column and click

on the types listed and set the column with two LP types
and two LP1 types. This sets up a template of a 6th order
filter with two 2nd order lowpass sections and two 1st
order lowpass sections.

4. Enter the f

and Q coefficients as listed above. For a

Butterworth filter, use the same coefficients as the
example circuit above except set all of the f

to 1Hz.

5. Set the custom F

to the desired cutoff frequency. This

will automatically multiply all of the f

coefficients. You

have now finished the design of the filter and you can
click on the frequency response or step response
buttons to verify the filter's response.

6. Click on the Implement button to go on to the filter

implementation stage.

7. In the Enhanced Implement window, click on the Active

RC button to choose the LTC1563-2 part. You are now
done with the filter's implementation. Click on the
schematic button to view the resulting circuit.

Other Pseudo Filter Response Coefficients (All f

Are Normalized for a 1Hz Filter Cutoff)

BESSEL

0.1dB RIPPLE CHEBYSHEV

0.5dB RIPPLE CHEBYSHEV

TRANSITIONAL GAUSSIAN TO 12dB

TRANSITIONAL GAUSSIAN TO 6dB

1.9070

1.0600

1.0100

2.1000

1.5000

1.0230

3.8500

5.3000

2.2000

2.8500

1.6910

0.8000

0.7200

1.2500

1.0500

0.6110

1.0000

1.2000

0.8000

0.9000

1.6060

0.6000

0.5000

1.2500

0.9000

1.6060

1.0000

0.8000

1.2500

0.9000

LTC1563-2/LTC1563-3

TYPICAL APPLICATIO S

INVA

LPA

AGND

LPB

INVB

R31

82.5k

R32

78.7k

R22

137k

R21

243k

0.1

LTC1563-2

0.1

C11
560pF

R12 137k

26.7k

215k

REF

REFCOMP

AGND

DGND

11 TO 26

SHDN

CONVST

BUSY

OGND

LTC1604

560pF

2.2

49.9

5V OR 3V

16-BIT
PARALLEL BUS

CONTROL
LINES

1563 TA10

100

120

140

36.58

73.15

109.73

146.30

FREQUENCY (kHz)

AMPLITUDE (dB)

SAMPLE

= 292.6kHz

= 20kHz

SINAD = 85dB
THD = 91.5dB

1563 TA10a

4096 Point FFT of the Output Data

22kHz, 5th Order, 0.1dB Ripple Chebyshev Lowpass Filter

Driving the LTC1604, 16-Bit ADC

LTC1563-2/LTC1563-3

TYPICAL APPLICATIO S

50kHz Wideband Bandpass

4th Order Bessel Lowpass at 128kHz with Two Highpass Poles at 11.7kHz Yields a Wideband Bandpass Centered at 50kHz

INVA

LPA

AGND

LPB

INVB

OUT

1563 TA12

R31

20k

R32

20k

R22

20k

R21

20k

R11

20k

R12
20k

0.1

LTC1563-3

0.1

C12
680pF

C11

680pF

10k

100k

FREQUENCY (Hz)

GAIN (dB)

1563 TA12a

To design these wideband bandpass filters with the
LTC1563, start with a 4th order lowpass filter and add two
highpass poles with the input, AC coupling capacitors. The
lowpass cutoff frequency and highpass pole frequencies
depend on the specific application. Some experimentation
of lowpass and highpass frequencies is required to achieve
the desired response. FilterCAD does not directly support
this configuration. Use the custom design window in
FilterCAD get the desired response and then use FilterCAD
to give the schematic for the lowpass portion of the filter.
Calculate the two highpass poles using the following
formulae:

f HPA

f HPB

( )

· ·

The design process is as follows:

1. After starting FilterCAD, select the Enhanced Design

window.

2. Choose a 4th order Bessel or Butterworth lowpass filter

response and set the cutoff frequency to the high
frequency corner of the desired bandpass.

3. Click on the custom response button. This copies the

lowpass coefficients into the custom design Coeffi-
cients table.

4. In the Coefficients table, the first two rows are the LP

Type with the f

and Q as previously defined. Go to the

third and fourth rows and click on the Type column
(currently a hyphen is in this space). Change the Type
of each of these rows to type HP1. This sets up a
template of a 6th order filter with two 2nd order lowpass
sections and two 1st order highpass sections.

5. Change the frequency of the highpass (HP1) poles to

get the desired frequency response.

6. You may have to perform this loop several times before

you close in on the correct response.

7. Once you have reached a satisfactory response, note

the highpass pole frequencies. The HP1 highpass poles
must now be removed from the Custom design coeffi-
cients table. After removing the highpass poles, click on
the Implement button to go on to the filter implementa-
tion stage.

8. In the Enhanced Implement window, click on the Active

RC button and choose the LTC1563-2 part. Click on the
schematic button to view the resulting circuit.

9. You now have the schematic for the 4th order lowpass

part of the design. Now calculate the capacitor values
from the following formulae:

f HPA

f HPB

( )

· ·

LTC1563-2/LTC1563-3

150kHz, 0.5dB Ripple, 4th Order Chebyshev with 10dB of DC Gain

INVA

LPA

AGND

LPB

INVB

OUT

1563 TA11

R31

9.76k

R32

12.7k

R22

21k

R21

76.8k

R11

24.3k

R12
21k

0.1

LTC1563-2

0.1

10k

100k

FREQUENCY (Hz)

GAIN (dB)

1563 TA11a

GN Package

16-Lead Plastic SSOP (Narrow 0.150)

(LTC DWG # 05-08-1641)

PACKAGE DESCRIPTIO

Dimensions in inches (millimeters) unless otherwise noted.

GN16 (SSOP) 1098

* DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH

SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE

** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD

FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE

0.229 0.244

(5.817 6.198)

0.150 0.157**

(3.810 3.988)

16 15 14 13

0.189 0.196*

(4.801 4.978)

12 11 10 9

0.016 0.050

(0.406 1.270)

0.015

0.004

(0.38

0.10)

TYP

0.007 0.0098

(0.178 0.249)

0.053 0.068

(1.351 1.727)

0.008 0.012

(0.203 0.305)

0.004 0.0098

(0.102 0.249)

0.0250

(0.635)

BSC

0.009

(0.229)

REF

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

TYPICAL APPLICATIO S

LTC1563-2/LTC1563-3

INVA

LPA

AGND

LPB

INVB

OUT

3.3V

ENABLE

1563 TA07

10k

0.1

LTC1563-3

0.1

FREQUENCY (Hz)

10k

GAIN (dB)

100k

1563 TA08

Single 3.3V, 256kHz Bessel Lowpass Filter

Frequency Response

156323f LT/TP 0800 4K · PRINTED IN USA

LINEAR TECHNOLOGY CORPORATION 2000

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900

FAX: (408) 434-0507

www.linear-tech.com

RELATED PARTS

PART NUMBER

DESCRIPTION

COMMENTS

LTC1560-1

5-Pole Elliptic Lowpass, f

= 1MHz/0.5MHz

No External Components, SO-8

LTC1562

Universal Quad 2-Pole Active RC

10kHz < f

< 150kHz

LTC1562-2

Universal Quad 2-Pole Active RC

20kHz < f

< 300kHz

LTC1569-6

Low Power 10-Pole Delay Equalized Elliptic Lowpass

< 80kHz, One Resistor Sets f

, SO-8

LTC1569-7

10-Pole Delay Equalized Elliptic Lowpass

< 256kHz, One Resistor Sets f

, SO-8

LTC1565-31

650kHz Continuous Time, Linear Phase Lowpass

= 650kHz, Differential In/Out

TYPICAL APPLICATIO S

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LTC1563-3LTC1563-2

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LTC1563-3LTC1563-2