1
LTC1416
Low Power 14-Bit, 400ksps
Sampling ADC
U
A
O
PPLICATI
TYPICAL
Complete, 70mW, 14-Bit ADC with 80.5dB S/(N + D)
BUSY
CS
CONVST
RD
SHDN
14-BIT ADC
14
S/H
BUFFER
4k
LTC1416
D13 (MSB)
D0 (LSB)
5V
V
SS
A
IN
+
A
IN
V
REF
REFCOMP
DV
DD
AV
DD
1
F
22
F
10
F
10
F
AGND
1416 TA01
DGND
2.5V
REFERENCE
TIMING
AND
LOGIC
OUTPUT
BUFFERS
INPUT FREQUENCY (Hz)
1k
EFFECTIVE BITS
SIGNAL/(NOISE + DISTORTION) (dB)
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
86
80
74
68
62
10k
100k
1416 TA02
1M 2M
f
SAMPLE
= 400kHz
NYQUIST
FREQUENCY
Effective Bits and
Signal-to-(Noise + Distortion)
vs Input Frequency
S
FEATURE
s
Sample Rate: 400ksps
s
Power Dissipation: 70mW
s
Guaranteed
1.5LSB DNL,
2LSB INL (Max)
s
80.5dB S/(N + D) and 93dB THD at 100kHz
s
80dB S/(N + D) and 90dB THD at Nyquist
s
Nap and Sleep Shutdown Modes
s
Operates with Internal or External Reference
s
True Differential Inputs Reject Common Mode Noise
s
15MHz Full Power Bandwidth Sampling
s
2.5V Bipolar Input Range
s
28-Pin SSOP Package
U
S
A
O
PPLICATI
, LTC and LT are registered trademarks of Linear Technology Corporation.
s
Telecommunications
s
Digital Signal Processing
s
Multiplexed Data Acquisition Systems
s
High Speed Data Acquisition
s
Spectrum Analysis
s
Imaging Systems
The LTC
1416 is a 2.2
s, 400ksps, 14-bit sampling A/D
converter that draws only 70mW from
5V supplies. This
easy-to-use device includes a high dynamic range sample-
and-hold and a precision reference. Two digitally select-
able power shutdown modes provide flexibility for low
power systems.
The LTC1416's full-scale input range is
2.5V. Maximum
DC specifications include
2LSB INL,
1.5LSB DNL over
temperature. Outstanding AC performance includes 80.5dB
S/(N + D) and 93dB THD with a 100kHz input, and 80dB
S/(N + D) and 90dB THD at the Nyquist input frequency of
200kHz.
The unique differential input sample-and-hold can ac-
quire single-ended or differential input signals up to its
15MHz bandwidth. The 60dB common mode rejection
allows users to eliminate ground loops and common
mode noise by measuring signals differentially from the
source.
The ADC has a
P compatible, 14-bit parallel output port.
There is no pipeline delay in the conversion results. A
separate convert start input and a data ready signal
(BUSY) ease connections to FIFOs, DSPs and micropro-
cessors.
D
U
ESCRIPTIO
2
LTC1416
AV
DD
= DV
DD
= V
DD
(Notes 1, 2)
Supply Voltage (V
DD
) ................................................ 6V
Negative Supply Voltage (V
SS
)................................ 6V
Total Supply Voltage (V
DD
to V
SS
) .......................... 12V
Analog Input Voltage
(Note 3) ......................... (V
SS
0.3V) to (V
DD
+ 0.3V)
Digital Input Voltage (Note 4) .......... (V
SS
0.3V) to 10V
Digital Output Voltage ....... (V
SS
0.3V) to (V
DD
+ 0.3V)
Power Dissipation ............................................. 500mW
Operating Temperature Range
Commercial ............................................ 0
C to 70
C
Industrial ........................................... 40
C to 85
C
Storage Temperature Range ................ 65
C to 150
C
Lead Temperature (Soldering, 10 sec)................. 300
C
A
U
G
W
A
W
U
W
A
R
BSOLUTE
XI
TI
S
W
U
U
PACKAGE/ORDER I FOR ATIO
ORDER
PART NUMBER
LTC1416CG
LTC1416IG
T
JMAX
= 110
C,
JA
= 95
C/W
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
A
IN
+
A
IN
V
REF
REFCOMP
AGND
D13(MSB)
D12
D11
D10
D9
D8
D7
D6
DGND
AV
DD
DV
DD
V
SS
BUSY
CS
CONVST
RD
SHDN
D0
D1
D2
D3
D4
D5
G PACKAGE
28-LEAD PLASTIC SSOP
TOP VIEW
Consult factory for Military grade parts and for A grade parts.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
IN
Analog Input Range (Note 9)
4.75V
V
DD
5.25V, 5.25V
V
SS
4.75V
q
2.5
V
I
IN
Analog Input Leakage Current
CS = High
q
1
A
C
IN
Analog Input Capacitance
Between Conversions
15
pF
During Conversions
5
pF
t
ACQ
Sample-and-Hold Acquisition Time
(Note 9)
q
100
400
ns
t
AP
Sample-and-Hold Aperture Delay Time
1.5
ns
t
jitter
Sample-and-Hold Aperture Delay Time Jitter
2
ps
RMS
CMRR
Analog Input Common Mode Rejection Ratio
2.5V < (A
IN
= A
IN
+
) < 2.5V
60
dB
(Note 5)
PUT
U
I
A
A
U
LOG
C
C
HARA TERISTICS
CO
U
VERTER
With Internal Reference (Notes 5, 6)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Resolution (No Missing Codes)
q
13
Bits
Integral Linearity Error
(Note 7)
q
0.8
2
LSB
Differential Linearity Error
q
0.7
1.5
LSB
Offset Error
(Note 8)
q
5
20
LSB
Full-Scale Error
Internal Reference
20
60
LSB
External Reference = 2.5V
10
40
LSB
Full-Scale Tempco
I
OUT(REF)
= 0
15
ppm/
C
3
LTC1416
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
S/(N + D)
Signal-to-(Noise + Distortion) Ratio
100kHz Input Signal
q
77
80.5
dB
200kHz Input Signal
80
dB
THD
Total Harmonic Distortion
100kHz Input Signal, First 5 Harmonics
q
93
86
dB
200kHz Input Signal, First 5 Harmonics
90
dB
SFDR
Spurious-Free Dynamic Range
100kHz Input Signal
q
95
86
dB
IMD
Intermodulation Distortion
f
IN1
= 87.01172kHz, f
IN2
= 113.18359kHz
90
dB
Full Power Bandwidth
15
MHz
Full Linear Bandwidth
(S/(N + D)
77dB)
0.8
MHz
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
IH
High Level Input Voltage
V
DD
= 5.25V
q
2.4
V
V
IL
Low Level Input Voltage
V
DD
= 4.75V
q
0.8
V
I
IN
Digital Input Current
V
IN
= 0V to V
DD
q
10
A
C
IN
Digital Input Capacitance
5
pF
V
OH
High Level Output Voltage
V
DD
= 4.75V
I
OUT
= 10
A
4.5
V
I
OUT
= 200
A
q
4.0
V
V
OL
Low Level Output Voltage
V
DD
= 4.75V
I
OUT
= 160
A
0.05
V
I
OUT
= 1.6mA
q
0.10
0.4
V
I
OZ
Hi-Z Output Leakage D13 to D0
V
OUT
= 0V to V
DD
, CS High
q
10
A
C
OZ
Hi-Z Output Capacitance D13 to D0
CS High (Note 9 )
q
15
pF
I
SOURCE
Output Source Current
V
OUT
= 0V
10
mA
I
SINK
Output Sink Current
V
OUT
= V
DD
10
mA
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
REF
Output Voltage
I
OUT
= 0
2.480
2.500
2.520
V
V
REF
Output Tempco
I
OUT
= 0
15
ppm/
C
V
REF
Line Regulation
4.75V
V
DD
5.25V
0.05
LSB/V
5.25V
V
SS
4.75V
0.05
LSB/V
V
REF
Output Resistance
0.1mA
I
OUT
0.1mA
4
k
COMP Output Voltage
I
OUT
= 0
4.06
V
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
DD
Positive Supply Voltage
(Note 10)
4.75
5.25
V
V
SS
Negative Supply Voltage
(Note 10)
4.75
5.25
V
I
DD
Positive Supply Current
q
7
10
mA
Nap Mode
SHDN = 0V, CS = 0V
0.8
1.2
mA
Sleep Mode
SHDN = 0V, CS = 5V
1
A
I
SS
Negative Supply Current
q
7
10
mA
Nap Mode
SHDN = 0V, CS = 0V
20
A
Sleep Mode
SHDN = 0V, CS = 5V
15
A
I TER AL REFERE CE CHARACTERISTICS
U
U
U
DY
A
IC ACCURACY
U
W
(Note 5)
(Note 5)
DIGITAL I PUTS A D DIGITAL OUTPUTS
U
U
(Note 5)
POWER REQUIRE E TS
W
U
(Note 5)
4
LTC1416
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
POWER REQUIRE E TS
W
U
(Note 5)
P
DISS
Power Dissipation
q
70
100
mW
Power Dissipation, Nap Mode
SHDN = 0V, CS = 0V
4
6
mW
Power Dissipation, Sleep Mode
SHDN = 0V, CS = 5V
0.1
mW
Note 6: Linearity, offset and full-scale specifications apply for a single-
ended A
IN
+
input with A
IN
grounded.
Note 7: Integral nonlinearity is defined as the deviation of a code from a
straight line passing through the actual endpoints of the transfer curve.
The deviation is measured from the center of the quantization band.
Note 8: Bipolar offset is the offset voltage measured from 0.5LSB when
the output code flickers between 0000 0000 0000 00 and
1111 1111 1111 11.
Note 9: Guaranteed by design, not subject to test.
Note 10: Recommended operating conditions.
Note 11: The falling CONVST edge starts a conversion. If CONVST returns
high at a critical point during the conversion it can create small errors. For
best results ensure that CONVST returns high either within 900ns after the
start of the conversion or after BUSY rises.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
f
SAMPLE(MAX)
Maximum Sampling Frequency
q
400
kHz
t
CONV
Conversion Time
q
1.5
1.9
2.2
s
t
ACQ
Acquisition Time
(Note 9)
q
100
400
ns
t
ACQ+CONV
Acquisition + Conversion Time
q
2
2.5
s
t
1
CS to RD Setup Time
(Notes 9, 10)
q
0
ns
t
2
CS
to CONVST
Setup Time
(Notes 9, 10)
q
10
ns
t
3
CS
to SHDN
Setup Time
(Notes 9, 10)
q
10
ns
t
4
SHDN
to CONVST
Wake-Up Time
(Note 10)
400
ns
t
5
CONVST
Low Time
(Notes 10, 11)
q
40
ns
t
6
CONVST to BUSY Delay
C
L
= 25pF
25
ns
q
50
ns
t
7
Data Ready Before BUSY
75
100
ns
q
50
ns
t
8
Delay Between Conversions
(Note 10)
q
40
ns
t
9
Wait Time RD
After BUSY
q
5
ns
t
10
Data Access Time After RD
C
L
= 25pF
15
25
ns
q
35
ns
C
L
= 100pF
20
35
ns
q
50
ns
t
11
Bus Relinquish Time
8
20
ns
0
C
T
A
70
C
q
25
ns
40
C
T
A
85
C
q
30
ns
t
12
RD Low Time
q
t
10
ns
t
13
CONVST High Time
q
40
ns
(Note 5, see Figures 15 to 21)
TI I G CHARACTERISTICS
W U
The
q
denotes specifications which apply over the full operating
temperature range; all other limits and typicals at T
A
= 25
C.
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: All voltage values are with respect to ground with DGND and
AGND wired together unless otherwise noted.
Note 3: When these pin voltages are taken below V
SS
or above V
DD
, they
will be clamped by internal diodes. This product can handle input currents
greater than 100mA below V
SS
or above V
DD
without latchup.
Note 4: When these pin voltages are taken below V
SS
, they will be clamped
by internal diodes. This product can handle input currents greater than
100mA below V
SS
without latchup. These pins are not clamped to V
DD
.
Note 5: V
DD
= 5V, V
SS
= 5V, f
SAMPLE
= 400kHz, t
r
= t
f
= 5ns unless
otherwise specified.
5
LTC1416
TYPICAL PERFOR
M
A
N
CE CHARACTERISTICS
U
W
Distortion vs Input Frequency
Differential Nonlinearity
vs Output Code
Input Common Mode Rejection
vs Input Frequency
INPUT FREQUENCY (Hz)
1k
SIGNAL/(NOISE + DISTORTION) (dB)
90
80
70
60
50
40
30
20
10
0
10k
100k
1416 G01
1M 2M
V
IN
= 0dB
V
IN
= 20dB
V
IN
= 60dB
S/(N + D) vs Input Frequency
and Amplitude
INPUT FREQUENCY (Hz)
1k
SPURIOUS-FREE DYNAMIC RANGE (dB)
0
10
20
30
40
50
60
70
80
90
100
10k
100k
1416 G04
1M 2M
Spurious-Free Dynamic Range
vs Input Frequency
OUTPUT CODE
0
DNL ERROR (LSB)
16384
V
OUT
=
2.5V
V
REF
= 2.5V
1416 G06
4096
8192
12288
1.0
0.5
0
0.5
1.0
OUTPUT CODE
0
INL ERROR (LSB)
16384
V
OUT
=
2.5V
V
REF
= 2.5V
1416 G07
4096
8192
12288
1.0
0.5
0
0.5
1.0
Integral Nonlinearity
vs Output Code
INPUT FREQUENCY (Hz)
1k
COMMON MODE REJECTION (dB)
80
70
60
50
40
30
20
10
0
10k
100k
1416 G09
1M 2M
INPUT FREQUENCY (Hz)
1k
AMPLITUDE (dB BELOW THE FUNDAMENTAL)
0
10
20
30
40
50
60
70
80
90
100
110
10k
100k
1416 G03
1M 2M
THD
2ND
3RD
Signal-to-Noise Ratio
vs Input Frequency
Intermodulation Distortion Plot
Power Supply Feedthrough
vs Ripple Frequency
INPUT FREQUENCY (Hz)
1k
SIGNAL-TO-NOISE RATIO (dB)
90
80
70
60
50
40
30
20
10
0
10k
100k
1416 G02
1M 2M
FREQUENCY (Hz)
0
AMPLITUDE (dB)
0
20
40
60
80
100
120
140
20
100
140
1416 G05
80
180 200
40 60
120
160
f
SAMPLE
= 400kHz
f
a
=87.01171876kHz
f
b
=113.1835938kHz
RIPPLE FREQUENCY (Hz)
1k
AMPLITUDE OF
POWER SUPPLY FEEDTHROUGH (dB)
0
10
20
30
40
50
60
70
80
90
100
10k
100k
1416 G08
1M 2M
DGND (V
IN
= 100mV)
V
SS
(V
IN
= 10mV)
V
DD
(V
IN
= 10mV)
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