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Электронный компонент: ADCS7476

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ADCS7476/ADCS7477/ADCS7478
1MSPS, 12-/10-/8-Bit A/D Converters in 6-Lead SOT-23
General Description
The ADCS7476, ADCS7477, and ADCS7478 are low power,
monolithic CMOS 12-, 10- and 8-bit analog-to-digital con-
verters that operate at 1 MSPS. The ADCS7476/77/78 are
drop-in replacements for Analog Devices' AD7476/77/78.
Each device is based on a successive approximation regis-
ter architecture with internal track-and-hold. The serial inter-
face is compatible with several standards, such as SPI
TM
,
QSPI
TM
, MICROWIRE
TM
, and many common DSP serial in-
terfaces.
The ADCS7476/77/78 uses the supply voltage as a refer-
ence. This enables the devices to operate with a full-scale
input range of 0 to V
DD
. The conversion rate is determined
from the serial clock (SCLK) speed. These converters offer a
shutdown mode, which can be used to trade throughput for
power consumption. The ADCS7476/77/78 is operated with
a single supply that can range from +2.7V to +5.25V. Normal
power consumption during continuous conversion, using a
+3V or +5V supply, is 2 mW or 10 mW respectively. The
power down feature, which is enabled by a chip select (CS)
pin, reduces the power consumption to under 5 W using a
+5V supply. All three converters are packaged in a 6-lead,
SOT-23 package that provides an extremely small footprint
for applications where space is a critical consideration.
These products are designed for operation over the
automotive/extended industrial temperature range of -40C
to +125C.
Features
n
Variable power management
n
Packaged in 6-lead, SOT-23
n
Power supply used as reference
n
Single +2.7V to +5.25V supply operation
n
SPI
TM
/QSPI
TM
/MICROWIRE
TM
/DSP compatible
Key Specifications
n
Resolution with no Missing Codes
12/10/8 bits
n
Conversion Rate
1 MSPS
n
DNL
+0.5, -0.3 LSB (typ)
n
INL
0.4 LSB (typ)
n
Power Consumption
3V Supply
2 mW (typ)
5V Supply
10 mW (typ)
Applications
n
Automotive Navigation
n
FA/ATM Equipment
n
Portable Systems
n
Medical Instruments
n
Mobile Communications
n
Instrumentation and Control Systems
Connection Diagram
20057701
MICROWIRE
TM
is a trademark of National Semiconductor Corporation.
TRI-STATE
is a trademark of National Semiconductor Corporation.
QSPI
TM
and SPI
TM
are trademarks of Motorola, Inc.
June 2003
ADCS7476/ADCS7477/ADCS7478
1MSPS,
12-/10-/8-Bit
A/D
Converters
in
6-Lead
SOT
-23
2003 National Semiconductor Corporation
DS200577
www.national.com
Ordering Information
Order Code
Temperature Range
Description
Top Mark
ADCS7476AIMF
-40C to +125C
6-Lead, SOT-23 Package
X01A
ADCS7477AIMF
-40C to +85C
6-Lead, SOT-23 Package
X02A
ADCS7478AIMF
-40C to +85C
6-Lead, SOT-23 Package
X03A
ADCS7476AIMFX
-40C to +125C
6-Lead SOT-23 Package, Tape & Reel
X01A
ADCS7477AIMFX
-40C to +85C
6-Lead SOT-23 Package, Tape & Reel
X02A
ADCS7478AIMFX
-40C to +85C
6-Lead SOT-23 Package, Tape & Reel
X03A
Pin Descriptions
Pin No.
Symbol
Description
ANALOG I/O
3
V
IN
Analog input. This signal can range from 0V to V
DD
.
DIGITAL I/O
4
SCLK
Digital clock input. The range of frequencies for this input is 10 kHz to 20 MHz, with
guaranteed performance at 20 MHz. This clock directly controls the conversion and readout
processes.
5
SDATA
Digital data output. The output words are clocked out of this pin by the SCLK pin.
6
CS
Chip select. A conversion process begins on the falling edge of CS.
POWER SUPPLY
1
V
DD
Positive supply pin. These pins should be connected to a quiet +2.7V to +5.25V source and
bypassed to GND with 0.1 F and 1 F monolithic capacitors located within 1 cm of the
power pin. The ADCS7476/77/78 uses this power supply as a reference, so it should be
thoroughly bypassed.
2
GND
The ground return for the supply.
Block Diagram
20057718
ADCS7476/ADCS7477/ADCS7478
www.national.com
2
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage V
DD
-0.3V to +6.5V
Voltage on Any Analog Pin to GND
-0.3V to V
DD
+0.3V
Voltage on Any Digital Pin to GND
-0.3V to 6.5V
Input Current at Any Pin (Note 3)
10 mA
ESD Susceptibility
Human Body Model
Machine Model
3500V
200V
Soldering Temperature, Infrared,
10 seconds
215C
Junction Temperature
+150C
Storage Temperature
-65C to +150C
Operating Ratings
Operating Temperature Range
T
MIN
= -40C
T
A
T
MAX
= +125C
V
DD
Supply Voltage
+2.7V to +5.25V
Digital Input Pins Voltage Range
(Note 4)
+2.7V to +5.25V
Package Thermal Resistance
Package
JA
6-Lead, SOT-23
265C / W
ADCS7476/ADCS7477/ADCS7478 Specifications
(Note 2)
ADCS7476 Converter Electrical Characteristics
The following specifications apply for V
DD
= +2.7V to 5.25V, f
SCLK
= 20 MHz, f
SAMPLE
= 1 MSPS unless otherwise noted. Bold-
face limits apply for T
A
= -40C to +85C: all other limits T
A
= 25C, unless otherwise noted.
Symbol
Parameter
Conditions
Typical
Limits
Units
STATIC CONVERTER CHARACTERISTICS (V
DD
= 2.7V to 3.6V)
Resolution with No Missing Codes
-40C
T
A
125C
12
Bits
INL
Integral Non-Linearity
-40C
T
A
85C
0.4
1
LSB (max)
T
A
= 125C
+1
-1.1
LSB (min)
LSB (max)
DNL
Differential Non-Linearity
-40C
T
A
85C
+0.5
-0.3
+1
-0.9
LSB (max)
LSB (min)
T
A
= 125C
1
LSB (max)
V
OFF
Offset Error
-40C
T
A
125C
0.1
1.2
LSB (max)
GE
Gain Error
-40C
T
A
125C
0.2
1.2
LSB (max)
DYNAMIC CONVERTER CHARACTERISTICS (f
IN
= 100 kHz, -0.02 dBFS sine wave unless otherwise noted)
SINAD
Signal-to-Noise Plus Distortion Ratio
-40C
T
A
125C
72
70
dB (min)
SNR
Signal-to-Noise Ratio
-40C
T
A
85C
72.5
70.8
dB (min)
T
A
= 125C
70.6
dB (min)
THD
Total Harmonic Distortion
-80
dB
SFDR
Spurious-Free Dynamic Range
82
dB
IMD
Intermodulation Distortion, Second
Order Terms
f
a
= 103.5 kHz, f
b
= 113.5 kHz
-78
dB
Intermodulation Distortion, Third
Order Terms
f
a
= 103.5 kHz, f
b
= 113.5 kHz
-78
dB
FPBW
-3 dB Full Power Bandwidth
+5V Supply
11
MHz
+3V Supply
8
MHz
POWER SUPPLY CHARACTERISTICS
V
DD
Supply Voltage
-40C
T
A
125C
2.7
V (min)
5.25
V (max)
ADCS7476/ADCS7477/ADCS7478
www.national.com
3
ADCS7476/ADCS7477/ADCS7478 Specifications
(Note 2)
(Continued)
ADCS7476 Converter Electrical Characteristics
(Continued)
The following specifications apply for V
DD
= +2.7V to 5.25V, f
SCLK
= 20 MHz, f
SAMPLE
= 1 MSPS unless otherwise noted. Bold-
face limits apply for T
A
= -40C to +85C: all other limits T
A
= 25C, unless otherwise noted.
Symbol
Parameter
Conditions
Typical
Limits
Units
POWER SUPPLY CHARACTERISTICS
I
DD
Normal Mode (Static)
V
DD
= +4.75V to +5.25V,
SCLK On or Off
2
mA
V
DD
= +2.7V to +3.6V,
SCLK On or Off
1
mA
Normal Mode (Operational)
V
DD
= +4.75V to +5.25V,
f
SAMPLE
= 1 MSPS
2.0
3.5
mA (max)
V
DD
= +2.7V to +3.6V,
f
SAMPLE
= 1 MSPS
0.6
1.6
mA (max)
Shutdown Mode
V
DD
= +5V, SCLK Off
0.5
A
V
DD
= +5V, SCLK On
60
A
P
D
Power Consumption, Normal Mode
(Operational)
V
DD
= +5V, f
SAMPLE
= 1 MSPS
10
17.5
mW (max)
V
DD
= +3V, f
SAMPLE
= 1 MSPS
2
4.8
mW (max)
Power Consumption, Shutdown Mode
V
DD
= +5V, SCLK Off
2.5
W
V
DD
= +3V, SCLK Off
1.5
W
ANALOG INPUT CHARACTERISTICS
V
IN
Input Range
0 to V
DD
V
I
DCL
DC Leakage Current
1
A (max)
C
INA
Analog Input Capacitance
30
pF
DIGITAL INPUT CHARACTERISTICS
V
IH
Input High Voltage
2.4
V (min)
V
IL
Input Low Voltage
V
DD
= +5V
0.8
V (max)
V
DD
= +3V
0.4
V (max)
I
IN
Input Current
V
IN
= 0V or V
DD
10 nA
1
A (max)
C
IND
Digital Input Capacitance
2
4
pF (max)
DIGITAL OUTPUT CHARACTERISTICS
V
OH
Output High Voltage
I
SOURCE
= 200 A,
V
DD
= +2.7V to +5.25V
V
DD
-0.2
V (min)
V
OL
Output Low Voltage
I
SINK
= 200 A
0.4
V (max)
I
OL
TRI-STATE Leakage Current
10
A (max)
C
OUT
TRI-STATE Output Capacitance
2
4
pF (max)
Output Coding
Straight (Natural) Binary
AC ELECTRICAL CHARACTERISTICS
f
SCLK
Clock Frequency
20
MHz (max)
DC
SCLK Duty Cycle
40
60
% (min)
% (max)
t
TH
Track/Hold Acquisition Time
400
ns (max)
f
RATE
Throughput Rate
See Serial Interface Section
1
MSPS
(max)
t
AD
Aperture Delay
3
ns
t
AJ
Aperture Jitter
30
ps
ADCS7476/ADCS7477/ADCS7478
www.national.com
4
ADCS7476/ADCS7477/ADCS7478 Specifications
(Note 2)
(Continued)
ADCS7477 Converter Electrical Characteristics
The following specifications apply for V
DD
= +2.7V to 5.25V, f
SCLK
= 20 MHz, f
SAMPLE
= 1 MSPS unless otherwise noted. Bold-
face limits apply for T
A
= -40C to +85C: all other limits T
A
= 25C, unless otherwise noted.
Symbol
Parameter
Conditions
Typical
Limits
Units
STATIC CONVERTER CHARACTERISTICS
Resolution with No Missing Codes
10
Bits
INL
Integral Non-Linearity
0.2
0.7
LSB (max)
DNL
Differential Non-Linearity
+0.3
-0.2
0.7
LSB (max)
LSB (max)
V
OFF
Offset Error
0.1
0.7
LSB (max)
GE
Gain Error
0.2
1
LSB (max)
DYNAMIC CONVERTER CHARACTERISTICS
SINAD
Signal-to-Noise Plus Distortion Ratio
f
IN
= 100 kHz
61.7
61
dBFS (min)
SNR
Signal-to-Noise Ratio
f
IN
= 100 kHz
62
dB
THD
Total Harmonic Distortion
f
IN
= 100 kHz
-77
-73
dB (max)
SFDR
Spurious-Free Dynamic Range
f
IN
= 100 kHz
78
74
dB (min)
IMD
Intermodulation Distortion, Second
Order Terms
f
a
= 103.5 kHz, f
b
= 113.5 kHz
-78
dB
Intermodulation Distortion, Third
Order Terms
f
a
= 103.5 kHz, f
b
= 113.5 kHz
-78
dB
FPBW
-3 dB Full Power Bandwidth
+5V Supply
11
MHz
+3V Supply
8
MHz
POWER SUPPLY CHARACTERISTICS
V
DD
Supply Voltage
2.7
5.25
V (min)
V (max)
I
DD
Normal Mode (Static)
V
DD
= +4.75V to +5.25V,
SCLK On or Off
2
mA
V
DD
= +2.7V to +3.6V,
SCLK On or Off
1
mA
Normal Mode (Operational)
V
DD
= +4.75V to +5.25V,
f
SAMPLE
= 1 MSPS
2.0
3.5
mA (max)
V
DD
= +2.7V to +3.6V,
f
SAMPLE
= 1 MSPS
0.6
1.6
mA (max)
Shutdown Mode
V
DD
= +5V, SCLK Off
0.5
A (max)
V
DD
= +5V, SCLK On
60
A (max)
P
D
Power Consumption, Normal Mode
(Operational)
V
DD
= +5V, f
SAMPLE
= 1 MSPS
10
17.5
mW (max)
V
DD
= +3V, f
SAMPLE
= 1 MSPS
2
4.8
mW (max)
Power Consumption, Shutdown Mode
V
DD
= +5V, SCLK Off
2.5
W (max)
V
DD
= +3V, SCLK Off
1.5
W (max)
ANALOG INPUT CHARACTERISTICS
V
IN
Input Range
0 to V
DD
V
I
DCL
DC Leakage Current
1
A (max)
C
INA
Analog Input Capacitance
30
pF
DIGITAL INPUT CHARACTERISTICS
V
IH
Input High Voltage
2.4
V (min)
V
IL
Input Low Voltage
V
DD
= +5V
0.8
V (max)
V
DD
= +3V
0.4
V (max)
I
IN
Input Current
V
IN
= 0V or V
DD
10 nA
1
A (max)
C
IND
Digital Input Capacitance
2
4
pF (max)
ADCS7476/ADCS7477/ADCS7478
www.national.com
5