ADS7822
DESCRIPTION
The ADS7822 is a 12-bit sampling analog-to-digital (A/D)
converter with ensured specifications over a 2.7V to 5.25V
supply range. It requires very little power even when oper-
ating at the full 75kHz rate. At lower conversion rates, the
high speed of the device enables it to spend most of its time
in the power-down mode--the power dissipation is less than
60
W at 7.5kHz.
The ADS7822 also features operation from 2.0V to 5V, a
synchronous serial interface, and a pseudo-differential input.
The reference voltage can be set to any level within the
range of 50mV to V
CC
.
Ultra low power and small size make the ADS7822 ideal for
battery-operated systems. It is also a perfect fit for remote
data acquisition modules, simultaneous multi-channel sys-
tems, and isolated data acquisition. The ADS7822 is avail-
able in a plastic mini-DIP-8, an SOIC-8, or an MSOP-8
package.
12-Bit, High-Speed, 2.7V
microPower Sampling
ANALOG-TO-DIGITAL CONVERTER
FEATURES
q
75kHz SAMPLING RATE
q
MICRO POWER:
0.54mW at 75kHz
0.06mW at 7.5kHz
q
POWER DOWN: 3
A max
q
MINI-DIP-8, SOIC-8, AND MSOP-8
q
PSEUDO-DIFFERENTIAL INPUT
q
SERIAL INTERFACE
SAR
Control
Serial
Interface
D
OUT
Comparator
S/H Amp
CS/SHDN
DCLOCK
+In
V
REF
In
CDAC
APPLICATIONS
q
BATTERY-OPERATED SYSTEMS
q
REMOTE DATA ACQUISITION
q
ISOLATED DATA ACQUISITION
q
SIMULTANEOUS SAMPLING,
MULTI-CHANNEL SYSTEMS
OPA658
ADS7
822
ADS7
822
SBAS062A JANUARY 1996 REVISED MARCH 2005
www.ti.com
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright 1996-2005, Texas Instruments Incorporated
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
ADS7822
2
SBAS062A
www.ti.com
SPECIFICATIONS: +V
CC
= +2.7V
At 40
C to +85
C, +V
CC
= +2.7V, V
REF
= +2.5V, f
SAMPLE
= 75kHz, f
CLK
= 16 f
SAMPLE
, unless otherwise specified.
ADS7822
ADS7822B
ADS7822C
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
ANALOG INPUT
Full-Scale Input Span
+In (In)
0
V
REF
0
V
REF
0
V
REF
V
Absolute Input Range
+In
0.2
V
CC
+0.2
0.2
V
CC
+0.2
0.2
V
CC
+0.2
V
In
0.2
+1.0
0.2
+1.0
0.2
+1.0
V
Capacitance
25
25
25
pF
Leakage Current
1
1
1
A
SYSTEM PERFORMANCE
Resolution
12
12
12
Bits
No Missing Codes
11
12
11
Bits
Integral Linearity Error
2
0.5
+2
1
0.5
+1
0.75
0.25
+0.75
LSB
(1)
Differential Linearity Error
2
0.5
+2
1
0.5
+1
0.75
0.25
+0.75
LSB
Offset Error
3
+3
3
+3
1
+1
LSB
Gain Error
3
+3
3
+3
1
+1
LSB
Noise
33
33
33
Vrms
Power Supply Rejection
82
82
82
dB
SAMPLING DYNAMICS
Conversion Time
12
12
12
Clk Cycles
Acquisition Time
1.5
1.5
1.5
Clk Cycles
Throughput Rate
75
75
75
kHz
DYNAMIC CHARACTERISTICS
Total Harmonic Distortion
V
IN
= 2.5Vp-p at 1kHz
82
82
82
dB
SINAD
V
IN
= 2.5Vp-p at 1kHz
71
71
71
dB
Spurious Free Dynamic Range
V
IN
= 2.5Vp-p at 1kHz
86
86
86
dB
REFERENCE INPUT
Voltage Range
0.05
V
CC
0.05
V
CC
0.05
V
CC
V
Resistance
CS = GND, f
SAMPLE
= 0Hz
5
5
5
G
CS = V
CC
5
5
5
G
Current Drain
At Code 710h
8
40
8
40
8
40
A
f
SAMPLE
= 7.5kHz
0.8
0.8
0.8
A
CS = V
CC
0.001
3
0.001
3
0.001
3
A
DIGITAL INPUT/OUTPUT
Logic Family
CMOS
CMOS
CMOS
Logic Levels:
V
IH
I
IH
= +5
A
2.0
5.5
2.0
5.5
2.0
5.5
V
V
IL
I
IL
= +5
A
0.3
0.8
0.3
0.8
0.3
0.8
V
V
OH
I
OH
= 250
A
2.1
2.1
2.1
V
V
OL
I
OL
= 250
A
0.4
0.4
0.4
V
Data Format
Straight Binary
Straight Binary
Straight Binary
POWER SUPPLY REQUIREMENTS
V
CC
Specified Performance
2.7
3.6
2.7
3.6
2.7
3.6
V
See Notes 2 and 3
2.0
2.7
2.0
2.7
2.0
2.7
V
See Note 3
3.6
5.25
3.6
5.25
3.6
5.25
V
Quiescent Current
200
325
200
325
200
325
A
f
SAMPLE
= 7.5kHz
(4,5)
20
20
20
A
f
SAMPLE
= 75kHz
(5)
180
180
180
A
Power Down
CS = V
CC
3
3
3
A
TEMPERATURE RANGE
Specified Performance
40
+85
40
+85
40
+85
C
NOTES: (1) LSB means Least Significant Bit. With V
REF
equal to +2.5V, one LSB is 0.61mV.
(2) The maximum clock rate of the ADS7822 is less than 1.2MHz in this power supply range.
(3) See the Typical Performance Curves for more information.
(4) f
CLK
= 1.2MHz, CS = V
CC
for 145 clock cycles out of every 160.
(5) See the Power Dissipation section for more information regarding lower sample rates.
ADS7822
3
SBAS062A
www.ti.com
SPECIFICATIONS: +V
CC
= +5V
At 40
C to +85
C, +V
CC
= +5V, V
REF
= +5V, f
SAMPLE
= 200kHz, f
CLK
= 16 f
SAMPLE
, unless otherwise specified.
ADS7822
ADS7822B
PARAMETER
CONDITIONS
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
ANALOG INPUT
Full-Scale Input Span
+In (In)
0
V
REF
0
V
REF
V
Absolute Input Range
+In
0.2
V
CC
+0.2
0.2
V
CC
+0.2
V
In
0.2
+1.0
0.2
+1.0
V
Capacitance
25
25
pF
Leakage Current
1
1
A
SYSTEM PERFORMANCE
Resolution
12
12
Bits
No Missing Codes
11
12
Bits
Integral Linearity Error
2
+2
1
+1
LSB
(1)
Differential Linearity Error
0.8
1
0.5
+1
LSB
Offset Error
3
+3
3
+3
LSB
Gain Error
4
+4
3
+3
LSB
Noise
33
33
Vrms
Power Supply Rejection
70
70
dB
SAMPLING DYNAMICS
Conversion Time
12
12
Clk Cycles
Acquisition Time
1.5
1.5
Clk Cycles
Throughput Rate
200
200
kHz
DYNAMIC CHARACTERISTICS
Total Harmonic Distortion
V
IN
= 5Vp-p at 10kHz
78
78
dB
SINAD
V
IN
= 5Vp-p at 10kHz
71
71
dB
Spurious Free Dynamic Range
V
IN
= 5Vp-p at 10kHz
79
79
dB
REFERENCE INPUT
Voltage Range
0.05
V
CC
0.05
V
CC
V
Resistance
CS = GND, f
SAMPLE
= 0Hz
5
5
G
CS = V
CC
5
5
G
Current Drain
At Code 710h
40
100
40
100
A
f
SAMPLE
= 12.5kHz
2.5
2.5
A
CS = V
CC
0.001
3
0.001
3
A
DIGITAL INPUT/OUTPUT
Logic Family
CMOS
CMOS
Logic Levels:
V
IH
I
IH
= +5
A
3.0
5.5
3.0
5.5
V
V
IL
I
IL
= +5
A
0.3
0.8
0.3
0.8
V
V
OH
I
OH
= 250
A
3.5
3.5
V
V
OL
I
OL
= 250
A
0.4
0.4
V
Data Format
Straight Binary
Straight Binary
POWER SUPPLY REQUIREMENTS
V
CC
Specified Performance
4.5
5.25
4.75
5.25
V
Quiescent Current
f
SAMPLE
= 200kHz
320
550
320
550
A
Power Down
CS = V
CC
3
3
A
TEMPERATURE RANGE
Specified Performance
40
+85
40
+85
C
NOTES: (1) LSB means Least Significant Bit. With V
REF
equal to +5V, one LSB is 1.22mV.
ADS7822
4
SBAS062A
www.ti.com
ELECTROSTATIC
DISCHARGE SENSITIVITY
Electrostatic discharge can cause damage ranging from per-
formance degradation to complete device failure. Texas
Instruments recommends that all integrated circuits be handled
and stored using appropriate ESD protection methods.
ESD damage can range from subtle performance degrada-
tion to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet
published specifications.
ABSOLUTE MAXIMUM RATINGS
(1)
V
CC
....................................................................................................... +6V
Analog Input .............................................................. 0.3V to (V
CC
+ 0.3V)
Logic Input ............................................................................... 0.3V to 6V
Case Temperature ......................................................................... +100
C
Junction Temperature .................................................................... +150
C
Storage Temperature ..................................................................... +125
C
External Reference Voltage .............................................................. +5.5V
NOTE: (1) Stresses above these ratings may permanently damage the device.
PIN
NAME
DESCRIPTION
1
V
REF
Reference Input.
2
+In
Non Inverting Input.
3
In
Inverting Input. Connect to ground or to remote ground sense point.
4
GND
Ground.
5
CS/SHDN
Chip Select when LOW, Shutdown Mode when HIGH.
6
D
OUT
The serial output data word is comprised of 12 bits of data. In operation the data is valid on the falling edge of DCLOCK. The
second clock pulse after the falling edge of CS enables the serial output. After one null bit the data is valid for the next 12 edges.
7
DCLOCK
Data Clock synchronizes the serial data transfer and determines conversion speed.
8
+V
CC
Power Supply.
PIN CONFIGURATION
PIN ASSIGNMENTS
1
2
3
4
8
7
6
5
+V
CC
DCLOCK
D
OUT
CS/SHDN
V
REF
+In
In
GND
ADS7822
PACKAGE/ORDERING INFORMATION
(1)
MAXIMUM
MAXIMUM
INTEGRAL
DIFFERENTIAL
LINEARITY
LINEARITY
SPECIFICATION
ERROR
ERROR
PACKAGE
TEMPERATURE
PACKAGE
ORDERING
TRANSPORT
PRODUCT
(LSB)
(LSB)
PACKAGE
DESIGNATOR
RANGE
MARKING
(2)
NUMBER
(3)
MEDIA
ADS7822E
2
2
MSOP-8
DGK
40
C to +85
C
A22
ADS7822E/250
Tape and Reel
ADS7822E
"
"
"
"
"
"
ADS7822E/2K5
"
ADS7822EB
1
1
MSOP-8
DGK
40
C to +85
C
A22
ADS7822EB/250
Tape and Reel
ADS7822EB
"
"
"
"
"
"
ADS7822EB/2K5
"
ADS7822EC
0.75
0.75
MSOP-8
DGK
40
C to +85
C
A22
ADS7822EC/250
Tape and Reel
ADS7822EC
"
"
"
"
"
"
ADS7822EC/2K5
"
ADS7822P
2
2
Plastic DIP-8
P
40
C to +85
C
ADS7822P
ADS7822P
Rails
ADS7822PB
1
1
Plastic DIP-8
P
40
C to +85
C
ADS7822PB
ADS7822PB
Rails
ADS7822PC
0.75
0.75
Plastic DIP-8
P
40
C to +85
C
ADS7822PC
ADS7822PC
Rails
ADS7822U
2
2
SOIC-8
D
40
C to +85
C
ADS7822U
ADS7822U
Rails
ADS7822U
"
"
"
"
"
"
ADS7822U/2K5
Tape and Reel
ADS7822UB
1
1
SOIC-8
D
40
C to +85
C
ADS7822UB
ADS7822UB
Rails
ADS7822UB
"
"
"
"
"
"
ADS7822UB/2K5
Tape and Reel
ADS7822UC
0.75
0.75
SOIC-8
D
40
C to +85
C
ADS7822UC
ADS7822UC
Rails
ADS7822UC
"
"
"
"
"
"
ADS7822UC/2K5
Tape and Reel
NOTES: (1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at
www.ti.com.
(2) Performance Grade information is marked on the reel.
(3) Models with a slash(/) are available only in tape and reel in quantities indicated (e.g. /250 indicates 250 units per reel, /2K5 indicates 2500
devices per reel). Ordering 2500 pieces of "ADS7822E/2K5" will get a single 2500-piece tape and reel.
Top View
DIP, MSOP, SO
ADS7822
5
SBAS062A
www.ti.com
TYPICAL PERFORMANCE CURVES
At T
A
= +25
C, V
CC
= +2.7V, V
REF
= +2.5V, f
SAMPLE
= 75kHz, f
CLK
= 16 f
SAMPLE
, unless otherwise specified.
DIFFERENTIAL LINEARITY ERROR vs CODE
1.00
0.75
0.50
0.25
0.00
0.25
0.50
0.75
1.00
Differential Linearity Error (LSB)
0
2048
4095
Code
INTEGRAL LINEARITY ERROR vs CODE
1.00
0.75
0.50
0.25
0.00
0.25
0.50
0.75
1.00
Integral Linearity Error (LSB)
0
2048
4095
Code
QUIESCENT CURRENT vs V
CC
400
350
300
250
200
150
100
Quiescent Current (
A)
1
2
3
4
5
V
CC
(V)
MAXIMUM SAMPLE RATE vs V
CC
1000
100
10
1
Sample Rate (kHz)
1
2
3
4
5
V
CC
(V)
SUPPLY CURRENT vs TEMPERATURE
350
300
250
200
150
100
50
Supply Current (
A)
50
25
0
25
50
75
100
Temperature (
C)
POWER DOWN SUPPLY CURRENT
vs TEMPERATURE
120
100
80
60
40
20
0
Supply Current (nA)
50
25
0
25
50
75
100
Temperature (
C)
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