The ADS7841 is a 4-channel, 12-bit sampling analog-
to-digital converter (ADC) with a synchronous serial
interface. The resolution is programmable to either 8
or 12 bits. Typical power dissipation is 2mW at a
200kHz throughput rate and a +5V supply. The refer-
ence voltage (V
REF
) can be varied between 100mV and
V
CC
, providing a corresponding input voltage range of
0V to V
REF
. The device includes a shutdown mode
which reduces power dissipation to under 15µW. The
ADS7841 is guaranteed down to 2.7V operation.
Low power, high speed, and on-board multiplexer
make the ADS7841 ideal for battery operated systems
such as personal digital assistants, portable multi-
channel data loggers, and measurement equipment.
The serial interface also provides low-cost isolation
for remote data acquisition. The ADS7841 is available
in a 16-pin PDIP or a 16-lead SSOP package and is
guaranteed over the –40°C to +85°C temperature range.
APPLICATIONS
q
DATA ACQUISITION
q
TEST AND MEASUREMENT
q
INDUSTRIAL PROCESS CONTROL
q
PERSONAL DIGITAL ASSISTANTS
q
BATTERY-POWERED SYSTEMS
SAR
DCLK
CS
CH0
CH1
CH2
CH3
COM
V
REF
Four
Channel
Multiplexer
CDAC
Comparator
Serial
Interface
and
Control
SHDN
DIN
DOUT
MODE
BUSY
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equal to +5.0V, one LSB is 1.22mV. (2) First five harmonics of the test frequency. (3) Auto power-down mode
(PD1 = PD0 = 0) active or SHDN = GND.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
®
ADS7841
2
SPECIFICATION: +2.7V
At T
A
= –40°C to +85°C, +V
CC
= +2.7V, V
REF
= +2.5V, f
SAMPLE
= 125kHz, and f
CLK
= 16 • f
SAMPLE
= 2MHz, unless otherwise noted.
ADS7841E, P
PARAMETER
ANALOG INPUT
Full-Scale Input Span
Absolute Input Range
Capacitance
Leakage Current
SYSTEM PERFORMANCE
Resolution
No Missing Codes
Integral Linearity Error
Differential Linearity Error
Offset Error
Offset Error Match
Gain Error
Gain Error Match
Noise
Power Supply Rejection
SAMPLING DYNAMICS
Conversion Time
Acquisition Time
Throughput Rate
Multiplexer Settling Time
Aperture Delay
Aperture Jitter
DYNAMIC CHARACTERISTICS
Total Harmonic Distortion
(2)
Signal-to-(Noise + Distortion)
Spurious Free Dynamic Range
Channel-to-Channel Isolation
REFERENCE INPUT
Range
Resistance
Input Current
V
IN
V
IN
V
IN
V
IN
=
=
=
=
2.5Vp-p
2.5Vp-p
2.5Vp-p
2.5Vp-p
at
at
at
at
10kHz
10kHz
10kHz
50kHz
CONDITIONS
MIN
TYP
MAX
MIN
T
T
T
T
T
T
12
±0.8
0.15
0.1
30
70
±2
±3
1.0
±4
1.0
±0.5
T
T
T
T
±1
±1
T
T
±3
T
ADS7841EB, PB
TYP
MAX
T
T
T
UNITS
Positive Input - Negative Input
Positive Input
Negative Input
0
–0.2
–0.2
25
±1
12
12
V
REF
+V
CC
+0.2
+0.2
V
V
V
pF
µA
Bits
Bits
LSB
(1)
LSB
LSB
LSB
LSB
LSB
µVrms
dB
Clk Cycles
Clk Cycles
kHz
ns
ns
ps
dB
dB
dB
dB
V
GΩ
µA
µA
µA
12
3
125
500
30
100
–77
71
78
100
–72
70
76
T
T
T
–79
72
80
T
T
T
T
–76
68
72
0.1
DCLK Static
f
SAMPLE
= 12.5kHz
DCLK Static
5
13
2.5
0.001
CMOS
| I
IH
|
≤
+5µA
| I
IL
|
≤
+5µA
I
OH
= –250µA
I
OL
= 250µA
+V
CC
• 0.7
–0.3
+V
CC
• 0.8
Straight Binary
Specified Performance
f
SAMPLE
= 12.5kHz
Power-Down Mode
(3)
, CS = +V
CC
2.7
280
220
+V
CC
40
3
T
T
T
T
T
T
T
T
T
DIGITAL INPUT/OUTPUT
Logic Family
Logic Levels
V
IH
V
IL
V
OH
V
OL
Data Format
POWER SUPPLY REQUIREMENTS
+V
CC
Quiescent Current
5.5
+0.8
0.4
T
T
T
T
T
T
T
V
V
V
V
3.6
650
3
1.8
T
T
T
T
T
T
T
Power Dissipation
TEMPERATURE RANGE
Specified Performance
T
Same specifications as ADS7841E, P.
–40
V
µA
µA
µA
mW
°C
+85
T
T
NOTE: (1) LSB means Least Significant Bit. With V
REF
equal to +2.5V, one LSB is 610mV. (2) First five harmonics of the test frequency. (3) Auto power-down mode
(PD1 = PD0 = 0) active or SHDN = GND.
®
3
ADS7841
PIN CONFIGURATIONS
Top View
DIP
SSOP
+V
CC
CH0
CH1
CH2
CH3
COM
SHDN
V
REF
1
2
3
4
5
6
7
8
ADS7841
16
15
14
13
12
11
10
9
DCLK
CS
DIN
BUSY
DOUT
MODE
GND
+V
CC
+V
CC
CH0
CH1
CH2
CH3
COM
SHDN
V
REF
1
2
3
4
5
6
7
8
ADS7841
16
15
14
13
12
11
10
9
DCLK
CS
DIN
BUSY
DOUT
MODE
GND
+V
CC
PIN DESCRIPTIONS
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
NAME
+V
CC
CH0
CH1
CH2
CH3
COM
SHDN
V
REF
+V
CC
GND
MODE
DOUT
BUSY
DIN
CS
DCLK
DESCRIPTION
Power Supply, 2.7V to 5V.
Analog Input Channel 0.
Analog Input Channel 1.
Analog Input Channel 2.
Analog Input Channel 3.
Ground Reference for Analog Inputs. Sets zero code voltage in single-ended mode. Connect this pin to ground or ground reference
point.
Shutdown. When LOW, the device enters a very low power shutdown mode.
Voltage Reference Input
Power Supply, 2.7V to 5V.
Ground
Conversion Mode. When LOW, the device always performs a 12-bit conversion. When HIGH, the resolution is set by the MODE bit in
the CONTROL byte.
Serial Data Output. Data is shifted on the falling edge of DCLK. This output is high impedance when CS is HIGH.
Busy Output. This output is high impedance when CS is HIGH.
Serial Data Input. If CS is LOW, data is latched on rising edge of DCLK.
Chip Select Input. Controls conversion timing and enables the serial input/output register.
External Clock Input. This clock runs the SAR conversion process and synchronizes serial data I/O.
ABSOLUTE MAXIMUM RATINGS
(1)
+V
CC
to GND ......................................................................... –0.3V to +6V
Analog Inputs to GND ............................................ –0.3V to +V
CC
+ 0.3V
Digital Inputs to GND ........................................................... –0.3V to +6V
Power Dissipation .......................................................................... 250mW
Maximum Junction Temperature ................................................... +150°C
Operating Temperature Range ....................................... –40°C to +85°C
Storage Temperature Range ......................................... –65°C to +150°C
Lead Temperature (soldering, 10s) ............................................... +300°C
NOTE: (1) Stresses above those listed under “Absolute Maximum Ratings”
may cause permanent damage to the device. Exposure to absolute maximum
conditions for extended periods may affect device reliability.
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and
installation procedures can cause damage.
ESD damage can range from subtle performance degradation 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 its published specifi-
cations.
PACKAGE
DRAWING
NUMBER
(1)
322
"
180
322
"
180
PACKAGE/ORDERING INFORMATION
MINIMUM
RELATIVE
ACCURACY
(LSB)
±2
"
±2
±1
"
±1
DIFFERENTIAL
NONLINEARITY
(LSB)
68
"
68
70
"
70
SPECIFICATION
TEMPERATURE
RANGE
–40°C to
"
–40°C to
–40°C to
"
–40°C to
+85°C
+85°C
+85°C
+85°C
PRODUCT
ADS7841E
"
ADS7841P
ADS7841EB
"
ADS7841PB
PACKAGE
16-Lead SSOP
"
16-Pin PDIP
16-Lead SSOP
"
16-Pin PDIP
ORDERING
NUMBER
(2)
ADS7841E
ADS7841E/2K5
ADS7841P
ADS7841EB
ADS7841EB/2K5
ADS7841PB
TRANSPORT
MEDIA
Rails
Tape and Reel
Rails
Rails
Tape and Reel
Rails
NOTES: (1) For detailed drawing and dimension table, please see end of data sheet, or Appendix C of Burr-Brown IC Data Book. (2) Models with a slash (/) are
available only in Tape and Reel in the quantities indicated (e.g., /2K5 indicates 2500 devices per reel). Ordering 2500 pieces of “ADS7841/2K5” will get a single
2500-piece Tape and Reel. For detailed Tape and Reel mechanical information, refer to Appendix B of Burr-Brown IC Data Book.
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