Burr Brown Corporation ADS7842EB-1K, ADS7842EB, ADS7842E-1K, ADS7842 Datasheet
ADS7842
12-Bit, 4-Channel Parallel Output Sampling
ANALOG-TO-DIGITAL CONVERTER
FEATURES
● SINGLE SUPPLY: 2.7V to 5V
● 4-CHANNEL INPUT MULTIPLEXER
● UP TO 200kHz SAMPLING RATE
● FULL 12-BIT PARALLEL INTERFACE
● ±1 LSB INL AND DNL
● GUARANTEED NO MISSING CODES
● 72dB SINAD
● LOW POWER: 2mW
● SSOP-28 PACKAGE
®
DESCRIPTION
The ADS7842 is a complete, 4-channel, 12-bit analogto-digital converter (ADC). It contains a 12-bit, capacitor-based, SAR A/D with a sample-and-hold amplifier, interface for microprocessor use and parallel,
three-state output drivers. The ADS7842 is specified
at a 200kHz sampling rate while dissipating only
2mW of power. The reference voltage can be varied
from 100mV to VCC with a corresponding LSB resolution from 24µV to 1.22mV. The ADS7842 is guaranteed down to 2.7V operation.
Low power, high speed and an on-board multiplexer
make the ADS7842 ideal for battery-operated systems such as portable, multi-channel dataloggers and
measurement equipment. The ADS7842 is available
in a SSOP-28 package and is guaranteed over the
–40°C to +85°C temperature range.
©
1998 Burr-Brown Corporation PDS-1484B Printed in U.S.A. March, 2000
APPLICATIONS
● DATA ACQUISITION
● TEST AND MEASUREMENT
● INDUSTRIAL PROCESS CONTROL
● MEDICAL INSTRUMENTS
● LABORATORY EQUIPMENT
International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111
Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
ADS7842
SAR
Output
Latches
and
Three
State
Drivers
Three
State
Parallel
Data Bus
Comparator
ADS7842
CS
WR
BUSY
CLK
RD
CDAC
V
REF
4-Channel
MUX
AIN2
AIN1
AIN0
A0
A1
AIN3
For most current data sheet and other product
information, visit www.burr-brown.com
®
2
ADS7842
SPECIFICATIONS: +5V
At TA = –40°C to +85°C, +VCC = +5V, V
REF
= +5V, f
SAMPLE
= 200kHz, and f
CLK
= 16 • f
SAMPLE
= 3.2MHz, unless otherwise noted.
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.
ADS7842E ADS7842EB
PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
RESOLUTION 12 ✻ Bits
ANALOG INPUT
Full-Scale Input Span 0 V
REF
✻✻V
Capacitance 25 ✻ pF
Leakage Current ±1 ✻ µA
SYSTEM PERFORMANCE
No Missing Codes 12 ✻ Bits
Integral Linearity Error ±2 ±1 LSB
(1)
Differential Linearity Error ±0.8 ±0.5 ±1 LSB
Offset Error ±3 ✻ LSB
Offset Error Match 0.15 1.0 ✻✻ LSB
Gain Error ±4 ±3 LSB
Gain Error Match 0.1 1.0 ✻✻LSB
Noise 30 ✻ µVrms
Power Supply Rejection 70 ✻ dB
SAMPLING DYNAMICS
Conversion Time 12 ✻ Clk Cycles
Acquisition Time 3 ✻ Clk Cycles
Throughput Rate 200 ✻ kHz
Multiplexer Settling Time 500 ✻ ns
Aperture Delay 30 ✻ ns
Aperture Jitter 100 ✻ ps
DYNAMIC CHARACTERISTICS
Total Harmonic Distortion
(2)
VIN = 5Vp-p at 10kHz –78 –72 –80 –76 dB
Signal-to-(Noise + Distortion) V
IN
= 5Vp-p at 10kHz 68 71 70 72 dB
Spurious Free Dynamic Range V
IN
= 5Vp-p at 10kHz 72 79 76 81 dB
Channel-to-Channel Isolation V
IN
= 5Vp-p at 50kHz 120 ✻ dB
REFERENCE INPUT
Range 0.1 +V
CC
✻✻V
Resistance DCLK Static 5 ✻ GΩ
Input Current 40 100 ✻✻ µA
f
SAMPLE
= 12.5kHz 2.5 ✻ µA
DCLK Static 0.001 3 ✻✻ µA
DIGITAL INPUT/OUTPUT
Logic Family CMOS ✻
Logic Levels
V
IH
| IIH | ≤ +5µA 3.0 5.5 ✻✻V
V
IL
| IIL | ≤ +5µA –0.3 +0.8 ✻✻V
V
OH
IOH = –250µA 3.5 ✻ V
V
OL
IOL = 250µA 0.4 ✻ V
Data Format Straight Binary ✻
External Clock 0.2 8 ✻✻MHz
POWER SUPPLY REQUIREMENTS
+V
CC
Specified Performance 4.75 5.25 ✻✻V
Quiescent Current 550 900 ✻✻ µA
f
SAMPLE
= 12.5kHz 300 ✻ µA
Power-Down Mode
(3)
, CS = +V
CC
3 ✻ µA
Power Dissipation 4.5 ✻ mW
TEMPERATURE RANGE
Specified Performance –40 +85 ✻✻°C
✻ Same specifications as ADS7842E.
NOTE: (1) LSB means Least Significant Bit. With V
REF
equal to +5.0V, one LSB is 1.22mV. (2) First five harmonics of the test frequency. (3) Power-down mode at
end of conversion when WR, CS, and BUSY conditions have all been met. Refer to Table III of this data sheet.
®
3
ADS7842
SPECIFICATION: +2.7V
At TA = –40°C to +85°C, +VCC = +2.7V, V
REF
= +2.5V, f
SAMPLE
= 125kHz, and f
CLK
= 16 • f
SAMPLE
= 2MHz, unless otherwise noted.
ADS7842E ADS7842EB
✻ Same specifications as ADS7842E.
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) Power-down mode at
end of conversion when WR, CS, and BUSY conditions have all been met. Refer to Table III of this data sheet.
PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
RESOLUTION 12 ✻ Bits
ANALOG INPUT
Full-Scale Input Span 0 V
REF
✻✻V
Capacitance 25 ✻ pF
Leakage Current ±1 ✻ µA
SYSTEM PERFORMANCE
No Missing Codes 12 ✻ Bits
Integral Linearity Error ±2 ±1 LSB
(1)
Differential Linearity Error ±0.8 ±0.5 ±1 LSB
Offset Error ±5 ✻ LSB
Offset Error Match 0.15 1.0 ✻✻ LSB
Gain Error ±4 ±3 LSB
Gain Error Match 0.1 1.0 ✻✻ LSB
Noise 30 ✻ µVrms
Power Supply Rejection 70 ✻ dB
SAMPLING DYNAMICS
Conversion Time 12 ✻ Clk Cycles
Acquisition Time 3 ✻ Clk Cycles
Throughput Rate 125 ✻ kHz
Multiplexer Settling Time 500 ✻ ns
Aperture Delay 30 ✻ ns
Aperture Jitter 100 ✻ ps
DYNAMIC CHARACTERISTICS
Total Harmonic Distortion
(2)
VIN = 2.5Vp-p at 10kHz –77 –70 –79 –74 dB
Signal-to-(Noise + Distortion) V
IN
= 2.5Vp-p at 10kHz 68 71 70 72 dB
Spurious Free Dynamic Range V
IN
= 2.5Vp-p at 10kHz 72 78 76 80 dB
Channel-to-Channel Isolation V
IN
= 2.5Vp-p at 50kHz 100 ✻ dB
REFERENCE INPUT
Range 0.1 +V
CC
✻✻V
Resistance DCLK Static 5 ✻ GΩ
Input Current 13 40 ✻✻ µA
f
SAMPLE
= 12.5kHz 2.5 ✻ µA
DCLK Static 0.001 3 ✻✻ µA
DIGITAL INPUT/OUTPUT
Logic Family CMOS ✻
Logic Levels
V
IH
| I
IH
| ≤ +5µA+V
CC
• 0.7 5.5 ✻✻V
V
IL
| I
IL
| ≤ +5µA –0.3 +0.8 ✻✻V
V
OH
IOH = –250µA+V
CC
• 0.8 ✻ V
V
OL
IOL = 250µA 0.4 ✻ V
Data Format Straight Binary ✻
External Clock 0.2 8 ✻✻MHz
POWER SUPPLY REQUIREMENTS
+V
CC
Specified Performance 2.7 3.6 ✻✻V
Quiescent Current 280 650 ✻✻ µA
f
SAMPLE
= 12.5kHz 220 ✻ µA
Power-Down Mode
(3)
, CS = +V
CC
3 ✻ µA
Power Dissipation 1.8 ✻ mW
TEMPERATURE RANGE
Specified Performance –40 +85 ✻✻°C
®
4
ADS7842
PIN CONFIGURATION
Top View SSOP
PIN DESCRIPTIONS
PIN NAME DESCRIPTION
1 AIN0 Analog Input Channel 0
2 AIN1 Analog Input Channel 1
3 AIN2 Analog Input Channel 2
4 AIN3 Analog Input Channel 3
5V
REF
Voltage Reference Input. See Specifications Tables
for ranges.
6 AGND Analog Ground
7 DB11 Data Bit 11 (MSB)
8 DB10 Data Bit 10
9 DB9 Data Bit 9
10 DB8 Data Bit 8
11 DB7 Data Bit 7
12 DB6 Data Bit 6
13 DB5 Data Bit 5
14 DGND Digital Ground
15 DB4 Data Bit 4
16 DB3 Data Bit 3
17 DB2 Data Bit 2
18 DB1 Data Bit 1
19 DB0 Data Bit 0 (LSB)
20 RD Read Input. Active LOW. Reads the data outputs in
combination with CS.
21 CS Chip Select Input. Active LOW. The combination of
CS taken LOW and WR taken LOW initiates a new
conversion and places the outputs in the tri-state
mode.
22 WR Write Input. Active LOW. Starts a new conversion
and selects an analog channel via address inputs A0
and A1, in combination with CS.
23 BUSY BUSY goes LOW and stays LOW during a
conversion. BUSY rises when a conversion is
complete and enables the parallel outputs.
24 CLK External Clock Input. The clock speed determines the
conversion rate by the equation f
CLK
= 16 • f
SAMPLE
.
25, 26 A0, A1 Address Inputs. Selects one of four analog input
channels in combination with CS and WR. The
address inputs are latched on the rising edge of
either RD or WR.
A0 A1 Channel Selected
0 0 AIN0
0 1 AIN1
1 0 AIN2
1 1 AIN3
27 V
DIG
Digital Supply Input. Nominally +5V.
28 V
ANA
Analog Supply Input. Nominally +5V.
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 specifications.
MINIMUM
RELATIVE SPECIFICATION PACKAGE
ACCURACY SINAD TEMPERATURE DRAWING ORDERING TRANSPORT
PRODUCT (LSB) (dB) RANGE PACKAGE NUMBER NUMBER
(1)
MEDIA
ADS7842E ±2 68 –40°C to +85°C SSOP-28 324 ADS7842E Rails
" " " " " " ADS7842E/1K Tape and Reel
ADS7842EB ±1 70 –40°C to +85°C SSOP-28 324 ADS7842EB Rails
" " " " " " ADS7842EB/1K Tape and Reel
NOTES: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /1K indicates 1000 devices per reel). Ordering 1000 pieces
of “ADS7842E/1K” will get a single 1000-piece Tape and Reel.
PACKAGE/ORDERING INFORMATION
1
2
3
4
5
6
7
8
8
10
11
12
13
14
AIN0
AIN1
AIN2
AIN3
V
REF
AGND
DB11
DB10
DB9
DB8
DB7
DB6
DB5
DGND
V
ANA
V
DIG
A1
A0
CLK
BUSY
WR
CS
RD
DB0
DB1
DB2
DB3
DB4
28
27
26
25
24
23
22
21
20
19
18
17
16
15
ADS7842E
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