AD7701AQ Analog Devices, AD7701AQ Datasheet - Page 4

• Manufacturer Part Number: AD7701AQ
• Description: LC2MOS 16-Bit A/D Converter
• Manufacturer: Analog Devices

AD7701
PIN FUNCTION DESCRIPTION
Pin
1
2
3
4, 17
5
6
7
8
9
10
11
12
13
14
15
16
18
19
20
DIP, Cerdip, SOIC
CLKOUT
MODE
CLKIN
DGND
AGND
DV
AV
V
Mnemonic
MODE
CLKOUT
CLKIN
SC1, SC2
DGND
DV
AV
AGND
A
V
SLEEP
BP/UP
CAL
AV
DV
CS
DRDY
SCLK
SDATA
SC1
REF
A
SS
SS
IN
IN
REF
SS
DD
10
SS
DD
1
2
3
4
5
6
7
8
9
(Not to Scale)
AD7701
TOP VIEW
PIN CONFIGURATIONS
20
19
18
17
16
15
14
13
12
11
Selects the Serial Interface Mode. If MODE is tied to –5 V, the AD7701 will operate in the asynchronous
Clock Output to generate an Internal Master Clock by connecting a crystal between CLKOUT and CLKIN.
Clock Input for External Clock.
Digital Ground. Ground reference for all digital signals.
Analog Ground. Ground reference for all analog signals.
Calibration Mode Pin. When CAL is taken high for more than 4 cycles, the AD7701 is reset and performs a
Serial Clock Input/Output. The SCLK pin in configured as an input or output, dependent on the type of se-
Serial Data Output. The AD7701’s output data is available at this pin as a 16-bit serial word. The transmis-
Description
communications (ac) mode. The SCLK pin is configured as an input, and data is transmitted in two bytes,
each with one start bit and two stop bits. If MODE is tied to DGND, the synchronous external clocking
(SEC) mode is selected. SCLK is configured as an input, and the output appears without formatting, the
MSB coming first. If MODE is tied to +5 V, the AD7701 operates in the synchronous self-clocking (SSC)
mode. SCLK is configured as an output, with a clock frequency of f
If an external clock is used, CLKOUT is not connected.
System Calibration Pins. The state of these pins, when CAL is taken high, determines the type of calibration
performed.
Digital Negative Supply, –5 V nominal.
Analog Negative Supply, –5 V nominal.
Analog Input.
Voltage Reference Input, +2.5 V nominal. This determines the value of positive full-scale in the unipolar
mode and of both positive and negative full-scale in the bipolar mode.
Sleep mode pin. When this pin is taken low, the AD7701 goes into a low-power mode with typically 10 W
power consumption.
Bipolar/Unipolar Mode Pin. When this pin is low, the AD7701 is configured for a unipolar input range going
from AGND to V
calibration cycle when CAL is brought low again. The CAL pin can also be used as a strobe to synchronize
the operation of several AD7701s.
Analog Positive Supply, +5 V nominal.
Digital Positive Supply, +5 V nominal.
Chip Select Input. When CS is brought low, the AD7701 will begin to transmit serial data in a format deter-
mined by the state of the MODE pin.
Data Ready output. DRDY is low when valid data is available in the output register. It goes high after transmission
of a word is completed. It also goes high for four clock cycles when a new data word is being loaded into the out-
put register, to indicate that valid data is not available, irrespective of whether data transmission is complete or not.
rial data transmission that has been selected by the MODE pin. When configured as an output in the syn-
chronous self-clocking mode, it has a frequency of f
sion format is determined by the state of the MODE pin.
SDATA
SCLK
DRDY
SC2
CS
DV
AV
CAL
BP/UP
SLEEP
DD
DD
CLKOUT
CLKIN
MODE
DGND
AGND
DV
AV
V
SC1
REF
REF
A
NC
NC
NC
NC
SS
SS
IN
10
11
12
13
14
1
2
3
4
5
6
7
8
9
. When Pin 12 is high, the AD7701 is configured for a bipolar input range, V
NC = NO CONNECT
SSOP
(Not to Scale)
AD7701
TOP VIEW
28
27
26
25
24
23
22
21
20
19
18
17
16
15
SDATA
SCLK
DRDY
SC2
CS
NC
NC
NC
DV
AV
NC
CAL
BP/UP
SLEEP
DD
DD
–4–
Model
AD7701AN
AD7701BN
AD7701AR
AD7701BR
AD7701ARS
AD7701AQ
AD7701BQ
AD7701SQ
AD7701TQ
NOTES
*N = Plastic DIP; Q = Cerdip; R = SOIC; RS = SSOP.
CLKIN
/4 and a duty cycle of 25%.
Temperature
–40 C to +85 C
–40 C to +85 C
–40 C to +85 C
–40 C to +85 C
–40 C to +85 C
–40 C to +85 C
–40 C to +85 C
–55 C to +125 C
–55 C to +125 C
Range
ORDERING GUIDE
CLKlN
/4 and 25% duty-cycle.
Linearity
Error (% FSR) Options*
0.003
0.0015
0.003
0.0015
0.003
0.003
0.0015
0.003
0.0015
Package
N-20
N-20
R-20
R-20
RS-28
Q-20
Q-20
Q-20
Q-20
REF
REV. D
.