Datasheet

4
ADS1250
®
PIN DESCRIPTIONS
PIN NAME PIN DESCRIPTION
1+V
IN
Analog Input: Positive Input of the Differential Analog Input.
2–V
IN
Analog Input: Negative Input of the Differential Analog Input.
3 AGND Analog Input: Analog Ground.
4+V
S
Analog Input: Analog Power Supply Voltage, +5V.
5V
REF
Analog Input: Reference Voltage Input.
6 DSYNC Digital Input: Data Synchronization. A falling edge on this input will reset the modulator count and place the modulator in a hold
state. The modulator is released from the hold state on the rising edge of DSYNC. This can be used to synchronize multiple
ADS1250s.
7+V
D
Digital Input: Digital Power Supply Voltage, +5V.
8 DGND Digital Input: Digital Ground.
9 DOUT Digital Output: Serial Data Output. The serial data is clocked out of the serial data output shift register through this pin. The pin
is driven when CS is LOW, and high impedance when CS is HIGH.
10 SCLK Digital Input: Serial Clock. The serial clock is in the form of a CMOS-compatible clock. The serial clock can operate up to the
device’s system clock frequency. The serial clock can be either a free-running clock or noncontinuous clock, with either type of
clock; the serial data output is gated by CS.
11 CLK Digital Input: Device System Clock. The system clock is in the form of a CMOS-compatible clock.
12 DRDY Digital Output: Data Ready. A falling edge on this output indicates that a new output word is available from the ADS1250 data output
register.
13 CS Digital Input: Chip Select. Active LOW logic input used to enable serial data output from the ADS1250. CS controls the state of
the DOUT pin. If CS is HIGH, DOUT is high impedance; if CS is LOW, DOUT drives the bus. CS can be used in three ways:
(1) If the ADS1250 shares the bus with other devices, CS is used as serial data output enable for communications.
(2) If the ADS1250 shares the bus with other devices and SCLK is a free-running clock, CS is used to gate serial data
out of the device.
(3) If the ADS1250 is the only device on the bus, CS can be tied LOW to always enable serial data output for a
two-wire interface.
Refer to the Serial Communications section of this data sheet for more detail.
14 G0 Digital Input: Gain Selection Control (LSB).
15 G1 Digital Input: Gain Selection Control (MSB).
16 DGND Digital Input: Digital Ground.
PIN CONFIGURATION
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
+V
IN
ADS1250
AGND
–V
IN
+V
S
V
REF
DSYNC
+V
D
DGND
DGND
G0 (LSB)
G1 (MSB)
CS
DRDY
CLK
SCLK
DOUT
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