Datasheet

IN0
IN7
MUX T/H
ADC128S022
SCLK
V
A
AGND
DGND
V
D
CS
DIN
DOUT
CONTROL
LOGIC
12-BIT
SUCCESSIVE
APPROXIMATION
ADC
.
.
.
AGND
ADC128S022
SNAS334E –AUGUST 2005–REVISED MARCH 2013 www.ti.com
Block Diagram
Pin Descriptions and Equivalent Circuits
Pin No. Symbol Equivalent Circuit Description
ANALOG I/O
4 - 11 IN0 to IN7 Analog inputs. These signals can range from 0V to V
REF
.
DIGITAL I/O
Digital clock input. The specified performance range of frequencies
16 SCLK for this input is 0.8 MHz to 3.2 MHz. This clock directly controls the
conversion and readout processes.
Digital data output. The output samples are clocked out of this pin on
15 DOUT
the falling edges of the SCLK pin.
Digital data input. The ADC128S022's Control Register is loaded
14 DIN
through this pin on rising edges of the SCLK pin.
Chip select. On the falling edge of CS, a conversion process begins.
1 CS
Conversions continue as long as CS is held low.
POWER SUPPLY
Positive analog supply pin. This voltage is also used as the
reference voltage. This pin should be connected to a quiet +2.7V to
2 V
A
+5.25V source and bypassed to GND with 1 µF and 0.1 µF
monolithic ceramic capacitors located within 1 cm of the power pin.
Positive digital supply pin. This pin should be connected to a +2.7V
13 V
D
to V
A
supply, and bypassed to GND with a 0.1 µF monolithic ceramic
capacitor located within 1 cm of the power pin.
3 AGND The ground return for the analog supply and signals.
12 DGND The ground return for the digital supply and signals.
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
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