ADC10D020 datasheet(4/32 Pages) NSC

4 / 32 page

Pin Descriptions and Equivalent Circuits

Pin No.

Symbol

Equivalent Circuit

Description

I+

I−

Analog inputs to “I” ADC. Nominal conversion range is 1.25V

to 1.75V with GAIN pin low, or 1.0V to 2.0V with GAIN pin

high.

Q+

Q−

Analog inputs to “Q” ADC. Nominal conversion range is 1.25V

to 1.75V with GAIN pin low, or 1.0V to 2.0V with GAIN pin

high.

REF

Analog Reference Voltage input. The voltage at this pin

should be in the range of 0.8V to 1.5V. With 1.0V at this pin

and the GAIN pin

low, the full scale differential inputs are

P-P. With 1.0V at this pin and the GAIN pin high, the full

scale differential inputs are 2 V

P-P. This pin should be

bypassed with a minimum 1 µF capacitor.

CMO

This is an analog output which can be used as a reference

source and/or to set the common mode voltage of the input. It

should be bypassed with a minimum of 1 µF low ESR

capacitor in parallel with a 0.1 µF capacitor. This pin has a

nominal output voltage of 1.5V and hasa1mA output source

capability.

Top of the reference ladder. Do not drive this pin. Bypass

this pin with a 10 µF low ESR capacitor and a 0.1 µF

capacitor.

Bottom of the reference ladder. Do not drive this pin.

Bypass this pin with a 10 µF low ESR capacitor and a 0.1 µF

capacitor.

ADC10D020 Datasheet(PDF) 4 Page - National Semiconductor (TI)