AD1990

Rev. 0 | Page 7 of 16

Pin No.

Mnemonic

In/Out

Description

52, 54, 59, 61

NC

No Connection—Should Be Left Floating.

53

AINR

I

Analog Input for Right Channel.

55

REF_FILT

O

Filter Pin for Band Gap Reference—Should Be Bypassed to AGND.

56

AGND

Negative Power Supply for Low Power Analog Circuitry.

57

AVDD

Positive Power Supply for Low Power Analog Circuitry.

58

MOD_FILT

O

Modulator Filter Pin—Used to Set Time Constant of Modulator Order Reduction Circuit.

60

AINL

O

Analog Input for Left Channel.

62

NFL−

I

Left Channel Negative Feedback—Inverting Input.

63

NFL+

I

Left Channel Negative Feedback—Noninverting Input.

64

PGND1

Negative Power Supply. Used for the A2 and B2 high power transistors.