SWIF

$

+

-

CONTROLLER

OSC

POR

VA

C3

C2

C1

NC

DBACK

DIN

ERRLVL

ERRB

ACKB

BASE

OUT

COMD

COMA

VD

LOW

COMA

40

80k

15k

15k

15k

VA

COMD

COMD

DAC161P997

SNAS515G – JULY 2011 – REVISED DECEMBER 2014

www.ti.com

7 Detailed Description

7.1 Overview

The DAC161P997 is a 16-bit DAC realized as a

∑Δ modulator. The DAC’s output is a current pulse train that is

filtered by the on-board low pass RC filter. The final output current is a multiplied copy of the filtered modulator

output. This architecture ensures an excellent linearity performance, while minimizing power consumption of the

device.

The DAC161P997 eases the design of robust, precise, long-term stable industrial systems by integrating all

precision elements on-chip. Only a few external components are needed to realize a low-power, high-precision

industrial 4-20 mA transmitter.

In case of a fault, or during initial power-up the DAC161P997 will output current in either upper or lower error

current band. The choice of band is user selectable via a device pin. The error current value is user

programmable via the SWIF link by the Master.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Error Detection and Reporting

The user can modify the CONFIG2:(LOOP | CHANNEL | PARITY | FRAME) bits to mask or enable the reporting

of any of the detectable fault conditions. The DAC161P997 reports errors by asserting the ERRB signal, and by

setting the current sourced by OUT to a value dictated by the state at ERRLVL pin and the contents of the

ERR_HIGH and ERR_LOW registers. Once the condition causing the fault is removed the OUT will return to the

last valid output level prior to the occurrence of the fault.

10

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