Thermoelectric Cooler (TEC) Controller

Data Sheet

ADN8831

Rev. A

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibilityisassumedbyAnalogDevicesforitsuse,norforanyinfringementsofpatentsorother

rightsofthirdpartiesthatmayresultfromitsuse.Specificationssubjecttochangewithoutnotice.No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarksandregisteredtrademarksarethepropertyoftheirrespectiveowners.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781.329.4700

www.analog.com

Fax: 781.461.3113

©2005–2012 Analog Devices, Inc. All rights reserved.

FEATURES

Two integrated zero drift, rail-to-rail, chop amplifiers

TEC voltage and current operation monitoring

Programmable TEC maximum voltage and current

Programmable TEC current heating and cooling limits

Configurable PWM switching frequency up to 1 MHz

Power efficiency: > 90%

Temperature lock indication

Optional internal or external clock source

Clock phase adjustment for multiple drop operation

Supports negative temperature coefficient (NTC) thermistors

or positive temperature coefficient (PTC) resistance

thermal detectors (RTDs)

5 V typical and optional 3 V supplies

Standby and shutdown mode availability

Adjustable soft start feature

5 mm × 5 mm 32-lead LFCSP

APPLICATIONS

Thermoelectric cooler (TEC) temperature control

DWDM optical transceiver modules

Optical fiber amplifiers

Optical networking systems

Instruments requiring TEC temperature control

GENERAL DESCRIPTION

The ADN8831 is a monolithic TEC controller. It has two inte-

grated, zero drift, rail-to-rail comparators, and a PWM driver.

A unique PWM driver works with an analog driver to control

external selected MOSFETs in an H-bridge. By sensing the

thermal detector feedback from the TEC, the ADN8831 can

drive a TEC to settle the programmable temperature of a laser

diode or a passive component attached to the TEC module.

The ADN8831 supports NTC thermistors or positive tempera-

ture coefficient (PTC) RTDs. The target temperature is set as an

analog voltage input either from a DAC or from an external

resistor divider driven by a reference voltage source.

A proportional integral differential (PID) compensation

network helps to quickly and accurately stabilize the ADN8831

thermal control loop. An adjustable PID compensation network

example is described in the AN-695 Application Note, Using the

ADN8831 TEC Controller Evaluation Board. A typical reference

voltage of 2.5 V is available from the ADN8831 for thermistor

temperature sensing or for TEC voltage/current measuring and

limiting in both cooling and heating modes.

FUNCTIONAL BLOCK DIAGRAM

AMPLIFIER

Chop2

AMPLIFIER

Chop1

IN1P

IN1N

OUT1

IN2P

IN2N

OUT2

LIMITER/MONITOR

REF

SOFT START

SHUTDOWN

OSCILLATOR

TMPGD VREF

SS/SB

PHASE

FREQ

SYNCI/SD

LINEAR

MOSFET

DRIVER

PWM

MOSFET

DRIVER

LFB

LPGATE

LNGATE

SFB

SPGATE

SNGATE

COMPSW

SW

COMPOSC

SYNCO

CONTROL

ILIMC

ILIMH

ITEC

VLIM

VTEC

CS

Figure 1.