GENERAL DESCRIPTION

The SGM41298 is a monolithic thermoelectric cooling

(TEC) thermostat driver device with two-stage feedback

amplifier. The device includes a differential driver

(output) stage, an internal 2.5V output reference voltage

and two zero-drift, rail-to-rail chopper amplifiers. The

first chopper amplifier biases the sensed temperature

signal and another is an error amplifier for

compensating the closed loop temperature control.

This amplifier can be used with a digital controller as

well.

The TEC is driven differentially between a linear

push-pull stage and a pulse-width modulation (PWM)

switching stage. A linear push-pull stage forms one of

the arms of the differential output which has a relatively

high gain and saturates if the error signal is not close to

zero (> 2.5%). This means that the TEC is effectively

driven by the other arm. The other arm has a lower gain,

and high frequency PWM switching driver that can

drive the TEC with high efficiency. The PWM switching

driver output is passed through an LC filter to remove

large voltage ripple before reaching the TEC. It can sink

or source current for both the heating and cooling modes

connected to the TEC and stabilize its temperature at

the set point.

The SGM41298 is available in a Green WLCSP-2.55×2.55-25B

package. It operates over the -40℃ to +125℃ junction

temperature range.

FEATURES

● High Efficiency Single Inductor Architecture

● Single-ended to Differential Driver with Low RDSON

MOSFETs inside

● TEC Voltage and Current Monitoring

● No External Sense Resistor Required

● Independent Heating and Cooling Current/Voltage

Limits Programming

● PWM Driver Switching Frequency: 2.0MHz (TYP)

● Two Rail-to-Rail, Zero-Drift Chopper Amplifiers

● Compatible with RTD or NTC Thermal Sensors

● 2.5V Output Reference Voltage

● Patent Pending

● Available in a Green WLCSP-2.55×2.55-25B Package

APPLICATIONS

TEC Temperature Controls

Instruments Requiring TEC Temperature Controls

Optical Modules

Optical Fiber Amplifiers

Optical Networking Systems