MAX1968

The MAX1968/MAX1969 are highly integrated and costeffective, high-efficiency, switch-mode drivers for Peltier thermoelectric cooler (TEC) modules. Both devices utilize direct current control to eliminate current surges in the TEC. On-chip FETs minimize external components while providing high efficiency. A 500kHz/1MHz switching frequency and a unique ripple cancellation scheme reduce component size and noise.

The MAX1968 operates from a single supply and provides bipolar ±3A output by biasing the TEC between the outputs of two synchronous buck regulators. Bipolar operation allows for temperature control without "dead zones" or other nonlinearities at low load currents. This arrangement ensures that the control system does not hunt when the set point is very close to the natural operating point, requiring a small amount of heating or cooling. An analog control signal precisely sets the TEC current. The MAX1969 provides unipolar output up to 6A. Reliability is optimized with settable limits for both TEC voltage and current, with independently set limits for heating and cooling current. An analog output also monitors TEC current.

The MAX1968/MAX1969 are available in a low-profile 28-pin TSSOP-EP package and is specified over the -40°C to +85°C temperature range. The thermallyenhanced TSSOP-EP package with exposed metal pad minimizes operating junction temperature. An evaluation kit is available to speed designs.