Temperature Controller Is Immune To Ambient Crossover

Upgraded to offer better temperature stability and reduced internal voltage drop, the HTC Series precision temperature controller now provides improved operating efficiency. Stability is a measure of how close the actual load temperature stays to setpoint temperature over time. Often there can be a “dead band” when scanning across ambient temperature, during the transition between heating and cooling control. The upgraded HTC is immune to ambient crossover. Short term off-ambient stability is 0.0009°C and long term off-ambient stability is 0.0015°C. On-ambient stability of 0.002°C has been achieved with thermistors. The low-profile package is suitable for designs with space constraints. The controller provides up to 3 A of heating or cooling current for medical, defense, communications, or manufacturing applications. The linear, PI (Proportional, Integral) control loop offers maximum stability while the bipolar current source has been designed for higher efficiency. Optimized for ultra-stable thermoelectric temperature control applications, the HTC maintains precision temperature regulation using an adjustable sensor bias current and error amplifier circuit that operates directly with thermistors, RTDs and AD590- and LM33-type temperature sensors. An evaluation board is available to expedite prototyping; evaluation quantities are typically available from stock. WAVELENGTH ELECTRONICS INC., Bozeman, MT (406) 587-4910.