Demonstration circuit DC2902A is a thermoelectric cooler (TEC) regulator featuring the LTM4663 μModule regulator. The demo board has a 2.7V to 5.5V input voltage range and can deliver up to 1.5A of sinking or sourcing current. Inside the LTM4663, a linear power stage works together with a PWM power stage to form an H-bridge configuration. The direction of the current fed through the TEC can be either positive (for cooling mode), or negative (for heating mode). The LTM4663 has two built-in zero drift, rail-to-rail chopper amplifiers which can serve as a thermistor input amplifier and form an analog temperature control loop. The LTM4663 provides a 1% accuracy 2.5V internal reference voltage to bias the thermistor temperature sensing circuit and to program the maximum TEC current and voltage limits for both the cooling and heating modes.
The demo board has a default 2MHz switching frequency and can be synchronized to an external clock from 1.85MHz to 3.25MHz applied to the EN/SY input pin (JP1: EN/SY). The clock high level must be above 2.1V and the clock low level must be below 0.8V. Maximum TEC current limit can be programmed with a resistor, R7 (default: 1.5A for cooling mode; –1.5A for heating mode). Maximum TEC voltage limit can be programmed with a resistor, R10 (default: 5V for cooling mode; –4.8V for heating mode). Other features include VTEC output for TEC voltage monitor and ITEC output for TEC current monitor
The LTM4663 datasheet gives a complete description of the operation and application information. The datasheet must be read in conjunction with the demo manual.