ADN8831 Datasheet

• 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

• Thermoelectric cooler (TEC) temperature control
• DWDM optical transceiver modules
• Optical fiber amplifiers
• Optical networking systems
• Instruments requiring TEC temperature control

The ADN8831 is a monolithic TEC controller. It has two integrated, 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 temperature 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 ADN8831TEC 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.