The ADN8835 is a monolithic TEC controller with an integrated TEC controller. It has a linear power stage, a pulse-width modulation (PWM) power stage, and two zero-drift, rail-to-rail chopper amplifiers. The linear controller works with the PWM driver to control the internal power MOSFETs in an H bridge configuration. By measuring the thermal sensor feedback voltage and using the integrated operational amplifiers as a proportional integral differential (PID) compensator to condition the signal, the ADN8835 drives current through a TEC to settle the temperature of a laser diode or a passive component attached to the TEC module to the programmed target temperature.
The ADN8835 supports negative temperature coefficient (NTC) thermistors as well as positive temperature coefficient (PTC) resistive temperature detectors (RTDs). The target temperature is set as an analog voltage input either from a digital-to-analog converter (DAC) or from an external resistor divider.
The temperature control loop of the ADN8835 is stabilized by PID compensation utilizing the built in, zero-drift chopper amplifiers. The internal 2.50 V reference voltage provides a 1% accurate output that biases a thermistor temperature sensing bridge as well as a voltage divider network to program the maximum TEC current and voltage limits for both the heating and cooling modes. With the zero-drift chopper amplifiers, excellent long-term temperature stability is maintained via an autonomous analog temperature control loop.
**Applications**
TEC temperature control
Optical modules
Optical fiber amplifiers
Optical networking systems
Instruments requiring TEC temperature control
### Features and Benefits
High efficiency single inductor architecture
Integrated low RDSON MOSFETs for the TEC controller
TEC voltage and current operation monitoring
No external sense resistor required
Independent TEC heating and cooling current-limit settings
Programmable maximum TEC voltage
2.0 MHz (typical) PWM driver switching frequency
External synchronization
Two integrated, zero-drift, rail-to-rail chopper amplifiers
