Thermoelectric Cooler (TEC)
Controller
Preliminary Technical Data
ADN8831
FEATURES
True current sensing and over current protection
Separate heating and cooling current limits
High efficiency: >90%
Long-term temperature stability: 0.1°C
Temperature lock indication
Temperature monitoring output
Oscillator synchronization with an external signal
Clock phase adjustment for multiple controllers
Programmable switching frequency up to 1MHz
Programmable maximum TEC voltage
Low noise: <0.05% TEC current ripple
TEC current monitoring
Compact 5mm x 5mm LFCSP
APPLICATIONS
Thermoelectric Cooler (TEC) temperature control
Resistive heating element control
Temperature-Stabilization Substrate (TSS) control

FUNCTIONAL BLOCK DIAGRAM

MOSFET
Drivers
Heating
ILim
Limiter
Controls
PID
Compensation
Network
Error
Amplifier
Oscillator
2.5V
Reference
Cooling
ILim
VLim Freq/Phase
Control
Temp
Set Input
Thermistor
Input





GENERAL DESCRIPTION
The ADN8831 is a monolithic controller that drives a
Thermoelectric Cooler (TEC) to stabilize the temperature of a
laser diode or a passive component used in
telecommunications equipment.
This device relies on a Negative Temperature Coefficient
(NTC) thermistor or a positive temperature coefficient RTD
device to sense the temperature of the object attached to the
TEC. The target temperature is set with an analog input
voltage either from a DAC or with an external resistor divider.
The loop is stabilized by a PID compensation amplifier with
high stability and low noise. The compensation network can
be adjusted by the user to optimize temperature settling time.
The component values for this network can be calculated
based on the thermal transfer function of the laser diode or
obtained from the look-up table given in the applications
notes.
Voltage outputs are provided to monitor both the temperature
of the object and the voltage across the TEC. A 2.5V voltage
reference is provided for the thermistor temperature sensing
bridge.
An external sense resistor provides true current sensing.
Current limits for both heating and cooling can be set
independently.










Rev. PrC
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