Document
Thermoelectric Cooler Controller ADN8830
FEATURES High Efficiency Small Size: 5 mm ؋ 5 mm LFCSP Low Noise: <0.5% TEC Current Ripple Long-Term Temperature Stability: ؎0.01؇ C Temperature Lock Indication Temperature Monitoring Output Oscillator Synchronization with an External Signal Clock Phase Adjustment for Multiple Controllers Programmable Switching Frequency up to 1 MHz Thermistor Failure Alarm Maximum TEC Voltage Programmability APPLICATIONS Thermoelectric Cooler (TEC) Temperature Control Resistive Heating Element Control Temperature Stabilization Substrate (TSS) Control GENERAL DESCRIPTION
The ADN8830 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 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 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 lookup table given in the Application Notes section. Voltage outputs are provided to monitor both the temperature of the object and the voltage across the TEC. A voltage reference of 2.5 V is also provided.
FUNCTIONAL BLOCK DIAGRAM
PID COMPENSATION NETWORK
FROM THERMISTOR TEMPERATURE SET INPUT VREF
P-CHANNEL (UPPER MOSFET) TEMPERATURE MEASUREMENT AMPLIFIER PWM CONTROLLER MOSFET DRIVERS P-CHANNEL (LOWER MOSFET) N-CHANNEL N-CHANNEL
VOLTAGE REFERENCE
OSCILLATOR
FREQUENCY/PHASE CONTROL
REV. C
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 www.analog.com Fax: 781/326-8703 © 2003 Analog Devices, Inc. All rights reserved.
V = 3.3 V to 5.0 V, V = 0 V, T = 25؇C, T = 25؇C, using typical application configuration as shown in Figure 1, unless otherwise noted.) ADN8830–SPECIFICATIONS (@
DD GND A SET
Parameter TEMPERATURE STABILITY Long-Term Stability PWM OUTPUT DRIVERS Output Transition Time Nonoverlapping Clock Delay Output Resistance Output Voltage Swing Output Voltage Ripple Output Current Ripple LINEAR OUTPUT AMPLIFIER Output Resistance Output Voltage Swing POWER SUPPLY Power Supply Voltage Power Supply Rejection Ratio Supply Current Shutdown Current Soft-S.