I am trying to build TEC controller system for DFB laser diode. The temperature control stability we expect is less than 10mK level. Which TEC controller ADN8834 or LTC1923? Thanks,
LTC1923 can achieve typical temperature setpoint accuracy of 0.1 deg. C. Adding an instrumentation amplifier front end allows setpoint stability approaching 0.01 deg. C. Thanks.
Thanks for your reply. We currently use LTC1923 for our existing design. Do you have any idea about the temp stability performance of ADN8834? The design of ADN8834 is simpler than LTC1923. So I wonder if we can switch to ADN8834 in my application to achieve similar temperature stability performance. Thanks,
The temperature stability is a combinational result of the system including the thermistor, biasing resistor and offset drift of the front end circuit. Having that said, we can do a rough estimation based on performance of the front-end circuit of ADN8834 which is “the % voltage error of VOUT1” and “the temp range which VOUT1 maps to”. VOUT1 is a convenient measure to gauge the thermal instability of the ADN8834. If the thermal loop is in steady state, the VOUT1 voltage equals the TEMPSET voltage, meaning that the temperature of the controlled object equals the target temperature. For example, if the temp range is 20~40degC, this 20degC will be mapped to the 0~2.5V scale of VOUT1. Let’s say VOUT1 has 0.01% error (from 15degC to 55degC ambient based in the distribution in figure 11 of the ADN8834 datasheet), using the ratio of 20degC/2.5V, the corresponding temp error that’ll be caused by our part is ~0.0008C.