Driving circuit of thermal electric cooler (TEC)

Abstract

The invention discloses a driving circuit of a thermal electric cooler (TEC), which comprises a single-channel DC-DC (direct current-direct current) conversion chip and a bridge circuit. The bridge circuit is connected with an output end of the single-channel DC-DC conversion chip, two output ends of the bridge circuit are respectively connected with two input ends of the TEC, and the bridge circuit is controlled by two channels of driving voltage. Current direction of the TEC can be controlled by controlling level of the two channels of driving voltage, so that running states of the TEC can be controlled. Since directions of current flowing through the TEC are switched by the bridge circuit, the output end of the single-chip DC-DC conversion chip keeps working in an output current state, limitation of current absorption capacity when in use of a double-channel DC-DC conversion chip is avoided, and the capacity of the DC-DC conversion chip for driving the TEC is improved.

Description

technical field [0001] The invention relates to the field of semiconductor refrigeration, in particular to a TEC drive circuit for a semiconductor refrigerator. Background technique [0002] In the prior art, the driving circuit of the semiconductor refrigerator (TEC, Thermoelectric Cooler) uses a dual-channel DC-DC conversion chip as the driver of the TEC, such as figure 1 As shown, the positive and negative ends of the TEC are respectively connected to figure 1 TEC+ and TEC- in the circuit control the output voltages of the two channels of the dual-channel DC-DC conversion chip, SW1 and SW2, respectively, by controlling the output voltages of the two digital-to-analog converters DAC0 and DAC1, thereby controlling the flow through The current direction and magnitude of the TEC achieve the purpose of controlling the TEC to switch between cooling and heating working states and controlling the cooling and heating power. When the output voltage of SW1 is greater than the outp...

AI Technical Summary

Problems solved by technology

[0003] However, since the ability of the DC-DC converter chip to absorb current is only half of the output current capacity, when the voltage output terminals SW1 and SW2 of the DC-DC converter chip U401 work in the state of output current, they can output a current of 800mA; when they work in the state of absorbing current state, it can only sink 400mA current

When the DC-DC conversion chip drives the TEC, the TEC works in the heating and cooling state. The DC-DC conversion chip of the drive circuit has one channel working in the state of absorbing current, and the other channel is working in the state of output current. In the state of sinking current, the sinking current capability of the channel is limited, and the DC-DC conversion chip can only provide a driving current of 400mA to the TEC at most, so its driving ability can only be used in half.

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