摘要 |
A comparator circuit cell has an output which switches between first and second states when an input voltage (or current) reaches a controlled trip point having a controllable positive, zero or negative temperature coefficient. First and second common emitter transistors are forced to operate at different emitter current densities at the trip point thus requiring the operation of a DELTA VBE across a first resistor coupled between the bases of the first and second transistors in order to get the circuit output to switch. The positive temperature coefficient current which flows through the first resistor to generate DELTA VBE is summed at the base of the second transistor with a negative temperature coefficient current flowing through a second resistor. This creates a required input current having a controllable magnitude and temperature coefficient. The input current may be provided through an additional resistor to the base of the second transistor to create a voltage input trip point having a controllable magnitude and temperature coefficient.
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