Circuit for automatically measuring gain of built-in trans-impedance amplifier
AssigneeXiamen Ux High-Speed Ic Co., Ltd.
InventorShaoheng Lin
Life of this patent
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Abstract
A circuit for automatically measuring gain of a built-in trans-impedance amplifier includes a current source built in a trans-impedance amplifier chip for generating a constant current to an input end of the trans-impedance amplifier. The circuit samples a voltage amplitude at an output end of the trans-impedance amplifier using a voltage amplitude sampling device, and calculates the gain of the trans-impedance amplifier. The current source has a constant reference voltage source, a reference current generator, a clock source, an AC switch, and an off-chip precision resistor. The circuit is configured to measure gain of trans-impedance amplifiers directly.
Claims4
A circuit for automatically measuring gain of a built-in trans-impedance amplifier, comprising a current source that is built in a trans-impedance amplifier chip for generating a stable, constant current to an input end of the trans-impedance amplifier;
- the circuit sampling a voltage amplitude at an output end of the trans-impedance amplifier using a voltage amplitude sampling device and calculating the gain of the trans-impedance amplifier;
- the current source comprising a constant reference voltage source, a reference current generator, a clock source, an AC switch and an off-chip precision resistor;
- the clock source opening or closing the AC switch, thereby disconnecting or connecting an output end of the reference current generator from or to the input end of the trans-impedance amplifier;
- and the off-chip precision resistor being connected to the reference current generator for modulating a current output by the reference current generator.
Dependencies are inferred from the claim text.