Patent ID: 9559694
Date: 2017-01-31
CPC Classifications: H03K

Claim:
1. An integrated circuit having a reference-voltage generation circuit comprising: a reference resistor (e.g., Rtrip) connected to an input node at an input supply voltage level (VIN); a constant current source configured to generate a constant current signal; current mirror circuitry configured to generate a reference current signal based on the constant current signal, wherein the reference current signal is applied to the reference resistor to generate a reference voltage signal; voltage-protection circuitry configured to shield the current mirror circuitry from relatively high voltage levels at the input node, by lowering a voltage applied to the current mirror circuitry; and bypass circuitry configured to bypass at least some of the voltage-protection circuitry at relatively low voltage levels at the input node to ensure proper operation of the current mirror circuitry at the relatively low voltage levels, by providing, when active, a path, for at least a portion of the reference current, that is in parallel with the bypassed voltage-protection circuitry.