Patent ID: 7800429
Filing Date: 2010-09-21
Classification: G01R

Abstract:
1. A temperature compensated reference circuit operable throughout linear, saturated and sub-threshold regions for use in a voltage detection circuit comprising: a cascode-connected transistor wherein the cascode-connected transistor includes a gate having a fixed voltage and is biased in a linear region; a diode-connected transistor; a first resistor; and a second resistor, wherein the cascode-connected transistor, the diode-connected transistor, the first resistor, and the second resistor are coupled in series between a first source of power supply voltage and a second source of power supply voltage, and wherein the diode-connected transistor has a negative temperature coefficient, the resistance of the cascode-connected transistor has a positive temperature coefficient, and the size of the cascode-connected transistor is selected to substantially cancel the temperature coefficient of the detection circuit, wherein a voltage output of the voltage detection circuit comprises the junction of the first and second resistors; and wherein the cascode-connected transistor comprises a gate coupled directly to VDD.