ZHCSKS4H October 2009 – January 2025 TL331-Q1 , TL331B-Q1 , TL391B-Q1
PRODMIX
The TL331-Q1 consists of a PNP Darlington pair input, allowing the device to operate with very high gain and fast response with minimal input bias current. The input Darlington pair creates a limit on the input common mode voltage capability, allowing TL331-Q1 to accurately function from ground to VCC – 1.5V differential input. A clamp (Q15) was added around Q3 to force the output low when both inputs are taken above the VCM range.
The output consists of an open collector NPN (pull-down or low side) transistor. The output NPN sinks current when the negative input voltage is higher than the positive input voltage and the offset voltage. The VOL is resistive and scales with the output current. Please see Output Low Voltage vs. Output Sinking Current at 5V for VOL values with respect to the output current.