High precision reference voltage source - has closed control loop in which current from band-gap element acts as control current over current mirror

摘要

The reference voltage source includes a reference voltage producing bandgap circuit. A closed control loop is generated in which a PTC-transistor (PTAT) current is generated directly from the bandgap. The connecting point of the bandgap resistors (R6,R6) and the emitter of a transistor (T14) of the bandgap circuit (B) leads to one base of a first transistor of a differential amplifier (T3,T4). The emitters of both transistors of the differential amplifier are connected over a resistor (R2) to ground. The collectors of both transistors are connected to the emitter of a first transistor (T5) of a current mirror (T5,T6,T7,T9). ADVANTAGE - Automatically corrects for all process variations.