Electrical characteristics of these devices such as drift versus initial offset voltage, noise, and the exponential relationship of base-emitter voltage to collector current closely approach those of a theoretical transistor. Extrinsic base and emitter resistances is very low, giving very low noise and operating over a wide current range.
To guarantee long term stability of matching parameters, internal clamp diodes have been added across the emitter-base junction of each transistor. These prevent degradation due to reverse biased emitter current, the most common cause of field failures in matched devices. The parasitic isolation junction formed by the diodes also clamps the substrate region to the most negative emitter to ensure complete isolation between devices.
We also have the AS194H transistor pair with more exact matching characteristics.
Parameter | AS194H | AS394* | ||||
---|---|---|---|---|---|---|
Min | Typ | Max | Min | Typ | Max | |
Current Gain @ Ic=1mA @ Ic=100µA @ Ic=10µA @ Ic=1µA | 350 350 300 | 700 550 450 300 | 300 250 200 | 700 550 450 300 | ||
Current Gain Match | 0.5% | 2% | 0.5% | 4% | ||
Emitter-Base Offset Voltage | 25µV | 100µV | 150µV | |||
Change in E-B Offset Voltage versus C-B Voltage | 10µV | 25µV | 10µV | 50µV | ||
Change in E-B Offset Voltage versus Collector Current | 5µV | 25µV | 5µV | 50µV | ||
Collector-Base Leakage | 0.05nA | 0.3nA | 0.05nA | 0.5nA |
Features
Package: TO5-8