This document introduces the SAP series of Darlington transistors, which feature built-in temperature compensation diodes and emitter resistors, real-time temperature compensation, and symmetrical design for PNP and NPN pinouts. These products are suitable for audio amplifier applications.
The SAP series Darlington transistors from Allegro incorporate built‑in temperature‑compensation diodes and an emitter resistor in a single package, reducing part count and simplifying assembly for audio‑amplifier designs. Real‑time temperature compensation stabilizes the idle current and helps prevent thermal runaway.
The datasheet provides electrical characteristics, recommended operating conditions, and guidelines for adjusting the idle current with an external variable resistor. It also details the destruction capacity of the built‑in resistor and outlines application notes for parallel push‑pull configurations.
| Weight | ≈ 8.3 g |
|---|---|
| Absolute Maximum Vceo | 160 V |
By adding a variable resistor (VR) between the diode terminals; the resistor (0 – 2000 Ω) is set so the idling current reaches about 40 mA.
They are mounted on the chip to detect temperature rises directly and stabilize the idle current, preventing thermal runaway.
For SAP08P/N the resistor is polysilicone; for SAP10P/N and SAP15P/N it is a thick‑film resistor that may fail before the transistor under short‑circuit conditions.
Set the forward current through the diodes to 2.5 mA and adjust the idle current to 40 mA using the external variable resistor.