SAP15P Datasheet, PDF (2/6 Pages) Sanken electric – Darlington transistors with built-in temperature compensation diodes for audio amplifier applications

Application Information
1. Recommended Operating Conditions
➀Add a variable resistor (VR) between diode terminals to adjust the idling current. The
resistor having 0 to 200Ω is to be used.
➁Adjust the forward current flowing over the diodes at 2.5mA.
➂Adjust the idling current at 40mA with the external variable resistor.
Both the temperature coefficients for the transistor and the diodes are matched under the above conditions.
Both the PNP and the NPN are Darlington transistors, so the temperature change ratio of the total four VBE
of the transistors is subject to the compensation. One PN junction diode in the NPN and five Schottky
barrier diodes in the PNP are built-in, and the total six diodes are operating as the temperature compensation.
The temperature coefficient of the total diodes (its variable value) becomes smaller with a larger forward
current (approximately – 0.2mV/°C to 1mA), and the coefficient of the total transistors (its variable value)
also becomes smaller with a larger idling current (approximately – 0.1mV/°C to 10mA), but the both variable
values are small.
Thus, the distortion of the temperature coefficient caused by the different current is small, so the thermal
runaway may not be occurred due to the changes of the recommended ratings; however, the actual operation
is to be confirmed by using an experimental equipment or board.
NPN
B
+VCC
C
S
External variable
resistor (VR)
(0 to 200Ω)
D
E
40mA
2.5mA
E
D
S
B
PNP
C
–VCC