PSSI2021SAY Transistor: PSSI2021SAY Datasheet PDF, Circuit, SOT-353

PSSI2021SAY is a resistor-equipped PNP  transistor with two diodes on one chip in a SOT353 (SC-88A) plastic package. The stabilized output current of between 15 µA and 50 mA by the connection of an external resistor between pins 4 and 5.

■ One chip integrated constant current source
■ Output current setting by use of an external resistor
■ Very small package
■ Reduces component count and board space

■ Automotive applications 

■ The generic constant current source 

■ Constant current LED driver

■ Active bias control for audio amplifiers

The following figure shows a typical application circuit for an LED driver. The constant current ensures a constant LED brightness.

PSSI2021SAY-LED Driver Application Diagram

The output can be switched ON and OFF by connecting a resistor-equipped transistor (RET, e.g. PDTC124XU) as shown below.

PSSI2021SAY-Switching the current ON/OFF; application Diagram

The PSSI2021SAY supplies a constant current to the Zener diode regardless of supply voltage variation, resulting in a constant reference voltage (see below).

PSSI2021SAY-Voltage Reference Application Diagram

Nexperia USA Inc. PSSI2021SAY,115 technical specifications, attributes, parameters and parts with similar specifications to Nexperia USA Inc. PSSI2021SAY,115.

Nexperia is a dedicated global leader in Discretes, Logic and MOSFETs devices. This new company became independent at the beginning of 2017. Focused on efficiency,  Nexperia produces consistently reliable semiconductor components at a high volume: 85 billion annually. The company’s extensive portfolio meets the stringent standards set by the Automotive industry. And industry-leading small packages, produced in their own manufacturing facilities, combine power and thermal efficiency with best-in-class quality levels. Built on over half a century of expertise,  Nexperia has 11,000  employees across  Asia,  Europe and the  U.S.  supporting customers globally.