S19200 datasheet(11/28 Pages) SII

11 / 28 page

FOR AUTOMOTIVE HIGH-WITHSTAND VOLTAGE LOW CURRENT CONSUMPTION LOW DROPOUT 105

°C OPERATION CMOS VOLTAGE REGULATOR

Rev.1.2_00

S-19200 Series

Seiko Instruments Inc.



Operation

1. Basic operation

Figure 9 shows the block diagram of the S-19200 Series.

The error amplifier compares the reference voltage (Vref) with feedback voltage (Vfb), which is the output voltage

resistance-divided by feedback resistors (Rs and Rf). It supplies the gate voltage necessary to maintain the constant

output voltage which is not influenced by the input voltage and temperature change, to the output transistor.

VOUT

VSS

VIN

Error amplifier

Current

supply

Vref

Vfb

−

Reference voltage

circuit

*1. Parasitic diode

Figure 9

2. Output transistor

In the S-19200 Series, a low on-resistance P-channel MOS FET is used as the output transistor.

Be sure that VOUT does not exceed VIN

+ 0.3 V to prevent the voltage regulator from being damaged due to reverse

current flowing from the VOUT pin through a parasitic diode to the VIN pin, when the potential of VOUT became

higher than VIN.

S19200 Datasheet(PDF) 11 Page - Seiko Instruments Inc