S-1170B Seiko Instruments, S-1170B Datasheet - Page 13

• Manufacturer Part Number: S-1170B
• Description: Voltage Regulator
• Manufacturer: Seiko Instruments

www.DataSheet4U.com
DataSheet U .com
4
HIGH RIPPLE-REJECTION LOW DROPOUT HIGH OUTPUT CURRENT CMOS VOLTAGE REGULATOR
Rev.3.0
Operation
2. Output transistor
1. Basic operation
Figure 12 shows the block diagram of the S-1170 Series.
The error amplifier compares the reference voltage (V
divided by feedback resistors R
to ensure a certain output voltage free of any fluctuations of input voltage and temperature.
The S-1170 Series uses a low on-resistance P-channel MOS FET as the output transistor.
Be sure that V
to inverse current flowing from VOUT pin through a parasitic diode to VIN pin.
_00
OUT
does not exceed V
*1.
VSS
VIN
Current
supply
Reference voltage
Parasitic diode
V
ref
s
circuit
and R
IN
Seiko Instruments Inc.
f
+ 0.3 V to prevent the voltage regulator from being damaged due
. It supplies the output transistor with the gate voltage necessary
−
+
amplifier
Error
Figure 12
ref
) with V
R
R
s
f
fb
V
*1
, which is the output voltage resistance-
fb
VOUT
S-1170 Series
13