s-1135a13-u5t1g Seiko Instruments Inc., s-1135a13-u5t1g Datasheet - Page 20

• Manufacturer Part Number: s-1135a13-u5t1g
• Description: High Ripple-rejection Low Dropout Middle Output Current Cmos Voltage Regulator
• Manufacturer: Seiko Instruments Inc.

20
HIGH RIPPLE-REJECTION LOW DROPOUT MIDDLE OUTPUT CURRENT CMOS VOLTAGE REGULATOR
S-1135 Series
Operation
1. Basic operation
2. Output transistor
The error amplifier compares the reference voltage (V
feedback resistors R
not influenced by the input voltage and temperature change, to the output transistor.
In the S-1135 Series, a low on-resistance P-channel MOS FET is used as the output transistor.
Be sure that V
current flowing from the VOUT pin through a parasitic diode to the VIN pin.
Figure 20 shows the block diagram of S-1135 Series.
OUT
*1. Parasitic diode
Current
VSS
VIN
supply
does not exceed V
s
Reference voltage
and R
V
ref
circuit
f
. It supplies the gate voltage necessary to maintain the constant output voltage which is
IN
+ 0.3 V to prevent the voltage regulator from being damaged due to inverse
−
+
amplifier
Seiko Instruments Inc.
Error
Figure 20
ref
) with V
fb
, which is the output voltage resistance-divided by
R
R
s
f
V
*1
fb
VOUT
Rev.1.1
_00