s-l2985 Seiko Instruments Inc., s-l2985 Datasheet - Page 11

• Manufacturer Part Number: s-l2985
• Description: High Ripple-rejection Wlp Package Low Dropout Cmos Voltage Regulator
• Manufacturer: Seiko Instruments Inc.

Rev.2.1
Operation
2. Output transistor
1. Basic operation
HIGH RIPPLE-REJECTION WLP PACKAGE LOW DROPOUT CMOS VOLTAGE REGULATOR
Figure 11 shows the block diagram of the S-L2985 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-L2985 Series uses a low on-resistance P-channel MOS FET as the output transistor.
Be sure that V
to inverse current flowing from the VOUT pin through a parasitic diode to the VIN pin.
_00
OUT
does not exceed V
*1.
VSS
VIN
Current
supply
Reference voltage
V
Parasitic diode
ref
s
circuit
and R
IN
f
+ 0.3 V to prevent the voltage regulator from being damaged due
. It supplies the output transistor with the gate voltage necessary
−
+
amplifier
Seiko Instruments Inc.
Error
Figure 11
ref
) with V
R
R
s
f
fb
V
, which is the output voltage resistance-
*1
fb
VOUT
S-L2985 Series
11