HIGH RIPPLE-REJECTION AND SMALL PACKAGE CMOS VOLTAGE REGULATOR
S-1323 Series
Rev.5.0_00
10
Seiko Instruments Inc.
Explanation of Terms
1. Low dropout voltage regulator
The low dropout voltage regulator is a voltage regulator whose dropout voltage is low due to its built-in
low on-resistance transistor.
2. Low ESR
A capacitor whose ESR (Equivalent Series Resistance) is low. The S-1323 Series enables use of a low
ESR capacitor, such as a ceramic capacitor, for the output-side capacitor C
L
. A capacitor whose ESR is
10 Ω or less can be used.
3. Output voltage (V
OUT
)
The accuracy of the output voltage is ensured at ±1.0% under the specified conditions of fixed input
voltage
*1
, fixed output current, and fixed temperature.
*1. Differs depending the product.
Caution If the above conditions change, the output voltage value may vary and exceed the
accuracy range of the output voltage. Please see the electrical characteristics and
attached characteristics data for details.
4.
OUTIN V ΔV
ΔV
OUT1
regulation Line
Indicates the dependency of the output voltage on the input voltage. That is, the values show how much
the output voltage changes due to a change in the input voltage with the output current remaining
unchanged.
5. Load regulation (ΔV
OUT2
)
Indicates the dependency of the output voltage on the output current. That is, the values show how
much the output voltage changes due to a change in the output current with the input voltage remaining
unchanged.
6. Dropout voltage (V
drop
)
Indicates the difference between the input voltage V
IN1
, which is the input voltage (V
IN
) at the point where
the output voltage has fallen to 98% of the output voltage value V
OUT3
after V
IN
was gradually decreased
from V
IN
= V
OUT(S)
+ 1.0 V, and the output voltage at that point (V
OUT3
× 0.98).
V
drop
= V
IN1
(V
OUT3
× 0.98)
HIGH RIPPLE-REJECTION AND SMALL PACKAGE CMOS VOLTAGE REGULATOR
Rev.5.0_00
S-1323 Series
Seiko Instruments Inc. 11
7.
Δ
Δ
OUT
OUT
V Ta
V
voltageoutput oft coefficien eTemperatur
The shadowed area in Figure 11 is the range where V
OUT
varies in the operating temperature range
when the temperature coefficient of the output voltage is ±100 ppm/°C.
V
OUT
(
E
)
*1
Ex. S-1323B28 Typ.
40 25
+
0.28 mV/°C
V
OUT
[V]
*1. V
OUT(E)
is the value of the output voltage measured at 25°C.
85
Ta [°C]
0.28 mV/°C
Figure 11
A change in the temperature of the output voltage [mV/°C] is calculated using the following equation.
[] [] []
1000Cppm/
VTa
V
VVCmV/
Ta
V
OUT
OUT
OUT(S)
OUT
÷°
Δ
Δ
×=°
Δ
Δ
3*2**1
*1. Change in temperature of output voltage
*2. Specified output voltage
*3. Output voltage temperature coefficient
HIGH RIPPLE-REJECTION AND SMALL PACKAGE CMOS VOLTAGE REGULATOR
S-1323 Series
Rev.5.0_00
12
Seiko Instruments Inc.
Operation
1. Basic operation
Figure 12 shows the block diagram of the S-1323 Series.
The error amplifier compares the reference voltage (V
ref
) with V
fb
, which is the output voltage resistance-
divided by feedback resistors R
s
and R
f
. It supplies the output transistor with the gate voltage necessary
to ensure a certain output voltage free of any fluctuations of input voltage and temperature.
Reference voltage
circuit
VOUT
*1
*1.
Parasitic diode
VSS
VIN
R
s
R
f
Error
amplifier
Current
supply
V
ref
+
V
fb
Figure 12
2. Output transistor
The S-1323 Series uses a low on-resistance P-channel MOS FET as the output transistor.
Be sure that V
OUT
does not exceed V
IN
+ 0.3 V to prevent the voltage regulator from being damaged due
to inverse current flowing from VOUT pin through a parasitic diode to VIN pin.

S-1323B36PF-N8VTFU

Mfr. #:
Manufacturer:
ABLIC
Description:
LDO Voltage Regulators LINEAR LDO REG HI 70UA IQ 150MA IOUT
Lifecycle:
New from this manufacturer.
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