S-812C40AMC-C2U-T2 Seiko Instruments, S-812C40AMC-C2U-T2 Datasheet - Page 7

• Manufacturer Part Number: S-812C40AMC-C2U-T2
• Description: Low Dropout (LDO) Regulators 4.0V 1.2uA 2.0%
• Manufacturer: Seiko Instruments

Specifications of S-812C40AMC-C2U-T2

• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 18 V
• Output Voltage: 4 V
• Output Voltage Tolerance: +/- 2 %
• Output Type: Fixed
• Dropout Voltage (max): 0.95 V
• Output Current: 75 mA
• Line Regulation: 20 mV
• Load Regulation: 65 mV
• Voltage Regulation Accuracy: 2 %
• Maximum Power Dissipation: 600 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23-5
• Minimum Operating Temperature: - 40 C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Rev.1.0
T Description of Operation
1. Basic operation
2. Output transistor
5. Dropout voltage (Vdrop)
6. Temperature coefficient of output voltage [ V
Temperature change ratio for output voltage [mV/°C] is calculated by using the following equation.
Temperatures change ratio for output voltage
Figure 9 shows the block diagram of the S-812C
series.
The error amplifier compares a reference voltage
V
feedback resistors Rs and Rf, and supplies the gate
voltage to the output transistor, necessary to ensure
certain output voltage independent from change of
input voltage and temperature.
The S-812C Series uses a Pch MOS transistor as the output transistor.
The voltage at VOUT must not exceed VIN+0.3V. When the VOUT voltage becomes higher than that of VIN,
reverse current flows and may break the regulator since a parasitic diode between VOUT and VIN exists
inevitably.
This parameter indicates the difference between the input voltage (V
voltage falls to 98 % of V
Vdrop = V
The output voltage lies in the shaded area in the whole operating temperature shown in figure 8 when the
temperature coefficient of the output voltage is 100 ppm/ C.
ref
V
Ta
OUT
with a part of the output voltage divided by the
mV/ C
IN
1-[V
Specified output voltage
OUT
V
V
OUT
V
[V]
OUT
(E) × 0.98]
OUT
(E)
(S) V
Figure 8 Example for the S-812C30A
OUT
-40
(E) by gradually decreasing the input voltage (V
HIGH OPERATING VOLTAGE CMOS VOLTAGE REGULATOR
Ta V
V
OUT
Output voltage temperature coefficient
OUT
25
Seiko Instruments Inc.
ppm/ C
OUT
/( Ta V
85
1000
Current
source
VSS
VIN
+0.30mV/ C
-0.30mV/ C
OUT
V
output voltage at 25 C.
OUT
Vref
Reference
)]
voltage
Ta [ C]
(E) is a measured value of
Figure 9 Block Diagram
Error amplifier
IN
1) and the output voltage when output
IN
).
Rf
Rs
S-812C Series
* : Parasitic diode
*
VOUT
7