S-1137 Series
www.sii-ic.com
HIGH RIPPLE-REJECTION LOW DROPOUT
SOFT-START FUNCTION CMOS VOLTAGE REGULATOR
© Seiko Instruments Inc., 2009-2010 Rev.2.0_01
Seiko Instruments Inc. 1
S-1137 Series, developed using the CMOS technology, is a positive voltage regulator IC which has the low dropout voltage,
the high-accuracy output voltage and the soft-start function (300 mA output current).
A 1.0 μF small ceramic capacitor can be used. It operates with low current consumption of 45 μA typ.
The overcurrent protection circuit prevents the load current from exceeding the capacitance of output transistor. The
power-off circuit ensures longer battery life.
Compared to the conventional CMOS technology regulator ICs, various capacitors including small ceramic capacitors can be
used for this IC.
Furthermore a small SOT-89-5, SOT-23-5, and SNT - 6A(H) packages realize high-density mounting.
Features
• Output voltage: 1.2 V to 3.5 V, selectable in 0.05 V step.
• Low equivalent series resistance capacitor : Ceramic capacitor of 1.0 μF or more can be used as the I/O capacitor.
• Wide input voltage range: 1.7 V to 5.5 V
• High-accuracy output voltage: ±1.0% (1.2 V to 1.45 V output product : ±15 mV)
• Low dropout voltage: 210 mV typ. (products having the output of 2.8 V, IOUT = 300 mA)
• Low current consumption: During operation: 45 μA typ., 65 μA max.
During power-off: 0.1 μA typ., 1.0 μA max.
• Output current: Possible to output 300 mA (at VIN ≥ VOUT(S) + 1.0 V)*1
• Soft-start circuit with external capacitor: Soft-start time : 0.7 ms (CSS = 1.0 nF)
• High ripple rejection: 70 dB typ. (at 1.0 kHz)
• Built-in overcurrent protection circuit: limits overcurrent of output transistor
• Built-in power-off circuit: Ensures long battery life.
• Discharge shunt circuit can be selected.
• Pull-down resistor is selectable
• Lead-free, Sn 100%, halogen-free*2
*1. Attention should be paid to the power dissipation of the package when the out put current is large.
*2. Refer to “ Product Name Structure” for details.
Applications
• Power supply for battery-powered devices
• Power supply for cellular phones, portable devices
• Power supply for digital still cameras, TVs, DVD recorders
Packages
• SOT-89-5
• SOT-23-5
• SNT-6A(H)