S-8351A50MC-J3JT2G Datasheet, PDF (1/51 Pages) Seiko Instruments Inc – STEP-UP, BUILT-IN / EXTERNAL FET PFM CONTROL SWITCHING REGULATOR / SWITCHING REGULATOR CONTROLLER

S-8351/8352 Series
www.sii-ic.com
© Seiko Instruments Inc., 2002-2010
STEP-UP, BUILT-IN / EXTERNAL FET PFM CONTROL SWITCHING
REGULATOR / SWITCHING REGULATOR CONTROLLER
Rev.3.0_00
The S-8351/8352 Series is a CMOS step-up switching regulator controller which mainly consists of a reference voltage
source, an oscillation circuit, a comparator and PFM control circuit. The PFM control circuit allows the duty ratio to be
automatically switched according to the load (at light load : 50%, at high output current : 75%), enabling products with a low
ripple over a wide range, high efficiency, and high output current (A, B, and D type). Products with a fixed duty ratio of 75%
are also available (C type).
The S-8351 Series can configure a step-up switching regulator with an external coil, capacitor, and diode. A protection
circuit turns off the built-in MOS FET when the voltage at the CONT pin exceeds the limit to prevent it from being damaged.
In addition to the above features, the small package and low current consumption, makes the S-8351 Series ideal for
applications such as the power supply unit of portable equipment.
The S-8352 Series, which features an external transistor, is suitable for applications requiring a high output current.
„ Features
• Low voltage operation : Startup at 0.9 V min. (I_OUT = 1 mA) guaranteed
• Low current consumption : During operation 23.2 μA (V_OUT = 3.3 V, typ.)
During shutdown 0.5 μA (max.)
• Duty ratio : 50 % / 75 % built-in auto-switching-type PFM control circuit (A, B, and D type)
75 % built-in fixed-type PFM control circuit (C type)
• External parts : Coil, capacitor, and diode
• Output voltage : Selectable in 0.1 V steps between 2.0 V to 6.5 V (A, B, and C type)
Selectable in 0.1 V steps between 1.5 V to 6.5 V (D type)
• Output voltage accuracy : ±2.4%
• Shutdown function (A type)
• V_DD / V_OUT separate type (D type)
• External transistor type available (S-8352 Series)
• Lead-free, Sn 100%, halogen-free^*1
*1. Refer to “„ Product Name Structure” for details.
„ Applications
• Power supplies for portable equipment such as digital cameras, electronic notebooks, and PDAs
• Power supplies for audio equipment such as portable CD / MD players
• Constant voltage power supplies for cameras, video equipment, and communications equipment
• Power supplies for microcomputers
„ Packages
• SOT-23-3
• SOT-23-5
• SOT-89-3
Seiko Instruments Inc.
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