March 24, 2009

Sanken Released SI-8010P/SI-8010PQ
Step-down Switching Regulator IC Ideal for POL Power Supplies
Achieves Accurate Reference Voltage for the First Time in the Industry (±0.5%)

Sanken Electric Co., Ltd. has developed and started shipping samples of the SI-8010P (output current: 2 A) and SI-8010PQ (output current: 3 A) step-down switching regulator ICs, which have variable output voltages from 1.0 to 10 V. For these ICs, the accuracy of the internal reference voltage (*1) has been significantly improved from ±2% to ±0.5%, the best in the industry (*2). Mass production starting at 50,000 units is scheduled for summer of 2009, with plans to increase the production scale to 500,000 units per month by the end of 2010. The price of a sample is 400 yen (tax excluded).
*1: An internally held reference voltage of an IC for setting the output voltage
*2: As of March 2009, based on a Sanken survey
1. Development Background and Product Overview
  Flat panel TVs, DVD recorders, and other digital audio-video (AV) equipment use ICs such as microcomputers, memory, and digital signal processors. To suppress the increase in power consumption by ICs as a result of their higher performance, the power supply voltage for ICs is being reduced. As the power supply voltage range where ICs normally operate narrows due to lowered power supply voltage, more accurate output voltage is required for POL power supplies (*) in order to prevent IC malfunctions.

* POL (Point Of Load) power supply
A power supply located near an IC to suppress fluctuation in the power supply voltage due to voltage drops or noise generation on the power line.

A POL power supply consists of regulator ICs, voltage setting resistors, choke coils, I/O capacitors, and other components, the characteristics of which affect the output voltage accuracy. Conventionally, the reference voltage accuracy of regulator ICs was ±2% to ±3%, and the voltage setting resistor was adjusted during production to improve the output voltage accuracy.

Sanken has significantly improved the reference voltage accuracy through review of the internal reference voltage circuits of regulator ICs and segmentation for reference voltage adjustment. We thus developed the SI-8010P and SI-8010PQ step-down switching regulator ICs that have a ±0.5% reference voltage accuracy for the first time in the industry.

By using the SI-8010P and SI-8010PQ, you can easily configure a POL power supply that has a high output voltage accuracy and reduce the man-hours required for adjustment during production.

Because the SI-8010P and SI-8010PQ use the current mode control system, small ceramic capacitors can be used as the output capacitors. With their small, surface-mounted packages (HSOP8), you can make a POL power supply smaller.
In addition, a function that turns on and off the output to suppress the circuit current (1 µA max.) during power-off is used to help reduce the standby power consumption for the equipment.
2. Applications
  The applications include digital audio-video equipment such as flat panel TVs and DVD recorders, as well as office automation equipment such as PCs and printers.
3. Features
(1) Highly accurate reference voltage (1.0 V ±0.5%)
(2) Current mode control system
The use of small ceramic capacitors can reduce the size of a POL power supply by about 50% compared to the size when using a voltage mode control system.
(3) Function that turns the output on and off to suppress the current when the circuit is off (1 µA max.)
Helps reduce the standby power consumption for the equipment
(4) Built-in MOS FET that has an ON resistance of 190 mΩ max., output current: 2 A and 3 A models are available.
(5) Small, surface-mounted HSOP8 package (with rear heatsink)
(6) Input voltage range: 4.75 to 16 V, rated voltage: 18 V max.
(7) Output voltage range: 1.0 to 10 V
The output voltage is variable even at a low voltage of 1.0 V and can thus be used with low power supply voltage ICs.
(8) High efficiency
Max. 85% (when VIN = 12 V, Vo = 3.3 V, Io = 2 A)
(9) Protection functions
- Fold-back overcurrent protection function
- Overheat protection function
(10) Auxiliary functions
- Soft start function
- Low voltage lockout (UVLO) function
4.  Specifications Overview
Parameter SI-8010P SI-8010PQ Unit
Output current 2.0 3.0 A
Output voltage range 1.0~10 V
Circuit current during power-off 1max µA
Efficiency 85max %
Line regulation 1typ mV
Load regulation 5typ mV
Operating frequency 500typ kHz
Package (resin part dimensions) HSOP8( mm
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