March 24, 2005

Realizing Low Power Consumption (100mW max) at No Load
STR-A6200 Series
ICs for Switching Mode Power Supplies (SMPS)
= Optimum for auxiliary power supplies at standby condition for equipment =

Sanken Electric has developed the STR-A6200 Series ICs for small-capacity SMPS. The power consumption of the ICs is less 100 mW at 264 VAC input under no load condition.
The ICs will be launched in March CY05 starting with 1,000k pcs/month, then ramping up to 2,000k pcs/month in April. (Sample price: 180 Yen)
STR-A6200 Series

1.  Development Background and Product Overview
  With the recent increase of remote controlled equipment such as TV and DVD, and the spread of cell phones and other electronic mobile equipment, the demand is growing for power supplies and adapters of low standby-power consumptions. To meet this, reducing the power consumption in power supply parts at standby condition is the key issue. Reducing discrete part count is also required for downsizing and lower price of equipment
Thus, Sanken Electric has developed the SMPS purpose-built STR-A6200 Series ICs with an built-in Auto Burst Standby Function for less 100 mW power consumption at 264VAC under no load. In addition, the audible noise of transformer is reduced at light load and the combination of Pulse Width Modulation (PWM) system and Frequency Jitter Operation realizes lower EMI compared with our existing products.
The STR-A6200 Series is the optimum IC for SMPS ranging 5 to 25 W, such as standby power supplies for AV and OA equipment, auxiliary power supplies for DVD/CD players or white goods, as well as adapters for cell phones, digital cameras and game machines.
The STR-A6200 Series has versatile built-in protection circuits such as overcurrent, overvoltage, overload, and overheat. Additionally, this IC contributes to the downsizings and cost savings in power supply system because the IC itself is downsized and space saving, and realizes the reduction of discrete-part count for the power supply system by employing DIP8 package and a built-in start-up circuit, and also by having the anti-EMI filter simplified (i.e. cost-saving) due to the low EMI of the IC itself.

* Auto burst standby function:
This function suppresses loss by having the IC operate intermittently at light load such as standby, etc. During the operation of this function, the internal oscillator is stopped to reduce the circuit current and consequently the power consumption is reduced.

* Frequency Jitter Operation:
This operation realizes the EMI reduction by shifting the oscillation frequency of PWM operation slightly from the basic frequency (approx.. 3kHz shift from the oscillation frequency 67 kHz) to reduce EMI.

* Electromagnetic Interference (EMI)
This is an electromagnetic noise flowing out to an AC power cable through a power line

2.  Features
· Built-in Auto Burst Standby Function: Less 100 mW power consumption under no load condition (at 264 VAC input) *50mW or less at 100 VAC
· Frequency Jitter Operation together with PWM allows the anti-EMI filter to be simplified.
· Built-in Start-up Circuit realizes higher power supply efficiency and lower power consumption at standby condition
* Start-up circuit:
Start-up circuit is activated only at the starting up stage of the IC and is deactivated after this stage to improve efficiency and especially to reduce power consumption at standby condition.
· Overload Protection (OLP) with built-in timer without a delay-time setting capacitor
· On Overcurrent Protection (OCP), constant current drooping method can be taken by adding two resistors.
· Built-in Soft Start Function to reduce a stress on the power MOS FET at power-on
· Reduction of the audible noise from a transformer at burst operation
· Built-in power MOS FET guaranteeing avalanche energy capability allows to simplify the surge-absorbing circuit
· Versatile built-in protective functions: Overcurrent, Overvoltage, Overload, and Overheat protections
3.  Lineup

Part No. Fosc MOS FET Pout
(kHz) VDSS(V) RDS(ON) (Ω) 230V/85V to 264V
STR-A6252 50 650 2.8 24W/20W
STR-A6252M 67
STR-A6251 50 650 3.95 21W/15W
STR-A6251M 67
STR-A6259M 67 650 6.0 17W/13W
STR-A6259H 100
STR-A6269M 67 800 19.2 10W/6W
STR-A6269H 100
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