July 19, 2005

Step-down Switching Regulator IC
SI-8000T Series
Reduces mounting area for external choke coils by 50%

Sanken Electric Co., Ltd. has developed the Step-down Switching Regulator IC, SI-8000T Series, and will start sample shipments on July 25 (mass production shipments will launch in October.)
The SI-8000T Series enables downsizing of external smoothing choke coils by 50% (compared to conventional company products) thanks to its high operating frequency (300kHz). The product lineup includes two packages (Surface mount type: TO252-5. Thru-hole type: TO220F-5) with four product types at output voltages of 3.3V, 5.0V, 12V, and variable voltage (reference voltage is 0.8V) with 1.5A output current.
SI-8000T Series production will start with 200k pcs/month, then ramping up to 500k pcs/month in CY06. Sample price: 300 yen.
SI-8000T Image Phot

1. Development Background and Product Overview
  Recently, the power supply voltages for digital ICs used for current telephones and OA equipment are becoming lower in accordance with power-saving trend, and are becoming of various voltages. In addition, the demand for switching regulator ICs is increasing in order to improve efficiency. Especially for business phones, the 24V from phone lines must be reduced to 5V for digital ICs, and therefore, switching regulator ICs are needed.
SI-8000T Series enables downsizing of the external smoothing choke coils (50% reduction in mounting area compared to our 125kHz product) by increasing the oscillating frequency (300kHz). Moreover, low power consumption at standby mode can be realized thanks to a low consumption current (less than 400µA when output is OFF.) As the product lineup includes an output voltage variable type (reference voltage 0.8V), low voltage for recent digital ICs can be easily set (from 0.8V).

  · On-board local power supplies for phones (business phones, household cordless phones), OA equipment and other electronics devices.
  · For stabilization of the secondary-side output voltage in switching power supplies.

2. Features
· Output current: 1.5A
· High efficiency: 81% TYP (SI-8008T: When Vo=5V)
· Two types of package are available:
TO252-5 (surface mount type) : SI8000TM Series
TO220F-5 (thru-hole type) : SI-8000TFE Series
· High operating frequency (300kHz): Enables downsizing of smoothing choke coils.
· Built-in drooping-type overcurrent and thermal protection functions
· Built-in output ON/OFF control function (Soft start is also available)
· Circuit current is 400µA or lower (TYP: 200µA) when output is OFF: Enables low power consumption at standby
· Requires only 4 discrete components: Input and output smoothing capacitors, a flywheel diode, and a smoothing choke coil
· External dimensions
SI-8000TM Image Phot
3. Specification Overview
Input Voltage(VIN,Max) 43V
Power Dissipation (PD) SI-8000TM:1.65W,SI-8000TFE:17.8W
Output Current (IO) 0 to 1.5A
Output Voltage (VO) 0.8V
3.3V 5.0V 12.0V
Efficiency (η,Typ) 81%
(at 5V output)
76% 81% 87%
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