Characteristics of sn6505b

Push pull drive for transformers

Wide input voltage range: 2.25V to 5.5V

High output drive: 1A at 5V power supply

Low Ron, maximum 0.25 Ω at 4.5V power supply

Ultra low EMI

Spread spectrum clock

Precision internal oscillator options: 160kHz (sn6505a) and 420khz (sn6505b)

Synchronize multiple devices through external clock input

Conversion rate control

1.7A current limiting

Low off current: <1 µ a

Thermal shutdown

Wide temperature range: - 55 ° C to 125 ° C

Small 6-pin SOT23 (dbv) package

Soft start to reduce surge current

Description of sn6505b

Sn6505 is a low noise, low EMI, push-pull transformer driver designed for small isolated power supplies. The device drives a thin, middle tapped transformer through a 2.25V to 5V DC power supply.

The ultra-low noise and EMI can be realized through the conversion rate control of the output switching voltage and the spread spectrum clock (SSC). Sn6505 contains an oscillator followed by a gate driver circuit that provides a compensated output signal to drive the ground reference n-channel power switch. The device includes two 1A power MOSFET switches to ensure normal startup under heavy load conditions. The switching clock can also be provided externally to ensure accurate positioning of switching harmonics or to be used with multiple transformer drivers. The internal protection function includes a 1.7A current limiting, undervoltage locking, thermal shutdown and break before make type circuit. Sn6505 has soft start characteristics, which can prevent high surge current of large load capacitor during power on. The sn6505 can be packaged in a small 6-pin SOT23 / dbv package. The operating temperature range of the device is – 55 ° C to 125 ° C.