AS80M1801

Compatible with most PWM controllers
`Works with both current mode and voltage mode
`PWM controllers.
Input frequency ranges:
`50 KHz to 400 KHz (AS80M1800)
`400 KHz to 1 MHz (AS80M1801)
`This is the input frequency range the device can accommodate from the external PWM controller.
Wide input PWM duty cycle range of 10% to 90%
Supports an extremely wide range of line and load regulation conditions.
Output drive current of 200 mA
Drives most popular power MOSFETs used in SMPS designs.
Supply voltage range of 7 V to 20 V
Under voltage lockout
Spread spectrum modulation with adjustable spread
Output short circuit sense with adjustable level and automatic recovery
No-load condition sense
Power savings feature
Frequency skip at no-load allows implementation of Energy Star and other next generation power savings modes
Loss of input detect
Protects SMPS from catastrophic failure by shut-ting off the output driver if the input PWM signal is lost
Under voltage lock-out
Protects SMPS from catastrophic failure by shut-ting off the output drive if the supply voltage drops below input VCC range
Available in 8-pin SOIC package

AS80M1800 and AS80M1801 are programmable spread spectrum frequency modulators designed for Switched Mode Power Supply (SMPS) applications. These devices work as companion ICs to the pulse width modulation (PWM) controller. As such, AS80M1801 can be used as a simple drop-in solution between the PWM controller and  MOSFET to tackle most EMI problems in the SMPS.

The AS80M1800 and AS80M1801 reduce electro-magnetic interference (EMI) by applying spread spectrum modulation to the PWM gate drive signal at the gate of the power MOSFET. Gate drive modulation of AS80M1801 significantly reduces the conducted and radiated emissions usually generated by di/dt and dv/dt switching in a SMPS.

These are the first general purpose EMI reduction ICs  iof AS80M1801 specifically designed for use in SMPS systems. No other manufacturer to date has a device that can frequency modulate a PWM train and still maintain the input PWM content. AS80M1801 can be used in popular DC/DC converter, and AC/DC inverter and DC/AC inverters designs.

Besides providing EMI reduction functionality, the AS80M1800 and AS80M1801 provide additional features that extend the capabilities of the power system.