Switching power supply IC features synchronized PFC and PWM stages
Device offers best combination of efficiency, PFC, and ripple voltage
The ML4826 is offered as the industry's first synchronized switching power
supply chip. The device uses a technique that synchronizes the switching of its
power factor correction (PFC) stage with its dual-output pulse width modulation
(PWM) stage.
The two stages work in unison to give the chip an efficiency of greater than
85%, a power factor correction of greater than 0.99, and an output ripple
voltage that is claimed to be 30% better than state-of-the-art. Synchronizing
the two stages also allows the use of smaller, less expensive capacitors.
The ML4826 operates with power line input voltages from 85 to 265 V. An
overvoltage comparator shuts down the PFC section in the event of a sudden
decrease in load. The PFC section also includes peak current limiting and input
voltage brown-out protection. The PWM section can be operated in current mode
or voltage mode and includes a precision duty cycle limit to prevent
transformer saturation. The ML4826 comes in 20-pin DIPs and SOPs. (From $4.50
ea/1,000–available now.)
Micro Linear Corp., San Jose, CA
Literature 408-433-5200
CAPTION:
The ML4826 power supply IC contains the circuitry needed to design switching
power supplies with automatic power factor correction.
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