The synchronous rectified buck converter incorporates simple, single feedback loop, voltage-mode control with fast transient response. Both the switching regulator and linear regulator provide a maximum static regulation tolerance of ±1% over line, load, and temperature ranges. Each output is user-adjustable by means of external resistors.
An integrated soft-start feature brings both supplies into regulation in a controlled manner. Each output is monitored via the FB pins for undervoltage events. If either output drops below 75% of the nominal output level, both converters are shut off and go into retry mode.
The ISL6549 is available in a 14 Ld SOIC package, 16 Ld QSOP, or 16 Ld 4x4 QFN packages.
- Single 12V bias supply (no 5V supply is required)
- Provides two regulated voltages
- One synchronous rectified buck PWM controller
- One linear controller
- Both controllers drive low cost N-Channel MOSFETs
- Small converter size
- Adjustable frequency 150kHz to 1MHz
- Small external component count
- Excellent output voltage regulation
- Both outputs: ±1% over temperature
- 12V down conversion
- PWM and linear output voltage range: down to 0.8V
- Simple single-loop voltage-mode PWM control design
- Fast PWM converter transient response
- High-bandwidth error amplifier
- Undervoltage fault monitoring on both outputs
- Pb-free plus anneal available (RoHS compliant)