The MAX8576–MAX8579 synchronous PWM buck controllers use a hysteretic voltage-mode control algorithm to achieve a fast transient response without requiring loop compensation. The MAX8576/MAX8577 contain an internal LDO regulator allowing the controllers to function from only one 3V to 28V input supply. The MAX8578/MAX8579 do not contain the internal LDO and require a separate supply to power the IC when the input supply is higher than 5.5V. The MAX8576–MAX8579 output voltages are adjustable from 0.6V to 0.9 x VIN at loads up to 15A. Nominal switching frequency is programmable over the 200kHz to 500kHz range. High-side MOSFET sensing is used for adjustable hiccup current-limit and short-circuit protection. The MAX8576/MAX8578 can start up into a precharged output without pulling the output voltage down. The MAX8577/MAX8579 have startup output overvoltage protection (OVP), and will pull down a precharged output.
Feature
- 3V to 28V Supply Voltage Range
- 1.2% Accurate Over Temperature
- Adjustable Output Voltage Down to 0.6V
- 200kHz to 500kHz Switching Frequency
- Adjustable Temperature-Compensated Hiccup Current Limit
- Lossless Peak Current Sensing
- Monotonic Startup into Prebias Output (MAX8576/MAX8578)
- Startup Overvoltage Protection (MAX8577/MAX8579)
- Enable/Shutdown
- Adjustable Soft-Start
Applications
- AGP and PCI Express? Power Supplies
- Graphic-Card Power Supplies
- Motherboard Power Supplies
- Point-of-Load Power Supplies
- Set-Top Boxes
