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.
The MAX8576‑MAX8579 family are synchronous PWM step‑down (buck) controllers that use a hysteretic voltage‑mode control algorithm for fast transient response. The MAX8576 and MAX8577 include an internal LDO regulator and operate from a single 3 V to 28 V supply, while the MAX8578 and MAX8579 require an external supply when the input exceeds 5.5 V. All devices provide adjustable output voltage from 0.6 V up to 0.9 × Vin and support output currents up to 15 A.
Key features include programmable switching frequency (200 kHz‑500 kHz), high‑side MOSFET current‑sense for hiccup current‑limit and short‑circuit protection, startup over‑voltage protection (MAX8577/9), and soft‑start control. The datasheet details absolute maximum ratings, electrical characteristics, typical operating curves, pin functions, and recommended external component manufacturers.
| Input voltage range | 3 V to 28 V |
|---|---|
| Switching frequency (programmable) | 200 kHz to 500 kHz |
| Output voltage range | 0.6 V to 0.9 × Vin |
| Maximum output current | 15 A |
| Internal LDO regulator | Present in MAX8576 and MAX8577 |
| Startup over‑voltage protection | Provided in MAX8577 and MAX8579 |
They operate from a single 3 V to 28 V supply.
The switching frequency can be programmed between 200 kHz and 500 kHz.
The output voltage is set by a feedback resistor divider to achieve 0.6 V up to 0.9 × Vin.
Yes, they need a separate supply when the input voltage is higher than 5.5 V because they lack the internal LDO.