The MAX786 is a system-engineered power-supply controller for notebook computers or similar battery-powered equipment. It provides two high-performance step-down (buck) pulse-width modulators (PWMs) for +3.3V and +5V. Other features include dual, low-dropout, micropower linear regulators for CMOS/RTC back-up, and two precision low-battery-detection comparators. High efficiency (95% at 2A; greater than 80% at loads from 5mA to 3A) is achieved through synchronous rectification and PWM operation at heavy loads, and Idle ModeTM operation at light loads. The MAX786 uses physically small components, thanks to high operating frequencies (300kHz/200kHz) and a new current-mode PWM architecture that allows for output filter capacitors as small as 30µF per ampere of load. Line- and load-transient responses are terrific, with a high 60kHz unity-gain crossover frequency allowing output transients to be corrected within four or five clock cycles. Low system cost is achieved through a high level of integration and the use of low-cost, external N-channel MOSFETs. Other features include low-noise, fixed-frequency PWM operation at moderate to heavy loads, and a synchronizable oscillator for noise-sensitive applications such as electromagnetic pen-based systems and communicating computers. The MAX786 is a monolithic, BiCMOS IC available in fine-pitch, surface-mount SSOP packages.
The MAX786 is a system‑engineered power‑supply controller designed for notebook computers and other battery‑powered equipment. It delivers two high‑performance step‑down (buck) PWM converters for +3.3 V and +5 V, includes low‑dropout linear regulators for CMOS/RTC backup, and features precision low‑battery‑detection comparators.
The device operates with synchronous rectification, achieving up to 95 % efficiency at 2 A load, and supports an input range of 5.5 V to 30 V. It is offered in a fine‑pitch 28‑pin SSOP package and includes extensive pin‑level control for shutdown, soft‑start, and external MOSFET driving.
| Input Supply Range | 5.5 V to 30 V |
|---|---|
| Fixed Output Voltage (3.3 V) | 3.35 V (typical) |
| Efficiency at 2 A | ≈95 % |
| Quiescent Current | 420 nA |
The MAX786 operates with an input supply range of 5.5 V to 30 V.
Standard output is 3.3 V, with options for 3.45 V for high‑speed Pentium and 3.6 V for PowerPC applications.
The device achieves about 95 % efficiency at a 2 A load.
The quiescent current is specified as 420 nA.