The MAX796/MAX797/MAX799 are high-performance, step-down DC-DC converters with single or dual outputs that provide main CPU power in battery-powered systems. These buck controllers achieve 96% efficiency by using synchronous rectification and Maxim’s proprietary Idle Mode™ control scheme to extend battery life at full-load (up to 10A) and no-load outputs. Excellent dynamic response corrects output transients caused by the latest dynamic-clock CPUs within five 300kHz clock cycles. Unique bootstrap circuitry drives inexpensive N-channel MOSFETs, reducing system cost and eliminating the crowbar switching currents found in some PMOS/NMOS switch designs. The MAX796/MAX799 are specially equipped with a secondary feedback input (SECFB) for transformer-based dual-output applications. This secondary feedback path improves cross-regulation of positive (MAX796) or negative (MAX799) auxiliary outputs. The MAX797 has a logic-controlled and synchronizable fixed-frequency pulse-width-modulating (PWM) operating mode, which reduces noise and RF interference in sensitive mobile-communications and pen-entry applications. The SKIP override input allows automatic switchover to idle-mode operation (for high-efficiency pulse skipping) at light loads, or forces fixed-frequency mode for lowest noise at all loads. The MAX796/MAX797/MAX799 are all available in 16-pin DIP and narrow SO packages.
The MAX796, MAX797, and MAX799 are high‑performance step‑down DC‑DC converters designed to provide main CPU power in battery‑powered systems. They achieve up to 96% efficiency using synchronous rectification and Maxim’s Idle Mode™ control, supporting up to 10 A output current.
These converters are available in 16‑pin DIP and narrow SO packages and are used in notebook and sub‑notebook computers, PDAs, mobile communicators, and cellular phones. Ordering information, pin configurations, and typical application circuits are provided for easy integration.
| Efficiency | 96% |
|---|---|
| Input Voltage Range | 4.5 V to 30 V |
| Adjustable Output Voltage Range | 2.5 V to 6 V |
| Preset Output Options | 3.3 V and 5 V up to 10 A |
| Quiescent Current (typical) | 375 µA (VIN=12 V, VOUT=5 V) |
| Shutdown Current (typical) | 1 µA |
They achieve up to 96% efficiency.
They operate from 4.5 V to 30 V input.
They are offered in 16‑pin DIP and narrow SO packages.
Typical applications include notebook and sub‑notebook computers, PDAs, mobile communicators, and cellular phones.