Features Fixed 5-V and 3.3-V buck converters with less than 500- quiescent current per converter
25-A shutdown current
5.5- V to 30 V operating range

Describes the pin-out and functional compatibility of the dual-controller Si786 laptop power supply controller with the MAX786 dual-output power controller for laptop computers. The device is designed to be a drop-in replacement for this circuit. The circuit is two system-level integrated buck controllers, micro 5-V and 3.3-V linear regulators and two comparators. The controller performs high-efficiency conversion of energy from batteries (typically 12 V) or at an AC-to-DC converter output wall (typically 18-V to 24 V DC) to 5-V and 3.3-V system supply voltages. Micropower linear regulators can be used to keep power management and backup circuits off during normal operation of the buck converter. The comparator can be biased at any voltage at 2.7 V and input voltage, simplifying battery monitoring or providing enough voltage to boost the gate. A low on-resistance N-channel FET switching power supply is used in different areas of the system. A complete power conversion and management system can be implemented with the Si786 dual controller for laptop power conversion, an inexpensive linear regulator, the SMP controller for high performance processors, the Si9140 power supply, and the five Si4410 N-channel TrenchFET power supplies FET, one Si4435 p-channel TrenchFET power MOSFET and two Si9712 PC card (PCMCIA) interface switches. The Si9130 PIN Programmable Controller for Portable Dual Personal Computers is another comprehensive system-level device for portable computer power systems. The Si786 is available in standard and lead (Pb)-free 28-pin SSOP packages and is specified over the (0°C to 70°C), (Billage C to 90°C) and (Billage C to 85°C) temperature ranges. See the appropriate section for ordering information numbers.