Multi-function quad output controller supports three major power functions in notebook computing

The ISL6236 is the industry’s only power supply controller that provides designers the flexibility to externally program the switchers and the LDO to different voltages to support either 3.3V to 5V system regulation, DDR (double data rate) memory or graphics processing.

The ability to externally program the switchers and LDO allows for greater design flexibility. Using one chip for all three power functions saves engineering time and costs associated with qualifying parts.
The ISL6236 has a wide input voltage range of 5.5V to 25V, and it utilises a constant on-time topology that eliminates the need for compensation, minimising external components and offering fast transient response. Other features include pulse skip mode and ultrasonic pulse skip mode that provide high light-load efficiency and extended battery life. Ultrasonic pulse-skipping maintains the switching frequency above 25kHz to eliminate noise in audio applications.

Intersil’s ISL6236 is a dual step-down switch-mode power supply (SMPS) controller that generates logic supply voltages in battery-powered systems. The device includes two adjustable PWM (pulse width modulation) controllers that can be configured to two fixed-output combinations: 5V/3.3V or 1.5V/1.05V. The output of SMPS1 can also be adjusted from 0.7V to 5.5V, while the SMPS2 output can be adjusted from 0.5V to 2.5V by setting the REFIN2 voltage. LDO output is either fixed 3.3V/5.0V or adjustable from 0.7V to 4.5V. The fourth output of this quad controller is the voltage reference that can either be 3.3V or 2.0V.

A constant on-time PWM control scheme operates without sense resistors and provides 100ns response to load transients while maintaining a relatively constant switching frequency. The ISL6236 includes on-board power-up sequencing, power good (POK) outputs, digital soft start and internal soft stop output discharge that prevents negative voltages on shutdown.

The ISL6236 features secondary feedback input (maintains charge pump voltage), boot capacitor UV detection, 3.3V ref voltage +/-1.5%: 5mA, 2.0V ref voltage +/-1.0%: 50µA, frequency selectable, RDSON current sensing, and programmable current limit with foldback capability.

Other key features include temperature compensation for RSDON sensing, selectable PWM, skip or ultrasonic mode, independent POK1 and POK2 comparators, independent enable, high efficiency – up to 97%, 5mW quiescent power dissipation, thermal shutdown, and an extremely low component count.
Target applications for the device include notebook and sub-notebook computers, PDAs and mobile communication devices, 3- and 4-cell Li+ battery-powered devices, DDR1, DDR2 and DDR3 power supplies, graphic cards, game consoles, and telecommunications. The ISL6236 is available now in a 32-lead thin QFN package.