ISL8501
Triple Output Controller with 1A Standard Buck PWM and Dual LDOs

Key Features

• Standard Buck Controller with Integrated Switching Power MOSFET and Dual LDOs
• Integrated Boot Diode
• Input Voltage Range
• Fixed 5V ±10%
• Variable 6V to 25V
• PWM Output Voltage Adjustable from 0.6V to 20V with Continuous Output Current up to 1A
• Voltage Mode Control with Voltage Feed Forward
• Fixed 500kHz Switching Frequency
• Externally Adjustable Soft-Start Time
• Output Undervoltage Protection
• Dual LDO Adjustable Options
• LDO1, 0.6V to 4.2V 500mA
• LDO2, 0.6V to 4.2V 500mA
• Individual Enable Inputs
• Two PGOOD Outputs (PWM and both LDOs)
• Overcurrent Protection
• Thermal Overload Protection
• Internal 5V LDO regulator
• Pb-Free Plus Anneal Available (RoHS Compliant)

Description

The ISL8501 is a high-performance, triple output controller that provides a single, high frequency power solution for a variety of point of load applications. The ISL8501 integrates a 1A standard buck PWM controller and switching MOSFET with two 500mA LDOs.

The PWM controller in the ISL8501 drives an internal switching N-Channel power MOSFET and requires an external Schottky diode to generate an output voltage from 0.6V to 20V. The integrated power switch is optimized for excellent thermal performance up to 1A of output current. The standard buck input voltage range supports a fixed 5V or variable 6V to 25V range. The PWM regulator switches at a fixed frequency of 500kHz and utilizes simple voltage mode control with input voltage feed forward to provide flexibility in component selection and minimize solution size. Protection features include overcurrent, undervoltage, and thermal overload protection integrated into the IC. The ISL8501 power good signal output indicates loss of regulation on the PWM output.

The ISL8501 features two adjustable LDO regulators using internal PMOS transistors as pass devices. Separate enable pins (EN_LDO1, EN_LDO2) control each LDO output. A single power good signal output indicates loss of regulation on either of the two LDO outputs. Independent overcurrent and thermal fault shutdown monitors are integrated into the LDO section.

ISL8501 is available in a small 4mmx4mm Quad Flat No- Lead (QFN) package.

Applications

• General Purpose
• WLAN Cards-PCMCIA, Cardbus32, MiniPCI Cards-Compact Flash Cards
• Hand-Held Instruments