ISL6442

Features:

• 4.5V to 5.5V or 5.5V to 24V Input Voltage Range
• ±1.5% PWM Switcher Reference Accuracy Over Line and Temperature
• Three Programmable Power Output Voltages
- Two PWM Controllers with Out-of-Phase Operation
- Voltage-Mode PWM Control
- One Linear Controller
• Programmable Switching Frequency from 300kHz to 2.5MHz
• Fast Transient Response
- High-Bandwidth Error Amplifier
• Extensive Circuit Protection Functions
- Overvoltage, Undervoltage, and Over-temperature
- Programmable Overcurrent Limit with Hiccup Mode Operation
- Lossless Current Sensing (no Sense Resistor needed)
• Externally Adjustable Soft-Start Time
- Independent Enable Control
- Voltage Tracking Capability
• PGOOD Output with Delay
• 24 Ld QSOP
• Pb-Free Plus Anneal Available (RoHS Compliant)




Application

• Complete 1 Chip Solution for DSL Modems/Routers
• DSP, ASIC, and FPGA Point of Load Regulation
• Broadband and Networking Applications
• ADSL




Pinout






Description

The ISL6442 is a high-performance, triple output controller that provides a single high-frequency power solution primarily for Broadband, DSL and Networking applications. This device integrates complete control, monitoring and protection functions for two synchronous buck PWM controllers and one linear controller. Input voltage ripple and total RMS input current is substantially reduced by synchronized 180 out-of-phase operation of the two PWMs. The two PWM buck converters provide simple voltage mode control. The output voltage of the converters can be precisely regulated to as low as 0.6V, with a maximum tolerance of ±1.5% over temperature and line variations. Programmable switching frequency up to 2.5MHz provides fast transient response and small external components. The linear controller provides a low-current output. The ISL6442 has voltage-tracking capability. Each controller has soft-start and independent enable functions combined on a single pin. A capacitor from SS/EN to ground sets the soft-start time; pulling SS/EN pin below 1V disables the controller. Both outputs can soft-start into a pre-biased load. The ISL6442 incorporates robust protection features. An adjustable overcurrent protection circuit monitors the output current by sensing the voltage drop across the upper MOSFET rDS(ON). Hiccup mode overcurrent operation protects the DC/DC converters from damage under over load and short circuit conditions. A PGOOD signal is issued when soft-start is complete and PWM outputs are within 10% of their regulated values and the linear regulator output is higher than 75% of its nominal value. Thermal shut-down circuitry turns the device off if the IC temperature exceeds +150C.