Renesas ISL6442IA

Overview

ISL6442IA from Renesas Electronics (formerly Intersil) is a triple-output power controller integrating two 180° out-of-phase voltage-mode PWM buck controllers and one linear controller for broadband, DSL, and networking point-of-load regulation. It delivers ±1.5% reference accuracy, programmable 300kHz–2.5MHz switching frequency, and supports soft-start into pre-biased loads with independent enable/soft-start pins (SS1/EN1, SS2/EN2). Designed for dual-rail DSP/FPGA supplies and linear-biased auxiliary rails.

For engineers reviewing the ISL6442IA datasheet, ISL6442IA pinout, ISL6442IA application, or ISL6442IA equivalent, key selection criteria include its dual-phase ripple cancellation, lossless rDS(ON)-based overcurrent protection, PGOOD timing dependency on switching frequency, and voltage-tracking capability via proportional soft-start capacitance.

Technical Context

The ISL6442IA implements synchronized 180° out-of-phase operation between two PWM channels to reduce input RMS current and input capacitor stress. Each PWM uses voltage-mode control with a 0.6V internal reference, high-bandwidth error amplifier (15MHz GBWP), and type-III compensation support.

Its linear controller employs an open-drain PNP driver (LCDR) with LCFB feedback threshold of 0.570–0.620V and sink capability up to 50mA. Protection includes hiccup-mode OCP using upper MOSFET rDS(ON), independent UVP/OVP comparators, thermal shutdown at +150°C, and PGOOD monitoring with 370ms delay at 1.4MHz.

Key Specifications

Pinout & Package

ISL6442IA is housed in a 24-lead QSOP package (M24.15, Pb-free, RoHS compliant) with 0.635mm lead pitch and exposed pad not present.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-output controller applications.

Compared with ISL6442IA, ISL65412IRZ offers higher frequency but lacks integrated linear regulation, while TPS51220ARGER provides advanced control architecture but requires external circuitry for the third output-making ISL6442IA uniquely suitable for compact, fully integrated triple-rail designs.

Availability

ISL6442IA is available at Aetrix Electronics and suitable for DSL modems, FPGA power management, and broadband router designs requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL6442IA includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and connectivity solutions for automotive, industrial, and infrastructure markets.

The ISL6442IA belongs to Renesas' legacy Intersil power management portfolio, designed specifically for high-density, multi-rail DC/DC conversion in broadband communications equipment with emphasis on efficiency, sequencing, and protection integration.

FAQ

What is the minimum output voltage supported by the ISL6442IA PWM controllers?

The ISL6442IA PWM controllers support output voltages as low as 0.6V, set by the internal precision reference voltage. This value is maintained with ±1.5% tolerance across line, load, and the full -40°C to +85°C operating temperature range. The actual regulated output is determined by the external resistor divider connected to FB1 or FB2, referencing this 0.6V bandgap.

How does the ISL6442IA achieve lossless overcurrent protection?

The ISL6442IA achieves lossless overcurrent protection by using the upper MOSFET's intrinsic rDS(ON) as the current-sense element. An internal 110µA current source pulls down the OCSET1 or OCSET2 pin, establishing a voltage threshold. When the PHASE node voltage (during high-side conduction) falls below this threshold, an overcurrent condition is detected-eliminating the need for a discrete sense resistor and associated power loss.

Can the ISL6442IA soft-start into a pre-biased output voltage?

Yes, the ISL6442IA supports soft-start into pre-biased loads. During startup, the low-side MOSFET remains disabled until the soft-start ramp voltage exceeds the existing output voltage. This prevents reverse inductor current and enables seamless ramp-up from voltages below or above the target-provided the pre-bias does not exceed the OVP threshold (116% of nominal).

What determines the PGOOD assertion delay for the ISL6442IA?

The PGOOD assertion delay for the ISL6442IA is determined solely by the switching frequency (FSW) and follows the formula tPGOOD = 0.5236 / FSW (seconds). At 1.4MHz, the delay is 370ms; at 524kHz, it extends to 1 second. There is no independent adjustment-designers must select RT to balance transient response, EMI, and PGOOD timing requirements.

Does the ISL6442IA linear controller include soft-start functionality?

No, the ISL6442IA linear controller does not include soft-start. Its output (driven by LCDR and regulated via LCFB) enables immediately after the VCC power-on reset threshold (~4.4V) is crossed. However, if the linear controller's input is sourced from one of the PWM outputs, it will inherently follow that rail's soft-start ramp, enabling indirect sequencing.