Renesas ISL6442IAZ-TK

Overview

ISL6442IAZ-TK from Renesas (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 - enabling compact, high-efficiency dual-rail supplies in DSL modems and FPGA/ASIC power systems.

For engineers reviewing the ISL6442IAZ-TK datasheet, ISL6442IAZ-TK pinout, ISL6442IAZ-TK application, or ISL6442IAZ-TK equivalent, key selection considerations include its lossless rDS(ON)-based overcurrent protection, independent SS/EN pins with voltage tracking capability, PGOOD delay tied to switching frequency, and 24-lead QSOP package with separate PGND/SGND routing requirements.

Technical Context

The ISL6442IAZ-TK implements synchronous buck control using voltage-mode architecture with dedicated error amplifiers (88 dB DC gain, 15 MHz GBWP) and internal 0.6V reference. Its two PWM channels operate 180° out-of-phase to reduce input ripple and RMS current draw, while the third output uses an external PNP transistor driven by LCDR to form a low-current linear regulator.

Protection is implemented per-channel: hiccup-mode overcurrent sensing via OCSET pins (110 µA current source), independent OVP/UVP comparators (116%/82% thresholds), and thermal shutdown at +150°C. The PGOOD signal asserts only after both PWM outputs settle within ±10% and the linear output exceeds 75% of nominal - with delay inversely proportional to FSW (e.g., 370 ms at 1.4 MHz).

Key Specifications

Pinout & Package

ISL6442IAZ-TK is housed in a 24-lead QSOP (M24.15) package with exposed pad not electrically connected. Pin layout separates high-current PGND (Pin 18) from signal ground SGND (Pin 6); VIN (Pin 24) powers both controllers and upper FETs; VCC (Pin 19) supplies gate drivers and internal logic.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual PWM + linear controller applications.

Compared with MP2942AGQSE-LF-Z and TPS51220ARUKT, the ISL6442IAZ-TK uniquely integrates a linear controller with LCDR/LCFB interface and true voltage tracking via shared SS/EN ramp - making it the only option among the three that supports three-rail sequencing with zero external components for the linear stage.

Availability

ISL6442IAZ-TK is available at Aetrix Electronics and suitable for DSL modems, FPGA power systems, DSP point-of-load regulation, and networking ASIC supplies requiring stable component supply across extended product lifecycles.

Supply support for ISL6442IAZ-TK 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 acquired Intersil in 2017 and maintains full support for legacy power management ICs. Renesas is a global semiconductor leader focused on embedded solutions for automotive, industrial, and infrastructure markets.

The ISL6442IAZ-TK belongs to Intersil's high-density multi-output controller family, designed specifically for broadband and networking equipment requiring compact, sequenced, and robust power delivery with minimal external components.

FAQ

What is the maximum supported switching frequency for ISL6442IAZ-TK?

The ISL6442IAZ-TK supports a programmable switching frequency range from 300 kHz to 2.5 MHz, set by an external resistor from the RT pin to SGND. At 5.23 kΩ, the device operates at 2.5 MHz (typical) with VIN = 12 V. Higher frequencies improve transient response and allow smaller magnetics but increase gate drive losses - especially when VIN exceeds 12 V due to higher VCC regulator dissipation.

Does ISL6442IAZ-TK support soft-start into a pre-biased output?

Yes, the ISL6442IAZ-TK supports soft-start into pre-biased loads on both PWM outputs. When the SS/EN ramp voltage is below the existing output voltage, the low-side MOSFET remains disabled until the ramp crosses that level - enabling monotonic rise without reverse inductor current or overshoot. This behavior is confirmed in Figure 8 of the FN9204 datasheet and applies independently to each channel.

How does overcurrent protection work on ISL6442IAZ-TK?

The ISL6442IAZ-TK implements lossless overcurrent protection using the upper MOSFET's rDS(ON). A 110 µA current source pulls down the OCSET pin, establishing a threshold voltage. During the high-side on-time, the PHASE node voltage is compared to OCSET - if PHASE falls below OCSET, an overcurrent is detected. After 32 consecutive cycles, hiccup mode initiates: the SS/EN capacitor discharges and a new soft-start cycle begins.

Can ISL6442IAZ-TK generate three independent output voltages?

Yes, the ISL6442IAZ-TK provides three independent regulated outputs: two from synchronous buck PWM controllers (adjustable down to 0.6 V via FB dividers) and one from the linear controller (set via LCFB divider and delivered through an external PNP transistor driven by LCDR). Each output has independent enable/soft-start control, OVP/UVP monitoring, and can be configured for voltage tracking or standalone operation.

What is the role of the PGOOD signal on ISL6442IAZ-TK?

The PGOOD signal on ISL6442IAZ-TK is an open-drain output that goes high only after all three outputs meet regulation criteria: both PWM outputs within ±10% of target and the linear output above 75% of nominal. It includes a fixed delay inversely proportional to switching frequency (e.g., 370 ms at 1.4 MHz), ensuring stable power sequencing before downstream logic enables - critical for FPGA and ASIC boot integrity.