Renesas ISL88739HRZ-T

Overview

ISL88739HRZ-T from Renesas Electronics is a configurable Hybrid Power Boost (HPB) and Narrow VDC (NVDC) battery charger IC supporting 2-, 3-, or 4-cell Li-ion batteries, featuring SMBus interface, R3™ modulation, 350kHz–1MHz switching frequency, and hardware-based adapter/battery current limits for notebook and ultrabook power systems.

For engineers reviewing the ISL88739HRZ-T datasheet, ISL88739HRW-T pinout, ISL88739HRW-T application, or ISL88739HRW-T equivalent, key selection considerations include Turbo mode behavior (HPB vs NVDC), NFET-only switch architecture, PROCHOT# compliance, adapter/battery current monitoring accuracy, and QFN-32 package thermal performance in high-power portable systems.

Technical Context

The ISL88739HRW-T implements dual-mode operation via SMBus configuration: HPB mode reverse-boosts battery energy to VSYS during system load surges, while NVDC mode rapidly enables BGATE to parallel battery with adapter. Both modes support system Turbo operation where battery supplements adapter current when load exceeds adapter capability.

It uses an internal charge pump to drive all-NFET power switches (UGATE, LGATE, BGATE, ASGATE, SFET), enabling fast turn-on to prevent VSYS droop during sudden battery removal-critical in Battery Learn and Turbo modes. The Robust Ripple Regulator (R3™) scheme ensures fast transient response and high light-load efficiency without external compensation.

Key Specifications

Pinout & Package

ISL88739HRW-T is housed in a thermally enhanced 32-pin QFN package (4mm × 4mm, 0.5mm pitch) with exposed thermal pad (EP) on underside for PCB-level heat sinking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery charger IC applications.

Compared with bq24780SRGER and RT9466E, the ISL88739HRW-T uniquely combines HPB/NVDC configurability, R3™ fast-response regulation, and Intel PROCHOT#-compliant hardware protection-making it the only option qualified for high-end notebook Turbo mode with live battery swapping and adapter overload handling.

Availability

ISL88739HRW-T is available at Aetrix Electronics and suitable for ultrabooks, gaming laptops, 2-in-1 detachables, and mobile workstations requiring stable component supply, long-term lifecycle support, and Intel-platform compatibility.

Supply support for ISL88739HRW-T 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 is a global semiconductor leader delivering trusted embedded solutions for automotive, industrial, infrastructure, and IoT applications, with >40 years of analog and power management IP heritage.

The ISL88739HRW-T belongs to Renesas' high-precision battery charger IC product line, engineered specifically for Intel-compliant notebook platforms requiring adaptive power-path control, Turbo mode resilience, and PROCHOT#-driven thermal throttling coordination.

FAQ

What is the primary function of the ISL88739HRW-T in a notebook power system?

The ISL88739HRW-T serves as a dual-mode battery charger IC that dynamically manages power delivery between AC adapter and Li-ion battery pack. It enables either Hybrid Power Boost (HPB) or Narrow VDC (NVDC) operation to sustain system load during adapter overload-commonly called Turbo mode. Its core function is to prevent VSYS collapse under transient loads while maintaining Intel PROCHOT# compliance and supporting live battery removal. The ISL88739HRW-T achieves this using all-NFET switching, R3™ modulation, and hardware-enforced current limits.

Does the ISL88739HRW-T support both 3-cell and 4-cell battery configurations?

Yes, the ISL88739HRW-T explicitly supports 2-, 3-, and 4-cell Li-ion battery configurations through SMBus register programming. Cell count selection determines voltage regulation thresholds, charge termination criteria, and overvoltage protection levels. The device's adaptive gate drivers and R3™ control loop maintain stability across the full 8.4V–16.8V input range. This flexibility allows one ISL88739HRW-T design to scale across multiple notebook SKUs without hardware changes.

How does the ISL88739HRW-T implement PROCHOT# signaling, and what triggers it?

The ISL88739HRW-T asserts the open-drain PROCHOT# signal per Intel specification when detecting system low voltage (VSYS < 11.4V), adapter overcurrent, battery overcurrent, or system overheating. Triggering is handled by dedicated hardware comparators-not software polling-ensuring sub-1µs response time. The ISL88739HRW-T also supports SMBus-readback of fault status registers to identify root cause after assertion. This dual-path (hardware-fast + SMBus-detailed) approach meets Intel's thermal and power integrity requirements for modern platforms.

Can the ISL88739HRW-T operate without an SMBus host controller?

No-the ISL88739HRW-T requires SMBus communication for initialization, mode selection (HPB/NVDC), cell count configuration, current limit setting, and fault logging. While hardware protection features (e.g., adapter/battery overcurrent cutoff) remain active without SMBus, functional operation-including Turbo mode enablement, PROCHOT# calibration, and battery learn sequence-is SMBus-dependent. The ISL88739HRW-T does not support standalone "default mode" boot-up; absence of SMBus results in disabled power-path control.

What thermal management features does the ISL88739HRW-T provide?

The ISL88739HRW-T integrates thermal monitoring with automatic derating: junction temperature is sensed internally, and switching frequency is reduced above 105°C to lower power dissipation. It also asserts PROCHOT# on system overheating detected via external NTC thermistor connected to the THERM pin. The 4mm × 4mm QFN package includes an exposed thermal pad requiring ≥6 thermal vias to inner ground planes for effective heat transfer. These features collectively ensure reliable operation up to 105°C ambient in fanless ultrabook chassis.