Renesas ISL9301IRZ

Overview

ISL9301IRZ from Intersil is a fully integrated high-input-voltage single-cell Li-ion battery charger with power path management. It delivers 4.5V regulated system output, supports 50–450mA programmable charge current, features 1% V_BAT accuracy at 4.2V, and operates across –40°C to +85°C for handheld power management in space-constrained designs.

For engineers reviewing the ISL9301IRZ datasheet, ISL9301IRZ pinout, ISL9301IRZ application, or ISL9301IRZ equivalent, key selection criteria include its 28V input tolerance with 10.5V OVP threshold, dual open-drain status pins (PPR/CHG), thermal foldback at 115°C, and dynamic power path control enabling simultaneous system operation and battery charging from a discharged state.

Technical Context

The ISL9301IRZ implements linear charging with CC/CV regulation targeting 4.2V Li-ion cells, using separate internal MOSFETs for system supply (VOUT) and battery charging (VBAT). Its power path architecture dynamically allocates input current between system load and battery charge based on DPPM threshold (4.35V typical), preventing system brownout during high-load charging.

It integrates intelligent timeout scaling-based on actual delivered charge current-and preconditioning (16% I_REF below 2.8V), with end-of-charge detection triggered when charge current falls below programmable IMIN (e.g., 23mA with 137kΩ). Thermal foldback begins at 115°C, reducing I_CHG while preserving VOUT regulation.

Key Specifications

Pinout & Package

ISL9301IRZ uses a thermally enhanced 10-lead 3×3 mm DFN package with exposed pad (L10.3x3C) for efficient heat dissipation in compact PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar single-cell Li-ion charger applications.

Compared with BQ24075RGTR and MAX1555EUT+, the ISL9301IRZ provides superior input voltage resilience (28V), autonomous DPPM-based current arbitration, and integrated thermal foldback - making it optimal for ruggedized, high-reliability portable designs where input source variability and thermal management are critical.

Availability

ISL9301IRZ is available at Aetrix Electronics and suitable for mobile phones, Bluetooth headsets, MP3 players, and portable medical monitors requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ISL9301IRZ 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

Intersil Corporation (now part of Renesas Electronics) designs high-performance analog and mixed-signal ICs for power management, precision analog, and interface applications.

The ISL9301IRZ belongs to Intersil's high-voltage battery charger product line, engineered specifically for portable electronics needing robust input tolerance, autonomous power path control, and precision Li-ion charging in space-constrained 3×3 mm DFN packages.

FAQ

What is the maximum input voltage rating for the ISL9301IRZ, and how does its overvoltage protection work?

The ISL9301IRZ has a 28V absolute maximum input voltage rating at the VIN pin but disables charging when VIN exceeds 10.5V (typical OVP threshold). This built-in protection eliminates the need for external overvoltage circuitry. The OVP feature includes 400mV hysteresis to prevent oscillation near the threshold, and the IC remains powered for system operation while blocking battery charge - ensuring safe operation with unregulated or faulty adapters. The ISL9301IRZ thus delivers both ruggedness and design simplification.

How does the ISL9301IRZ manage power distribution between the system load and battery charging?

The ISL9301IRZ implements Dynamic Power Path Management (DPPM) to autonomously allocate available input current. When VOUT drops to the DPPM threshold (4.35V typical), it reduces charge current to prioritize system load - maintaining stable 4.5V regulation. If load demand exceeds input capability, the battery supplements VOUT via internal FET. This occurs without host intervention, enabling immediate system operation from a dead battery. The ISL9301IRZ thus decouples system uptime from battery state, a core advantage over basic chargers.

Can the ISL9301IRZ safely charge a deeply discharged Li-ion battery, and what safeguards apply?

Yes - the ISL9301IRZ initiates trickle preconditioning at 16% of the programmed IREF when VBAT falls below 2.8V (typical), gradually raising cell voltage before entering constant-current mode. This prevents lithium plating and cell damage. Once VBAT exceeds 3.0V, it transitions to full-rate CC charging. The ISL9301IRZ also incorporates thermal foldback (starting at 115°C) and overtemperature shutdown (142°C) to protect against unsafe conditions during recovery. These layered safeguards make the ISL9301IRZ suitable for consumer devices prone to deep discharge.

What are the key timing-related functions of the TIME pin on the ISL9301IRZ?

Connecting a resistor (e.g., 1MΩ) between the TIME pin and GND sets the oscillator period (75µs typical), which serves two critical timing functions: (1) defining the nominal timeout interval (≈5.6 hours with 1MΩ), and (2) enabling intelligent timeout scaling - the ISL9301IRZ extends the timeout proportionally when thermal foldback or DPPM reduces average charge current, ensuring full mAh delivery. The TIME pin thus provides both deterministic safety limits and adaptive behavior, a unique capability not found in fixed-timer chargers like the ISL9301IRZ.

How do the PPR and CHG pins function, and what design considerations apply for interfacing them?

PPR is an open-drain output that pulls LOW when VIN is within the power-good range (above POR, below OVP, and sufficient VOUT margin); CHG pulls LOW during active charging and goes HIGH at end-of-charge (EOC). Both sink ≥10mA and tolerate up to 7V, allowing direct LED drive or µP GPIO connection. A 1ms deglitch delay is recommended to suppress transients. For µP interfaces, CHG's latched HIGH state after EOC and blinking fault indication (3s period on timeout) provide unambiguous status without polling - simplifying firmware for the ISL9301IRZ.