Renesas ISL9305IRTWLNCZ-T

Overview

ISL9305IRTWLNCZ-T from Renesas Electronics is a dual-output PMIC integrating two 3MHz synchronous step-down converters (800mA each) and two low-input LDOs (300mA each), with I²C programmability for dynamic voltage scaling in battery-powered microprocessor systems. It supports 2.3V–5.5V input, delivers factory pre-set DCD1=1.2V/DCD2=2.9V/LDO1=3.3V/LDO2=1.8V outputs, and operates in skip mode or forced PWM for efficiency optimization in portable electronics.

For engineers reviewing the ISL9305IRTWLNCZ-T datasheet, ISL9305IRTWLNCZ-T pinout, ISL9305IRTWLNCZ-T application, or ISL9305IRTWLNCZ-T equivalent, key selection considerations include I²C-controlled slew rate (0.225–28.8 mV/µs), programmable power-good delay (1–200 ms), dual-buck + dual-LDO integration in 4mm×4mm TQFN, and support for single Li-ion/Li-Polymer battery systems requiring tightly regulated core and I/O rails.

Technical Context

The ISL9305IRTWLNCZ-T implements peak-current-mode PWM control for both buck converters, enabling fast transient response and pulse-by-pulse current limiting. Its 3MHz switching frequency allows use of compact 1.5µH inductors and low-ESR ceramic capacitors while maintaining stable regulation across 0–800mA load range per channel.

I²C interface (400kb/s) provides full configuration of output voltages (25mV/step for bucks, 50mV/step for LDOs), slew rates, skip/PWM mode selection, active discharge enablement, and power-good delay timing - all without external component changes. The device uses internal P/N-channel MOSFETs with ON-resistances of 0.14Ω/0.11Ω (P/N at 3.6V) and integrates thermal shutdown (155°C) and UVLO (2.2V typical on VINDCD1).

Key Specifications

Pinout & Package

ISL9305IRTWLNCZ-T is housed in a thermally enhanced 4mm × 4mm, 16-lead TQFN package with exposed E-pad for PCB heat dissipation. Pin assignment follows standard Renesas TQFN layout with dedicated ground planes for buck and LDO sections to minimize noise coupling.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-buck + dual-LDO PMIC applications.

Compared with TPS65023RSBR and RT8070ZSP, the ISL9305IRTWLNCZ-T uniquely combines dual 800mA 3MHz bucks with full I²C configurability in a 4mm×4mm footprint - enabling true dynamic power management for multi-core SoCs where independent rail control and voltage ramping are mandatory.

Availability

ISL9305IRTWLNCZ-T is available at Aetrix Electronics and suitable for smartphone power management, wearable sensor hubs, portable medical monitors, and industrial handheld terminals requiring stable component supply across long production lifecycles.

Supply support for ISL9305IRTWLNCZ-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 markets, with deep expertise in power management and mixed-signal design.

The ISL9305 series belongs to Renesas' mini-PMIC product line, engineered specifically for space-constrained, battery-powered portable devices requiring high-efficiency, multi-rail power delivery with intelligent digital control.

FAQ

What are the factory pre-set output voltages for ISL9305IRTWLNCZ-T?

The ISL9305IRTWLNCZ-T is configured at manufacturing with fixed output voltages: DCD1 = 1.2V, DCD2 = 2.9V, LDO1 = 3.3V, and LDO2 = 1.8V. These values are confirmed in the Ordering Information table (Page 4 of FN7605 Rev 2.00) and cannot be altered by external resistors - though all four outputs remain fully programmable via I²C interface within their respective ranges (0.825–3.6V for bucks at 25mV/step; 0.9–3.6V for LDOs at 50mV/step).

Does ISL9305IRTWLNCZ-T support forced PWM mode for noise-sensitive applications?

Yes, ISL9305IRTWLNCZ-T supports forced PWM mode for both DCD1 and DCD2 independently via the DCD_PARAMETER register (address 0x04h, bits B0/B1). When enabled, the buck converters maintain constant 3MHz switching regardless of load current - eliminating audible noise and spectral artifacts associated with skip (PFM) mode, which is critical for RF sections, audio codecs, and precision analog signal chains.

How is power sequencing managed between the buck and LDO outputs on ISL9305IRTWLNCZ-T?

Power sequencing on ISL9305IRTWLNCZ-T is managed through independent I²C-controlled enable bits in the SYS_PARAMETER register (0x05h): DCD1_EN (B0), DCD2_EN (B1), LDO1_EN (B2), and LDO2_EN (B3). Each rail can be powered up/down in any order with software-defined timing, while the DCDPG pin provides synchronized power-good status for system-level coordination - eliminating need for external sequencers.

What thermal performance can be expected from ISL9305IRTWLNCZ-T in its 4mm×4mm TQFN package?

ISL9305IRTWLNCZ-T features θJA = 40.2°C/W and θJC = 5°C/W in its 16-lead TQFN package. With proper PCB layout - including soldering the exposed E-pad to a minimum 9-via thermal pad connected to internal ground plane - the device sustains continuous 800mA per buck at ambient temperatures up to +85°C. Thermal shutdown activates at +155°C (with 30°C hysteresis), ensuring robust protection during transient overloads or poor airflow conditions.

Can ISL9305IRTWLNCZ-T actively discharge its buck outputs when disabled?

Yes, ISL9305IRTWLNCZ-T includes an internal 115Ω bleeding resistor for each buck converter, enabled by default and controllable per-channel via DCD_PARAMETER register bits B2 (DCD1_BLD) and B3 (DCD2_BLD). When a buck is disabled, this feature rapidly discharges its output capacitor to near-zero voltage - preventing unintended back-powering of upstream circuitry and ensuring deterministic power-down behavior required in safety-critical or multi-PMIC systems.