Renesas IW1791-23

Overview

The iW1791-23 from Renesas Electronics is an AC/DC primary-side rapid charge PWM controller supporting USB Power Delivery (USB PD) and Qualcomm Quick Charge 2.0/3.0 protocols. It delivers high-resolution voltage/current control with 10mV DLNK step resolution, multi-level constant-voltage/constant-current regulation without secondary feedback, and <20mW no-load power consumption at 230VAC with 5V output. It operates in quasi-resonant mode and integrates SmartDefender+™ for soft-short protection in fast-charging adapters.

For engineers reviewing the iW1791-23 datasheet, iW1791-23 pinout, iW1791-23 application, or iW1791-23 equivalent, key selection considerations include its DLNK-based digital communication with secondary controllers, configurable CC shutdown thresholds per VBUS range, 10mV-step voltage request capability for USB PD PPS, and SOIC-8 package compatibility with Renesas' iW657P/iW676 chipset reference designs.

Technical Context

The iW1791-23 implements primary-side regulation using VSENSE and ISENSE inputs to achieve tight CV/CC control across 3V–20V output ranges, eliminating optocoupler and TL431 dependencies. Its DLNK pin enables bidirectional digital communication-carrying output voltage requests, current limits, undershoot detection, and overvoltage signals-via a single optocoupler link to Renesas secondary-side controllers like iW657P.

It features source-charging VCC startup technology, removing external active start-up circuits while maintaining ultra-low standby power. The device supports multi-mode PWM/PFM operation, load-adaptive maximum constant frequency switching, and user-configurable 4-level cable drop compensation independent of output voltage.

Key Specifications

Pinout & Package

The iW1791-23 is housed in an 8-lead SOIC-8 package with standard 1.27 mm pitch and exposed pad (non-electrical). Pin 1 is GND; pins are numbered counterclockwise from the notch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar primary-side rapid charge controller applications.

Compared with MP6908A and UCC28780, the iW1791-23 provides native 10mV DLNK resolution for PPS, eliminates both optocoupler and ASU circuitry, and integrates cable drop compensation - reducing component count by ≥4 and enabling faster time-to-market for USB-C PD/QC3.0 adapters.

Availability

iW1791-23 is available at Aetrix Electronics and suitable for USB PD fast-charging adapters, QC3.0 wall chargers, and smartphone OEM reference designs requiring stable component supply, full lifecycle support, and traceable sourcing.

Supply support for iW1791-23 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 microcontrollers, analog, power, and SoC products for automotive, industrial, infrastructure, and IoT applications.

The iW1791-23 belongs to Renesas' Rapid Charge™ controller family, engineered specifically for high-efficiency, low-noise, multi-protocol AC/DC adapters targeting mobile device charging ecosystems.

FAQ

What is the primary function of the iW1791-23 in an AC/DC power supply?

The iW1791-23 serves as a primary-side PWM controller that enables rapid charging protocols including USB PD and QC3.0 without secondary-side feedback. It regulates output voltage and current using VSENSE and ISENSE inputs, communicates digitally via the DLNK pin, and supports 10mV-step voltage requests. The iW1791-23 replaces traditional optocoupler-based feedback loops while maintaining tight regulation across 3V–20V outputs.

How does the iW1791-23 achieve <20mW no-load power consumption?

The iW1791-23 uses source-charging VCC technology to charge its internal supply rail directly from the MOSFET source node during startup, eliminating the need for an external active start-up (ASU) circuit. This architecture, combined with ultra-low quiescent current design, allows the iW1791-23 to meet stringent global energy efficiency standards such as DOE Level VI and EU CoC Tier 2 at 230VAC with a 5V output.

What is the significance of the DLNK pin on the iW1791-23?

The DLNK pin on the iW1791-23 receives serial digital commands from Renesas secondary-side controllers (e.g., iW657P) via a single optocoupler. It carries output voltage requests, current limits, undershoot detection flags, and overvoltage alerts - enabling full protocol negotiation without analog feedback components. For the iW1791-23, DLNK supports 10mV resolution, essential for USB PD Programmable Power Supply compliance.

Does the iW1791-23 support USB PD Programmable Power Supply (PPS)?

Yes, the iW1791-23 supports USB PD PPS through its 10mV DLNK voltage step resolution, which meets the USB-IF PPS specification requirement. When paired with a compatible Renesas secondary-side controller like iW657P, the iW1791-23 enables dynamic, fine-grained voltage adjustments (e.g., 5.00V → 5.01V → 5.02V) in response to real-time device requests - critical for minimizing heat generation during high-current charging.

What protection features are integrated into the iW1791-23?

The iW1791-23 integrates built-in protections including output over-voltage (OVP), output over-current (OCP), output short-circuit (soft/half short), and thermal shutdown. Its SmartDefender+™ technology actively reduces average output power during soft-short faults without latching, improving system reliability. The iW1791-23 also includes auxiliary winding open-circuit detection via the CFG pin and VCC undervoltage lockout.