Renesas IW1790-18B

Overview

The iW1790-18B from Renesas Electronics is a primary-side AC/DC PWM controller optimized for rapid charge adapters supporting Qualcomm Quick Charge 2.0/3.0 and Power Delivery (PE) protocols. It delivers multi-level constant voltage/current regulation without secondary-side feedback, achieves <20mW no-load power at 5V/2A, and operates in quasi-resonant mode with XM-Comm transformer-based communication to iW662-18.

For engineers reviewing the iW1790-18B datasheet, iW1790-18B pinout, iW1790-18B application, or iW1790-18B equivalent, key selection considerations include its SOIC-8 package, source-charging VCC startup, 4-level cable drop compensation, SmartDefender+ fault handling, and compatibility with Dialog's iW662-18 secondary controller for QC/PE negotiation.

Technical Context

The iW1790-18B implements primary-side regulation using VSENSE-based auxiliary winding sensing and ISENSE-based cycle-by-cycle current limiting, eliminating optocouplers and loop compensation components. Its XM-Comm interface enables bidirectional communication-voltage requests, current limits, and over-voltage/undershoot status-directly across the main transformer with iW662-18.

It employs load-adaptive maximum constant-frequency PWM switching with quasi-resonant operation, multi-mode PWM/PFM control, and EZ-EMI® design to optimize size, efficiency, and common-mode noise. The device integrates dual over-temperature protection (internal OTP + external NTC via SD pin) and supports soft-short detection without latching via SmartDefender+ technology.

Key Specifications

Pinout & Package

Package: 8-Lead SOIC-8 (standard industry footprint, RoHS-compliant).

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 iW1790-18B uniquely integrates XM-Comm, source-charging startup, and SmartDefender+, enabling fully self-contained rapid charge control without optocouplers, ASU circuits, or external protocol processors-reducing total solution size and component count by up to 25%.

Availability

iW1790-18B is available at Aetrix Electronics and suitable for USB-C PD/QC rapid chargers, multi-protocol travel adapters, and tablet fast-charging power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for iW1790-18B 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 solutions for automotive, industrial, infrastructure, and IoT applications.

The iW1790-18B belongs to Renesas' Dialog-branded rapid charge controller family, designed specifically for compact, high-efficiency AC/DC adapters targeting smartphone, tablet, and portable device charging markets.

FAQ

What is the role of the iW1790-18B in a rapid charge adapter design?

The iW1790-18B serves as the primary-side PWM controller in AC/DC rapid charge adapters, executing quasi-resonant switching, multi-level constant voltage/current regulation, and XM-Comm-based communication with iW662-18. It replaces traditional optocoupler feedback loops and eliminates external active start-up circuitry, enabling compact, efficient, and protocol-aware power supplies. The iW1790-18B is essential for achieving <20 mW no-load power and fast dynamic load response in certified QC/PE designs.

Does the iW1790-18B require an external optocoupler?

No, the iW1790-18B does not require an external optocoupler. It uses Dialog's proprietary XM-Comm technology to communicate output voltage and current commands bidirectionally across the main transformer with compatible secondary-side controllers like iW662-18. This eliminates isolation components, reduces BOM cost, improves reliability, and simplifies PCB layout. The iW1790-18B achieves full regulation and fault reporting without any optocoupler or secondary-side feedback circuitry.

What secondary-side controller is paired with the iW1790-18B?

The iW1790-18B is specifically designed to pair with the iW662-18 secondary-side controller, which handles USB PD, QC2.0, QC3.0, and Power Delivery (PE) protocol negotiation. Together, they form a complete rapid charge solution where the iW662-18 sends voltage/current requests and fault data via XM-Comm, and the iW1790-18B executes precise primary-side regulation. This pairing is confirmed in Renesas' ordering information and application schematics for the iW1790-18B.

How does the iW1790-18B achieve ultra-low no-load power consumption?

The iW1790-18B achieves <20 mW no-load power consumption through source-charging VCC technology, which charges the internal VCC capacitor directly from the MOSFET source node before startup-eliminating the need for an external active start-up (ASU) circuit. Combined with multi-mode PWM/PFM control and optimized quiescent current, this architecture meets stringent energy-efficiency standards such as DOE Level VI and EU CoC Tier 2. The iW1790-18B maintains this performance across 90–264 VAC input ranges.

What protection features are integrated into the iW1790-18B?

The iW1790-18B integrates comprehensive protection including output over-voltage (OVP), output over-current (OCP), output short-circuit (soft/half short), dual over-temperature (internal junction + external NTC via SD pin), and auxiliary winding open-circuit detection. Its SmartDefender+ technology actively manages soft-short faults by reducing average output power without latching, enhancing safety in real-world cable failure scenarios. All protections are implemented in hardware with fast response times verified in iW1790-18B application testing.