Renesas IW1790-08B

Overview

The iW1790-08B from Renesas Electronics is a primary-side AC/DC PWM controller optimized for rapid charge adapters supporting Qualcomm Quick Charge 2.0 and 3.0 protocols via XM-Comm transformer communication. It delivers multi-level constant voltage/current regulation without optocoupler or secondary feedback, achieves <20mW no-load power at 230VAC/5V–2A, and operates in quasi-resonant mode with 4-level cable drop compensation.

For engineers reviewing the iW1790-08B datasheet, iW1790-08B pinout, iW1790-08B application, or iW1790-08B equivalent, key selection considerations include its kCC startup coefficient (0.422), VBUS-dependent CC shutdown voltage (6.5V at 9V VBUS, 66% otherwise), SOIC-8 package, and native pairing with iW662-00/iW662-05 secondary controllers for QC2.0/QC3.0 compliance.

Technical Context

The iW1790-08B implements primary-side regulation using auxiliary winding sensing (VSENSE) and cycle-by-cycle current limiting (ISENSE), eliminating need for secondary feedback components. Its XM-Comm interface enables bidirectional communication with iW662-00/iW662-05 to dynamically adjust output voltage, current limits, and overvoltage protection thresholds across protocol transitions.

It integrates source-charging VCC startup technology to remove external active start-up circuits and supports multi-mode PWM/PFM control with load-adaptive maximum frequency tuning. The device uses SmartDefender+™ for soft-short mitigation and dual OTP protection-internal junction-based and external NTC-driven via SD pin.

Key Specifications

Pinout & Package

Package: 8-lead SOIC-8 (standard body, 150 mil width), surface-mount, 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 iW1790-07 and iW1790-09B, the iW1790-08B offers a lower kCC (0.422) for tighter current limit control and matches iW662-00/05 - enabling optimized QC3.0 negotiation latency and reduced component count in new designs targeting <20mW no-load power.

Availability

iW1790-08B is available at Aetrix Electronics and suitable for USB-C rapid charge adapters, QC2.0/QC3.0 wall chargers, and multi-voltage tablet power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for iW1790-08B 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 markets.

The iW1790-08B belongs to Renesas' Dialog-branded AC/DC rapid charge controller family, designed specifically for high-efficiency, low-noise, optocoupler-free USB power delivery adapters supporting AFC, QC, FCP, and PE protocols.

FAQ

What is the primary function of the iW1790-08B in an AC/DC rapid charge adapter?

The iW1790-08B serves as the primary-side PWM controller in quasi-resonant flyback converters, executing constant voltage and constant current regulation without secondary feedback. It communicates with iW662-00/iW662-05 via XM-Comm to dynamically adjust output parameters, enabling QC2.0/QC3.0 compliance. The iW1790-08B eliminates the optocoupler, reduces BOM count, and maintains <20mW no-load power in typical 15W designs.

How does the iW1790-08B achieve ultra-low no-load power consumption?

The iW1790-08B uses source-charging VCC startup technology to charge its internal supply rail directly from the MOSFET source node, removing the need for an external active start-up circuit. This architecture, combined with optimized quiescent current and multi-mode PFM operation at light loads, enables <20mW no-load power consumption at 230VAC with a 5V/2A output configuration. The iW1790-08B sustains this performance across its full operating temperature range.

Which secondary-side controllers are compatible with the iW1790-08B?

The iW1790-08B is explicitly qualified for use with iW662-00 and iW662-05 secondary-side controllers, as confirmed in the official ordering information table. These pairings enable full Qualcomm Quick Charge 2.0 and 3.0 protocol implementation, including dynamic voltage requests, current limit updates, and overvoltage protection signaling via XM-Comm. The iW1790-08B does not support iW660 or iW663 variants for its default configuration.

What does the "B" suffix in iW1790-08B signify?

The "B" suffix in iW1790-08B indicates it is the recommended version for new designs, as stated in the official Renesas ordering information table. It shares identical electrical specifications, pinout, and functional behavior with iW1790-08 but reflects updated manufacturing, qualification, or packaging consistency. Both iW1790-08 and iW1790-08B are SOIC-8 packaged, tape-and-reel delivered, and support the same QC2.0/QC3.0 protocols with iW662-00/iW662-05.

Does the iW1790-08B support cable drop compensation, and how is it configured?

Yes, the iW1790-08B supports user-configurable 4-level cable drop compensation, independent of output voltage setting. Compensation level is set via external resistors on the CFG pin, allowing adjustment of output voltage boost based on load current to maintain target VBUS at the device connector. This feature is implemented entirely in hardware and requires no firmware or digital interface - a key advantage of the iW1790-08B for cost-sensitive rapid charge designs.