Renesas RAA457100GBM#HC0

Overview

RAA457100GBM from Renesas Electronics is a wireless charging receiver IC for low-power Li-ion battery applications, integrating full-wave rectification, 12-bit ADC monitoring (RECT, BAT, THM, RICHG, RIMON), bi-directional WPT communication (125/250 bps), and programmable DC-DC conversion (1.2/1.5/1.8/3.0 V output). It supports automatic charge control with temperature-compensated voltage settings (4.05/4.20/4.35 V) and operates across -20°C to +50°C ambient.

For engineers reviewing the RAA457100GBM datasheet, RAA457100GBM pinout, RAA457100GBM application, or RAA457100GBM equivalent, this page delivers verified technical context on WPT receiver operation modes (shut down, charge mode 1/2, discharge), integrated protection (discharge overcurrent/short-circuit, low-battery detection), and register-configurable timing (trickle/fast charge timers: 60–360 min).

Technical Context

The RAA457100GBM implements a dual-path power architecture: rectified AC input (125 kHz) feeds a synchronous full-wave rectifier with adaptive gate control (half/full sync based on VCC current thresholds), while battery power supplies the IC in discharge mode via internal DFET. Its 12-bit ADC samples five critical analog nodes every 4 ms for real-time thermal and voltage feedback used in closed-loop transmission power control and charge state management.

Bi-directional communication uses load modulation (COM1/COM2) and clamp drivers (CLMP1/CLMP2) to encode data onto the coupling coil, enabling transmitter-side register access (e.g., 0x02–0x0A for temperature thresholds) and 2-wire serial interface (SCL/SDA) bridging to host systems. Operation mode transitions are governed by SD pin level detection (>1 s), VRECT vs. VBAT comparisons, and UVLO/OVLO thresholds (VRECT_UVLO = 3.0 V, VRECT_OVD = 14 V typ).

Key Specifications

Pinout & Package

RAA457100GBM is housed in a 40-pin QFN package (6 mm × 6 mm, 0.5 mm pitch) with exposed thermal pad. Pin assignment follows bottom-view ball grid layout: A1–A7, B1–B7, C1–C7, D1–D7, E1–E7, F1–F7 (excluding unused positions). Grounding is segregated into RGND (rectifier/driver), SGND (DC-DC), and GND (system) for noise isolation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar wireless charging receiver applications.

Compared with RAA457100GBM, bq51222RGER offers higher power but sacrifices precision analog monitoring and multi-voltage DC-DC flexibility, while MP-A21 reduces cost and complexity at the expense of configurability and thermal safety-making RAA457100GBM optimal for safety-critical, firmware-managed low-power receivers.

Availability

RAA457100GBM is available at Aetrix Electronics and suitable for wearable fitness trackers, wireless earbud charging cases, medical sensor patches, and smart ring chargers requiring stable component supply, long-term lifecycle support, and compliance with wireless power consortium guidelines.

Supply support for RAA457100GBM 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 specializing in microcontrollers, analog, and power management solutions for automotive, industrial, and IoT markets.

The RAA457100GBM belongs to Renesas' Wireless Power Transfer (WPT) receiver product line, designed specifically for compact, low-power consumer electronics requiring integrated charging, power conversion, and intelligent thermal/battery protection.

FAQ

What is the primary function of the RAA457100GBM in a wireless charging system?

The RAA457100GBM serves as a complete wireless charging receiver IC that converts induced AC power (125 kHz) into regulated DC for battery charging and system power. It integrates full-wave rectification, 12-bit ADC-based monitoring of battery voltage, rectified output, and thermistor voltage, bi-directional communication with the transmitter (e.g., RAA458100), and a programmable step-down DC-DC converter. The RAA457100GBM enables autonomous charge control with temperature compensation and comprehensive protection-eliminating the need for external controllers in low-power applications.

How does the RAA457100GBM handle battery temperature monitoring and charge control?

The RAA457100GBM uses its 12-bit ADC to measure voltage at the THM pin, which is part of a resistor-NTC divider referenced to VDDW (2.7 V). This measurement determines battery temperature and maps it to one of three zones (low, suitable, high), each with independently programmable charge voltage (4.05/4.20/4.35 V) and fast-charge current (0.25×/0.5×/1× ICHGR). Thresholds (e.g., THM_TH_M_H, THM_TH_H_HE) are stored in registers 0x05–0x0A and can be tuned for specific NTC characteristics. The RAA457100GBM enforces lower charge voltages in extreme temperatures to ensure safety and longevity.

What are the operating modes of the RAA457100GBM and how are they triggered?

The RAA457100GBM operates in four modes: shut down, charge mode 1, charge mode 2, and discharge. Shut down activates when VRECT < 3.0 V and SD = L for >1 s, or VDDB < 2.5 V. Charge mode 1 begins when VRECT > 3.0 V (e.g., coil energized), powering internal circuits but not charging. Charge mode 2 starts when VRECT > 4.5 V and VRECT > VBAT + 100 mV, enabling battery charging, WPT communication, and VCC regulator operation. Discharge mode engages when SD = H for >1 s and VBAT > VRECT, allowing battery-powered system operation. Mode transitions are fully hardware-driven with no firmware dependency.

Can the RAA457100GBM be used without a microcontroller, and what interfaces does it support?

Yes, the RAA457100GBM supports standalone operation using pin-strapping (e.g., DDST0/DDST1 for DC-DC voltage, ATCHG for auto-charge enable) and open-drain status outputs (CHG/INT, MODE, BUZ). For advanced control, it provides a 2-wire serial interface (SCL/SDA) compatible with standard I²C protocols, allowing a host MCU to read ADC results, configure registers (e.g., charge timers, temperature thresholds), and monitor real-time status. The RAA457100GBM also supports bi-directional WPT communication with compatible transmitters like the RAA458100, enabling remote parameter updates without physical connections.

What protection features does the RAA457100GBM provide for battery safety?

The RAA457100GBM integrates multiple hardware-level protections: discharge short-circuit detection (160 mV across SGND–GND, 250 µs delay), discharge overcurrent (80 mV, 4 ms delay), discharge overvoltage (2.8 V, 32 ms delay), low-battery detection (3.20–3.55 V depending on SYS voltage, 256 ms delay), and charge overvoltage (VCHG + 0.1 V, 256 ms delay). All triggers force the internal discharge FET (DFET) into high-impedance state, isolating the battery. These functions operate autonomously without MCU intervention, ensuring fail-safe behavior even during firmware crashes or power loss-critical for certified medical and wearable applications.