Nexperia USA Inc. RP604Z301B-E2-F

Overview

RP604Z301B-E2-F from Ricoh Electronic Devices is an ultra-low-quiescent-current (0.3 µA) buck-boost DC/DC converter in WLCSP-20-P2 package, designed for intermittent battery-powered systems. It delivers 300 mA output at 3.0 V with ±1.5% accuracy, supports 1.8–5.5 V input (coin cell to USB), and includes auto-discharge functionality for rapid VOUT discharge during standby-critical for wearable health monitors and BLE sensors.

For engineers reviewing the RP604Z301B-E2-F datasheet, RP604Z301B-E2-F pinout, RP604Z301B-E2-F application, or RP604Z301B-E2-F equivalent, key selection criteria include quiescent current vs. load efficiency trade-offs, auto-discharge timing behavior, WLCSP thermal performance under 85°C ambient, and compatibility with 2.2 µH inductors and 22 µF ceramic output capacitors in space-constrained PCB layouts.

Technical Context

The RP604Z301B-E2-F implements a synchronous four-switch buck-boost topology with integrated 0.12 Ω PMOS/NMOS power FETs, enabling seamless transition between buck and boost modes across its 1.8–5.5 V input range. Its VFM (Variable Frequency Modulation) control maintains >85% efficiency at 10 µA load while limiting switching noise in sensitive RF bands.

Internal protection includes UVLO (1.55 V release), OVP (6.0 V detection), LX peak-current limiting (900 mA), and thermal shutdown (140°C). The auto-discharge function-enabled by internal 100 Ω NMOS-actively discharges VOUT to 0 V within milliseconds after CE deactivation, eliminating residual voltage that could interfere with system-level power sequencing.

Key Specifications

Pinout & Package

RP604Z301B-E2-F uses the WLCSP-20-P2 package (1.71 × 2.315 × 0.40 mm), optimized for ultra-thin wearables and implantable-grade PCBs. Its 20-bump array features dedicated analog/digital ground separation and dual power input pins (PVIN/AVIN) to suppress switching noise coupling into feedback paths.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar buck-boost converter applications.

Compared with TPS63802DLAR and ADP5070ACPZ-R7, RP604Z301B-E2-F uniquely balances ultra-low IQ, integrated auto-discharge, and WLCSP size for wearables-whereas alternatives prioritize current capacity or industrial robustness at the expense of standby efficiency and board area.

Availability

RP604Z301B-E2-F is available at Aetrix Electronics and suitable for wearable appliances, low-power wireless communication equipment, and energy-harvesting IoT endpoints requiring stable component supply and long-term design-in support.

Supply support for RP604Z301B-E2-F 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

Ricoh Electronic Devices Co., Ltd. is a Japanese semiconductor manufacturer specializing in power management ICs, voltage regulators, and battery management solutions for portable and industrial applications.

The RP604x series was developed specifically for ultra-low-power, space-constrained battery-operated devices-including medical wearables, BLE peripherals, and environmental sensors-where minimizing quiescent current and enabling rapid power-state transitions are critical system requirements.

FAQ

What is the purpose of separate PVIN and AVIN pins?

The PVIN pin supplies high-current switching paths (FETs, LX nodes), while AVIN powers the analog control circuitry (error amplifier, reference, soft-start). Separating them prevents switching noise from modulating the feedback reference, maintaining ±1.5% output accuracy even under dynamic load. Layout best practice requires individual ceramic bypass capacitors (≥1 µF) on each pin, referenced to their respective ground planes.

How does the auto-discharge function behave during CE deactivation?

When CE transitions from high to low, the internal 100 Ω NMOS switch connects VOUT to PGND, actively discharging the output capacitor. For a typical 22 µF output cap, VOUT falls from 3.0 V to <100 mV in under 5 ms. This prevents residual voltage from powering downstream circuitry unintentionally-critical for systems requiring strict power-domain isolation during sleep.

Can RP604Z301B-E2-F operate with input voltages below 1.8 V?

No. The absolute minimum input voltage is 1.8 V per datasheet specifications. Below this, UVLO activates and disables switching. At 1.75 V input, the device enters undervoltage lockout (VUVLOF = 1.40–1.65 V), halting regulation and dropping VOUT. Designers must ensure battery discharge curves stay above 1.8 V or implement upstream supervision circuitry.

Why does efficiency drop above 100 mA in buck mode despite 300 mA rating?

The 300 mA rating reflects maximum continuous output in buck configuration, but conduction losses from the 0.12 Ω FETs and inductor DCR cause efficiency to decline above ~100 mA. At 300 mA and 3.6 V input, typical efficiency is 88% (vs. 94% at 10 mA). Thermal limits (1490 mW in WLCSP) constrain sustained high-current operation-designers should verify junction temperature rise using θ_JA = 67°C/W under actual PCB conditions.