Microchip Technology RE46C119S16F

Overview

RE46C119S16F from Microchip Technology (via R&E International) is a mixed-signal IC integrating a 3V low-dropout regulator, 12V switched-capacitor boost converter, and dual-output piezoelectric horn driver. It delivers 12.7V VPOS output at −16mA load, maintains 6.5µA quiescent current in standby, and includes low-battery detection (LBAT), power-good monitoring (PG), and bidirectional interconnect logic. It is used in battery-powered smoke/CO detectors for audible alarm generation and microcontroller supply regulation.

For engineers reviewing the RE46C119S16F datasheet, RE46C119S16F pinout, RE46C119S16F application, or RE46C119S16F equivalent, key selection criteria include its integrated 12V horn drive capability, 3V/50mA LDO with 90mV load regulation, LBST-strobed low-battery sensing, PG threshold hysteresis (72–94% VREG), and bidirectional IO1/IO2 interconnect for multi-unit alarm coordination.

Technical Context

The RE46C119S16F implements a charge-pump-based 12V boost regulator with internal 150kHz oscillator and voltage-comparator feedback control, delivering regulated VPOS from 6–12V input. Its horn driver outputs (HORNB/HORNS) swing rail-to-rail between VPOS and VSS with <0.5V saturation voltage at 16mA sink/source.

It integrates a bandgap-referenced 3V LDO (VREG) with overvoltage clamp (3.7–4.3V), brownout protection, and dedicated LBAT analog output proportional to VDD. The IO1/IO2 bidirectional interface operates under IODIR-controlled direction logic, enabling daisy-chained communication across multiple RE46C119S16F units without external transceivers.

Key Specifications

Pinout & Package

RE46C119S16F is housed in a 16-pin SOIC package (width 7.5mm, body size 10.3×7.5mm), RoHS-compliant and Pb-free capable.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar piezoelectric horn driver and low-voltage regulation applications.

Compared with TPS61088RHLR and MAX680CPA+, the RE46C119S16F uniquely consolidates 3V regulation, 12V piezo drive, low-battery analog output, power-good flag, and multi-unit interconnect into one SOIC-16 package-reducing design cycle time and certification effort for life-safety devices.

Availability

RE46C119S16F is available at Aetrix Electronics and suitable for smoke detectors, CO detectors, and personal security alarms requiring stable component supply, long-term lifecycle support, and UL/EN compliance documentation.

Supply support for RE46C119S16F 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

R&E International, acquired by Microchip Technology in 2006, specializes in highly integrated analog and mixed-signal ICs for safety-critical and battery-operated systems.

The RE46C119S16F belongs to Microchip's legacy R&E smoke/CO detector ASIC family, designed specifically to replace discrete power, audio, and monitoring circuits in UL-listed life-safety equipment.

FAQ

What is the maximum continuous output current capability of the RE46C119S16F horn driver outputs?

The RE46C119S16F HORNB and HORNS outputs each support up to 50mA continuous current, with guaranteed performance at −16mA sink/source per output. This rating applies under thermal limits at TA = 85°C and ensures reliable piezoelectric horn actuation without external current boosting. The RE46C119S16F datasheet specifies 50mA as the absolute maximum continuous operating current for either horn output or VPOS.

Does the RE46C119S16F require external components to operate its 3V regulator and 12V boost converter?

Yes, the RE46C119S16F requires external capacitors: a minimum 10µF low-ESR capacitor between VREG and VSS for LDO stability, and two external ceramic capacitors - 1µF between VCAP+ and VCAP−, and ≥10µF between VPOS and VSS - for charge-pump operation and ripple suppression. No external inductors or diodes are needed, as the boost converter uses an integrated switched-capacitor topology.

How does the LBAT output of the RE46C119S16F interface with a microcontroller ADC?

The LBAT output of the RE46C119S16F is a buffered analog voltage proportional to VDD (0.17–0.23×VDD), designed to connect directly to a standard 10-bit or higher MCU ADC input. With a 9V supply, LBAT ranges from ~1.53V to ~2.07V - well within typical 0–3.3V or 0–5V ADC input ranges - eliminating the need for external voltage dividers or op-amps. The RE46C119S16F's LBST pin allows timed sampling to minimize ADC-related power consumption.

Can the RE46C119S16F drive piezoelectric horns in push-pull mode?

Yes, the RE46C119S16F supports true push-pull excitation using its dual horn driver outputs HORNB and HORNS. These outputs deliver complementary rail-to-rail (VPOS-to-VSS) voltage swings, enabling differential drive across the piezoelectric element. This configuration doubles effective voltage swing versus single-ended drive, increasing sound pressure level (SPL) by up to 6dB without increasing supply current - a key advantage confirmed in the RE46C119S16F functional block diagram and application notes.

What is the purpose of the FEED pin on the RE46C119S16F, and what voltage range does it accept?

The FEED pin on the RE46C119S16F serves as the feedback input for the horn driver stage, accepting a wide-range signal (−10V to +22V) to monitor piezoelectric transducer impedance and ensure stable drive under varying acoustic loads. Unlike standard logic inputs, FEED is designed for direct connection to the horn element itself, enabling closed-loop amplitude control and fault detection. Its extended voltage tolerance prevents damage during piezo ringing or ESD events, as specified in the RE46C119S16F Absolute Maximum Ratings table.