Microchip Technology RE46C141S16F

Overview

RE46C141S16F from R&E International (a Microchip Technology subsidiary) is a CMOS photoelectric smoke detector ASIC with integrated interconnect functionality, 4 µA standby current at 9 V, temporal horn pattern compliance with NFPA 72, and UL 217/UL 268 recognition. It integrates gain-selectable photoamplifier, strobed detection circuitry, low-battery/chamber integrity self-test, and bidirectional IO for up to 40-unit interconnection - deployed in residential and commercial hardwired smoke alarms.

For engineers reviewing the RE46C141S16F datasheet, RE46C141S16F pinout, RE46C141S16F application, or RE46C141S16F equivalent, key selection considerations include its 16-pin SOIC-W package, 8.1 s nominal strobe period, VDD=6–12 V operating range, UL-recognized smoke detection architecture, and interconnect timing behavior under local vs. remote alarm conditions.

Technical Context

The RE46C141S16F implements a dual-gain photoamplifier architecture: C2 sets normal standby gain (e.g., for ambient smoke sampling every 8.1 s), while C1 enables high-gain push-button chamber testing. Its internal oscillator drives synchronized IRED pulsing (100 µs width), STROBE activation, and LED timing - all gated to minimize quiescent current.

Detection logic uses three consecutive valid smoke samples to trigger local alarm; battery and chamber tests occur every 32 s using dedicated voltage reference and high-gain path. The bidirectional IO pin supports active pull-up during local alarm and filtered input detection (450 ms digital filter) for remote alarm signaling across mixed-sensor networks.

Key Specifications

Pinout & Package

RE46C141S16F is housed in a 16-lead Wide SOIC (SOIC-W) package with 1.27 mm pitch, RoHS-compliant lead finish, and thermal pad-compatible footprint per Microchip DS22177B.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar photoelectric smoke detection applications.

Compared with MC145012P and RE46C161S16F, the RE46C141S16F uniquely balances UL 217/268 compliance, 4 µA ultra-low standby, and integrated interconnect in a mature, production-proven 16L W SOIC package - making it optimal for cost-sensitive, high-volume residential alarm platforms requiring certification continuity.

Availability

RE46C141S16F is available at Aetrix Electronics and suitable for residential fire alarm systems, commercial building life-safety networks, and portable battery-powered smoke detectors requiring stable component supply, long-term lifecycle assurance, and UL-recognized performance.

Supply support for RE46C141S16F 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 is a wholly owned subsidiary of Microchip Technology Inc., specializing in safety-critical analog ASICs for fire and life-safety applications since acquisition in 2007.

The RE46C141S16F belongs to R&E's photoelectric smoke detector ASIC product line, engineered specifically to replace discrete analog front-ends in UL-certified smoke alarms while minimizing external components and validation effort.

FAQ

What is the operating voltage range for the RE46C141S16F?

The RE46C141S16F operates over a supply voltage range of 6 V to 12 V DC, supporting both standard 9 V alkaline batteries and hardwired 12 V systems. Its internal regulators maintain stable biasing across this range, and the low-battery alarm threshold is programmable between 6.9 V and 7.5 V using external resistors R14 and R15. This ensures reliable operation across battery discharge curves and varying line voltages without external LDOs.

How does the RE46C141S16F implement interconnect functionality?

The RE46C141S16F implements interconnect via its bidirectional IO pin, which actively drives high during local alarm to trigger connected units, and monitors for remote alarm signals with a 450 ms digital filter to reject noise. It supports up to 40 detectors on a single bus, includes a 1 s charge-dump discharge after local alarm to clear line capacitance, and tolerates supply mismatches between interconnected units - all without requiring external transceivers or level shifters.

What self-test capabilities does the RE46C141S16F provide?

The RE46C141S16F performs two autonomous self-tests every 32 seconds in standby: a low-battery check comparing VDD against an internal reference (triggering 7.9 ms chirps if below 6.9–7.5 V), and a chamber integrity test using the C1 high-gain path to detect background reflections. Both tests are disabled during alarm states, and failure of either causes distinct chirp patterns timed 16.2 s apart to aid field diagnostics.

Is the RE46C141S16F compatible with existing MC145012-based designs?

Yes, the RE46C141S16F is pin-compatible and functionally backward-compatible with the Motorola MC145012, sharing identical pinout, basic detection architecture, and LED/horn timing. However, the RE46C141S16F adds interconnect capability, temporal horn pattern generation, lower standby current (4 µA vs. 15 µA), and UL 268 recognition - enabling drop-in upgrades that enhance system-level functionality without PCB changes.

What packaging options are available for the RE46C141S16F?

The RE46C141S16F is offered in a 16-lead Wide SOIC (SOIC-W) package with 1.27 mm lead pitch, RoHS-compliant matte tin plating, and moisture sensitivity level (MSL) 3. This package provides improved thermal dissipation and creepage distance versus standard SOIC, critical for safety-certified smoke detector assemblies. Tape-and-reel and tube packaging options are available for automated assembly and manual prototyping.