Microchip Technology RE46C190S16TF

Overview

RE46C190S16TF from Microchip Technology is a low-power, low-voltage CMOS photoelectric smoke detector ASIC with integrated IRED driver, programmable gain photo amplifier, 9-minute hush timer, NFPA 72 temporal horn pattern support, and interconnect capability for up to 40 detectors. It operates from two AA batteries, features internal power-on reset, 2% low-battery detection set point, and supports UL217/UL268 compliance in standalone or interconnected systems.

For engineers reviewing the RE46C190S16TF datasheet, RE46C190S16TF pinout, RE46C190S16TF application, or RE46C190S16TF equivalent, this device serves as a complete system-on-chip solution for battery-powered photoelectric smoke alarms - requiring no external oscillator, minimal passive components, and supporting critical safety functions including chamber integrity test, local alarm memory, and end-of-life indication.

Technical Context

The RE46C190S16TF integrates a gain-selectable photo amplifier with four user-programmable integration limits (Normal/Hysteresis, Hush, Chamber Test), programmable IRED drive current (50–200 mA), and adjustable IRED pulse width (100–400 µs). Its internal trimmed oscillator triggers smoke sampling every 10 seconds in standby, increasing frequency upon detection to confirm alarm conditions.

Supervisory functions include low-battery checks every 86 s (with loaded/unloaded sampling) and chamber integrity tests every 43 s using high-gain mode. The bidirectional IO pin enables interconnect signaling with 336 ms digital filtering, charge-dump discharge (1.31 s), and voltage-tolerant input protection for mixed-alarm-system compatibility.

Key Specifications

Pinout & Package

RE46C190S16TF is housed in a 16-lead narrow SOIC (150 mil) package with θ_JA = 86.1°C/W thermal resistance, optimized for compact PCB layout in battery-powered enclosures.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RE46C190S16TF, the RE46C191S16TF adds long-term drift compensation and wider temperature operation for next-gen certifications, while SM5201-16 omits hush timing, interconnect filtering, and EOL tracking - making RE46C190S16TF the only option supporting full UL217/UL268 dual compliance with field-configurable sensitivity.

Availability

RE46C190S16TF is available at Aetrix Electronics and suitable for residential smoke alarm manufacturing, commercial interconnected fire safety systems, hotel room safety modules, and smart home integration nodes requiring stable component supply and long-lifecycle support.

Supply support for RE46C190S16TF 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

Microchip Technology Inc. is a global semiconductor company specializing in microcontrollers, analog devices, and security ICs, with deep expertise in safety-critical and ultra-low-power applications.

The RE46C190S16TF belongs to Microchip's RE46C family of photoelectric smoke detector ASICs, designed specifically to integrate all analog, timing, and power functions required for UL217/UL268-certified battery-operated smoke alarms - eliminating external oscillators, boost controllers, and discrete horn drivers.

FAQ

What is the primary function of the RE46C190S16TF in a smoke detector system?

The RE46C190S16TF serves as the central analog and timing controller in photoelectric smoke detectors, integrating IRED drive, photo-amplifier signal conditioning, programmable smoke detection thresholds, NFPA 72-compliant horn timing, interconnect signaling, and battery supervision - enabling full UL217/UL268 certification with minimal external components. RE46C190S16TF replaces multiple discrete functions in traditional designs.

How does the RE46C190S16TF support UL217 and UL268 compliance?

The RE46C190S16TF embeds hardwired timing logic for UL-mandated functions: 470–530 ms temporal horn on/off periods, 43 s chamber test intervals, 86 s low-battery checks, and 9-minute hush mode duration. Its programmable IRED current and integration limits allow calibration to meet sensitivity and false-alarm requirements across production units. RE46C190S16TF also supports interconnect signaling per UL268 Annex D.

Can the RE46C190S16TF operate from two AA batteries throughout its service life?

Yes - RE46C190S16TF draws only 1 µA typical in standby mode and uses pulsed IRED operation (100–400 µs every 10 s) to minimize average current. Combined with its 2.1–2.8 V programmable low-battery threshold and 9.6 V internal boost for horn drive, RE46C190S16TF enables >5-year battery life in UL-certified two-AA configurations under defined environmental conditions.

What is the role of the IO pin on the RE46C190S16TF?

The IO pin on RE46C190S16TF is a bidirectional interconnect terminal: during local alarm, it actively drives high-boost voltage to trigger other detectors; when idle, it monitors remote alarm signals with a 336 ms digital filter to reject noise and support mixed-alarm-system compatibility (e.g., CO detectors). RE46C190S16TF's IO pin enables daisy-chained networks of up to 40 units without external transceivers.

Is the RE46C190S16TF still recommended for new designs?

No - Microchip explicitly states "Not Recommended for New Designs" and recommends RE46C191S16TF instead, which adds long-term drift compensation, improved EOL tracking, and extended temperature range. However, RE46C190S16TF remains fully supported for legacy production, repair, and replacement in existing UL-certified products where design change validation is not feasible.