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Microchip Technology RE46C143SW16TF
- Part No.:
- RE46C143SW16TF
- Manufacturer:
- Microchip Technology
- Category:
- Sensor and Detector Interfaces
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
RE46C143SW16TF.pdf
- Description:
- IC SMOKE DETECTOR CMOS 16-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,890
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Product details
Overview
RE46C143SW16TF from R&E International (a Microchip Technology subsidiary) is a CMOS photoelectric smoke detector ASIC with integrated interconnect functionality, low-power standby current (4 µA typical at 9 V), programmable gain photoamplifier (via C1/C2 capacitors), and UL217/UL268 recognition. It drives infrared emitters and piezoelectric horns, performs automatic low-battery and chamber-integrity checks every 40 seconds, and supports daisy-chained alarm propagation across up to 40 units in residential fire safety systems.
For engineers reviewing the RE46C143SW16TF datasheet, RE46C143SW16TF pinout, RE46C143SW16TF application, or RE46C143SW16TF equivalent, key selection considerations include its 16-pin SOIC-W package, 75% duty-cycle horn pattern, interconnect timing delay (0.75–1.65 s), strobe output regulation (VDD − 5 V), and compatibility with Motorola MC145010 in photoelectric detector designs.
Technical Context
The RE46C143SW16TF integrates a dual-gain photoamplifier (normal mode via C2, high-gain test mode via C1), a precision internal oscillator (10.5 ms nominal period), and synchronized 100 µs IRED pulses timed to STROBE activation. Its analog detection path compares photodiode output against an internal reference (VDD − 3.5 V typical) and requires three consecutive valid smoke samples to trigger local alarm.
Interconnect operation uses bidirectional IO pin with 500 ms digital filtering, constant-current drive during local alarm, and 1.46 s charge-dump discharge after alarm termination. Standby current is minimized by powering analog circuitry only once per 10.5 ms cycle, while battery and chamber tests execute every 40 s using dedicated timing windows and gain switching.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 6–12 V - Supports standard 9 V alkaline and carbon-zinc batteries with built-in low-battery detection at ~7.2 V. |
| Standby Current | 4 µA typical at 9 V - Enables >5 years battery life in smoke detectors with periodic 10 ms wake-ups. |
| Oscillator Period | 10.5 ms nominal - Controls smoke sampling interval and synchronizes IRED pulsing and STROBE activation. |
| Horn Duty Cycle | 75% - Delivers loud, attention-grabbing audible alarm with optimized piezoelectric transducer drive efficiency. |
| Interconnect Capacity | Up to 40 detectors - Enables whole-home or multi-room alarm synchronization without external logic. |
| UL Recognition | UL217 & UL268 File S24036 - Certified for use in listed photoelectric smoke alarms meeting North American safety standards. |
| Gain Control | C1/C2 capacitor-selectable - Allows field-tuning of sensitivity for chamber geometry and background reflection compensation. |
Pinout & Package
RE46C143SW16TF is housed in a 16-lead Wide SOIC (SOIC-W) package with 1.27 mm pitch, surface-mount footprint, and RoHS-compliant Pb-free finish.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 C1 | High-gain photoamp capacitor input | Sets gain for push-to-test and chamber integrity check (A = 1 + C1/10 pF); limits max gain to <10,000. |
| 2 C2 | Normal-gain photoamp capacitor input | Sets standby smoke sensitivity (A = 1 + C2/10 pF); enables fine-tuning for target obscuration threshold. |
| 3 DETECT | Photoamplifier non-inverting input | Connects to photodiode cathode at zero bias; accepts low-level current from IR scattering chamber. |
| 4 STROBE | Regulated negative supply rail | Outputs VDD − 5 V during smoke sampling; powers photoamp circuitry and defines common-mode range. |
| 5 VDD | Positive power supply | Accepts 6–12 V DC; powers all internal blocks and provides reference for LBSET and TEST thresholds. |
| 6 IRED | Infrared emitter pre-driver output | Supplies regulated pulsed voltage to NPN transistor base; controls 94–115 µs IRED on-time. |
| 7 IO | Bidirectional interconnect interface | Drives high during local alarm; senses remote alarm pulses with 500 ms digital filter; includes 1.46 s discharge post-alarm. |
| 8 HB | Horn metal-electrode driver | Complementary output to HS; delivers high-voltage AC waveform to piezoelectric transducer for audible alarm. |
| 9 HS | Horn ceramic-electrode driver | Complementary output to HB; forms full bridge drive for maximum sound pressure level (SPL). |
| 10 FEED | Feedback electrode interface | Connects to chamber feedback electrode via current-limiting resistor; enables hysteresis when pulled high in normal mode. |
| 11 LED | Open-drain visible indicator | Drives status LED at 40 s intervals in standby; increases to 0.5 s frequency during local alarm or test. |
| 12 COSC | Oscillator timing capacitor node | With parallel resistor, sets internal clock low time (~10 ms period); connects to external RC network (R9/C5). |
| 13 ROSC | Oscillator timing resistor node | With COSC, sets clock high time and IRED pulse width (100–200 µs); determines detection timing resolution. |
| 14 VSS | Negative power supply | Ground reference for all analog and digital circuitry; must be low-impedance connection to battery negative. |
| 15 LBSET | Low-battery threshold adjust | Configures VDD divider ratio (with R14/R15) to set ~7.2 V alarm threshold; also selects C1/C2 in diagnostic mode. |
| 16 TEST | Push-button test control | Pull high to initiate 330 ms smoke sampling rate and high-gain chamber test; internal pull-down ensures safe default. |
Key Features
| Feature | Design Value |
|---|---|
| Interconnect support | Enables daisy-chaining of up to 40 detectors with automatic alarm propagation and noise-immune 500 ms input filtering. |
| Ultra-low standby current | 4 µA typical at 9 V extends battery life beyond 5 years in 9 V-powered smoke alarms without compromising detection reliability. |
| Dual-gain photoamplifier | Separate C1 (test/chamber) and C2 (standby) capacitor inputs allow independent optimization of sensitivity and false-alarm immunity. |
| Integrated diagnostics | Automated 40 s low-battery and chamber-integrity checks eliminate need for external supervision circuitry or manual testing. |
| UL217/UL268 recognition | Approved under UL File S24036 for use in certified photoelectric smoke detectors-reduces certification effort for end-product OEMs. |
| 75% horn duty cycle | Maximizes acoustic output from piezoelectric transducers while maintaining thermal safety and driver FET reliability. |
Applications
| Residential Smoke Alarms | Multi-Unit Interconnected Systems |
|---|---|
|
Use Scenario: Battery-powered ceiling-mounted smoke detector in single-family homes. IC Role / Device Role / Timing Role: Primary smoke sensing ASIC performing periodic IR scattering analysis, low-battery monitoring, and audible alarm generation. Use Value: 4 µA standby current enables >5-year battery life; UL217 recognition satisfies mandatory listing requirements for residential installations. |
Use Scenario: Interconnected alarm network across apartments or hotel rooms. IC Role / Device Role / Timing Role: Interconnect-capable node that detects local smoke and propagates alarm signal via IO pin to up to 39 other units. Use Value: Eliminates need for separate interconnect wiring or hub controllers; 0.75–1.65 s remote alarm delay ensures reliable signal capture across long cable runs. |
| Chamber Integrity Monitoring | Push-to-Test Functionality |
|
Use Scenario: Preventing nuisance alarms caused by dust accumulation or optical misalignment in detector chambers. IC Role / Device Role / Timing Role: Performs automated chamber self-test every 40 seconds using high-gain C1 configuration and background reflection analysis. Use Value: Detects degraded chamber performance before failure occurs; triggers distinct 10 ms chirp pattern to alert maintenance personnel. |
Use Scenario: End-user verification of detector functionality without generating false alarms. IC Role / Device Role / Timing Role: Enters accelerated 330 ms smoke sampling mode upon TEST pin activation, simulating smoke via amplified background reflections. Use Value: Confirms full signal chain (IRED → chamber → photodiode → amplifier → comparator → horn) operates correctly in <1 second. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar photoelectric smoke detector ASIC applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MC145010P | Legacy Motorola part; no interconnect capability; higher 15 µA standby current; lacks programmable gain and chamber test features. | Requires external interconnect logic and discrete low-battery monitoring; limited to single-unit standalone alarms. | Choose only for legacy redesign where RE46C143SW16TF's interconnect and ultra-low power are not required. |
| RE46C123SW16F | Same family, no interconnect pin (IO pin omitted); identical photoamp, oscillator, and horn architecture; same UL recognition. | Designed for cost-sensitive standalone detectors where multi-unit synchronization is unnecessary. | Select when system-level interconnect is handled externally or not needed; offers identical core detection performance at lower BOM cost. |
Compared with MC145010P and RE46C123SW16F, the RE46C143SW16TF uniquely integrates interconnect signaling, reduces standby current by 73%, and adds automated chamber integrity verification-making it optimal for modern interconnected residential fire alarm systems requiring long battery life and self-diagnostic capability.
Availability
RE46C143SW16TF is available at Aetrix Electronics and suitable for residential fire safety systems, interconnected alarm networks, battery-powered smoke detectors, and UL-certified life-safety equipment requiring stable component supply and long-term lifecycle support.
Supply support for RE46C143SW16TF 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 highly integrated, safety-critical analog and mixed-signal ICs for fire and life safety applications.
The RE46C143SW16TF belongs to R&E's photoelectric smoke detector ASIC product line, engineered specifically to replace discrete analog front-ends with a single UL-recognized chip that simplifies certification, reduces bill-of-materials, and improves reliability in battery-operated alarms.
FAQ
What is the standby current specification for the RE46C143SW16TF?
The RE46C143SW16TF draws 4 µA typical supply current at 9 V in standby mode, measured with COSC tied to VSS and no alarm active. This ultra-low quiescent current enables over five years of operation on a standard 9 V alkaline battery, as confirmed in DS22178B-page 2 DC Electrical Characteristics under IDD1 test condition.
Does the RE46C143SW16TF support interconnection with other smoke detectors?
Yes, the RE46C143SW16TF supports interconnection of up to 40 detectors via its bidirectional IO pin. When one unit enters local alarm, it drives IO high, triggering remote alarm in all connected units after a 0.75–1.65 s delay. The pin includes 500 ms digital filtering to reject noise and supports mixed-signal interconnect (e.g., CO alarms) as documented on DS22178B-page 8.
How does the RE46C143SW16TF perform low-battery and chamber-integrity testing?
The RE46C143SW16TF performs both tests automatically every 40 seconds in standby mode. Low-battery detection compares divided VDD against an internal reference, latching at ~7.2 V. Chamber testing switches to high-gain mode (C1) to analyze background reflections; two consecutive failures trigger a 10 ms horn chirp. Neither test runs during active alarm, per DS22178B-page 8–9.
What is the purpose of the STROBE pin on the RE46C143SW16TF?
The STROBE pin (Pin 4) outputs a regulated voltage of VDD − 5 V during smoke sampling periods. It serves as the negative-side supply rail for the photoamplifier circuitry, establishing precise common-mode voltage and enabling accurate differential measurement of photodiode current. Its activation is synchronized with IRED pulsing and detection window timing, as defined in DS22178B-page 5 PIN DESCRIPTIONS.
Is the RE46C143SW16TF UL-recognized, and for which standards?
Yes, the RE46C143SW16TF is UL-recognized under File S24036 for compliance with UL217 (Standard for Single and Multiple Station Smoke Alarms) and UL268 (Standard for Smoke Detectors). This recognition applies to the device itself and permits its use in end-products seeking UL listing, as stated in the General Description on DS22178B-page 1.
RE46C143SW16TF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Programmable:
- Not Verified
- Type:
- Smoke Detector
- Input Type:
- Photoelectric
- Output Type:
- Voltage
- Current - Supply:
- 8 µA
- Operating Temperature:
- -25°C ~ 75°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
RE46C143SW16TF FAQ
1.How can I place an order for RE46C143SW16TF through Aetrix?
Please submit a Request for Quotation (RFQ) for RE46C143SW16TF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for RE46C143SW16TF reliable?
The price and inventory of RE46C143SW16TF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RE46C143SW16TF is usually 5 days.
3.What payment methods are accepted for RE46C143SW16TF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RE46C143SW16TF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RE46C143SW16TF?
RE46C143SW16TF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RE46C143SW16TF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for RE46C143SW16TF?
For technical support, including RE46C143SW16TF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RE46C143SW16TF requirements.
6.How does Aetrix verify that RE46C143SW16TF is sourced from the original manufacturer or authorized distributors?
All RE46C143SW16TF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that RE46C143SW16TF meets industry standards.
7.What is the process for return or replacement of RE46C143SW16TF?
All RE46C143SW16TF units undergo pre-shipment inspection (PSI). If there is an issue with RE46C143SW16TF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The RE46C143SW16TF part is unused and in its original packaging.
Return procedure for RE46C143SW16TF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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