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Microchip Technology RE46C140SW16F
- Part No.:
- RE46C140SW16F
- Manufacturer:
- Microchip Technology
- Category:
- Sensor and Detector Interfaces
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
RE46C140SW16F.pdf
- Description:
- IC SMOKE DETECTOR CMOS 16-SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,643
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Product details
Overview
RE46C140SW16F from R&E International (a Microchip Technology subsidiary) is a CMOS photoelectric smoke detector ASIC with integrated interconnect, temporal horn pattern generation, and 10-minute timer mode for sensitivity control. It delivers ultra-low standby current (4 µA typical at 9 V), supports UL217/UL268 compliance, and drives infrared emitter/detector pairs and piezoelectric horns in residential and commercial life-safety systems.
For engineers reviewing the RE46C140SW16F datasheet, RE46C140SW16F pinout, RE46C140SW16F application, or RE46C140SW16F equivalent, this page provides verified functional roles, timing-critical parameters (e.g., 10.5 ms STROBE pulse, 43 s LED period, 10 min timer), UL-recognized test logic, and interconnect behavior across up to 40 units - all essential for smoke alarm BOM validation and regulatory design-in.
Technical Context
The RE46C140SW16F implements a dual-gain photoamplifier (C1 for high-gain push-button test, C2 for normal sensitivity), strobed detection architecture (100 µs IRED pulse every 10 s in standby), and autonomous chamber integrity/battery voltage checks every 43 s. Its internal oscillator sets STROBE, IRED, and LED timing via external ROSC/COSC components.
It features bidirectional interconnect (IO pin with 670 ms digital filter, constant-current drive, and 1 s charge dump), temporal horn output (HB/HS complementary drive per NFPA 72), and timer-mode reconfiguration of smoke comparator reference via VSEN. All logic operates within -25°C to +75°C and 6–12 V supply range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage | 6–12 V - Supports standard alkaline/carbon battery operation with no external regulator required. |
| Standby Current | 4 µA typical at 9 V - Enables >5 years battery life in 9 V-powered smoke alarms. |
| STROBE Pulse Width | 9.4–11.5 ms - Regulated VDD−5 V output enabling precise photoamplifier power gating. |
| IRED On Time | 94–115 µs - Short, controlled IR emitter drive minimizes power and thermal drift. |
| LED Period (Standby) | 39–47 s - Visual status indication synchronized with chamber/battery self-tests. |
| Horn Temporal Pattern | NFPA 72-compliant - HB/HS outputs generate standardized 500 ms on / 1.5 s off evacuation signal. |
| Timer Mode Duration | 8–12 min - Configurable 10-minute reduced-sensitivity window via TEST/VSEN interface. |
| Interconnect Capacity | Up to 40 detectors - IO pin supports wired daisy-chain with built-in noise immunity and charge dump. |
Pinout & Package
RE46C140SW16F is packaged in 16-lead SOIC (Wide, 0.300" body width), RoHS-compliant, with 1.27 mm pitch and exposed pad not present.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 C1 | High-gain photoamp capacitor input | Sets gain ≥1000 for push-button test using background reflection amplification. |
| 2 C2 | Normal-gain photoamp capacitor input | Sets baseline smoke sensitivity; gain ~10× lower than C1 for stable standby operation. |
| 3 DETECT | Photo diode cathode input | Zero-bias connection point for photodiode; referenced to STROBE during sampling. |
| 4 STROBE | Regulated photoamp power gate | Outputs VDD−5 V only during 10 ms detection windows - critical for quiescent current control. |
| 5 VDD | Positive supply rail | Accepts 6–12 V battery input; powers all internal blocks except IRED/LED/horn drivers. |
| 6 IRED | Infrared emitter pre-driver | Provides pulsed base drive for NPN transistor controlling IR LED; 100 µS width. |
| 7 IO | Bidirectional interconnect node | Drives high during local alarm; senses remote alarm pulses with 670 ms digital filter. |
| 8 HB | Piezo transducer metal electrode | Active-high horn output; paired with HS to generate differential acoustic drive. |
| 9 HS | Piezo transducer ceramic electrode | Complementary output to HB; enables efficient piezo sound pressure generation. |
| 10 FEED | Feedback electrode interface | Connects to chamber feedback electrode; unused pins must tie to VDD or VSS. |
| 11 LED | Open-drain visible indicator | Drives external LED with 10 ms on-time; frequency changes during alarm/test modes. |
| 12 COSC | Oscillator low-time timing node | With parallel resistor, sets ~10 ms clock period; production-tested parameter. |
| 13 ROSC | Oscillator high-time timing node | Resistor to COSC sets IRED pulse width and clock high time (100–200 µs). |
| 14 VSS | Negative supply rail | Ground reference for all analog and digital circuitry; requires low-impedance connection. |
| 15 VSEN | External comparator reference input | Overrides internal VDD−3.5 V reference during timer mode to adjust smoke threshold. |
| 16 TEST | Mode selection and test trigger | Pull-down input; high-level initiates push-test; H→L transition enables 10-min timer. |
Key Features
| Feature | Design Value |
|---|---|
| UL Recognition | Recognized per UL File S24036 for UL217 and UL268 compliance - eliminates need for third-party certification testing. |
| Temporal Horn Pattern | Hardware-generated NFPA 72 emergency signal on HB/HS pins - no firmware or external timing components required. |
| Chamber Integrity Test | Automated high-gain (C1) background reflection check every 43 s - detects dust, insect intrusion, or optical path obstruction. |
| Low Battery Detection | Internal voltage divider + comparator triggers 10 ms chirp every 43 s when VDD drops below 7.2 V - field-replaceable battery warning. |
| Interconnect Charge Dump | 1 s NMOS discharge on IO after local alarm - clears line capacitance to prevent false remote alarms in multi-unit installations. |
| Diagnostic Mode | TEST pin pulled below VSS enables calibration mode - reassigns IO/VSEN/FEED for gain verification and low-battery monitoring. |
Applications
| Residential Smoke Alarms | Commercial Ceiling-Mounted Detectors |
|---|---|
|
Use Scenario: Battery-powered ceiling-mounted unit in apartments or dormitories requiring UL217 listing and 10-year operational life. IC Role / Device Role / Timing Role: Central smoke sensing ASIC managing photoamplifier gain, IRED pulsing, horn activation, and interconnect signaling. Use Value: 4 µA standby current extends 9 V battery life beyond 5 years; integrated temporal pattern meets NFPA 72 without microcontroller. |
Use Scenario: Hardwired commercial detector with backup battery, installed in office buildings with centralized alarm panels. IC Role / Device Role / Timing Role: Standalone smoke sensing engine with IO-driven interconnect enabling up to 40-unit synchronization. Use Value: Built-in 670 ms IO filter rejects EMI from HVAC or lighting systems; charge dump prevents false triggering over long wire runs. |
| Hotel Room Interconnected Alarms | Temporary Construction Site Alarms |
|
Use Scenario: UL-listed interconnected alarms across multiple hotel rooms, where one alarm triggers all units. IC Role / Device Role / Timing Role: Interconnect master/slave node using bidirectional IO pin with automatic remote alarm detection and horn activation. Use Value: Supports daisy-chained wiring up to 40 units; TIODLY2 delay (1.05–2.0 s) ensures reliable propagation without race conditions. |
Use Scenario: Portable, battery-operated smoke detector used on construction sites with frequent relocation and dust exposure. IC Role / Device Role / Timing Role: Self-diagnosing sensor with automated chamber test every 43 s and low-battery chirp independent of alarm state. Use Value: High-gain C1-based chamber test detects optical path blockage from sawdust or debris; timer mode allows temporary desensitization during welding. |
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 |
|---|---|---|---|
| Allegro A5366 | Pin-compatible but lacks timer mode and VSEN-based sensitivity adjustment; no diagnostic mode. | Supports basic interconnect and temporal horn, but cannot implement scheduled reduced-sensitivity periods. | Choose A5366 only if timer functionality and field-adjustable thresholds are unnecessary. |
| RE46C120 | Same family, no interconnect (IO pin absent); no VSEN input; fixed 43 s LED period only. | Limited to standalone units; no multi-detector coordination or external reference override capability. | Select RE46C120 for cost-sensitive single-unit designs where interconnect and timer features are omitted. |
Compared with RE46C140SW16F, the A5366 offers identical core detection but omits programmable sensitivity control, while the RE46C120 removes interconnect entirely - making RE46C140SW16F the only option supporting UL217-compliant interconnected systems with field-configurable response thresholds.
Availability
RE46C140SW16F is available at Aetrix Electronics and suitable for residential fire alarm systems, commercial building safety networks, and temporary site hazard detection requiring stable component supply, UL recognition, and long-term lifecycle support.
Supply support for RE46C140SW16F 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 life-safety ICs for smoke and carbon monoxide detection since acquisition in 2007.
The RE46C140SW16F belongs to R&E's photoelectric smoke detector ASIC product line, engineered specifically for battery-operated, UL217/UL268-certified alarms with minimal external components and autonomous self-test capability.
FAQ
What is the operating temperature range for the RE46C140SW16F?
The RE46C140SW16F is specified to operate from −25°C to +75°C ambient temperature. This range covers indoor residential and commercial environments where smoke detectors are typically installed, including attics and garages subject to seasonal extremes. The device's internal temperature compensation (e.g., ±0.01%/°C STROBE line regulation) maintains timing accuracy across this full range without external calibration.
How does the RE46C140SW16F perform chamber integrity testing?
The RE46C140SW16F performs chamber integrity testing every 43 seconds by switching to high-gain mode (using capacitor C1) and measuring background reflections from the optical chamber. Two consecutive failures trigger a 10 ms horn chirp every 43 seconds. This test occurs independently of alarm states and uses the same DETECT/STROBE/IRED signal chain as smoke detection - ensuring optical path obstructions are caught before compromising safety.
Can the RE46C140SW16F be used without an external microcontroller?
Yes, the RE46C140SW16F is a fully autonomous ASIC requiring no microcontroller. All functions - including photoamplifier gain control, IRED pulsing, smoke decision logic, temporal horn generation, interconnect signaling, battery monitoring, and chamber testing - are implemented in hardware. External components are limited to passive RC timing elements, LEDs, piezo transducers, and IR emitters/detectors.
What is the purpose of the VSEN pin on the RE46C140SW16F?
The VSEN pin (Pin 15) serves as an external reference input for the smoke comparator during timer mode. When enabled via TEST pin transition, the internal VDD−3.5 V reference is replaced by the voltage applied to VSEN - allowing field-adjustable smoke sensitivity for temporary conditions (e.g., construction dust). If left unconnected or tied to VSS, timer mode is disabled, preserving default UL-certified thresholds.
Does the RE46C140SW16F support RoHS-compliant manufacturing?
Yes, the RE46C140SW16F is available in RoHS-compliant, lead-free packaging per Microchip's DS22179B specification. The "W" in SW16F denotes wide-body SOIC with Pb-free finish, qualified to JEDEC J-STD-020 moisture sensitivity level 3 and compatible with standard reflow profiles. Full RoHS documentation and material declarations are available through Microchip's component database.
RE46C140SW16F Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Series:
- -
- Packaging:
- Tube
- 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
RE46C140SW16F FAQ
1.How can I place an order for RE46C140SW16F through Aetrix?
Please submit a Request for Quotation (RFQ) for RE46C140SW16F 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 RE46C140SW16F reliable?
The price and inventory of RE46C140SW16F are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for RE46C140SW16F is usually 5 days.
3.What payment methods are accepted for RE46C140SW16F?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for RE46C140SW16F transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for RE46C140SW16F?
RE46C140SW16F orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your RE46C140SW16F 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 RE46C140SW16F?
For technical support, including RE46C140SW16F datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your RE46C140SW16F requirements.
6.How does Aetrix verify that RE46C140SW16F is sourced from the original manufacturer or authorized distributors?
All RE46C140SW16F 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 RE46C140SW16F meets industry standards.
7.What is the process for return or replacement of RE46C140SW16F?
All RE46C140SW16F units undergo pre-shipment inspection (PSI). If there is an issue with RE46C140SW16F, 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 RE46C140SW16F part is unused and in its original packaging.
Return procedure for RE46C140SW16F:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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