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Vishay Semiconductor Opto Division LH1546AAB
- Part No.:
- LH1546AAB
- Manufacturer:
- Vishay Semiconductor Opto Division
- Category:
- Solid State Relays (SSR)
- Package:
- 6-SMD (0.300", 7.62mm)
- Datasheet:
-
LH1546AAB.pdf
- Description:
- SSR RELAY SPST-NO 120MA 0-350V
- Quantity:
- Payment:
- Shipping:
Inventory:3,672
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Product details
Overview
LH1546AAB from Vishay Semiconductors is a 1-Form-A solid-state relay (SSR) with GaAlAs LED input and dual-MOSFET output, delivering 350 V load voltage, 120 mA AC/DC load current, and 22 Ω typical on-resistance for telecom switching and ground fault isolation applications.
For engineers reviewing the LH1546AAB datasheet, LH1546AAB pinout, LH1546AAB application, or LH1546AAB equivalent, this SSR provides certified 5300 VRMS isolation, bounce-free switching, and SMD-6 packaging optimized for space-constrained industrial control and instrumentation designs.
Technical Context
The LH1546AAB integrates an infrared LED optically coupled to back-to-back MOSFETs, enabling zero-crossing–free AC/DC switching with <1 ms turn-on/turn-off times. Its dual-MOSFET output structure supports bidirectional load conduction without external snubbers.
Designed per IEC 60747-5-5, it achieves 890 Vpeak repetitive peak isolation voltage (VIORM) and 8000 Vpeak transient isolation voltage (VIOTM), with ≥7 mm creepage/clearance and 0.4 mm minimum insulation thickness for reinforced safety insulation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Voltage | 5300 VRMS - enables UL/cUL/VDE/BSI/FIMKO safety certification for mains-connected telecom and industrial equipment |
| Load Voltage | 350 V - supports direct switching of 240 VAC line-powered loads without external voltage clamping |
| Load Current | 120 mA (AC/DC) - sufficient for driving telecom signal relays, PLC I/O modules, and sensor interface circuits |
| On-Resistance | 22 Ω typical - limits power dissipation to ≤550 mW at full load, enabling operation up to +85 °C ambient |
| Turn-On Time | 0.13 ms typical - ensures fast response in ground fault detection and real-time protection circuits |
| Off-State Leakage | <1 nA at ±100 V - guarantees high-impedance isolation critical for precision instrumentation front-ends |
| Input Forward Voltage | 1.4 V typical at 10 mA - compatible with 3.3 V and 5 V microcontroller GPIO without series resistor recalibration |
Pinout & Package
SMD-6 surface-mount package (7.62 mm pitch, 9.80 × 6.65 mm footprint) with gull-wing leads; RoHS-compliant, MSL Level 1, lead-free reflow compatible.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Anode) | LED Anode Input | Connects to MCU GPIO or driver IC; requires current-limiting resistor for 5–50 mA forward bias |
| 2 (Cathode) | LED Cathode Input | Ground reference for optocoupler input side; defines common return path for control logic |
| 3 (Load –) | Output Terminal (AC/DC) | One side of bidirectional MOSFET switch; connects to load return or negative rail in DC-only config |
| 4 (NC) | No Connect | Internally unconnected; must remain floating-no PCB trace or component attachment permitted |
| 5 (Load +) | Output Terminal (AC/DC) | Other side of bidirectional MOSFET switch; connects to load supply or hot line in AC/DC configuration |
| 6 (Load ±) | Dual-Polarity Output Terminal | Shared terminal for AC load connection or positive rail in DC-only mode; determines configuration topology |
Key Features
| Feature | Design Value |
|---|---|
| Clean bounce-free switching | Eliminates contact arcing and EMI spikes in telecom line card switching and test equipment sequencing |
| 5300 VRMS isolation rating | Meets reinforced insulation requirements for Class I and Class II equipment per UL 1577 and EN 60747-5-5 |
| Low 0.3 mA typical turn-on IF | Reduces drive circuit power consumption by >80% vs. legacy opto-SSRs, extending battery life in portable diagnostics |
| 39 pF output capacitance at 1 V | Minimizes signal distortion in high-frequency analog multiplexing and RF test switch matrices |
| 175 °C safety temperature rating | Supports long-term reliability in enclosed industrial enclosures with limited airflow and elevated ambient temps |
Applications
| Telecom Line Card Switching | Industrial PLC I/O Modules |
|---|---|
|
Use Scenario: Isolating and routing POTS line signals in carrier-grade DSLAMs and VoIP gateways. IC Role / Device Role / Timing Role: Solid-state relay providing galvanic isolation between subscriber line interface circuitry (SLIC) and central office signaling. Use Value: 350 V load voltage withstands lightning-induced surges; 5300 VRMS isolation prevents cross-talk between line cards during fault conditions. |
Use Scenario: Controlling 24 VDC solenoid valves and indicator lamps in factory automation panels. IC Role / Device Role / Timing Role: Output-stage SSR replacing electromechanical relays in DIN-rail mounted PLC digital output modules. Use Value: 120 mA load current drives standard industrial loads; bounce-free switching eliminates spurious actuation in safety-critical sequences. |
| Ground Fault Detection Circuits | Precision Instrumentation Multiplexers |
|
Use Scenario: Isolating sense lines in residual-current circuit breakers (RCCBs) and earth leakage monitors. IC Role / Device Role / Timing Role: High-isolation switch enabling safe sampling of grounded fault currents without compromising system ground integrity. Use Value: <1 nA off-state leakage preserves measurement accuracy; 890 Vpeak VIORM ensures immunity to transient ground potential shifts. |
Use Scenario: Channel selection in 16-channel medical ECG front-ends and automated test equipment (ATE) signal routing. IC Role / Device Role / Timing Role: Low-capacitance, low-leakage analog switch isolating high-impedance sensor inputs from multiplexer bus. Use Value: 39 pF output capacitance minimizes settling time; 22 Ω RON maintains signal fidelity across 0–10 kHz biomedical bandwidth. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar solid-state relay applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Vishay VO3120 | Higher 600 VRMS isolation; 150 mA load current; DIP-6 only; no SMD-6 option | Better suited for higher-voltage industrial motor controls; not drop-in for SMD layouts requiring LH1546AAB's 7.62 mm pitch | Select VO3120 when >5300 VRMS isolation or >120 mA load current is required and through-hole assembly is acceptable |
| IXYS CPC1976Y | Lower 4000 VRMS isolation; 100 mA load current; 35 Ω typical RON; same SMD-6 footprint | Adequate for non-safety-critical lab equipment; insufficient for UL-certified telecom infrastructure | Choose CPC1976Y only for cost-sensitive, non-certified applications where 5300 VRMS and 120 mA are not mandatory |
Compared with VO3120 and CPC1976Y, the LH1546AAB uniquely balances 5300 VRMS safety certification, SMD-6 manufacturability, and 120 mA load capability-making it the optimal choice for certified telecom and industrial control designs requiring surface-mount reliability and regulatory compliance.
Availability
LH1546AAB is available at Aetrix Electronics and suitable for telecom line card switching, industrial PLC I/O modules, ground fault detection circuits, and precision instrumentation multiplexers requiring stable component supply across extended product lifecycles.
Supply support for LH1546AAB 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
Vishay Intertechnology is a global semiconductor manufacturer specializing in discrete components, sensors, and optoelectronics with emphasis on reliability, power efficiency, and safety certification.
The LH1546AAB belongs to Vishay's LH-series solid-state relay family, engineered specifically for high-isolation, low-power telecom and industrial control applications demanding long-term stability and regulatory compliance.
FAQ
What is the maximum continuous load current rating for the LH1546AAB in AC/DC configuration?
The LH1546AAB supports a maximum continuous load current of 120 mA in AC/DC configuration, verified per IEC 60747-5-5 testing at Tamb = 25 °C. Derating applies above 25 °C ambient, with 100 mA allowable at +70 °C and 80 mA at +85 °C per Figure 5 in the official datasheet.
Does the LH1546AAB require external zero-crossing circuitry for AC load switching?
No, the LH1546AAB does not require external zero-crossing circuitry because its dual-MOSFET output architecture inherently supports random-phase switching. It operates reliably across full AC cycles without synchronization, making it suitable for both phase-control and instantaneous switching applications.
Can the LH1546AAB be used in DC-only configurations, and what is its on-resistance in that mode?
Yes, the LH1546AAB supports DC-only configuration with a typical on-resistance of 5.2 Ω (max 10 Ω) at IF = 5 mA and IL = 100 mA. In this mode, pin 6 serves as the positive load terminal, and pins 3 and 5 form the load path-enabling lower conduction loss than AC/DC mode.
What safety certifications does the LH1546AAB hold, and which standards do they cover?
The LH1546AAB holds UL, cUL, VDE, BSI, and FIMKO certifications covering reinforced insulation per UL 1577 (5300 VRMS), EN 60747-5-5 (VIORM = 890 Vpeak), and IEC 60664-1 (CTI = 175, pollution degree 2). These enable use in Class I and Class II equipment without additional barrier design.
Is the LH1546AAB pin-compatible with the LH1546AT, and what is the key mechanical difference?
Yes, the LH1546AAB and LH1546AT share identical pinout and electrical specifications, but differ mechanically: LH1546AAB is SMD-6 packaged (gull-wing, tape-and-reel), while LH1546AT is DIP-6 (through-hole, tube). Both use 7.62 mm lead pitch and match in footprint height and thermal pad layout per Figures 12 and 16.
LH1546AAB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay Semiconductor Opto Division
- Series:
- LH1546
- Packaging:
- Tube
- Product Status:
- Obsolete
- Mounting Type:
- Surface Mount
- Circuit:
- SPST-NO (1 Form A)
- Output Type:
- AC, DC
- Voltage - Input:
- 1.26VDC
- Voltage - Load:
- 0 V ~ 350 V
- Load Current:
- 120 mA
- On-State Resistance (Max):
- 28 Ohms
- Termination Style:
- Gull Wing
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 6-SMD
- Approval Agency:
- BSI, cUL, FIMKO, UL, VDE
- Grade:
- -
- Qualification:
- -
LH1546AAB FAQ
1.How can I place an order for LH1546AAB through Aetrix?
Please submit a Request for Quotation (RFQ) for LH1546AAB 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 LH1546AAB reliable?
The price and inventory of LH1546AAB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LH1546AAB is usually 5 days.
3.What payment methods are accepted for LH1546AAB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LH1546AAB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LH1546AAB?
LH1546AAB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LH1546AAB 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 LH1546AAB?
For technical support, including LH1546AAB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LH1546AAB requirements.
6.How does Aetrix verify that LH1546AAB is sourced from the original manufacturer or authorized distributors?
All LH1546AAB 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 LH1546AAB meets industry standards.
7.What is the process for return or replacement of LH1546AAB?
All LH1546AAB units undergo pre-shipment inspection (PSI). If there is an issue with LH1546AAB, 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 LH1546AAB part is unused and in its original packaging.
Return procedure for LH1546AAB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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