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Vishay Semiconductor Opto Division LH1520AB
- Part No.:
- LH1520AB
- Manufacturer:
- Vishay Semiconductor Opto Division
- Category:
- Solid State Relays (SSR)
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LH1520AB.pdf
- Description:
- SSR RELAY SPST-NO 110MA 0-350V
- Quantity:
- Payment:
- Shipping:
Inventory:633
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Product details
Overview
LH1520AB from Vishay Semiconductors is a dual-channel, 1 Form A solid-state relay (SSR) with optically isolated MOSFET outputs, designed to replace electromechanical relays in telecom and industrial control systems. It features 5300 VRMS isolation, 350 V load voltage rating, 140 mA per-channel load current at 25 °C, and typical on-resistance of 22 Ω - enabling clean, bounce-free switching in on/off hook control and ground fault protection circuits.
For engineers reviewing the LH1520AB datasheet, LH1520AB pinout, LH1520AB application, or LH1520AB equivalent, this device delivers verified safety-rated isolation (UL 1577, VDE 0884-5), low-power LED actuation (0.25–2 mA turn-on current), and DIP-8 package compatibility for legacy through-hole designs requiring reliable AC/DC load switching up to 350 V.
Technical Context
The LH1520AB integrates two independent GaAlAs LED input stages coupled to enhancement-mode MOSFET output switches, forming two isolated SPST normally open channels. Its internal architecture provides galvanic separation between input and output sides, with reinforced insulation validated per UL 1577 (5300 VRMS) and DIN EN 60747-5-5 (VIORM = 890 Vpeak).
Switching behavior is defined by LED forward current thresholds: turn-on occurs at IFon = 0.25–2 mA (IL = 100 mA, t = 10 ms), while turn-off requires IFoff ≤ 0.15 mA under ±350 V load conditions. Timing performance includes typ. ton = 0.13 ms and toff = 0.05 ms at IF = 5 mA and IL = 50 mA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Voltage | 5300 VRMS - enables safe operation across mains-referenced telecom and industrial interfaces without additional barrier components. |
| Load Voltage Rating | 350 V - supports direct switching of POTS line voltages, ring signals, and 24–48 V DC control loads. |
| Per-Channel Load Current | 140 mA at 25 °C - sufficient for driving telecom signaling coils, small solenoids, and LED indicators without external buffering. |
| On-Resistance | 22 Ω typical - limits power dissipation to <1 mW at 10 mA load, reducing thermal stress in compact PCB layouts. |
| Turn-On Current | 0.25–2 mA - allows direct drive from low-power microcontrollers or logic gates without current amplification. |
| Off-State Leakage | <1 nA at ±100 V, 6 nA at ±350 V - ensures minimal standby power loss and signal integrity in high-impedance sensing paths. |
| Package Type | DIP-8 - provides mechanical robustness and hand-soldering compatibility for prototyping and low-volume industrial assembly. |
Pinout & Package
DIP-8 package with 0.3″ (7.62 mm) lead pitch, 10.16 mm max body length, and >7 mm creepage/clearance - compliant with Pollution Degree 2 and CTI ≥175 requirements for functional insulation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2 | LED Anode / Cathode (Channel 1) | Optically couples input control signal; requires series resistor to limit IF ≤50 mA. |
| 3, 4 | LED Anode / Cathode (Channel 2) | Independent second channel input; electrically isolated from Channel 1 inputs. |
| 5, 6 | Output Drain / Source (Channel 1) | MOSFET switch terminals; bidirectional blocking up to ±350 V with RON = 22 Ω. |
| 7, 8 | Output Drain / Source (Channel 2) | Second isolated output path; shares no internal conduction path with Channel 1 outputs. |
Key Features
| Feature | Design Value |
|---|---|
| Dual independent SSR channels | Enables compact replacement of two discrete electromechanical relays in space-constrained telecom interface cards. |
| 5300 VRMS isolation rating | Meets UL 1577 and VDE 0884-5 safety standards - eliminates need for external isolation barriers in Class I equipment. |
| Clean bounce-free switching | Zero contact arcing or mechanical wear - critical for dial pulse generation and ground start timing accuracy. |
| Low 0.25 mA turn-on threshold | Reduces MCU GPIO current burden and enables direct interfacing with 3.3 V logic without level-shifting. |
| 1 pF input-to-output capacitance | Minimizes high-frequency noise coupling between control and load domains - essential for EMI-sensitive instrumentation. |
Applications
| Telecom On/Off Hook Control | Ring Delay Circuitry |
|---|---|
Use Scenario: Managing line seizure and release in analog telephone interface modules. IC Role / Device Role / Timing Role: Solid-state relay providing galvanically isolated SPST switching of tip/ring lines. Use Value: Eliminates mechanical relay chatter and contact oxidation, ensuring consistent loop closure timing over 1M+ operations. |
Use Scenario: Introducing precise delay between ring detection and call setup in PBX gateways. IC Role / Device Role / Timing Role: Isolated timing switch controlling capacitor discharge path in RC delay networks. Use Value: Sub-millisecond turn-on consistency (0.13 ms typ.) enables repeatable 20–500 ms delays without calibration drift. |
| Dial Pulse Generation | Ground Fault Protection Monitoring |
Use Scenario: Generating standardized 10-pulse-per-second sequences for rotary-dial legacy systems. IC Role / Device Role / Timing Role: High-speed load switch toggling tip/ring continuity with zero contact bounce. Use Value: Maintains pulse width fidelity (±1 ms) across temperature (-40 to +85 °C) due to stable MOSFET RON and timing. |
Use Scenario: Detecting and isolating earth leakage paths in industrial control cabinets. IC Role / Device Role / Timing Role: Isolated switch enabling safe injection of test current into grounded chassis during self-test. Use Value: 5300 VRMS isolation prevents fault propagation to controller side while supporting 350 V test voltage compliance. |
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 LH1520AAC | SMD-8 package; same electrical specs but surface-mount footprint. | Required for automated PCB assembly; unsuitable for through-hole prototyping or repair. | Select LH1520AAC when board space is constrained and reflow capability exists. |
| IXYS CPC1976Y | Single-channel SSR; 400 V load rating; 120 mA current; 0.5 pF CIO. | Lacks dual-channel integration - requires two devices for equivalent functionality. | Choose CPC1976Y only if higher voltage margin (400 V) is mandatory and board area permits duplication. |
Compared with LH1520AB, LH1520AAC offers identical performance in a surface-mount format ideal for volume production, while CPC1976Y trades channel count for slightly higher voltage rating - making LH1520AB the optimal choice for dual-channel, through-hole telecom interface designs requiring safety-certified isolation and minimal layout change.
Availability
LH1520AB is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control panels, and instrumentation systems requiring stable component supply with long-term lifecycle support and traceable sourcing.
Supply support for LH1520AB 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, optoelectronics, and passive devices with emphasis on reliability, precision, and safety certification.
The LH1520AB belongs to Vishay's LH15xx dual SSR family, engineered specifically for telecom switching applications where galvanic isolation, low drive power, and mechanical relay replacement are primary design goals.
FAQ
What is the maximum ambient temperature for continuous operation of the LH1520AB?
The LH1520AB supports continuous operation from -40 °C to +85 °C ambient temperature. At +85 °C, its per-channel load current derates to 100 mA (dual-channel mode) or 140 mA (single-channel mode), and output safety power remains within 600 mW limits per the PSO vs. Tamb curve in the datasheet.
Does the LH1520AB support AC load switching?
Yes, the LH1520AB supports both AC and DC load switching up to 350 V peak. Its MOSFET output stage is bidirectional and rated for ±350 V, making it suitable for POTS ring signal AC switching, 24 VAC control circuits, and other bipolar load applications without polarity constraints.
What is the minimum LED forward current required to turn on the LH1520AB?
The LH1520AB turns on with an LED forward current as low as 0.25 mA (typical) when IL = 100 mA and pulse width = 10 ms. This low threshold enables direct drive from low-power microcontrollers or logic outputs without external transistor buffers.
How does the LH1520AB achieve its 5300 VRMS isolation rating?
The LH1520AB achieves 5300 VRMS isolation via internal reinforced insulation between input LED and output MOSFET die, validated per UL 1577 and DIN EN 60747-5-5. Physical construction includes ≥7 mm creepage/clearance, ≥0.4 mm insulation thickness, and partial discharge testing at 1669 Vpeak during 100% production screening.
Can the LH1520AB replace mechanical relays in dial pulse applications?
Yes, the LH1520AB is explicitly qualified for dial pulse generation per Vishay's application notes. Its bounce-free switching, sub-millisecond timing consistency (ton = 0.13 ms typ.), and stable RON across temperature ensure accurate pulse width and spacing compliance with ITU-T Q.23 and ANSI T1.401 standards.
LH1520AB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay Semiconductor Opto Division
- Series:
- LH1520
- Packaging:
- Tube
- Product Status:
- Active
- Mounting Type:
- Through Hole
- Circuit:
- SPST-NO (1 Form A) x 2
- Output Type:
- AC, DC
- Voltage - Input:
- 1.26VDC
- Voltage - Load:
- 0 V ~ 350 V
- Load Current:
- 110 mA
- On-State Resistance (Max):
- 20 Ohms
- Termination Style:
- PC Pin
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 8-DIP
- Approval Agency:
- BSI, CQC, cUL, DIN, FIMKO, UL
- Grade:
- -
- Qualification:
- -
LH1520AB FAQ
1.How can I place an order for LH1520AB through Aetrix?
Please submit a Request for Quotation (RFQ) for LH1520AB 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 LH1520AB reliable?
The price and inventory of LH1520AB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LH1520AB is usually 5 days.
3.What payment methods are accepted for LH1520AB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LH1520AB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LH1520AB?
LH1520AB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LH1520AB 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 LH1520AB?
For technical support, including LH1520AB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LH1520AB requirements.
6.How does Aetrix verify that LH1520AB is sourced from the original manufacturer or authorized distributors?
All LH1520AB 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 LH1520AB meets industry standards.
7.What is the process for return or replacement of LH1520AB?
All LH1520AB units undergo pre-shipment inspection (PSI). If there is an issue with LH1520AB, 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 LH1520AB part is unused and in its original packaging.
Return procedure for LH1520AB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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