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Vishay Semiconductor Opto Division LH1529BACTR
- Part No.:
- LH1529BACTR
- Manufacturer:
- Vishay Semiconductor Opto Division
- Category:
- Solid State Relays (SSR)
- Package:
- 8-SMD (0.300", 7.62mm)
- Datasheet:
-
LH1529BACTR.pdf
- Description:
- SSR RELAY SPST-NO 120MA 0-350V
- Quantity:
- Payment:
- Shipping:
Inventory:2,272
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Product details
Overview
LH1529BACTR from Vishay Semiconductors is a telecom switch solid-state relay with integrated bidirectional optocoupler, featuring 5300 VRMS input/output isolation, 350 V load voltage rating, 120 mA continuous load current, and minimum 100 % DC current transfer ratio (CTR), used for on/off hook control and ring detection in legacy telephone line interface circuits.
For engineers reviewing the LH1529BACTR datasheet, LH1529BACTR pinout, LH1529BACTR application, or LH1529BACTR equivalent, key selection criteria include SSR on-resistance (12–25 Ω), CTR ≥100 %, DIP-8 package compatibility, and dual-function integration of switching and current sensing in telecom loop interfaces.
Technical Context
The LH1529BACTR integrates two optically isolated functional blocks: a solid-state relay (SSR) with current-limit protection and clean bounce-free switching, and a bidirectional phototransistor optocoupler for ring/loop current sensing. Both share 5300 VRMS isolation and operate across –40 °C to +85 °C ambient.
Its SSR section delivers typical RON = 20 Ω at ±50 mA load, supports ±350 V peak AC/DC load voltage, and exhibits turn-on/turn-off times of 1.3 ms / 0.6 ms (typ). The optocoupler provides CTR ≥100 % at IF = 6 mA, VCE = 0.5 V, enabling reliable low-current detection in telecom signaling paths.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Isolation Voltage | 5300 VRMS - enables safe galvanic separation between telecom line side and system logic side |
| Load Voltage Rating | ±350 V - supports full-range analog telephony line voltages including ringing (≈90 V RMS) and off-hook transients |
| Continuous Load Current | 120 mA - sufficient for driving standard telephone line interface relays and hybrid circuits |
| On-Resistance (RON) | 12–25 Ω (typ 20 Ω) - ensures low conduction loss and minimal self-heating during sustained hook-switch operation |
| CTR (min) | 100 % - guarantees robust optocoupler output under low LED drive (6 mA), critical for battery-backed or low-power ring detect |
| Turn-on Time | 1.3 ms (typ) - meets telecom dial-pulse timing requirements (≥10 ms pulse width tolerance) |
| Ambient Temp Range | –40 °C to +85 °C - validated for industrial-grade telecom equipment deployment |
Pinout & Package
DIP-8 through-hole package with 2.54 mm lead pitch, 7.62 mm row spacing, and 9.77 mm body length; RoHS-compliant, lead-free finish per Vishay specification.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2 | LED Anode / Cathode | Input side for optocoupler; bidirectional current detection enabled by internal symmetry |
| 3, 4 | SSR Output (+) | High-side SSR output terminals; pins 4 and 6 form ± load path (AC-capable) |
| 5, 6 | SSR Output (–) | Low-side SSR output terminals; paired with pins 3/4 for bipolar load switching |
| 7, 8 | Phototransistor C/E | Optocoupler collector/emitter; open-collector output for ring detection logic interfacing |
Key Features
| Feature | Design Value |
|---|---|
| Solid-state relay + optocoupler integration | Single DIP-8 package replaces discrete SSR + opto pair, reducing board area and interconnect complexity in line card designs |
| Current-limit protected SSR | 210 mA trip threshold (typ) prevents latch-up or thermal runaway during short-circuit or high-surge line events |
| Bidirectional optocoupler | Enables detection of both positive and negative ring signal half-cycles without external polarity reversal circuitry |
| Clean bounce-free switching | Eliminates mechanical contact chatter artifacts in hook-switch transitions, ensuring glitch-free CPU interrupt handling |
| 5300 VRMS isolation | Meets telecom safety standards for primary-to-secondary insulation in POTS line interface applications |
Applications
| On/Off Hook Control | Ring Detection |
|---|---|
Use Scenario: Managing telephone line connection state in analog PBX, VoIP gateway FXS ports, or fax modems. IC Role / Device Role / Timing Role: LH1529BACTR SSR acts as line-connect/disconnect switch; optocoupler monitors loop closure status. Use Value: Enables microcontroller-driven hook supervision with <1.3 ms response and no contact wear, supporting >1 million operations lifetime. | Use Scenario: Detecting incoming call ring signals (20 Hz, 90 V RMS) on POTS lines without transformer coupling. IC Role / Device Role / Timing Role: LH1529BACTR optocoupler provides isolated, bidirectional AC current sensing; SSR remains off during ring. Use Value: Achieves reliable ring detection at ≤5 mA LED drive due to CTR ≥100 %, eliminating need for external amplification. |
| Dial Pulse Switching | Loop Current Sensing |
Use Scenario: Generating rotary-dial pulse trains (3–10 pulses/sec, 10–70 ms on/off) for legacy telephone exchange compatibility. IC Role / Device Role / Timing Role: LH1529BACTR SSR performs fast, bounce-free make/break switching synchronized to MCU timer outputs. Use Value: 0.6 ms turn-off time ensures accurate pulse width fidelity and avoids double-counting in pulse decoders. | Use Scenario: Monitoring DC loop current (20–60 mA) to determine line seizure, busy signal, or fault conditions. IC Role / Device Role / Timing Role: LH1529BACTR optocoupler converts loop current into isolated logic-level signal via CTR-based scaling. Use Value: Supports precise current thresholding down to 1 mA resolution using standard comparator circuits on the phototransistor output. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar telecom switch and ring detection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Vishay LH1529BB | DIP-8 package, same CTR ≥100 %, but higher ILIMIT (210 mA typ) and faster ton/toff (1.3/0.6 ms); no tape-and-reel option | Identical function; preferred where surge immunity and speed are prioritized over cost-sensitive volume procurement | Select LH1529BB if design requires enhanced current-limit margin or tighter timing control in high-noise environments |
| Vishay LH1529BAC | SMD-8 package (same die), identical electrical specs, but surface-mount footprint and different thermal profile | Same telecom functions; used where automated assembly and space-constrained PCBs dictate SMT over through-hole | Choose LH1529BAC when migrating from DIP to SMT production or integrating into compact line-card modules |
Compared with LH1529BACTR, LH1529BB offers improved surge resilience without layout change, while LH1529BAC enables PCB miniaturization at the cost of reflow-compatible thermal management-both retain full functional equivalence for hook/ring/loop tasks.
Availability
LH1529BACTR is available at Aetrix Electronics and suitable for telecom line interface cards, analog PBX systems, and VoIP FXS port designs requiring stable component supply and long-lifecycle support despite EOL status.
Supply support for LH1529BACTR 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 Semiconductors is a global manufacturer of discrete semiconductors and passive components, specializing in high-reliability optoelectronics, power MOSFETs, and precision resistors.
The LH1529 family was developed specifically for analog telephony interface applications, combining SSR switching and optocoupled sensing to replace electromechanical relays and discrete optoisolators in legacy and transitional voice infrastructure.
FAQ
What is the isolation voltage rating of the LH1529BACTR and how is it verified?
The LH1529BACTR has an isolation test voltage of 5300 VRMS for 60 seconds, verified per UL1577 (pending) and FIMKO standards. This rating applies across the entire input-to-output barrier-including between LED/anode-cathode and SSR/optocoupler output sections-and ensures safe operation in telecom line-side applications where high-voltage transients occur. The LH1529BACTR maintains ≥10¹² Ω isolation resistance at 500 V and 25 °C.
Does the LH1529BACTR support bidirectional current detection for ring signal sensing?
Yes, the LH1529BACTR's optocoupler section is explicitly designed for bidirectional current detection, enabling direct sensing of both polarities of AC ring signals (e.g., 20 Hz, 90 V RMS) without external diode bridges or polarity-reversal circuitry. This functionality is confirmed in the device description and supported by its symmetric LED terminal configuration (pins 1 and 2).
What is the maximum continuous load current the LH1529BACTR SSR can switch, and what protection does it include?
The LH1529BACTR SSR supports a continuous DC load current of 120 mA, with built-in current-limit protection that trips at 170–250 mA (typ 210 mA) for 5 ms. This protects against short-circuit faults and inrush surges common in telephone line interfaces. The SSR also features clean bounce-free switching and low on-resistance (12–25 Ω), minimizing power dissipation during sustained operation.
How does the CTR specification of the LH1529BACTR impact its use in low-power ring detection circuits?
The LH1529BACTR guarantees a minimum DC current transfer ratio (CTR) of 100 % at IF = 6 mA and VCE = 0.5 V. This high CTR allows reliable ring detection with LED drive currents as low as 5 mA, reducing power consumption in battery-backed or energy-conscious telecom designs while maintaining noise-immune phototransistor output swing.
Is the LH1529BACTR still in production, and what support is available for legacy designs?
The LH1529BACTR was declared End of Life in January 2018. However, Aetrix Electronics maintains traceable inventory and offers lifecycle availability coordination, including last-time buy planning, BOM continuity management, and volume procurement assistance for OEMs sustaining legacy telecom infrastructure, analog PBX systems, and VoIP gateway platforms dependent on the LH1529BACTR.
LH1529BACTR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Vishay Semiconductor Opto Division
- Series:
- LH1529
- Packaging:
- Tape & Reel (TR)
- 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):
- 20 Ohms
- Termination Style:
- Gull Wing
- Operating Temperature:
- -40°C ~ 85°C
- Supplier Device Package:
- 8-SMD
- Approval Agency:
- BSI, FIMKO, UL
- Grade:
- -
- Qualification:
- -
LH1529BACTR FAQ
1.How can I place an order for LH1529BACTR through Aetrix?
Please submit a Request for Quotation (RFQ) for LH1529BACTR 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 LH1529BACTR reliable?
The price and inventory of LH1529BACTR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LH1529BACTR is usually 5 days.
3.What payment methods are accepted for LH1529BACTR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LH1529BACTR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LH1529BACTR?
LH1529BACTR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LH1529BACTR 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 LH1529BACTR?
For technical support, including LH1529BACTR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LH1529BACTR requirements.
6.How does Aetrix verify that LH1529BACTR is sourced from the original manufacturer or authorized distributors?
All LH1529BACTR 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 LH1529BACTR meets industry standards.
7.What is the process for return or replacement of LH1529BACTR?
All LH1529BACTR units undergo pre-shipment inspection (PSI). If there is an issue with LH1529BACTR, 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 LH1529BACTR part is unused and in its original packaging.
Return procedure for LH1529BACTR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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