PC817X3CSP9F
SHARP/Socle Technology
MOQ 5 · Tape & Reel (TR) · RoHS · EIA-481 · DAP/DDP · T/T
Technical specifications
| Parameter / Attribute | Specification / Value |
|---|---|
| Series | PC817 |
| Input type | DC |
| Output type | Transistor |
| Mounting | Surface Mount |
| Voltage - isolation | 5000Vrms |
| Voltage - output | 80V |
| Voltage - forward (Vf) | 1.2V |
| Current - output (Channel) | 50mA |
| Current transfer ratio | 600% @ 5mA |
| Current - DC forward (If) | 50 mA |
| Operating temperature | -30°C ~ 100°C |
| Package | Tape & Reel (TR) |
| Case | 4-SMD, Gull Wing |
| Channels | 1 |
| Vce saturation | 200mV |
| Rise (Fall time) | 4µs, 3µs |
Need Stock or a Drop-in Second-Source for PC817X3CSP9F?
Package: DIP-4 / SMD-4 · Pin-compatible replacements with immediate Shenzhen spot stock
The PC817 is the optocoupler of SMPS feedback loops and low-speed isolation across every price class of equipment - one of the highest-volume optos ever made. Genuine supply is continuous, but the part is a specification, not a single part number: the CTR rank (A / B / C / D or combined bins) and the isolation class decide whether a substitute works, and the second-source universe (LTV-817, EL817, TLP521-1, HCPL-817) is enormous precisely because designers treat the function as generic. The buying question is always which rank and which vendor, not whether the part exists.
Verified Pin-Compatible Replacements (4 verified alternatives)
The Standard Second Source
Shenzhen Spot Stock (24-48h Dispatch)
Pin-compatible 4-pin phototransistor optocoupler with the same CTR bin system (A / B / C / D and combined bins), 5kVrms isolation class and 35V collector-emitter rating.
VCEO 35V; IC 50mA; total power about 200mW; CTR measured at IF = 5mA, VCE = 5V.
Second Branded Source, Same Bins
Shenzhen Spot Stock (24-48h Dispatch)
Equivalent 4-pin phototransistor opto from Everlight with the same rank letters and isolation class.
Same ratings envelope: 35V VCEO, 50mA IC, 5kVrms isolation.
The Japanese-Classic Cross
Shenzhen Spot Stock (24-48h Dispatch)
Toshiba 4-pin phototransistor optocoupler long cross-referenced with the PC817 family; check the rank window in the Toshiba datasheet as its bin letters are cut differently.
Similar envelope; confirm VCEO and CTR window per the specific grade.
Branded Continental Source
Shenzhen Spot Stock (24-48h Dispatch)
Avago/Broadcom member of the same 4-pin phototransistor family, used where the documentation chain prefers a Western brand.
Same functional envelope; ranks per the vendor datasheet.
Buyer & Quality Checklist for Sourcing Alternatives
- Match the CTR rank, not just the part number: A = 80-160 percent, B = 130-260, C = 200-400, D = 300-600 (at IF 5mA, VCE 5V). Combined bins (AB, BC, CD) exist; a C-rank design fed a low A-rank part can fail to drive its load, especially at low LED current.
- Rank letters are not an industry standard - each vendor defines its own bins. Compare the actual CTR numbers across datasheets when crossing brands.
- The PC123 is NOT a PC817 variant: same manufacturer lineage and similar 4-pin look, but a different family with its own ratings. Check the part number character by character.
- Isolation class matters in mains-facing designs: the 5kVrms class is the norm for the PC817 family; higher-creepage variants exist for medical and high-voltage work and are not interchangeable by footprint alone.
- In SMPS feedback loops, avoid the highest CTR ranks (D) unless the loop was designed around them - very high CTR at low LED current can make the loop twitchy; designers usually chose B or C deliberately.
- Current-transfer degrades with LED aging - for life-critical timing, run the LED well inside its rating and re-check the CTR budget at end of life.
Frequently Asked Technical Questions
Q: Is LTV-817 the same as PC817?
A: Functionally pin-compatible with the same CTR bin letters and isolation class - it is the standard second source. Match the rank letter (A/B/C/D) to the BOM; the bins are identical across the two.
Q: What do the letters after PC817 mean?
A: The current transfer ratio bin: PC817A is 80-160 percent, B is 130-260, C is 200-400, D is 300-600, measured at IF 5mA and VCE 5V. The rank decides gain in the isolated loop and must match the original design.
Q: Can I use a PC123 instead of a PC817?
A: No - the PC123 is a different Sharp optocoupler family with its own ratings, not a ranking variant of the PC817. Despite the visual similarity of the 4-pin bodies, they are not interchangeable without a design review.