PC817 Datasheet Checks Before Selecting a Replacement
A PC817 part number alone does not guarantee identical transfer or isolation performance. Read the datasheet for the exact manufacturer suffix and package, then evaluate the device at the LED current, collector voltage, and temperature used by the circuit.
- Pin orientation: verify anode, cathode, collector, and emitter against the package drawing before comparing the PCB footprint.
- Input drive: calculate the series resistor with
RIN = (VDRIVE - VF) / IF, using worst-case LED forward voltage and the controller’s real output levels. - Current transfer ratio: compare the minimum CTR at the stated
IF,VCE, and ambient temperature; rank suffixes and aging margin can change the usable output current. - Output limits: check
VCEO, collector current, saturation voltage, and dark current against the pull-up resistor and receiving logic thresholds. - Speed and isolation: confirm switching times, coupling capacitance, creepage, clearance, and required approvals; an isolation test voltage is not a continuous working-voltage rating.
PC817 Introduction
PC817 photocoupler is an electronic component used for isolation amplification and signal transmission in various applications. It is a type of optocoupler that consists of an infrared light-emitting diode (LED) and a phototransistor or photodiode, enclosed in a single compact package. The LED emits light, which is then detected by the phototransistor or photodiode, causing a change in the output signal. This component is widely used in circuits that require electrical isolation, such as in power supplies, motor control, and audio equipment. The PC817 photocoupler is designed to withstand high temperatures and has a long lifespan, making it a reliable choice for many applications.
PC817 Pinout
PC817 Features
- High isolation voltage between input and output
- Compact dual-in-line package
- Low input current and a high transfer ratio
- Available in various package types
- Compatible with TTL, CMOS, and other digital logic families
- Meets various safety standards, including UL, RoHS, CSA, and VDE.
PC817 Parameters
| Attributes | Value |
|---|---|
| Current Transfer Ratio | 50% (minimum) |
| High Isolation Voltage | 5000V (RMS) |
| Forward Current (ICEO) | 50mA |
| Peak Forward Current (ICE max) | 1A |
| Reverse Voltage | 6V |
| Power Dissipation | 70mW |
| Collector-Emitter Voltage | 35V |
| Emitter-Collector Voltage | 6V |
| Collector Current | 50mA |
| Collector Power Dissipation | 150mW |
| Total Power Dissipation | 200mW |
| Operating Temperature | -30°C to +100°C |
| Collector-Emitter Saturation Voltage | 0.1V (typical) |
| Cutoff Frequency | 80kHz |
| Current Transfer Ratio Range | 50% to 600% |
| Package | DIP-4, SOP-4, and SSOP-4 |
PC817 Applications
- Computer terminals
- System appliances, measuring instruments
- Registers, copiers, automatic vending machines
- Electric home appliances, such as fan heaters
- Thyristor system equipment
- measuring instrument
- photocopier
- Automatic ticketing equipment
- Signal transmission between circuits of different potentials and impedances
