TLP521-4 Transistor Output Optocoupler DIP-16

TLP521-4 Transistor Output Optocoupler DIP-16 is a quad-channel photocoupler designed for complete galvanic isolation between high-voltage power circuits and low-voltage digital microcontrollers. Each of the four independent channels consists of an infrared emitting diode optically coupled to a phototransistor in a standard DIP-16 package. Consequently, this device prevents high-voltage transients from damaging sensitive control electronics while transferring clean signals. Furthermore, its high isolation voltage of 2500 Vrms ensures robust operation in noisy industrial environments. Therefore, design engineers widely select this component to achieve safe, reliable signal transmission in motor drives, programmable logic controllers, and switching power supplies.

Key Features:

• Quad-Channel Isolation: Houses four completely independent optocoupler channels within a single space-saving DIP-16 package.
• High Isolation Voltage: Provides robust dielectric withstand capability up to 2500 Vrms minimum between input and output pins.
• High Collector-Emitter Voltage: Supports a collector-emitter breakdown voltage rating of 55 V minimum for handling higher voltage loads.
• High Current Transfer Ratio: Delivers an efficient CTR ranging from 50% to 600% at an input current of 5 mA.
• Through-Hole Mounting: Utilizes standard DIP-16 lead spacing to simplify prototyping, breadboarding, and wave soldering.

Technical Specifications:

• Input Forward Current: 50 mA maximum per channel
• Input Forward Voltage: ≈ 1.15 V to 1.3 V at 10 mA
• Collector-Emitter Breakdown Voltage: 55 V minimum
• Emitter-Collector Breakdown Voltage: 7 V minimum
• Collector Current: 50 mA maximum per channel
• Isolation Breakdown Voltage: 2500 Vrms minimum
• Operating Temperature Range: -55 °C to ±100 °C

Mechanical Specifications:

• Package Type: DIP-16 (Dual In-line Package, 16 Pins)
• Pin Pitch: 2.54 mm (0.1 inch) standard grid spacing
• Row Spacing: 7.62 mm (0.3 inch)
• Housing Material: Flame-retardant epoxy molding compound

Dimensions:

• Body Length: ≈ 19.8 mm
• Body Width: ≈ 6.4 mm
• Overall Height: ≈ 3.5 mm (excluding pins)
• Lead Thickness: ≈ 0.25 mm

Pinout and Wiring:

• Pins 1 to 8 (Anode/Cathode Pairs): Connect input signal sources to the infrared LEDs through current-limiting resistors.
• Pins 9 to 16 (Emitter/Collector Pairs): Wire the output phototransistors to collector loads or microcontroller pull-up resistors.
• Channel 1: Pin 1 (Anode 1), Pin 2 (Cathode 1), Pin 16 (Emitter 1), Pin 15 (Collector 1)
• Channel 2: Pin 3 (Anode 2), Pin 4 (Cathode 2), Pin 14 (Emitter 2), Pin 13 (Collector 2)
• Channel 3: Pin 5 (Anode 3), Pin 6 (Cathode 3), Pin 12 (Emitter 3), Pin 11 (Collector 3)
• Channel 4: Pin 7 (Anode 4), Pin 8 (Cathode 4), Pin 10 (Emitter 4), Pin 9 (Collector 4)
• Note: However, always maintain physical isolation trace distances on the PCB layout between input and output pins to preserve maximum dielectric rating.

Datasheet Reference:

• Download Toshiba TLP521-4 Datasheet

Commonly Used in:

• Programmable Logic Controllers (PLCs): Interfacing high-voltage field sensor inputs to low-voltage internal CPU logic.
• Switching Power Supplies: Feedback control loops crossing primary-to-secondary isolation barriers safely.
• Industrial Automation Equipment: Isolating digital I/O lines from heavy electrical noise and ground loops.

Applications:

• Microcontroller Signal Level Shifting: Isolating 5 V or 3.3 V logic outputs from 24 V relay coils or solenoids.
• Ground Loop Elimination: Breaking ground pathways between distinct systems operating at different potential references.
• AC Main Monitoring: Providing safe isolated status detection for AC voltage presence detectors.

Equivalent Models:

• PC847: A pin-compatible quad-channel phototransistor optocoupler offering similar input/output isolation parameters.
• LTV-847: Lite-On equivalent quad-channel optocoupler packaged in a standard DIP-16 footprint.
• PS2501-4: NEC/Renesas high-isolation quad-channel optocoupler, although response times may vary slightly under light loads.

Package Includes:

• 1 x TLP521-4 Transistor Output Optocoupler DIP-16