Professional IC Distribution & Technical Solutions

Manufacturer: PANASONIC

Part Number: AQY212EHAX

Specifications:

• Type: Solid State Relay (SSR)
• Configuration: SPST-NO (1 Form A)
• Output Type: MOSFET
• Load Voltage: 60V (DC)
• Load Current: 1.2A (DC)
• On-State Resistance: 0.5Ω (max)
• Isolation Voltage: 1500Vrms
• Input Control Voltage: 1.2V to 1.4V (DC)
• Input Current: 5mA (max)
• Operating Temperature Range: -40°C to +85°C
• Package: SOP (Small Outline Package)
• Mounting Type: Surface Mount
• Life Expectancy: High reliability, long operational life

Descriptions:

The AQY212EHAX is a compact, surface-mount solid-state relay from Panasonic, designed for low-power DC switching applications. It features MOSFET output for efficient switching and provides high isolation between input and output.

Features:

• Low Power Consumption: Suitable for battery-operated devices.
• Fast Switching Speed: Enables quick response in control circuits.
• High Isolation: 1500Vrms isolation ensures safety in sensitive applications.
• Compact Design: SOP package saves board space.
• RoHS Compliant: Environmentally friendly construction.

This SSR is ideal for industrial automation, medical equipment, and low-voltage DC switching applications.

# AQY212EHAX Solid State Relay: Technical Analysis

## Practical Application Scenarios

The Panasonic AQY212EHAX is a photoMOS solid-state relay (SSR) designed for low-power signal switching in industrial, medical, and consumer electronics. Its optocoupler-based isolation and MOSFET output stage make it suitable for:

1. Industrial Automation – Used in PLCs (Programmable Logic Controllers) for switching sensor signals or low-current control circuits, eliminating mechanical relay wear.

2. Medical Devices – Provides noise-free switching in patient monitoring equipment, where EMI suppression is critical.

3. Test & Measurement Systems – Enables precise signal routing in data acquisition modules without contact bounce.

4. Consumer Electronics – Integrates into smart home controls (e.g., thermostat switching) due to its compact SOP package.

Key advantages include 1,500V AC isolation, a low 0.5mA trigger current, and a 0.2Ω on-resistance, making it ideal for applications requiring both efficiency and safety.

## Common Design Pitfalls and Mitigation Strategies

1. Thermal Management Missteps

• *Pitfall:* Overlooking heat dissipation in high-frequency switching, leading to premature failure.
• *Solution:* Ensure PCB traces are adequately sized and use thermal vias if switching near the 60mA max load current.

2. Inadequate Input Drive

• *Pitfall:* Underdriving the LED (below 0.5mA) causes unreliable switching.
• *Solution:* Verify input current with a series resistor calculation (e.g., \(R_{lim} = (V_{in} - V_f)/I_f\)).

3. Output Voltage Oversights

• *Pitfall:* Exceeding the 60V load voltage limit damages the MOSFET.
• *Solution:* Add a transient voltage suppressor (TVS) for inductive loads.

4. Poor Isolation Practices

• *Pitfall:* Creepage/clearance violations negate the SSR’s isolation.
• *Solution:* Follow IPC-2221 spacing rules for high-voltage designs.

## Key Technical Considerations

1. Load Compatibility – The AQY212EHAX supports resistive and capacitive loads but may require snubber circuits for inductive loads.

2. Switching Speed – 0.5ms turn-on/0.1ms turn-off times demand timing alignment in high-speed applications.

3. Package Constraints – The SOP-4 footprint requires precise soldering to avoid pin bridging.

By addressing these factors, designers can leverage the AQY212EHAX’s reliability while avoiding operational risks.