Solid-state relay with zero-cross switching for AC loads
The Panasonic AQH3213AX is a solid-state relay from the AQ-H series, designed for switching AC loads up to 1.2 A continuous with a load voltage range of 0 V to 600 V. The SPST-NO (1 Form A) output uses a zero-cross turn-on circuit, which means the relay switches at the AC voltage zero crossing — this minimises inrush current and reduces conducted EMI when driving resistive or lightly inductive loads like heaters, lamps, or solenoids. The input side requires a 1.21 VDC control signal to trigger the internal LED, making it compatible with 3.3 V logic outputs or low-voltage microcontroller GPIOs without an external level shifter.
Package and board integration
Housed in an 8-SMD package with 7 leads and gull-wing terminations, the AQH3213AX is a surface-mount component suited for automated assembly. The 0.300-inch (7.62 mm) body width and 7-lead footprint fit standard SSR layouts; the gull-wing leads provide a visual solder-joint inspection point and moderate strain relief for the ceramic substrate inside. The base part number AQH3213 indicates the functional variant; the 'AX' suffix denotes the Tape & Reel packaging option for pick-and-place. The relay is rated for AC-only loads — the zero-cross circuit prevents phase-angle control, so it is not suitable for dimming or soft-start applications.