Littelfuse CPC1601M Load-Powered 60V 2A Latching Solid-State Relay Enables Battery-Less Smart Thermostats and HVAC Controls

Littelfuse has released the CPC1601M, a 60 V, 2 A normally open (1-Form-A) solid-state latching relay in a 3 × 3 mm DFN package.

The CPC1601M operates in load-powered harvest mode using open-circuit load voltage or draws less than 1 µA from the system supply. It requires only a single pulse to latch or unlatch and includes a power output pin delivering up to 10 mW for external low-power circuits. The device supports zero-cross switching for AC loads and provides TTL/CMOS-compatible inputs.

Applications include:
- Smart thermostats
- Fire alarm panels
- Security and access control systems
- Building and HVAC automation
- Industrial control systems
- Utility metering and instrumentation

The relay eliminates the need for a common (C) wire in two-wire control systems and produces no mechanical clicking sound.