Ultra-compact relay enables battery-less or low-power operation for thermostats, building automation, HVAC, and security systems.
ROSEMONT, Ill., November 4, 2025 -- Littelfuse, Inc. (NASDAQ: LFUS), an industrial technology manufacturing company empowering a sustainable, connected, and safer world, today announced the launch of the CPC1601M, an innovative 60 V, 2 A normally open (1-Form-A) solid-state latching relay designed to address critical integration and power efficiency challenges in thermostats, HVAC systems, and building automation. (View the video in English, Chinese & Japanese.)
The CPC1601M is the first PCB-mounted solid-state relay of its kind that combines load-powered operation with a latching architecture in a 3 × 3 mm DFN package. Its ability to harvest operating power directly from the load or draw less than 1 μA from the system supply enables zero-power operation, dramatically extending battery life or eliminating the need for batteries.
“With the launch of the CPC1601M, we’re giving our customers a powerful new tool to design smarter, more efficient control systems, especially in space-constrained and energy-sensitive applications like building automation,” said Dr. Hugo Guzman, Product Marketing Manager at Littelfuse. “This innovative SSR (relay) reduces system power consumption through its unique load-powered operation and simplifies integration into both modern and legacy installations. It’s a natural extension of our solid-state relay portfolio, reinforcing our commitment to solving real-world design challenges with compact, reliable, and forward-thinking solutions.”
Solving Real-World Challenges
For engineers designing smart thermostats and two-wire control systems, the CPC1601M removes the need for a common (C) wire, simplifying installations, especially in older buildings. Its solid-state operation also eliminates clicking sounds and moving parts, offering a silent and long-lasting alternative to mechanical relays. End-users benefit from slimmer, quieter, and maintenance-free devices, while installers save time and cost by avoiding additional wiring or external power kits.
Features and Benefits
- Latching relay architecture requires only a single pulse to change states, minimizing energy draw.
- Harvest mode enables operation using only the open-circuit load—no system power required.
- Power output pin provides up to 10 mW to external circuits, supporting additional low-power functions.
- Compact 3 × 3 mm DFN package reduces PCB footprint and enables ultra-thin device profiles.
- Zero-cross switching reduces electrical noise and improves reliability in AC loads.
- TTL/CMOS-compatible inputs ensure easy integration with microcontrollers or logic circuits.
Markets & Application
- Smart thermostats
- Fire alarm panels
- Security and access control systems
- Building and HVAC automation
- Industrial control systems
- Utility metering and instrumentation
The CPC1601M marks a significant expansion of the Littelfuse solid-state relay portfolio, reinforcing its position as a leader in innovative switching solutions for next-generation control systems.
Availability
These solid-state relays are available in quantities of 2,000 per reel. Sample requests are accepted through authorized Littelfuse distributors worldwide. For a listing of Littelfuse distributors, please visit Littelfuse.com.
For More Information
Additional information is available on the CPC1601M Solid-State Relays product page. For technical questions, please contact:
- Hugo Guzman, Product Marketing Manager: hguzman@littelfuse.com;
- Juste Valentiniene, Product Manager: jvalentiniene@littelfuse.com;
- Anthony Konopka, Product Marketing Engineer: akonopka@littelfuse.com
About Littelfuse
Littelfuse, Inc. (NASDAQ: LFUS) is a diversified, industrial technology manufacturing company empowering a sustainable, connected, and safer world. Across more than 20 countries, and with approximately 16,000 global associates, we partner with customers to design and deliver innovative, reliable solutions. Serving over 100,000 end customers, our products are found in a variety of industrial, transportation, and electronics end markets–everywhere, every day. Littelfuse.com.