Littelfuse CPC1601M Load-Powered Latching Relay Simplifies Smart HVAC & Building Control Designs
November 26, 2025
New CPC1601M Ultra-Compact Relay Enables Battery-Less or Low-Power Operation for Thermostats, Building Automation, HVAC & Security Systems
Littelfuse has 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.
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 & 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 recognized name 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.
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
