Introduction
In January 2026, Excelitas Technologies introduced the PYD 2597 Ultra-Low Power DigiPyro sensor, designed specifically for battery-operated motion detection applications [citation:6]. With supply voltages as low as 1.4V and current consumption of just 2µA at 1.8V, it represents one of the lowest-power digital PIR sensors available on the market.
Key Technical Features
Ultra-Low Power Operation
The PYD 2597 operates from 1.4V to 3.6V with supply currents as low as 2µA at 1.8V, maximizing battery life in wireless and remote devices [citation:6]. This wide voltage range allows direct power from two AA or AAA batteries without boost converters, simplifying design and improving efficiency.
Integrated Motion Detection Unit
The sensor features a configurable Motion Detection Unit (MDU) with interrupt functionality. This allows systems to remain in low-power standby until motion is detected, eliminating the need for continuous polling by a microcontroller [citation:6]. The MDU continuously monitors for motion while drawing minimal current, asserting an interrupt when motion is detected to wake the host system.
One-Wire Digital Interface
A one-wire digital interface simplifies system integration and reduces overall design complexity [citation:6]. The sensor communicates detection events directly without requiring external ADC or comparator circuits, significantly reducing component count and PCB area.
Technical Specifications
| Parameter | Specification |
|---|---|
| Supply Voltage Range | 1.4V to 3.6V |
| Current Consumption | 2 µA at 1.8V (typical) |
| Package | TO-5 (compact, industry standard) |
| Field of View | 130° |
| Responsivity | 3.2 kV/W (typical) |
| Elements | Dual pyroelectric (differential) |
| EMI Immunity | Excellent – designed for electrically noisy environments [citation:6] |
| RoHS Compliance | Fully RoHS-compliant materials |
Wake-Up Mode Explained
The signature feature of the PYD 2597 is its wake-up mode. In this configuration, the sensor’s internal MDU continuously monitors for motion while drawing minimal current. When motion is detected, it asserts an interrupt signal that can wake a sleeping microcontroller [citation:6]. This enables true “zero-power standby” for battery-operated devices, where the main system remains completely off until motion occurs.
Improved Temperature Stability
The sensor features improved temperature stability, faster settling time, and enhanced resilience to rapid temperature changes [citation:6]. This makes it suitable for applications where environmental conditions may vary, such as outdoor installations or spaces with HVAC cycling.
Comparison with Alternative Technologies
Compared with other digital PIR sensors and camera- or radar-based motion detection technologies, the PYD 2597 offers [citation:6]:
- Lower power consumption: 2µA vs. mA for radar and camera-based systems
- Lower cost: Simple pyroelectric element without complex processing
- Inherent privacy advantages: No imaging, only motion detection
- Ideal wake-up sensor: Can trigger higher-power systems only when needed
Applications
- Long-range motion detection: Security and intrusion alarms
- Battery-operated IoT devices: Wireless sensors with 2-4 year battery life
- Energy-saving systems: Occupancy-based lighting and HVAC control
- Horizontal mounting designs: Flexible installation options
- Wake-up sensor: Trigger for higher-power systems like cameras
Design Considerations
The sensor operates down to 1.4V, allowing direct power from two AA or AAA batteries without boost converters. The one-wire digital interface requires careful attention to timing specifications, but Excelitas provides comprehensive application notes and reference designs. As a bare pyroelectric element in a TO-5 package, the PYD 2597 requires an external Fresnel lens matched to the desired detection pattern.
Conclusion
The Excelitas PYD 2597 represents a new benchmark for ultra-low power PIR sensing. With its 1.4V operation, 2µA current draw, and integrated wake-up functionality, it enables battery-powered motion detection applications that were previously impractical. The sensor is particularly well-suited for wireless IoT devices where extended battery life is critical [citation:6].