What is a chip-scale atomic clock (CSAC)?

A chip-scale atomic clock (CSAC) is a miniature atomic frequency standard that uses coherent population trapping (CPT) in a vapor cell to stabilize an oscillator. KCCS CSACs consume only 130 mW, making them suitable for battery-powered and portable applications where rubidium standards are too power-hungry.

How does CSAC compare to OCXO and rubidium?

CSAC offers better long-term stability than OCXO (ADEV <3E-11 at 1s vs <1E-12 for premium OCXO) but lower than rubidium (<1E-11). CSAC is much smaller and lower power (130 mW) than rubidium (<5 W), filling the gap between high-end OCXO and full-size atomic standards.

Is KCCS CSAC pin-compatible with Microsemi SA.45s?

Yes. KCCS CSAC uses the SA.45s pin-compatible DIP package, allowing direct drop-in replacement. The multi-frequency version outputs 10, 16.384, 20 and 24.576 MHz simultaneously at 150 mW, with I2C/UART digital interface.

What is the warm-up time for a CSAC?

KCCS chip-scale atomic clocks achieve rated stability within <3 minutes of power-on. This is comparable to high-end OCXOs and much faster than traditional rubidium standards (which typically require 5-10 minutes).

CPT Atomic Clock | ≤3W, ≤1μs Holdover | KCPTA50

Name: CPT-based Atomic Clock
Brand: KCCS
Availability: InStock

Key Specifications

Parameter	KCPTA50 Specification
Package (mm)	50.8 × 50.8 × 18
Output Frequency	10 MHz
Factory Frequency Offset	≤±5E-11
Frequency Stability	≤5E-11/s, ≤3E-11/10s, ≤1E-11/100s
Aging (after 24h continuous)	≤5E-12 / 24h
Frequency vs. Temperature	≤5E-11 (-40~+80℃)
Frequency Accuracy (after 2h 1PPS lock)	≤±1E-12 / 24h
Time to Lock (@25℃)	≤10 minutes
Holdover (after 24h discipline)	≤1 μs / 24h
Power Consumption	Steady-State ≤3W (12V), Max ≤14W (12V)
Supply Voltage (Vdc)	+5 ~ +12
Operating Temp. Range	-40 ~ +80℃

Frequently Asked Questions

What is a CPT-based atomic clock?

A CPT-based atomic clock uses Coherent Population Trapping technology to stabilize an oscillator with a rubidium vapor cell. Unlike traditional CSACs that use microwave interrogation, CPT clocks optically excite the atoms, eliminating the need for a microwave cavity. This results in an even smaller and lower-power atomic standard (~100 mW) suitable for the most demanding portable and battery-powered applications.

How does CPT atomic clock compare to conventional CSAC?

CPT-based clocks offer further miniaturization and lower power consumption (~100 mW vs 130 mW for standard CSAC) by integrating the optical and microwave excitation into a single compact package. While raw stability may be slightly lower than traditional CSAC, CPT technology provides the smallest form factor and lowest power in the atomic clock class, making it ideal for space-constrained and battery-operated systems.

What applications benefit most from a CPT atomic clock?

CPT atomic clocks excel in applications where GNSS signals are unavailable or unreliable and power/space are critical: tactical military communications, man-portable PNT devices, unattended ground sensors, underwater systems, and electronic warfare platforms. They provide holdover timing without the power penalty of rubidium standards.

How long does the CPT atomic clock take to warm up?

KCCS CPT-based atomic clocks achieve rated stability within under 2 minutes of power-on. This fast warm-up, combined with ~100 mW steady-state power, makes them suitable for duty-cycled and battery-powered deployments where instant-on timing is required.

CPT-based Atomic Clock