Frequency and Timing SA.45s Space CSAC Chip-Scale Atomic Clock Features Power consumption <120 mW The Microchip SA.45s Commercial The SA.45s provides 10 MHz and 1PPS Less than 17 cc volume, Space Chip-Scale Atomic Clock s outputs at standard CMOS levels, 1.6 1.39 0.45 (CSAC) potential for low size, weight, with short-term stability (Allan Deviation) 10 Radiation-tolerant: 20 krad and power (SWaP), and high timing of 3.0 10 at TAU = 1 sec, typical 2 10 SEL, SEU tested to 64 MeV-cm /mg performance at relatively low cost long-term aging of <9 10 /month, (contact factory for details) makes it very attractive for Low Earth and maximum frequency change of 10 MHz CMOS-compatible output 10 Orbit (LEO) applications. In addition to 5 10 over an operating temperature 1PPS output and 1PPS input for being a stand-alone atomic clock with a range of 10 C to 70 C. synchronization 10 MHz output, the CSAC also has a RS-232 interface for monitoring and A standard CMOS-level RS-232 serial 1PPS output and can be disciplined with control interface is built into the SA.45s. This a 1PPS input. The Space CSAC retains Short-term stability (Allan Deviation) of is used to control and calibrate the unit 10 this functionality and is a timing module 3.0 10 at TAU = 1 sec and to provide a comprehensive set of that can be disciplined with a GPS- Applications status monitors. The interface is also derived 1PPS input. Satellite timing and frequency control used to set and read the CSACs internal Satellite clock reference time-of-day clock. Assured Position, Navigation and Timing (PNT) Atomic clock accuracy Satellite cross-linking www.microchip.com1 Specifications Electrical Environmental RF Outputs Specification Details Frequency 10 MHz Operating Temperature 10 C to 70 C Maximum Frequency Change Format CMOS over Operating Temp Range 10 Amplitude 0 V to V CC 5 10 (Maximum Rate of Change Load Impedance 1 M 0.5 C per Minute) Quantity 1 Frequency Change Over -10 Allowable Input Voltage +/-4 10 1PPS Output Range Rise/fall Time (10%90%) <10 ns Magnetic sensitivity 11 9 10 /Gauss at Load Capacitance 10 pF (2.0 Gauss) 100 s Pulse Width Compliant to FCC part 15, Class B, Radiated Emissions Level 0 V to V when mounted properly onto host PCB CC 2.80 V Maintains lock under MIL-STD-810G, Logic High (V ) Min OH Vibration Operational, 7.7 g per Figure rms Logic Low (V ) Max 0.30 V OL 514.7E-1. Category 24 1 M Load Impedance 0%95% RH per MIL-STD-810, Humidity Quantity 1 Method 507.4 1PPS Input Storage and Transport (Non-operating) Rising edge Format Temperature 55 C to 85 C Low Level <0.5 V MIL-STD-810G, 7.7 g per Figure rms Vibration 514.7E-1. Category 24 2.5 V to V High Level CC MIL-STD-202-213A, Condition E, Load Impedance 1 M Shock 1000 g 1 Quantity Serial Communications Performance Parameters Protocol RS232 Specification Details CMOS 0 V to V Format CC Warm-up Time <180 s Tx/Rx Impedance 1 M 8 Range: 2.2 10 57600 Baud Rate 11 Analog Tuning Resolution: 1 10 Built-In Test Equipment (BITE) Output Input: 0 V2.5 V into 100 k 6 Range: 1 10 Format CMOS 0 V to V CC Digital Tuning 12 Resolution: 1 10 1 M Load Impedance 0= Normal operation Logic Phase Noise (SSB) 1= Alarm Frequency CSAC Power Input 1 Hz <50 dBc/Hz Operating <120 mW 10 Hz <70 dBc/Hz Warmup <140 mW 100 Hz <113 dBc/Hz Input Voltage (V ) 3.3 0.1 V CC DC 1 kHz <128 dBc/Hz 1 At input voltage V = 3.3 V and ambient temperature = 25 C, unless otherwise specified. CC DC 10 kHz <135 dBc/Hz 100 kHz <140 dBc/Hz Frequency Accuracy 11 Maximum Offset at Shipment 5 10 Maximum Retrace 10 5 10 (48 hrs Off) 100 ns 1 PPS Sync www.microchip.com