µPower Oscillator Delivers Unique Frequencies in a 1.2 mm2 Footprint for Portable Medical
Posted By: Piyush Sevalia

Optimized for ultra-low power, small form-factor applications, the new SiTime SiT1569 oscillator provides a new architectural alternative to legacy quartz technology or to power-consuming, internally generated clock sources that lack ppm-level accuracy. Unlike other oscillators, the SiT1569 operating frequency range is between 1 Hz and 462 kHz. Once you select a frequency, the frequency is factory programmed during final test and samples are shipped within 1 to 2 weeks. Need higher frequency? No problem. SiTime’s SiT1576 TCXO has an operating frequency range from 1 Hz to 2 MHz.

Both parts are sampling and in production. Sample lead-time is 1 to 2 weeks.

oscillators for portable medical applications

Packaged in a tiny 1.2mm2 CSP-4, the SiT1569 oscillator draws less than 3 µA and maintains ±50 ppm frequency stability over the -40°C to +85°C temperature range. If better frequency accuracy is required, SiTime’s SiT1576 maintains ±5 ppm frequency stability over temperature and comes in the same CSP-4 package and footprint.

Analog front ends (AFEs) are often used for input sensor signal conditioning. Today’s AFEs are lower power and smaller, making them ideal for portable medical and wearable applications. The SiT1569 and SiT1576 complement small AFEs with the following key features:

SiT1569 XO:

  • Over temp stability: ±50 ppm
  • Operating frequency range: 1 Hz to 462 kHz
  • CSP-4: 1.5 mm x 0.8 mm x 600 µm height
  • Ultra-low power: 2 µA typ at 100 kHz

SiT1576 TCXO:

  • Over temp stability: ±5 ppm
  • Operating frequency range: 1 Hz to 2 MHz
  • CSP-4: 1.5 mm x 0.8 mm x 600 µm height
  • Ultra-low power: 8 µA typ at 100 kHz

 

The SiT1552 TCXO is an ideal reference clock for RTC timekeeping and BLE sleep clocking. Consuming only 1 µA, frequency stability over temperature is as low as ±5 ppm. This provides another power-saving architectural option. Many medical and wearable applications use BLE as the low-power communication protocol, and this does not require continuous data transfer between the device and the master (e.g., phone). Therefore, the BLE connection interval can be longer, saving power. The limitation in interval duration is limited by the 32 kHz accuracy (SCA). This is where the benefit of the SiT1552 really shines: ±5 ppm accuracy is 30x better than a quartz XTAL, enabling sleep interval durations as long as the application desires because it is no longer limited by sleep clock accuracy. This translates to sleep durations as long as 30 minutes!

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Feb 11, 2022

Jan 11, 2022

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