The CSS555 is a very low power timer IC (active current < 5 micro-amps). It also has a programmable internal timing capacitor and a divider on the output which can be programmed to divide the output pulse in decades from 1 to a million. However, it was the very low power that attracted Epitel to the device. They wanted to use it in a medical application to study epilepsy – a battery powered sensor and data transmitter. Their first application used the CSS555 in a small custom package. This worked well, so they decided to build a custom ASIC with additional capabilities based on the CSS555 low power technology – the CSS094.
The CSS094 combines a low power 555 Timer with a 6-channel amplifier. It can be used to monitor up to 6 biometric parameters. The 555 circuit generates timing control clocks and a FM signal for the antenna. A high voltage driver has also been included to drive the antenna directly. An internal EEPROM provides storage for a serial number, calibration and configuration data. The low power specifications are impressive: 10 micro-amps operating current with less than 50 nano-amps in the sleep mode.
The resulting product from Epitel, the “epoch system” provides wireless in vivo recording for low-cost, long-term monitoring. Depending on the battery, the epoch transmitter (using the CSS094) can provide 2 months to 6 months of continuous monitoring. See the Transmitter Implant page on the Epitel webpage for more complete transmitter specifications.
Low power instrumentation ASICs are a specialty of CSS in our custom ASIC designs. We often combine this capability with our non-volatile memory latch technology to provide programming capability, as we did with the CSS094. If you have an application needing very low power in a mixed-signal technology (combined analog and digital), please call us at 949-797-9220 or use our contact form for a no obligation recommendation.