Space Asics' Products / SIF-ASIC

Key Information 

The SIF-ASIC architecture is a generic ASIC technology developed by SPACE-ASICS S.A. so that smart sensors can be interfaced through an ASIC. The main drive behind this effort was to develop an ASIC that would be the only component between a sensor and a digital processing unit. Such ASICs are presently available for the commercial sector but not for space applications. The complexity and characteristics of the commercial circuits makes their use in space prohibitive. The SIF-ASIC architecture would save customers considerable power and mass and at the same time increase reliability, radiation hardness and performance of their system.

The main functionalities of the pSIF device are listed below:

• Bias the sensor with either a constant voltage or a constant current so that optimum performance is obtained.
• Quantize the differential PT voltage and the PT temperature through a rad-hard 14-bit Analog-to-Digital Converter.
• Transmit the quantized sensor data to the S/C through an I2C or SPI bus.

Two different versions of the SIF-ASIC have been developed:

• A Generic SIF-ASIC space qualified as per ESCC9000
• A pSIF-ASIC version with sensor biasing capabilities with constant current or constant voltage suited for interfacing Pressure Transducers.

Key Features of the SIF-ASIC

• 14-bit ADC converter
• Sampling Rate: 200 KHz
• 8 Channels available for single-ended ADC measurements
• Up to 6 pressure sensors biased by the ASIC with a constant current.
• Instrumentation amplifier with adjustable gain (10 - 64 dB) for small differential signal measurements
• Adjustable gain (1-100 V/V) for various pressure range measurements
• Built in Voltage reference 1mV over -55 to 125 deg C with a Temperature coefficient of <3 μV/degC @ 1 Mrad
• Sensor Temperature measurements in 12 channels with increased accuracy. Both PTC and NTC Temperature Sensors supported
• Interfaces: I2C, SPI
• Single power supply (5.5V) (Internal voltage regulator)
• Low power consumption (<30 mW with all 8 channels on and <8 mW with 1 PT on)
• Autonomous operation on power up
• Wide Temperature Operating range (-55 to 125 deg C)
• Rad-hard up to TID > 1 Mrad
• SEL free up to > 81.6 MeV/mg/cm2
• SEFI immune to > 81.6 MeV/mg/cm2
• SEU free up to > 52.9 MeV/mg/cm2
• Available as bare die or in CQFP package
• The SIF-ASIC can be configured for operation: 
  - in one channel constantly (fix mode) 
  - scanning through 8 channels sequentially (scan mode)
• The device is space qualified as per ESCC 9000

Key Features of the pSIF-ASIC

• 14-bit ADC converter (12 true bits) with programmable gain front-end
• Sampling Rate: 200 KHz
• Up to 4 pressure sensors biased by the ASIC with a constant current or constant voltage
• Instrumentation amplifier for small differential signal measurements
• Input BW up to 500 Hz (programmable through an OTA_C filter)
• Adjustable gain to 100, 800, 6400, 10000 V/V for various pressure range measurements
• Built in Voltage reference 1mV over -55 to 125 degC
• Bias current to the PT Sensor up to 3 mA
• Can be used for temperature measurements (PRTs and NTCs supported)
• Interfaces: I2C, Parallel
• Single power supply (3.3 V)
• Low power consumption (<15 mW)
• Autonomous operation on power up
• Wide Temperature Operating range (-55 to 125 deg C)
• Rad-hard up to TID > 1 Mrad
• SEL free up to the tested LET of 60 MeV/mg/cm²
• No SEUs were observed up to the tested LET of 60 MeV/mg/cm²
• No SEFIs were observed
• Available as bare die or in CQFP 120 package

The pSIF-ASIC has been successfully interfaced with the Bradford piezo-resistive pressure transducers (PT) for space application. The flexibility of the calibration of the integrated pSIF+PT unit with respect to pressure range requirements was efficiently achieved with adjustment of the PT Bias Current and the Gain inside the ASIC.

SIF ASIC Applications

The pSIF-ASIC, as a generic data acquisition device, can be attached to various types of sensors for a series of applications, such as:

• Digital Pressure Sensors (PT)
• Other Strain Gauge types of sensors (Dispracement measurements, etc.)
• Temperature measurements with PTC or NTC sensors
• High-precision single-ended Voltage measurements
• Housekeeping in space instrumentation
• Total Ionizing Dose (TID) monitoring through a RADFET

Potential non space applications

Deep Sea applications.
Pressure field sensing for AUV navigation.

Contact us for available documentation

• SIF-ASIC Data Sheet
• SIF-ASIC Detail Specification
• pSIF-ASIC Brochure
• pSIF-ASIC Final Report to ESA