Industrial ASIC Design
System to ASIC has extensive experience in design and manufacturing of ASICs for industrial applications. Our very first production ASIC, some 20 years ago, was a transceiver IC for photoelectric proximity sensors. Over the years we have delivered successful ASIC solutions to a broad range of industrial applications including, inductive, capacitive, magnetostrictive, gas sensors, GFCI and AFCI breakers, passive infrared security sensors, temperature, strain, and many more.
An industrial ASIC must function flawlessly across wide temperature ranges and in the presence of conducted and radiated noise generated by motors, AC drives and high-power communication devices. An intimate knowledge of the impact that these interfering sources have on performance of analog and digital integrated elements is essential to the design of a noise immune, robust industrial ASIC.
We have a great deal of practical experience with the unique challenges presented by harsh operating conditions encountered on the factory floor, in warehouses and around saw mills, a few examples of our industrial ASICs are summarized below:
PIR (Passive InfraRed) Security Sensor
PIR sensors are used by security systems to detect motion by monitoring a change in long wavelength heat signatures and using that to trigger a response, such as an alarm or a camera activation. A high quality PIR sensor is capable of not only detecting motion, but differentiating between bodies of different size generating the motion, allowing first order discrimination between authorized and unauthorized individuals, pets and people, etc.
Key requirements for high quality PIR sensor product are near-zero false alarm activation, low power for extended battery operation and low cost. The ASIC combines’ very low current analog signal conditioning with sophisticated digital signal processing to minimize probability of false detects and enable multi-year single coin cell battery operation. Approximately 70% of silicon recourses are devoted to analog processing, including amplification, filtering and signal conditioning.
PIR ASIC Development – Results:
- Cost reduction – eliminated additional PCB, connector and 31 components, including precision low current opamps, comparators, a voltage regulator and a microcontroller.
- ROI < 2 month
- Development cycle 25 weeks
PIR ASIC’s Functional Features:
- Battery monitor and supervision with support for multiple battery technologies.
- Precision target size and rate of motion (thermal signature) detect/no detect differentiation
- Fully integrated multi-slope PIR temperature compensation – no external components
- Very low operating and sleep current
PIR ASIC’s Notable Performance Features:
- Voltage range 1.5-8VDC
- < 500nA, 100ppm, bandgap voltage reference
- 50dB, < 1.5µA, low 1/F noise, fully differential PIR front end
- < 200nA, 32.768Khz closed loop crystal oscillator
AFCI (Arc Fault Circuit Interrupter) Breaker ASIC
An Arc Fault Circuit Interrupter ASIC is employed in a AFCI breaker to accomplish the involved task of sensing arc fault, overload and short circuit conditions in electrical wiring. An arc fault condition occurs when electrical insulation between wires is damaged and current is able to jump or arc from one conductor to the other. The arc does not conduct enough energy to create an overload of short circuit condition, but it does cause heating and further breakdown of wire insulation. Undetected arc faults are dangerous and can result in home fires.
Electrical current arcing from one conductor to the other creates a high frequency noise signature that can be analyzed and detected. A good AFCI breaker will not only detect and interrupt an electric circuit in the case of an arc fault, but also avoid nuisance trips from electrically noisy home appliances, like a vacuum cleaner, that can often have a similar “electrical signature” to an actual arc fault. The Arc Fault ASIC monitors wires for an arc fault signature by continuously conditioning and processing incoming signal in the analog domain and then converting it into digital domain for further algorithmic processing by the controller to differentiate arc fault from other electrical noise.
AFCI ASIC development – Results:
- Cost reduction – 72 components, including high voltage buffer/amplifier, DACs, ADCs and microcontroller
- ROI < 6 month
- Development cycle 26 weeks
AFCI ASIC Functional Features:
- Arc fault detection with nuisance trip avoidance
- Ground fault detection with nuisance trip avoidance
- Overload and short circuit detection.
AFCI ASIC Performance Features:
- Offset compensated precision analog rectifier
- High RFI/EMI noise immunity input pin architecture.
- SAR DAC 10 bit – 3 channels
- ADC 12 bit
- 10KHz-100KHz, user configurable, temperature compensated programmable bandpass filter
- 200V interface buffer and high voltage differential amplifier with digitally programmable gain
- 8 bit microcontroller
Photoelectric Sensor ASIC
Photoelectric sensors are an essential component of modern manufacturing. They offer non-contact detection of object presence, absence, positioning, safety barrier encroachment, etc. These sensors operate in a very challenging environments filled with abusive electrical noise from large motors, relays, welders, as well as optical noise from other sensors, factory lighting, sunlight, etc. Within this environment a photoelectric sensor must process nA level electrical signals, ignore ambient noise, and still provide reliable detection results over full -55C to +85C temperature range.
The photoelectric sensor ASIC integrates all the resources required for operating a robust, responsive, high reliability low cost photoelectric sensor. The photoelectric sensor ASIC chip integrates a high gain transimpedance front end, which amplifies, filters and demodulates incoming low level analog signal, then conditioned signal is converted to the digital domain where it is evaluated against user programmable detection criteria.
PS ASIC Development – Results:
- Cost reduction – 23 components, including precision opamps, comparators and voltage regulators.
- ROI < 6 month
- Development cycle 19 weeks
PS ASIC’s Functional Features:
- Synchronous modulation/demodulation provides discrimination of in-band noise from EMI/RFI, and ambient lighting.
- Photodiode signal processing channel with high gain and high noise immunity
- Synchronous temperature compensated programmable closed-loop LED drive with pulse shaping to optimized LED/Photodiode photodynamics
- Discrete output drives with short-circuit protect and overload monitor
- LED indicator drivers for Detect State and sensor Power/Health
PS ASIC’s Performance Features:
- 5nA detection threshold
- 10M front end transconductance gain
- Programmable detection response time
- Programmable LED drive voltage
- Programmable LED Drive period and pulse width
- Adjustable gain and threshold
- Enhanced noise immunity algorithm