Sensor chips are dies incorporating semiconductor circuit elements that are used to convert changes to some physical parameter to an electrical signal. There are several kinds of sensor chips: temperature, gas and liquid pressure, load cells (force sensors), chemical (pH, oxygen, carbon dioxide), magnetic, mechanical (acceleration, position, pressure, knock, rotation), optical (single-chip cameras, edge detectors, and image pattern recognizers), medical (protein interactions) and others. Like other semiconductors, a sensor chip can be flexible, and can be manufactured as a signal conditioning chip, a stand-alone transducer, or a combination.
Infrared Multi-Function Board Demo
Performance specifications for pressure sensor chips include pressure range, supply voltage, impedance, impedance temperature coefficient, bandwidth, accuracy, and long term stability. Performance specifications for temperature sensor chips include temperature range, supply voltage, impedance, impedance temperature coefficient, bandwidth, and accuracy. Other sensor chips have specifications unique to the application. For example, single-chip cameras have array resolution, pixel pitch, fill factor, array size, peak responsivity, sensitivity, and dynamic range, among others.
Integrated Circuit (IC) Package Types
Sensor chips have several integrated circuit (IC) package types: SC-170, which is used in handheld devices such as cellular phones and personal digital assistants (PDAs), small outline transistor (SOT) packages like SOT23 and SOT123, small outline (SO) packages like SO-8 and SO-16, and transistor outline packages such as TO-8. Bare die and quarter size outline package (QSOP) devices are also available. Sensor chips can interface with several hardware busses, including the system management bus (SMBus), the industry standard architecture (ISA) bus, the I2C bus, and the actuator sensor interface, which is also called AS-I or ASi.
Sensor chips that meet the requirements of Institute of Electrical and Electronic Engineers (IEEE) Standard 1451 can transmit electronic data to a data acquisition system. Sensor chips used for machinery safety/emergency stop applications can provide safety support up to Safety Integrity Level (SIL) 3 according to International Electrotechnical Commission (IEC) standard IEC 61508.