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Datasheet A2TPMI
DESCRIPTION
The PerkinElmer A2TPMI is a versatile infrared thermopile sensor with an integrated configurable ASIC
for signal processing and ambient temperature compensation. This integrated infrared module senses
the thermal radiation emitted by objects and converts this to a analog voltage.
The A2TPMI can be delivered fully factory calibrated and adapted to the customer specification, as well
as customer programmable via the serial interface. In the pre-calibrated version, only three pins are
necessary for operation: object output voltage, 5V supply voltage, and ground.
As described in this specification, the temperature accuracy of the fully adjustable integrated circuit out-
performs that of the previous PerkinElmer thermopile modules with discrete components on pcb, be-
cause the A2TPMI features an offset correction of the amplifier and a factory calibrated ambient tem-
perature sensor. This makes the A2TPMI a versatile, compact and high precision device.
Due to the internal digital signal processing and 8 bit resolution of the internal control registers the
A2TPMI has improved accuracy for adjustment and improved performance. E2PROM technology allows
unlimited changing of the configuration.
For amplification of the highly sensitive thermopile signal in the micro- to millivolt range, a high resolu-
tion programmable low noise chopper amplifier is provided. An adjustable high precision ambient tem-
perature sensor followed by a signal processor, offers an accurate compensation signal with polynomial
characteristics that perfectly matches to that of the thermopiles output. Adding of these signals results in
an ambient independent object temperature signal over a large temperature range, which still can be
adapted / scaled to customer needs due to flexible offset and postgain adjustment facilities of the de-
vice.
The two configurable comparators of the A2TPMI, that can alternatively be used, enhance the function-
ality. This allows to employ the A2TPMI as an temperature dependent switch for alarm purposes.
Threshold temperatures and the hysteresis is free programmable for both comparators.
Due to integration of sensor and electronic in a compact TO 39 housing, the A2TPMI is robust and
insensitive to environmental influences like pcb contamination (leakage currents), humidity and electro-
magnetic interference.
A2TPMI Datasheet Rev4
Page 2 of 21
Rev. Oct 2003
PERKINELMER [ PERKINELMER OPTOELECTRONICS ]
