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Overview
The MPPC module is a semiconductor photo detector capable of detecting very low light levels. It has an
MPPC (multi-pixel photon counter) device which consists of multiple APD pixels operable in Geiger
mode with high gain (10
5
to 10
6
). The MPPC module is made up of an MPPC, current-to-voltage
conversion circuit, high-speed comparator circuit, high-voltage power supply circuit,
temperature-compensation circuit, counter circuit, and microcomputer. Handling the MPPC module is
very easy, since it operates on USB bus power and no external power supply is required. Three kinds of
outputs are available: analog output, comparator output, and counter output (via USB), which are
selectable according to the application. The threshold level of the counter can also be changed by USB
communication. Operating the MPPC module requires high-precision voltage control because the MPPC
is used in Geiger mode where the gain greatly depends on changes in bias voltage and also because
the usable bias voltage range is narrower than that for normal APD devices. This module uses a
microcomputer to control the bias voltage with high accuracy, allowing stable MPPC operation.
The MPPC module is expected to open up new applications in the photon counting region, including
fluorescence lifetime measurement, flow cytometry, drug discovery, scientific research, various
measurement, chemical analysis, and many more fields.
■
Features
♦
Integrates a signal readout circuit ideal for MPPC
♦
Built-in high-voltage circuit and temperature-compensated circuit
♦
Three types of output: analog, comparator and pulse calculation value
♦
USB interface for easy handling: driven by USB bus power
♦
Compact and lightweight
■
Applications
♦
Fluorescence lifetime measurement
♦
Biological flow cytometry
♦
Bioluminescence analysis
♦
Ultra low light detection
♦
Analysis equipment
■
Block diagram
