SPCM-AQ4C-IO

APPLICATION NOTE Photon Detection SPCM-AQ4C-IO P/N 760-1 Interface Board for SPCM-AQ4C Modules USERS GUIDE Document # EO-674-04 www.excelitas.com Page 1 of 6 SPCM-AQ4C-IO (2015-09) SPCM-AQ4C-IO SPCM-AQ4C Interface Board SPCM-AQ4C-IO Interface Board for the SPCM-AQ4C Photon Counting Module Users Guide This manual applies to the SPCM-AQ4C-IO (Excelitas internal #760-1) interface board when used with the SPCM- AQ4C 4-channel single photon counting modules. This board is used to facilitate connecting power and signal connections to the SPCM-AQ4C modules for users who do not wish to build their own interface. 1. When handling the module, ESD precautions must be observed. 2. The SPCM-AQ4C module contains a high voltage power supply. When the board is under power, high voltages are present on the board. Keep fingers and tools away from the components on the board. 3. Do not touch the gold contacts on the card edge connector with bare fingers. Do not modify or adjust any components. Do not pull on the FC connectors to remove the module from the card edge connector. 4. The SPCM-AQ4C has been designed to operate from 5°C to 40°C (10°C to 40° for CD3122 version). Make sure that the heatsink has good airflow. The temperature of the heatsink will be determined by two factors. The first will be the ambient temperature of the system in which the card is installed. The second is determined by the count rate of the card. Higher count rates will cause the detector to heat up. In turn, the cooler circuit will compensate by transferring the heat from the detector to the heatsink. As the heatsink gets warmer, the operating margin (temperature) gets smaller. At 40°C, the dark count will be stable, but above 2Mcps the operation may become unpredictable. 5. Refer to the SPCM-AQ4C data sheet for performance and operating data. 6. Each detector is individually calibrated. Do not attempt to adjust any of the potentiometers or jumpers on the SPCM-AQ4C PCB. To do so could cause damage to the detector or the module electronics. 7. If the board is operated in high-level ambient lighting, some photons may enter the detector through the glass seal around the pins at the back of the detector assembly. Try to keep stray light from shinning directly at the pins at the back of the detector assembly. The pins can be recognized by where they attach to the small flex circuit that connects the detector assembly to the PCB. 8. Use 18 gage wire or larger for the +2V supply and +2 V return. Keep the length as short as possible to avoid having a large voltage drop when the coolers are drawing maximum current (which can reach over 4 amps). If you need longer length, use heavier wire gage. You should design wiring harnesses to keep the total voltage drop to less than 100mV. www.excelitas.com Page 2 of 6 SPCM-AQ4C-IO (2015-09) SPCM-AQ4C-IO SPCM-AQ4C Interface Board 9. Connecting the Interface Board to the SPCM-AQ4C Module. Note that a power cable is supplied with each I/O board. 9.1. Locate the position of the key slot on the SPCM PCB before attempting to mate the module to the interface board. Refer to the connector pin-out diagram and figure 9.1. FIGURE 9.1 JUMPER SETTING FOR GATE CONTROL www.excelitas.com Page 3 of 6 SPCM-AQ4C-IO (2015-09) SPCM-AQ4C-IO SPCM-AQ4C Interface Board 9.2. Jumper Positions: There are a number of jumpers on the interface board that control how the gating functions of the module operate. The interface board can be configured to allow independent gating of each channel or it can be configured to allow simultaneous gating of all the channels from one GATE input. 9.3. As shipped, the I/O board has been configured to gate all channels of each module simultaneously. The gating can be accomplished by using a TTL level signal capable driving a 50 ohm load (100mA @ 5V). The signal can be connected to any one of the GATE Input connectors and all channels will be controlled in parallel. 9.4. To convert to independent gating of the channels, refer to the table in figure 9.1. You will need a different signal source for each channel that you want to gate. 9.5. Note that with no gate signal or floating gate inputs, the module will be in the gated “ON” position and ready to count photons. 9.6. The module channels will be “GATED ON” with a low-level TTL (2V,