Amptek Digital Pulse Processor
Re: Amptek Digital Pulse Processor
With the holiday past, I've been able to turn my attention back to my DP5/PC5. Unfortunately, I did not print the responses that were lost on this thread, which addressed issues of powering the boards. Mine will not power up from the USB connection, either with or without the PC5 attached. My intent is to use the DP5 with a photomultiplier output. The PC5 board is marked "Si-PIN Only," so I'm guessing that these are configured only for low voltage output and will not supply the full 1500 volts. So I'll likely be using the DP5 alone with an external power supply for the photomultiplier. Andrew indicated he had supplied power via the 5V external power pads on the PC5 board (I'm assuming the pads marked "GND" and "PWR EXT" next to the eight pin header). Has anyone tried powering just the DP5 from external power? It uses a rather uncommon (to me at least) Hirose MQ172-3PA(55) connector. Does anyone know where to find one of these? Digi-Key lists it as obsolete, but even if they weren't, it's probably an item where you'd have to buy a large quantity. Would those who posted lost responses be willing to repost?
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Andrew Seltzman
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Re: Amptek Digital Pulse Processor
Yes, supplying +5vdc to the pwr_ext pad on the PC 5 will power up the DP5 as well.
I believe you can solder across a resistor to allow usb power, though I think the previously posted manual is for an older version of the board.
From p22 on the manual (again I believe this manual might be for an older version of the board):
Some key points of the overall architecture are as follows:
□ The input power is nominally +5 VDC (4 V to 5.5 V acceptable). Power is usually drawn from the J9 connector. However, the DP5 may be powered from the USB bus or can be powered via the J5 interconnect. Alternately, the interconnect may be used to supply power to a daughter board.
□ To power the DP5 from the USB bus, replace R118 by a zero ohm jumper. Note that this ties the USB bus to the J9 power input and the J5 interconnects. Only power the DP5 from one source at a time. If one attempts to power simultaneously from the USB bus and from an external supply, the two regulators will be “fighting” each other, which is not good.
□ Reverse polarity protection is provided by F1 and D9. There is no over or under voltage protection.
□ F1 is a polyfuse, i.e. a resettable fuse. It goes to a high impedance with very high current but returns to low impedance after power is removed. It does not need replacing after use.
□ When the 5VDC is plugged in, the 3.3V supply in the DP5 turns on and the digital circuitry is powered. When the DP5 is configured, it then turns on its low voltage supplies (+/-5V, 2.5V, 1.2V) and the DP5 is powered. The DP5 can be configured for this to happen automatically when power is applied.
□ When the PC5 is used with the DP5, power is supplied to the PC5 via the J5 interconnect. The DP5 uses the PS Enable line to turn on the supplies in the PC5, after checking the HV polarity.
Nominal switching frequencies are >1 MHz.
I believe you can solder across a resistor to allow usb power, though I think the previously posted manual is for an older version of the board.
From p22 on the manual (again I believe this manual might be for an older version of the board):
Some key points of the overall architecture are as follows:
□ The input power is nominally +5 VDC (4 V to 5.5 V acceptable). Power is usually drawn from the J9 connector. However, the DP5 may be powered from the USB bus or can be powered via the J5 interconnect. Alternately, the interconnect may be used to supply power to a daughter board.
□ To power the DP5 from the USB bus, replace R118 by a zero ohm jumper. Note that this ties the USB bus to the J9 power input and the J5 interconnects. Only power the DP5 from one source at a time. If one attempts to power simultaneously from the USB bus and from an external supply, the two regulators will be “fighting” each other, which is not good.
□ Reverse polarity protection is provided by F1 and D9. There is no over or under voltage protection.
□ F1 is a polyfuse, i.e. a resettable fuse. It goes to a high impedance with very high current but returns to low impedance after power is removed. It does not need replacing after use.
□ When the 5VDC is plugged in, the 3.3V supply in the DP5 turns on and the digital circuitry is powered. When the DP5 is configured, it then turns on its low voltage supplies (+/-5V, 2.5V, 1.2V) and the DP5 is powered. The DP5 can be configured for this to happen automatically when power is applied.
□ When the PC5 is used with the DP5, power is supplied to the PC5 via the J5 interconnect. The DP5 uses the PS Enable line to turn on the supplies in the PC5, after checking the HV polarity.
Nominal switching frequencies are >1 MHz.
Andrew Seltzman
www.rtftechnologies.org
www.rtftechnologies.org
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Peter Schmelcher
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Re: Amptek Digital Pulse Processor
The attached file is for a different rev of the board
PC5 Power Supply User’s Manual Rev. A0
The HV feedback circuit uses a resistor divider which could be changed for a different bias voltage range.
One would need to know the HV capacitor ratings or that all model variations use the same HV capacitors.
I think the Si detector max bias voltage is +200V
BTW the Si Pin Only lid is not soldered to the board it pulls off. The lid covers a 1MHz 5V switcher with an output range from 1.1 to Vin, nothing special.
-Peter
PC5 Power Supply User’s Manual Rev. A0
The HV feedback circuit uses a resistor divider which could be changed for a different bias voltage range.
One would need to know the HV capacitor ratings or that all model variations use the same HV capacitors.
I think the Si detector max bias voltage is +200V
BTW the Si Pin Only lid is not soldered to the board it pulls off. The lid covers a 1MHz 5V switcher with an output range from 1.1 to Vin, nothing special.
-Peter
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- Amptek PC5 User's Manual Rev A0.pdf
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Jim Kovalchick
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Re: Amptek Digital Pulse Processor
I had some time this evening to tinker with my DP5 board. I put a dab of solder between the pads at R28. I connected it by usb to my Windows 10 laptop which auto detected and loaded the correct drivers. I installed the DppMCA software which connected to the DP5 without issue. When I get more time, I will connect a preamp signal and see if board does its thing.
Jim K
Jim K