SiPM digital control board power supplies

As seen in the SiPM digital control board netlist, the ICs on the control board have many different power requirements. In total there are 6 different voltages required. To minimize the number of actual power supplies needed, however, we plan on supplying only +5V, -5V, and +210V to the board from external power supplies. The other voltages will be created by appropriate voltage regulator ICs on the control board.

+5V supply

The +5V supply is responsible for powering most of the components on the control board. Here is a breakdown of those components by their voltage requirements. Voltages less than +5V will be created using voltage regulators

ICs requiring +5V

IC Name	Pin Name	Tolerance	Current Requirements	Description	Notes
AD5535	V+	±0.25V	0.5mA typ, 1mA max	Positive amplifier
AD5535	AVCC	±0.25V	15mA typ, 18mA max	Analog supply
AD7928	AVDD	±0.25V	2.7mA max operating	AVDD can be as low as 2.7V if voltages measured never exceed 2.5V

ICs requiring +3.3V

IC Name	Pin Name	Tolerance	Current Requirements	Description	Notes
AD5535	ANODE	large	set by external resistor	Temperature sensing diode	Diode drop varies w/ temperature. Requires external current limiting resistor.
AD5535	REF_IN	~±0.4V	1.25uA max	Reference voltage	Should be as high as possible but not exceed AVCC-1.15V
AD7314	VDD	±0.3V	1.2mA typ operating		Indicates ±1°C precision
AD7928	VDRIVE	??? CMOS logic tolerance	200uA	Logic output driver
CP2201	AV+	±0.3V	???	Analog supply pin
CP2201	VDD1	±0.3V	75mA typ, 155mA max operating	Digital supply pin
CP2201	VDD2	±0.3V	75mA typ, 155mA max operating	Digital supply pin

+3.3V supply

Use for:

• AD5535 DAC
  • ANODE
    • Used for temperature monitoring. Voltage drop across a temperature sensitive diode allows AD7928 to measure internal temperature of AD5535. External resistor on AD5535 CATHODE will help to limit current draw.
  • REF_IN supply
    • Using +3.3V for REF_IN limits the SiPM amplifier bias voltages to a maximum of 165V. If greater variability is needed (up to +200V max), a separate +4V supply can be used for REF_IN, perhaps taken from the +5V rail via a voltage divider.
• AD7314 temperature sensor
  • VDD supply
    • indicates ±1°C accuracy
    • should make compatible with 3.3V CMOS logic
• AD7928 ADC
  • VDRIVE output driver supply
• CP2201 Ethernet
  • AV+ analog supply
  • VDD1 digital supply
  • VDD2 digital supply
• FPGA
  • VCCAUX auxiliary supply
    • Can also operate at +2.5V
  • VCCO I/O logic supply
    • Makes it compatible with 3.3V CMOS logic
    • Puts it within acceptable range of voltages for communication with other ICs
• XCF01S EEPROM
  • VCCINT internal supply
  • VCCO output driver
    • Matches 3.3V I/O on FPGA
  • VCCJ JTAG output driver
    • Are we using this?
• AD5535 DAC
  • V+ amplifier supply pins
  • AVCC analog supply pins
  • DVCC digital supply pins
• AD7928 ADC
  • AVDD pins
    • indicates measuring range of 0 to 2xREF_IN voltage

+1.2V supply

Use for:

• FPGA
  • VCCINT internal logic supply

+2.5V supply

Use for:

• AD7928 ADC
  • REF_IN reference supply
    • Must be accurate to ±1%

+5V supply

Use for:

Suggested AD5535 power supply connections taken from AD5535 data sheet.

• AD5535 DAC
  • V+ amplifier supply pins
  • AVCC analog supply pins
  • DVCC digital supply pins
• AD7928 ADC
  • AVDD pins
    • indicates measuring range of 0 to 2xREF_IN voltage

-5V supply

Use for:

• AD5535 DAC
  • V- amplifier supply pins

+210V supply

Use for:

• AD5535 DAC
  • VPP high voltage supply
    • Using this high voltage will allow for large adjustments of the SiPM amplifier bias voltages. Large variations may be necessary because the MATLAB model showed that adjustments between 0 and +50V had no effect on the SiPM.