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20-85V Output Voltage
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10mA Output Current
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1mV Output Voltage step
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Less than 300uV rms noise
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User Selectable Digital / Analog output voltage control
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Automatic temperature feedback on the output voltage
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Multi device support using I2C
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Arduino library designed to manage multiple devices
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Evaluation kit include
- A7585DU HV with USB and I2C interface
- Arudino Uno
- Display with Keypad
- Bread Board
- Cables
- 12v Power Supply
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Fully working examples designed to control the module with keypad and display or monitor multiple devices using serial port
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Module compatible with ZEUS software for stand alone usage
The NIPM-12 SiPM Power Module is a compact and integrated solution to provide stable and noiseless power supply for single and array / matrix SiPM detectors.
High resolution Output Voltage and Output Current measurements enable the NIPM-12 to be used for I-V detector characterization.
Digital (UART, I2C and USB with adapter) and analog control interface are runtime selectable by a single pin or a digital command.
The module integrates a temperature HV loop that regulates the SiPM output voltage as a programmable function of the SiPM temperature coefficient.
The Arduino evaluation kit is a ready to use solution to discovery the capabilities of the A7585D integrated in a custom OEM solution. The A7585D library provide an high level abstraction of all commands supported by the module. It allows, for example, with a few lines of code to configure the module and readback voltage and current monitor values
In order to use the examples of this application note it is necessary to install A7585D library and LiquidCrystals library. A7585D library is a Nuclear Instruments library developed to interface with A7585D with an high level class while LiquidCrystals library is an opensource library for LCD display control.
To install the libraries open Arduino software, Sketch menu -> Add .ZIP library. Select the two library zip file from the repository
The A7585D can be controlled via UART, USB and I2C. While UART and USB are suited for PC control the I2C is the best solution to interface multiple modules with module with a single controller like an Arduino, a Raspberry PI or another microcontroller. I2C bus support device addressing: up to 120 A7585D/DU can be controlled by a single Arduino processor without any communication issue.
In application where a large number of channel is required, this design can be the ultimate solution in order to control and monitor multiple devices.
The I2C bus use just two wires to interface a master device with multiple slave. The master device is the Arduino Uno while the slave devices are the A7585DU modules.
The two wires are:
•SDA: data wire. Bidirectional, transport data between master and slaves. SDA is the green wire in the scheme
•SCL: clock wire. Generated by the master. SCL is the yellow wire in the scheme
Each device on the I2C has an address that must be unique. Read carefully the module address section if you need to operate with multiple A7585DU
The A7585DU must operate with a supply voltage greater than 6V. It is indeed impossible to connect the Vin pin to the Arduino 5V. An external power supply is required. Power Supply can be externally provided with the 12v power supply included in the kit through the Arduino power supply connector.
The 12V wire (violet) connect the VIN pin of the Arduino to the input voltage of the A7585DU
The A7585DU require an additional power supply of 5V (red) in order to power the I/O buffer for the I2C interface. This buffer allows to interface the A7585DU on the I2C with any chip operating with a voltage between 1.8V and 5.5V.
The black wire connects the Arduino ground to the HV module ground.
This is the minimal configuration to control with I2C the A7585DU module
In the following section a full description of all function of the A7585A library is provided
bool Init(int IICAddress)
IN IICAddress: address of the A7585A in 7 bit format
OUT bool: true if a valid module has been identified
Initialize the library providing the I2C module Address. The default module address is 0x70
void Set_MaxV(float v)
IN v: HV output compliance voltage
Set the hv output maximum output voltage (protection)
void Set_MaxI(float v)
IN v: HV maximum output currect
Set the hv output maximum output current. The module is switched off if current exceeds the limit
void Set_Enable(bool v)
IN
v: Enable the output
Enable the HV output. If the HV fails due to overcurrent Set_Enable false and true to restore HV
void Set_RampVs(float v)
IN
v: Ramp speed in V/s
Set the HV output ramp speed in V/S
void Set_TemperatureSensor(HVTemperatureSensors SensorModel, float term_m2, float term_m, float term_q )
IN
SensorModel: Select between standard thermometer already calibrated and custom model term_m2: quadratic fitting parameter between temperature and ref voltage term_m: linear fitting parameter between temperature and ref voltage term_q: offset
Configure the thermometer connected to the A7585A in order to operate in temperature compensated mode
void Set_Filter(float alfa_v, float alfa_i, float alfa_t)
IN
alfa_v: out voltage monitor filter coefficient alfa_i: out current monitor filter coefficient alfa_t: temperature monitor filter coefficient
Set the filter coefficient applied to the data monitor filter [0…0.9999]. A value closer to 1 means an higher number of averages and an higher resolution while a value closer to 0 means no filtering and faster response
void Set_SiPM_Tcoef (float tcomp)
IN tcomp: Thermal coefficient compensation
This is the coefficient provided by SiPM manufacturer expressed is V/°C to compensate the gain variation due to the temperature. A typically value is -34mV/°C
void EmergencyOff()
Switch off HV without ramp
void SetI0()
Compensate the current measured zeroing the measurement and removing biasing
void Set_DigitalFeedback(bool on)
IN on: Enable the internal PID controller
The internal PID controller use the voltage value read by the feedback ADC in order to compensate small static error in the feedforward output setpoint
void Set_IIC_baseaddress(uint8_t ba)
IN ba: new base address for the A7585D
Change the base address of the A7585D. The module address will be the ba added to the status of the address pins.
uint8_t GetDigitalPinStatus()
OUT uint8_t: binary encoded pin status
Read the status of all digital I/O of the module
float GetVin()
OUT float: power supply voltage
Read the power supply voltage
float GetVout()
OUT float: Output voltage
Read the power HV out voltage
float GetIout()
OUT float: Output current
Read the power HV output current
float GetVref()
OUT float: Reference pin voltage
Read the voltage on the reference (analog control only) pin
float GetTref()
OUT float: Temperature of the SiPM
Read the temperature of the SiPM through the temperature sensor connected to the Vref pin
float GetVtarget()
OUT float: Current voltage target
Read current output voltage target
float GetVtargetSP()
OUT float: Current output voltage set on the module
Read the current DAC set point in Volt
float GetVcorrection()
OUT float: correction voltage applied to the target
Read the correction voltage applied to the target in order to compensate the temperature
bool GetVCompliance()
OUT bool: flag indicating that the module output voltage is limited by compliance
When true, the output voltage is clamped to the compliance voltage
bool GetICompliance()
OUT bool: flag indicating a overcurrent protection
When true, the module has been switched off due to over current. To restore the module disable and enable the output.
uint8_t GetProductCode()
OUT uint8_t: product code of the device
Return the product code of the device
uint8_t GetFWVer()
OUT uint8_t: firmware version
Return the firmware version of the device
uint8_t GetHWVer()
OUT uint8_t : hardware version
Return the hardware version of the device
uint32_t GetSerialNumber()
OUT
uint32_t: serial number of the device Return the serial number of the device
bool GetHVOn()
OUT bool: hv status
Read the current HV status (true is on)
bool GetConnectionStatus()
OUT bool: flag indicating that Arduino is connected to the module
When true, the Arduino is connected to the module
void StoreCfgOnFlash ()
Save configuration on flash
Connect the module A7585D/U to the Arduino
#include <A7585lib.h>
#include <Wire.h>
#include <stdio.h>
#include <stdlib.h>
#define DEV_ADDRESS 0x70
A7585 A7585_dev;
// Initialize device
void InitNIPM(int device_address)
{
A7585_dev.Init(device_address);
A7585_dev.Set_Mode(0); //SET MODE DIGITAL
A7585_dev.Set_MaxV(80); //SET COMPLIANCE 80V
A7585_dev.Set_MaxI(10); //SET MAXIMUM CURRENT 10mA
A7585_dev.Set_RampVs(25); //SET RAMP UP SPEED 25V/s
}
void setup() {
Serial.begin(115200);
Wire.begin();
InitNIPM(DEV_ADDRESS);
if (A7585_dev.GetConnectionStatus())
Serial.println("Probe connection successful");
else
Serial.println("Error connecting device ");
A7585_dev.Set_V(50); //SET VOUT=50V
A7585_dev.Set_Enable(true); //ENABLE HV
}
void loop() {
cvout = A7585_dev.GetVout(); //READ VOLTAGE
ciout = A7585_dev.GetIout(); //READ CURRENT
Serial.print(" V: "); Serial.print(cvout); Serial.print(" I: "); Serial.println(ciout);
delay(1000);
}