The AD5628 device is a low power, octal, 12-bit, buffered voltage-output DAC. The device operates from a single 2.7 V to 5.5 V supply and is guaranteed monotonic by design. The AD5628 is available in both a 4 mm × 4 mm LFCSP and a 16-lead TSSOP.
The AD5628 has an on-chip reference with an internal gain of 2. The AD5628-1 has an 1.25 V 5 ppm/°C reference, giving a full-scale output range of 2.5 V; the AD5628-2, has a 2.5 V 5 ppm/°C reference, giving a full-scale output range of 5 V. The on-board reference is off, at power-up, allowing the use of an external reference. The internal reference is enabled via a software write.
The part incorporates a power-on reset circuit that ensures that the DAC output powers up to 0 V and remains powered up at this level until a valid write takes place. The part contains a power-down feature that reduces the current consumption of the device to 400 nA at 5 V and provides software-selectable output loads while in power-down mode for any or all DAC channels.
The outputs of all DACs can be updated simultaneously using the LDAC function, with the added functionality of user-selectable DAC channels to simultaneously update. There is also an asynchronous CLR that updates all DACs to a user-programmable code—zero scale, midscale, or full scale.
The AD5628 utilizes a versatile 3-wire serial interface that operates at clock rates of up to 50 MHz and is compatible with standard SPI®, QSPI™, MICROWIRE™, and DSP interface standards. The on-chip precision output amplifier enables rail-to-rail output swing.
The goal of this project (Microcontroller No-OS) is to be able to provide reference projects for lower end processors, which can't run Linux, or aren't running a specific operating system, to help those customers using microcontrollers with ADI parts. Here you can find a generic driver which can be used as a base for any microcontroller platform and also specific drivers for different microcontroller platforms.
The driver contains two parts:
The Communication Driver has a standard interface, so the AD5628 driver can be used exactly as it is provided.
There are three functions which are called by the AD5628 driver:
SPI driver architecture
The following functions are implemented in this version of AD5628 driver:
Function | Description |
---|---|
char AD5628_Init(void) | Resets the device and performs several initializations. |
void AD5628_PowerMode(unsigned char pwrMode, unsigned char channel) | Sets the device in a specific power mode. |
void AD5628_Reset(void) | Resets the device. |
void AD5628_SetInputRegister(unsigned long registerValue) | Writes a 32-bit data-word to the Input Register of the device. |
HW Platform(s):
This section contains a description of the steps required to run the AD5628 demonstration project on a Digilent Cerebot MX3cK platform.
The AD5628 demonstration project for PIC32MX320F128H consists of three parts: the AD5628 Driver, the PmodDA4 Demo for PIC32MX320F128H and the PIC32MX320F128H Common Drivers.
All three parts have to be downloaded.
The following commands were implemented in this version of AD5628 reference project for Cerebot MX3cK board.
Command | Description |
---|---|
help? | Displays all available commands. |
mode= | Selects a mode of operation for selected channel. Accepted values: channel: 0 .. 7 - Channel A .. H(one channel) 15 - All channels. mode: 0 - Normal operation. 1 - 1KOhm to GND(Power down mode). 2 - 100KOhm to GND(Power down mode). 3 - Three-state(Power down mode). |
mode? | Displays the selected mode of operation for the selected channel. Accepted values: 0 .. 7 - Channel A .. H(one channel) 15 - All channels. |
voltage= | Sets the output voltage for the selected channel. Accepted values: channel: 0 .. 7 - Channel A .. H(one channel) 15 - All channels. output voltage: 0 .. 2500 - Desired output voltage in milivolts. |
voltage? | Displays the output voltage of the selected channel. Accepted values: 0 .. 7 - Channel A .. H(one channel) 15 - All channels. |
register= | Writes the value into the DAC register of the selected channel. Accepted values: channel: 0 .. 7 - Channel A .. H(one channel) 15 - All channels. register value: 0 .. 4095 - The value written to the DAC. |
register? | Displays the value written in the DAC register of the selected channel. Accepted values: 0 .. 7 - Channel A .. H(one channel) 15 - All channels. |
Commands can be executed using a serial terminal connected to the UART1 peripheral of PIC32MX320F128H.
The following image shows a generic list of commands in a serial terminal connected to processor’s UART peripheral.
This section presents the steps for developing a software application that will run on the Digilent Cerebot MX3cK development board for controlling and monitoring the operation of the ADI part.
This section contains a description of the steps required to run the AD5628 demonstration project on a Digilent Cerebot MC7 platform.
Following commands were implemented in this version of AD5628 reference project for Cerebot MC7 board.
Command | Description |
---|---|
help? | Displays all available commands. |
mode= | Selects a mode of operation for the current channel. Accepted values: 0 – 3. |
mode? | Displays the selected mode of operation for the current channel. |
channel= | Selects the channel that will be affected by the other commands. Accepted values: 0 – 7 (one channel) or 15 (all channels). |
channel? | Displays the selected channel. |
voltage= | Sets the output voltage for the current voltage. Accepted values: 0 – 2.5 (volts). |
voltage? | Displays the output voltage of the current voltage. |
register= | Writes the value into the Input Register of the current channel. Accepted values: 0 – 4095. |
register? | Displays the value written in the Input Register of the current channel. |
Commands can be executed using a serial terminal connected to the UART1 peripheral of dsPIC33FJ128MC706A.
The following image shows a list of commands in a serial terminal connected to processor’s UART peripheral.
This section presents the steps for developing a software application that will run on the Digilent Cerebot MC7 development board for controlling and monitoring the operation of the ADI part.
This section contains a description of the steps required to run the AD5628 chipKIT demonstration project on a Digilent Cerebot MX3cK platform.
Following commands were implemented in this version of AD5628 chipKIT reference project for Cerebot MX3cK board.
Command | Description |
---|---|
help? | Displays all available commands. |
mode= | Selects a mode of operation for the current channel. Accepted values: 0 – 3. |
mode? | Displays the selected mode of operation for the current channel. |
channel= | Selects the channel that will be affected by the other commands. Accepted values: 0 – 7 (one channel). |
channel? | Displays the selected channel. |
voltage= | Sets the output voltage for the current voltage. Accepted values: 0 – 2.5 (volts). |
voltage? | Displays the output voltage of the current voltage. |
register= | Writes the value into the Input Register of the current channel. Accepted values: 0 – 4095. |
register? | Displays the value written in the Input Register of the current channel. |
Commands can be executed using the serial monitor.
Carriage return has to be selected as a line ending character. The required baud rate is 9600 baud.
The following image shows a list of commands in the serial monitor.
This section presents the steps for developing a chipKIT application that will run on the Digilent Cerebot MX3cK development board for controlling and monitoring the operation of the ADI part.
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