The PCT2075 is a temperature-to-digital converter featuring ±1 °C accuracy over -25 °C
to +100 °C range. It uses an on-chip band gap temperature sensor and Sigma-Delta A to-
D conversion technique with an overtemperature detection output. The device contains a number of
data registers: Configuration register (Conf) to store the device settings such as device
operation mode, OS operation mode, OS polarity and OS fault queue; temperature
register (Temp) to store the digital temp reading, set-point registers (Tos and Thyst) to
store programmable overtemperature shutdown and hysteresis limits, and programmable
temperature sensor sampling time Tidle, that can be communicated by a controller via
the 2-wire serial I2C-bus Fast-mode Plus interface
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The image below shows PCT2075DP Block diagram:
Boards: FRDM-MCXN947 , FRDM-MXCA153
Categories: Sensor
Peripherals: I2C
Toolchains: MCUXpresso IDE
- MCUXpresso SDK v25.03.00 for FRDM-MCXN947
- MCUXpresso SDK v25.03.00 for FRDM-MCXA153
- MCUXpresso IDE v24.12.148
- FRDM-MCXN947 MCU board
- FRDM-MCXA153 MCU board
- PCT2075DP-ARD
- Personal Computer
- Mini/micro C USB cable
- Jumper Wires
- Install MCUXpresso IDE v24.12.148
- Download and Install MCUXpresso SDK vv25.03.00 for FRDM-MCXN947.
- Download and Install MCUXpresso SDK vv25.03.00 for FRDM-MCXA153.
- Install Putty/Teraterm for UART.
- Clone this repository to get the example projects.
- Change directory to cloned project folder:
cd dm-pct2075dp-ard-temperature-sensor
Note: If using Windows to clone the project, then please configure filename length limit using below command
git config --system core.longpaths true
- Open MCUXpresso IDE and select a directory to create a workspace.
- Install MCXUpresso SDK v24.12.148 for FRDM-MCXN947/FRDM-MCXA153 (drag and drop SDK zip into "Installed SDK" view) into MCUXpresso IDE.
- Go to "Quickstart Panel" and click on "Import Project(s) from file system",
- Select "Project directory (unpacked)" and browse to the cloned project folder.
- Select example projects to open and run.
- Right click on project and select build to start building the project.
Hardware Configuration
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PCT2075DP :-
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Ensure that jumpers A0, A1, and A2 are set to the 2-3 position to configure the default device address to 0x48. This address can be modified by the user according to the datasheet. Additionally, make sure the J3 jumper is shorted to enable the Over-Temperature Shutdown (OTS) LED.
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PCT2075DP cannot be stacked over the boards MCXA153 and MCXN947 ,refer to the porting guide given below:-
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User need to check COM port after connecting USB cable between Host PC and Target Board via device manager.
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Open PUTTY/Teraterm application installed on Windows PC with Baudrate 115200 and assigned COM port as mentioned in above step.
Note : By default I2C controller operates in Interrupt mode. For I2C controller to operate in EDMA mode, Define RTE_I2C0_DMA_EN 1 in case of FRDM-MCXA153 and RTE_I2C2_DMA_EN 1 in RTE_Device.h file under the board directory in case of FRDM-MCXN947.
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After right-clicking on the project and selecting "Debug As", the demo application will launch in interactive mode. Once the demo runs successfully, the logs will be displayed in the termina
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The application starts by showing a main menu :
NOTE: Default Device conditions are given below:
- Device operational mode: Normal
- OS mode: Comparator
- Active polarity: Low
- Fault Queue: 1
And it can also be adjusted according to user requirements by selecting Option #2.
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Press #1 to read tempeature in Normal mode(Default).
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Current Temperature will be shown :
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Test over temperature shutdown condtion in Comparator(default) mode
NOTE: For over temperature condition to occur, current temperature should be greater than T-OS and T-HYS should always be less than T-OS.
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Select option #3 to set the T-HYS
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Select option #4 to set the T-OS
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Red coloured prompt as shown above and over temperature shutdown LED will glow up as shown below!
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To Reset the OS comparator mode, current temperature should be less than T-HYS and T-HYS should always be less than T-0S, then LED will stop glowing and same above steps can be performed again to activate the comparator mode.
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Test Over temperature condition in Interrupt Mode
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Select option #2 to set OS operational mode as Interrupt mode.
NOTE: For over temperature condition to occur, current temperature should be greater than T-OS and T-HYS should always be less than T-OS same as comparator mode.
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To Reset the OS Interrupt mode, Reading any temperature be it current, T-hys or T-os will work and OS LED will stop glowing.
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To again activate the OS Interrupt mode, Current Temperature should be less than T-HYS and T-HYS should always be less than T-OS. The OS interrupt operation would be continued in this sequence: T-OS trip, Reset, T-HYS trip, Reset, T-OS trip, Reset, T-HYS trip, Reset, etc.
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Enter #5 to Set Device Idle Time
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T-idle tells for how long device stays idle after doing ADC temperature measurement. Here, users have to provide the sampling period value between 1-31. Default is 1. More the sampling period, more will be idle time.
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Enter #2 to change the device operational mode to Shutdown mode
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Select #1 to set the shutdown mode.
NOTE: Now, device will hold the last temperature value and no further temperature conversions will take place.
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Press #6 for software reset
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This will reset your board to default settings and show a message " Device Reset successfull !!!".
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Press #7 to Exit the Application.
Questions regarding the content/correctness of this example can be entered as Issues within this GitHub repository.
Warning: For more general technical questions regarding NXP Microcontrollers and the difference in expected funcionality, enter your questions on the NXP Community Forum
| Version | Description / Update | Date |
|---|---|---|
| 1.0 | Initial release on Application Code Hub | Sep 12th 2025 |