购买 Sub-µA Current Sensor

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The NXP analog product development boards provide an easy-to-use platform for evaluating NXP products. The boards support a range of analog, mixed-signal and power solutions. They incorporate monolithic integrated circuits and system-in-package devices that use proven high-volume technology. NXP products offer longer battery life, a smaller form factor, reduced component counts, lower cost and improved performance in powering state-of-the-art systems.

This page will guide you through the process of setting up and using the RD-UAMP- SENSOR board.

1.1 Kit contents/packing list

The RD-UAMP-SENSOR contents include:

Assembled and tested board in an anti-static bag
Quick Start Guide

标记为完成:1.1 Kit contents/packing list

1.2 Additional hardware

In addition to the kit contents, the following hardware is necessary or beneficial when working with this kit.

FRDMKL25-A8471 or FRDM-K22F-AGMP03 sensor evaluation kits

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1.3 Software

The software collaterals enabling RD-UAMP-SENSOR board include:

MCUXpresso SDK based embedded software project for RD-UAMP-SENSOR board
IoT Sensing SDK based host i/o embedded project enabling sensor tool box GUI demo (for sensors evaluation kits, for example, FRDMKL25-A8471 and FRDM-K22F- AGMP03)
Sensor tool box windows GUI extension packages for visualizing current measurement output

标记为完成:1.3 Software

1.4 User manual

Refer to UM11470, RD-UAMP-SENSOR reference design for additional details on the featured components and board configuration.

标记为完成:1.4 User manual

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Get to know the hardware

2.1 Board description

The RD-UAMP-SENSOR reference design is a Cortex-M4-based current measurement board, for use with the Freedom Development Ecosystem or any other Arduino-like development boards.

The board embeds two controllable current measurement units that allow for signal filtering, automatic and manual range switching, as well as an LCD module and capacitive buttons for quick visualization and configuration.

标记为完成:2.1 Board description

2.2 Board features

Non-intrusive interfacing with any MCU board and 3.3 V shield
Measurement of a large range of low currents: ~60 nA – 5 mA
Multiple communication methods: LCD module, I²C sensor emulation, optional Bluetooth module, serial port / custom protocol through USB
Integration with Freedom Sensor Toolbox (CE)
Open-source firmware powered by FreeRTOS

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2.3 Board components

Overview of the RD-UAMP-SENSOR board

Table 1. Evaluation board component descriptions

Number	Label	Name	Description
1	J1	Micro-USB B female connector	Provides 5.0 V power supply to the board and access to K22F MCU USB pins
2	SW2	On/Off switch	When the board is equipped with a battery, slide to: Battery / left position to power On the board USB / right position to switch it Off or recharge the battery (if an external power source is connected) Otherwise set switch on the USB / right position
3	D9	Power indicator LED	LED turns red when the board is powered On
4	DS1	LCD module	Displays real-time current measurement results and the various menu pages and parameters
5	E1 to E6	Capacitive touch buttons	Allows navigation across all menu pages and parameters selection
6	U1	K22F Cortex M4 MCU	On-board MCU running a real-time firmware to emulate a microampere current sensor
7	SW1	Reset pushbutton	Manual reset for onboard K22F MCU
8	J3	10 pins JTAG header	Used to flash and debug onboard K22F MCU
9	U5, U6, U8, U12	Sensor shield current measurement unit	Arrangement of a precision LDO, a differential amplifier, sense resistors and filtering capacitors connected with CMOS switches
10	J6, J7, J11, J12	Sensor shield headers	Connect a sensor shield on top of the board in order to measure current
11	J4, J5, J9, J10	Freedom board connection headers	Plug the board onto the Freedom bottom board associated to the sensor top shield
12	J9 - pin 12	Shield current	Provides compatibility with LPCXpresso boards that incorporate the power measurement circuit for MCUXpresso IDE power measurement tool
13	U9, U10, U11	Freedom MCU current measurement unit	Arrangement of a differential amplifier, sense resistors and filtering capacitors connected with CMOS switches
14	J15	Header for shield ammeter	Remove jumper to measure current with an external micrometer (for verification/ calibration purpose)
15	J16	Header for MCU ammeter	Remove jumper to measure current with an external micrometer (for verification/ calibration purpose)
16	J13, J14	I²C selection headers	Set SDA and SCL jumpers onto pins 2-3 in order to select I2C1 lines (right position, contrary to picture)
17	SW3	RST header pushbutton	Manual reset of the RST line (J12-pin3)
18	J2, U2, D1, D2	Battery connector, charger and LEDs	Simply connect a LiPo/Lion battery to J2 in order to operate the board autonomously and even wirelessly with a BT module
19	J8	4 pins UART/Bluetooth connector	Can be used to connect a serial interface or Bluetooth module (necessitates K22F firmware customization)
20	TP1 to TP8	Test points	Easy access to current sense amplifier inputs and output

标记为完成:2.3 Board components

2.4 Additional board support

Refer to UM11470, RD-UAMP-SENSOR reference design for additional details on the featured components.

标记为完成:2.4 Additional board support

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下一页Configure the hardware

Configure the hardware

The RD-UAMP-SENSOR reference design is designed to interface with any existing 3.3 V MCU and shield combo, such as the NXP Freedom sensor development kits.

Note: RD-UAMP-SENSOR board has been tested with FRDMKL25-A8471 (FRDM-KL25Z MCU and FRDM-STBC-A8471 shield board) and FRDM-K22F-AGMP03 (FRDM-K22F MCU and FRDM-STBC-AGMP03 shield board) sensor evaluation kits.

The RD-UAMP-SENSOR board simply plugs in between the MCU and shield, mirroring all pins except for the 3.3 V supplies that now go through the current measurement units.

Note: The MCU current measurement is possible only when powered from the RD- UAMP-SENSOR’s onboard USB or battery.