HALL CURRENT 6 CLICK 数据手册
HALL CURRENT 6 CLICK
PID: MIKROE-3443 Weight: 26 g
Hall Current 6 Click is a very accurate current measurement Click board™, based on
the ACS723 IC. This IC is a galvanically isolated current sensor, which utilizes the Halleffect principle. Its most distinctive feature is its very low series resistance of only 0.65
mΩ, which makes this device a nearly-perfect ammeter. The maximum current which
can be measured with Hall Current 6 click ranges from -5 A to +5 A, with the optimized
precision. It features a dedicated bandwidth selection pin, which allows better noise
performance for a specific application.
Hall Current 6 Click is supported by a mikroSDK compliant library, which includes
functions that simplify software development. This Click board™ comes as a fully tested
product, ready to be used on a system equipped with the mikroBUS™ socket.
The ACS723 has a precisely trimmed analog output, which changes linearly with the
applied current. Its accuracy is further optimized through the Allegro’s patented digital
temperature compensation. Its excellent galvanic isolation simplifies the application,
allowing the Click board™ to be connected directly to the high side of the measured
circuit. It can be used to measure both DC and AC current. The ACS723 IC features a
bandwidth selection pin, used to adjust the measurement to a frequency bandwidth of
the application. Hall Current 6 click can be used in motor control applications, load
detection and management applications, switch-mode power supplies, overcurrent fault
protection applications, and similar applications that require accurate and reliable
current sensing.
DO NOT TOUCH THE BOARD WHILE THE EXTERNAL POWER
SUPPLY IS ON!
Note: The Click board™ is to be used by trained personnel only, while applying high
voltages. A special care should be taken when working with hazardous voltage levels.
HOW DOES IT WORK?
Hall Current 6 utilizes the ACS723(LLCTR-05AB-T), a high-accuracy, galvanically
isolated current sensor IC, from Allegro Microsystems. This sensor utilizes the Hall effect
phenomenon to measure the current passing through the internally fused input pins of
the IC. This allows the series resistance to stay very low. Current through the input rails
of the IC generates a magnetic field, causing the Hall effect on the current through the
integrated sensor. These two current circuits are completely isolated, with the basic
isolation working voltage of about 297VRMS, allowing the Click board™ to be used in
high-side current sensing applications.
The output voltage changes linearly with the current in the primary circuit, with the ratio
of 400mV/A, and it is fed to the MCP3221, a 12-bit analog to digital converter (ADC) with
I2C interface, from Microchip. This is a well-established converter used in many Click
board™ designs, thanks to its proven reliability, reasonably good sampling rate well
suited for instrumentation applications (22.3 ksps), and simplicity of use. It converts the
output voltage from the ACS723 into a digital value, which is available over the I2C
interface. The output voltage of the ACS723 has a very linear dependency of the current
through the primary pins, due to the Allegro’s patented digital temperature
compensation. Although it can be used in a rather limited current range of ±5A, it has a
great accuracy of ±3% (referred to as a Total Output Error in the datasheet).
The ACS723 IC features a bandwidth selection pin, which allows the bandwidth
selection according to the application it is used in. For example, when measuring
current in some applications that operate at lower frequencies, limiting the bandwidth
improves the noise performance, enabling to obtain results with higher accuracy. The
bandwidth selection pin acts as a filter on the measurement line, allowing two cutoff
frequencies: 20kHz and 80kHz. The BW_SEL pin of the ACS723 is routed to the small
SMD jumper, labeled as BW SEL. When the jumper is at the position 0, the bandwidth
of the device is 80kHz.
The secondary side of the ACS733 is powered from the 5V mikroBUS™ rail. As
explained earlier, current flowing through the primary conductors is galvanically isolated
from the rest of the IC, protecting low-voltage parts of the Click board™, as well as the
host MCU. The Click board™ should be connected in series with the load through which
the current is measured, by using the load connector, labeled with IP+ and IP-. A very
low internal resistance of only 0.65 mΩ across the primary conductors, will not disturb
the current through the circuit, so the Click board™ will not introduce its own error into
the measurement, thus acting as a nearly-perfect ammeter.
The voltage at which the I2C lines are pulled up can be selected using the VCC SEL
jumper. The ability to select the logic voltage level allows this Click board™ to be
interfaced with a wide range of different MCUs, operating at both 3.3V and 5V.
SPECIFICATIONS
Type
Current
Applications
It can be used in motor control applications, load detection and
management applications, switch-mode power supplies,
overcurrent fault protection applications, etc.
On-board
modules
ACS723, a high-accuracy, galvanically isolated current sensor IC,
from Allegro Microsystems; MCP3221, a 12-bit analog to digital
converter (ADC) with I2C interface, from Microchip.
Key Features
Very low series resistance, which makes this sensor an ideal
ammeter, wide current range, factory calibrated accuracy, low
count of external components, high isolation voltage, added ADC
for simpler interfacing to embedded systems.
Interface
I2C
Input Voltage
3.3V,5V
Click board
size
M (42.9 x 25.4 mm)
PINOUT DIAGRAM
This table shows how the pinout on Hall Current 6 click corresponds to the pinout on
the mikroBUS™ socket (the latter shown in the two middle columns).
Notes
Pin
Pin
Notes
NC
1
AN
PWM
16
NC
NC
2
RST
INT
15
NC
NC
3
CS
RX
14
NC
NC
4
SCK
TX
13
NC
NC
5
MISO
SCL
12
SCL
I2C Clock
NC
6
MOSI
SDA
11
SDA
I2C Data
Power Supply
3.3V
7
3.3V
5V
10
5V
Ground
GND
8
GND
GND
9
GND
Power Supply
Ground
HALL CURRENT 6 CLICK ELECTRICAL SPECIFICATIONS
Description
Min
Typ
Max
Unit
Primary conductor resistance
-
0.65
-
mΩ
Measurement range with optimized accuracy
-5
-
+5
A
Sensitivity
-
400
-
mV/A
Working voltage for basic isolation
-
-
297
V(RMS)
ONBOARD SETTINGS AND INDICATORS
Label
Name
Default
Description
PWR
PWR
-
VCC SEL
VCC SEL
Left
Logic voltage level selection: left position 3.3V,
right position 5V
BW SEL
BW SEL
Left
Bandwidth selection: left position 80kHz (0), right
position 20kHz (1)
Power LED indicator
SOFTWARE SUPPORT
We provide a library for the Hall Current 6 click on our LibStock page, as well as a
demo application (example), developed using MikroElektronika compilers. The demo
can run on all the main MikroElektronika development boards.
Library Description
This library provides basic functionality for reading the current value and controlling the
click board.
Key functions:
float hallcurrent6_getCurrent() - Reads Current data in mA.
uint16_t hallcurrent6_readData() - Reads ADC current data.
Examples description
The application is composed of the three sections :
System Initialization - Initializes I2C module.
Application Initialization - Initializations driver init.
Application Task - Reads Current data in mA and logs this data to USBUART every 1 sec.
void applicationTask()
{
char demoText[ 50 ];
float Current;
Current = hallcurrent6_getCurrent();
mikrobus_logWrite(" Current value: ", _LOG_TEXT);
FloatToStr(Current, demoText);
mikrobus_logWrite(demoText, _LOG_TEXT);
mikrobus_logWrite(" mA", _LOG_LINE);
mikrobus_logWrite(" ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ", _LOG_LINE );
Delay_ms( 1000 );
}
The full application code, and ready to use projects can be found on our LibStock page.
Other mikroE Libraries used in the example:
I2C
Conversions
Additional notes and informations
Depending on the development board you are using, you may need USB UART
click, USB UART 2 click or RS232 click to connect to your PC, for development systems
with no UART to USB interface available on the board. The terminal available in all
MikroElektronika compilers, or any other terminal application of your choice, can be
used to read the message.
MIKROSDK
This click board is supported with mikroSDK - MikroElektronika Software Development
Kit. To ensure proper operation of mikroSDK compliant click board demo applications,
mikroSDK should be downloaded from the LibStock and installed for the compiler you
are using.
For more information about mikroSDK, visit the official page.
https://www.mikroe.com/hall‐current‐6‐click//4‐9‐19