ALLEGRO CT456 Evaluation Board User Guide
- July 9, 2024
- ALLEGRO
Table of Contents
ALLEGRO CT456 Evaluation Board
DESCRIPTION
The Allegro CTD456 evaluation board demonstrates the advantages of the CT456
high dV/dt optimized Xtreme Sense™ TMR coreless current sensor in enabling
high-accuracy current measurements for many consumer, enterprise, and
industrial applications. The device supports a ±6 mT magnetic field range
where the CT456 senses and translates the magnetic field into a linear analog
output voltage. The device achieves a total error output of less than 1.0%
over voltage and temperature.
The device provides effective common-mode rejection of more than –50 dB,
enabling the CT456 to have greater than 90% immunity to stray magnetic fields,
thus having almost no impact on the accuracy of the current measurement. The
device has less than 300 ns output response time, while the current
consumption is approximately 6.0 mA. The CT456 is housed in a very low-
profile, industry-standard 8-lead TSSOP package that is both green and RoHS
compliant.
FEATURES
- Preset magnetic field range: ±6 mT
- Low-noise performance
- Optimized for high dV/dt applications
- Linear analog output voltage
- Response time: <300 ns
- Supply voltage: 5.0 V
- Operating temperature: –40°C to 125°C
Table 1: CTD456-BB-06B5 Evaluation Board Configurations
Configuration Name| Part Number| Magnetic Field Range|
Bandwidth
---|---|---|---
CTD456-BB-06B5| CT456-A06B5-TS08| ±6 mT| 1 MHz
Table 2: General Specifications
| Specification | Min. | Nom | Max | Units |
|---|---|---|---|---|
| Input Operating Temperature | –40 | – | 125 | °C |
| Input Operating Voltage | 4.75 | 5.0 | 5.50 | V |
USING THE EVALUATION BOARD
This section provides an overview of the connections and configuration options of the CTD456-BB-06B5 evaluation board. Figure 2 highlights the proper configuration. The CT456 datasheet contains detailed information on the use and functionality of each pin, detailed specifications about the sensor, and should be consulted for more information than is contained in this user guide.
Power Input and Board Configuration
When current is flowing through a busbar above or below the CT456, the Xtreme Sense TMR sensor inside the chip senses the field which in turn generates a differential voltage signal that then goes through the Analog Front-End (AFE) to output a current measurement as low as ±1.0% full-scale total output error (EOUT).
The chip is designed to enable a fast response time of 300 ns for the current measurement from the OUT pin as the bandwidth for the CT456 is 1.0 MHz. Even with a high bandwidth, the chip consumes a minimal amount of power.
Power-On Time
Power-On Time of 100 µs is the amount of time required by CT456 to start up, fully power the chip, and becoming fully operational from the moment the supply voltage is greater than the UVLO voltage. This time includes the ramp- up time and the settling time (within 10% of steady-state voltage under an applied magnetic field) after the power supply has reached the minimum VCC.
Response Time
Response Time of 300 ns for the CT456 is the time interval between the following terms: when the primary current signal reaches 90% of its final value, and when the chip reaches 90% of its output corresponding to the applied current.
SCHEMATIC
Figure 3 below shows the schematic of the CTD456-BB-06B5 evaluation board.
LAYOUT
Figures 4 and 5 below show the top and bottom layers of the CTD456-BB-06B5 evaluation board.
Bill of Materials
Table 3: CTD456-BB-06B5 Bill of Materials
Designator| Quantity| Description| Manufacturer|
Manufacturer Part Number
---|---|---|---|---
ELECTRICAL COMPONENTS
PCB| 1| CTD456-BB-06B5 Evaluation Board| Allegro Micro Systems| –
U$2| 1| CT456 Sensor| Allegro Micro Systems| –
JP3| 4| Male Header Connectors| Samtec| TSW-103-07-F-S
C1| 1| Capacitor, Ceramic, 1.0 µF, 25 V, 10% X7R 0603| TDK|
MSAST168SB7105KTNA01
VOUT| 1| SMA Connector| Samtec| SAM8971-ND
R0| 1| Resistor, 0 Ω| Yageo| RC1206FR-130RL
OTHER COMPONENTS
–| 1| Busbar (1/2” width, 1/16” thick)| –| –
–| 2| Connector Heads| TE Connectivity| 225693-E225693-E
–| 2| M3x6mm Metal Screws for Connector Heads| UXCell| a15120300ux0251
–| 2| Plastic High Temperature Screws for Busbar| Misumi| SPS-M5X15-C
–| 2| Plastic High Temperature Nuts for Busbar| Misumi| SPS-M5-N
–| 2| Plastic High Temperature Washers for Busbar| Misumi| SPS-6-W
RELATED LINKS
CT456 Product Page:
https://www.allegromicro.com/en/products/sense/current-sensor-ics/sip-
package-zero-to-thousand-amp-sensorics/CT456
Revision History
| Number | Date | Description |
|---|---|---|
| – | May 23, 2024 | Initial release |
CUSTOMER SUPPORT
Copyright 2024, Allegro Micro Systems.
The information contained in this document does not constitute any
representation, warranty, assurance, guaranty, or inducement by Allegro to the
customer with respect to the subject matter of this document. The information
being provided does not guarantee that a process based on this information
will be reliable, or that Allegro has explored all of the possible failure
modes. It is the customer’s responsibility to do sufficient qualification
testing of the final product to ensure that it is reliable and meets all
design requirements.
Copies of this document are considered uncontrolled documents.
For the latest version of this document, visit our website:
www.allegromicro.com
Allegro Micro Systems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
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