Technical Assistance | Allegro MicroSystems
Owner's Manual for ALLEGRO MICRO models including: CT427-20AC, CTD427-HSN820MR, CT427-20AC High Precision Xtreme Sense, CT427-20AC, High Precision Xtreme Sense, Precision Xtreme Sense, Xtreme Sense, Sense
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DocumentDocumentCTD427-HSN820MR CT427-20AC Evaluation Board User Guide DESCRIPTION The Allegro MicroSystems CTD427-20AC evaluation board contains the CT427--XtremeSenseTM tunnel magnetoresistance (TMR) integrated circuit (IC). This user guide describes the operation and use of the evaluation board as an engineering tool for evaluating the CT427 IC performance in application. FEATURES · Integrated current-carrying conductor · Linear analog output voltage · Response time: ~300 ns · Low noise · Filter function to reduce noise on output pin · Immunity to common mode fields: 54 dB · Overcurrent detection · Supply voltage: 3 V to 3.6 V EVALUATION BOARD CONTENTS · CT427-20AC evaluation board Figure 1: CT427-20AC Evaluation Board Table of Contents Description .......................................................................... 1 Features ............................................................................. 1 Evaluation Board Contents.................................................... 1 Using the Evaluation Board ................................................... 2 Introduction ...................................................................... 2 Power Input...................................................................... 2 Board Configuration .......................................................... 2 Schematic ........................................................................... 3 Layout ................................................................................ 4 Bill of Materials .................................................................... 5 Related Links....................................................................... 6 Revision History................................................................... 7 Table 1: CT427-20AC Evaluation Board Configurations Configuration Name Part Number CT427-20AC Evaluation Board CTD427-HSN820MR Table 2: General Specifications Specification Input Operating Temperature Input Operating Current Sensitivity 50 mV/V Bandwidth 1 MHz Min Nom Max Units 40 125 ºC 20 20 A CTD427-20AC-UM, Rev. 1 MCO-0001667 August 7, 2024 USING THE EVALUATION BOARD Introduction The CT427 is a high-bandwidth and ultra-low-noise integrated contact current sensor that uses Allegro-patented XtremeSenseTM TMR technology to enable high-accuracy current measurements for many consumer, enterprise, and industrial applications. The device supports eight current ranges where the integrated current-carrying conductor (CCC) handles up to 65 A of current and generates a current measurement as a linear analog output voltage. The device achieves a total output error of less than ±1% full-scale (FS).The device has a 300 ns output response time when the current consumption is ~6 mA, and it is immune to common-mode fields. The CT427 has an integrated overcurrent detection (OCD) circuit to identify out-of-range currents (OCD), and the result is output to the fault-bar (FLT) pin. The FLT is an open-drain, active-low digital signal that is activated by the CT427 to alert the microcontroller that a fault condition has occurred. The CT427 is offered in an industry-standard 8-lead small-outline integrated circuit (SOIC) package that is green and Restriction of Hazardous Substances (RoHS) compliant. This section provides an overview of the connections and configuration options of the CT427 evaluation board. The proper configuration is highlighted and detailed in Figure 2. The CT427 datasheet contains detailed information about the use and functionality of each pin and detailed specifications about the sensor. For more detailed information, refer to the product datasheet. Figure 2: CT427-20AC Evaluation Board Power Input The two large connectors (with screws) are used to connect and drive the external current to be measured. Due to the PCB trace thermal limitation of the CT427 evaluation board, do not exceed 20 APK. Board Configuration A fully assembled evaluation board is illustrated in Figure 1 and Figure 2. The current to be measured is connected to the screw connectors located on the right side of the PCB. These connectors are galvanically isolated from the rest of the PCB. The CT427 can be biased by applying a 3.3 V bias voltage between the VDD and GND pins on the PCB and its output can be measured either from the VOUT SMA connector or the VOUT header pin on the PCB. 2 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com SCHEMATIC The schematic of the CT427-20AC evaluation board is shown in Figure 3. Figure 3: CT427-20AC Evaluation Board Schematic 3 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com LAYOUT The top and bottom layers of the CT427-20AC evaluation board are shown in Figure 4 and Figure 5, respectively. Figure 4: Top Layer Figure 5: Bottom Layer 4 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com BILL OF MATERIALS Designator PCB U1 C1 R2 R1 Vout J1, J2 J2 J1 GND, FLTB_ VDD, FLTB, VDD, P2 Quantity Description 1 CT427-20AC evaluation board 1 CT427 sensor 1 1.0 µF, X5R or better SMD Capacitor 0603 1 10 k, ±10% or better SMD Resistor 0603 1 100 k, ±10% or better SMD Resistor 0603 1 SMA Connector 2 Screw Connectors 1 M3 Terminal Screw Red 1 M3 Terminal Screw Black 5 Male Header Connectors - Single pin Manufacturer Allegro MicroSystems Allegro MicroSystems TDK Panasonic, AVX, Yageo Yageo Clinch Connectivity Keystone, Blockmaster Keystone Keystone Manufacturer Part Number CGA3E1X7R1E105K080AC ERJ-3GEYJ103V RC0603FR-07100KL 142-0701-201 534-7701 36-7701-2 36-7701-3 Wurth Elektronik 732-5334-ND 5 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com RELATED LINKS CT427 product page: https://www.allegromicro.com/en/products/sense/current-sensor-ics/zero-to-fifty-amp-integrated-conductor-sensor-ics/ct425-6-7-8 For samples or applications support contact, visit https://www.allegromicro.com/en/about-allegro/contact-us/technical-assistance and navigate to the appropriate region. 6 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com Revision History Number Date June 7, 2024 1 August 7, 2024 Description Initial release Updated evaluation board image (pages 1 4) and BOM (page 5) Copyright 2024, Allegro MicroSystems. Allegro MicroSystems reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. Allegro's products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro's product can reasonably be expected to cause bodily harm. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use. Copies of this document are considered uncontrolled documents. 7 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com