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ASEK772CB-Eval-Board-User-Guide
ASEK772ECB-200B-T
ACS772CB Evaluation Board User Guide
DESCRIPTION
Evaluation boards offer a method for quickly evaluating Allegro current sensors in a lab environment without needing a custom circuit board. This document describes the use of the ACS772CB Evaluation Board. This evaluation board (TED-0003440) is intended for use with the ACS772CB custom 3-pin SOIC current sensor IC.
FEATURES
· 8-layer PCB with 4 oz. copper weight on all layers
· Flexible instrument connection:
Standard Keystone test points, banana jack connectors are provided
NOTE: If using the evaluation board with high currents, remove the banana jacks and use screws and lugs for connection.
EVALUATION BOARD CONTENTS
· Printed circuit board with populated components.
· Recommended bill of materials (BOM) for all compatible current sensor are listed in the "Bill of Materials" section below.
Table of Contents
Description .......................................................................... 1 Features ............................................................................. 1 Evaluation Board Contents.................................................... 1 Using the Evaluation Board ................................................... 2 Schematic ........................................................................... 3 Layout ................................................................................ 4 Thermal Data....................................................................... 5 Bill of Materials .................................................................... 6 Related links........................................................................ 7 Revision History................................................................... 8
Figure 1: ASC772CB Evaluation Board
Figure 2: CB Package
5 V
VOUT
CBYP 0.1 µF
CF
RF
1 VCC
5 IP
ACS772
2 GND
IP
4
3
IP+
VIOUT
Figure 3: ACS772 Typical Application and Pinout
ASEK772CB-UM MCO-0001405
June 21, 2023
USING THE EVALUATION BOARD Evaluation Board Components
1. U1 is an CB package footprint. The ACS772 should be populated here. See yellow highlight on Figure 4.
2. U1 pins (3 to 5; see top view of EVB) allow the option to connect: C4: Load capacitor on VIOUT, can be used to decrease the bandwidth of the sensor in order to optimize noise performance. C1/C2/C3: Bypass capacitor from VCC or VIN to GND. JP1: Connects the output of U2 to VCC. See blue highlight on Figure 4 for above connection locations.
3. Test points allowing easy access to sensor pins. See Test Point locations (VOUT, GND, and VCC) highlighted in orange. See TPGND allowing easy connection to GND highlighted in orange.
4. Standard banana jack connectors IP+ and IP- (primary current mounting position) highlighted in gray. Positive current flow direction is left to right.
5. RB1, RB2, RB3, and RB4: Rubber bumper mounting positions located in top and bottom left and right hand corners. Highlighted in gray.
Evaluation Board Procedure
CONNECTING TO THE EVALUATION BOARD The best way to connect measurement instruments to the evaluation board is to use the provided Keystone test points and banana jack connectors for the applied current.
Figure 4: ASEK772 Evaluation Board Reference Images
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Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com
SCHEMATIC
1
2
3
4
A
A
J3
11
IP-
Panduit LAMA6-14-QY
J4
U1 5 IP-
4 IP+ ACS772
VCC GND Viout
1 2 3
C1 100n
C2 DNI
VCC VCC
GND VOUT
Vout
J2 1 2 3 4
DNI
Scope GND TPGND
B
11
IP+
B
Panduit LAMA6-14-QY
1/4" steel nut 20tpi washer, 0.25" to 0.25" ID 0.5" OD 1/4" x 5/8" 20tpi steel phillips panhead
washer, 0.25" to 0.25" ID 0.5" OD
Place one washer under bolt head, the other under the nut. The lug is to sit on the PCB directly
1/4" steel nut 20tpi
C
C
washer, 0.25" to 0.25" ID 0.5" OD
washer, 0.25" to 0.25" ID 0.5" OD
1/4" x 5/8" 20tpi steel phillips panhead
4-40 FF hex threaded 0.5" standoff
4-40 FF hex threaded 0.5" standoff
4-40 FF hex threaded 0.5" standoff
D
4-40 FF hex threaded 0.5" standoff
4-40x0.25"screw 4-40x0.25"screw 4-40x0.25"screw 4-40x0.25"screw
1
2
PCB PCB PCB, as from TED-0003440-R1 gerber files
Logo? Allegro Logo
Fiducial_1
RoHS Fiducial_2 Logo_1
H1 Net
4-40 Hole
H3
H2
Net
Net
4-40 Hole 4-40 Hole
H4 Net
4-40 Hole
D
Title: ASEK772, Board, Demo, CB-PFF
Size: A
Number: TED-0003440 Author: Philip Treybig
Revision: 1
Date: 2/5/2021
Time: 10:32:46 AM Sheet 1 of 1
File: 3440.SchDoc
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Allegro MicroSystems, LLC 955 Perimeter Rd Manchester NH 03103
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Figure 5: ASEK772 Evaluation Board Schematic
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Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com
LAYOUT
Figure 6: ASEK772 Evaluation Board Top Layer (left) and Bottom Layer (right) Gerber files for the ASEK772 evaluation board are available for download from the Allegro website. See the technical documents section of the ACS772 device webpage.
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Thermal Rise vs. Primary Current
Self-heating due to the flow of current should be considered during the design of any current sensing system. The sensor, printed circuit board (PCB), and contacts to the PCB will generate heat as current moves through the system.
The thermal response is highly dependent on PCB layout, copper thickness, cooling techniques, and the profile of the injected current. The current profile includes peak current, current on-time, and duty cycle. While the data presented in this section was collected with direct current (DC), these numbers may be used to approximate thermal response for both AC signals and current pulses.
The plot in Figure 7 shows the measured rise in steady-state die temperature of the ACS772 versus continuous current at an ambient temperature, TA, of 25°C. The thermal offset curves may be directly applied to other values of TA. Conversely, Figure 8 shows the maximum continuous current at a given TA. Surges beyond the maximum current listed in Figure 8 are allowed given the maximum junction temperature, TJ(MAX) (165), is not exceeded.
Figure 8: Maximum Continuous Current at a Given TA
The thermal capacity of the ACS772 should be verified by the end user in the application's specific conditions. The maximum junction temperature, TJ(MAX) (165), should not be exceeded. Further information on this application testing is available in the DC and Transient Current Capability application note on the Allegro website.
Figure 7: Self-Heating in the CB Package Due to Current Flow
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Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com
BILL OF MATERIALS
Table 1: Evaluation Board Bill of Materials
Item Qty S Manufacturer
P/N
1 19
Allegro
ACS772
2 16
AVX
06035C104K4T2A
32
4 26
Panduit
LAMA6-14-QY
5 36
Keystone
5005
6 16
7 26
8 26
9 46
Keystone
1450C
10 4 6
11 4 10 McMaster-Carr 12 1 10
98017A655
Description
Designator
IC, through-hole, current sensor
U1
Capacitor, 0603, mono, X7R, 50 V, 100 nF
C1
Do not install
C2, J2
Connector, through-hole, mechanical lug, 14 g to 6 g, 0.25 inch stud // comes in package of 25
J3, J4
Test point, thro, compact, for 62 mil PCB, red
GND, VCC, VOUT
Jumper, through, used as scope gnd, bend from 18 g wire, install 0.25 inches above PCB
TPGND
Nut, metal, 1/4" 20 tpi // package of 100
nut1, nut2
screw, metal, zinc-plated, panhead, phillips, 1/4" × 5/8" 20 tpi // package of 50
screw1, screw2
Standoff, metal, hex-threaded, female-female, 4-40 × 0.5inch
standoff1, standoff2, standoff3, standoff4
Screw, metal, zinc-plated, button, slotted, 4-40 × 0.25 inch
screw1, screw2, screw3, screw4
Washer, flat, 1/4 inch, stainless // sold in package of 250 // use two per lug location
w1, w2, w3, w4
PCB, as from TED-0003440-R1 gerber files
PCB
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Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com
RELATED LINKS AND APPLICATION SUPPORT
Table 2: Related Documentation and Application Support
Documentation
Summary
Location
Allegro Current Sensors Webpage
Product datasheet defining common electrical https://www.allegromicro.com/en/products/ characteristics and performance characteristics sense/current-sensor-ics
Allegro Current Sensor Package Documentation Schematic files, step files, package images
https://www.allegromicro.com/en/designsupport/packaging
An Effective Method for Characterizing System Bandwidth in Complex Current Sensor Applications
Application note describing methods used by Allegro to measure and quantify system bandwidth
https://allegromicro.com/en/insights-andinnovations/technical-documents/hall-effectsensor-ic-publications/an-effective-method-forcharacterizing-system-bandwidth-an296169
DC and Transient Current Capability/Fuse Characteristics of Surface Mount Current Sensor ICs
DC and Transient Current Capability/Fuse Characteristics of Surface Mount Current Sensor ICs
https://www.allegromicro.com/en/Insights-andInnovations/Technical-Documents/Hall-EffectSensor-IC-Publications/DC-and-TransientCurrent-Capability-Fuse-Characteristics.aspx
High-Current Measurement with Allegro Current Sensor IC and Ferromagnetic Core: Impact of Eddy Currents
Application note focusing on the effects of alternating current on current measurement
https://allegromicro.com/en/insights-andinnovations/technical-documents/hall-effectsensor-ic-publications/an296162_a1367_ current-sensor-eddy-current-core
Secrets of Measuring Currents Above 50 Amps
Application note regarding current measurement greater than 50 A
https://allegromicro.com/en/insights-andinnovations/technical-documents/hall-effectsensor-ic-publications/an296141-secrets-ofmeasuring-currents-above-50-amps
Allegro Hall-Effect Sensor ICs
Application note describing Hall-effect principles
https://allegromicro.com/en/insights-andinnovations/technical-documents/hall-effectsensor-ic-publications/allegro-hall-effect-sensorics
Hall-Effect Current Sensing in Electric and Hybrid Vehicles
Application note providing a greater understanding of hybrid electric vehicles and the contribution of Hall-effect sensing technology
https://allegromicro.com/en/insights-andinnovations/technical-documents/hall-effectsensor-ic-publications/hall-effect-currentsensing-in-electric-and-hybrid-vehicles
Hall-Effect Current Sensing in Hybrid Electric Vehicle (HEV) Applications
Application note providing a greater understanding of hybrid electric vehicles and the contribution of Hall-effect sensing technology
https://allegromicro.com/en/insightsand-innovations/technical-documents/ hall-effect-sensor-ic-publications/hall-effectcurrent-sensing-in-hybrid-electric-vehicle-hevapplications
Achieving Closed-Loop Accuracy in Open-Loop Current Sensors
Application note regarding current sensor IC solutions that achieve near closed-loop accuracy using open-loop topology
https://allegromicro.com/en/insights-andinnovations/technical-documents/hall-effectsensor-ic-publications/achieving-closed-loopaccuracy-in-open-loop-current-sensors
Allegro Current Sensor ICs Can Take the Heat! Unique Packaging Options for Every Thermal Budget
Application note regarding current sensors and https://allegromicro.com/-/media/files/ package selection based on thermal capabilities application-notes/an296190-current-sensor-
thermals.pdf
Explanation Of Error Specifications For Allegro Linear Hall-Effect-Based Current Sensor Ics And Techniques For Calculating Total System Error
Application note describing error sources and their effect on the current sensor output
https://allegromicro.com/-/media/files/ application-notes/an296181-acs72981-errorcalculation.pdf
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Revision History
Number
Date
June 21, 2023
Initial release
Description
Copyright 2023, 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.
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