Texas Instruments LM74700DDFEVM User manual

User’s Guide
LM74700DDFEVM: Evaluation Module for LM74700-Q1
ABSTRACT
This user’s guide describes the evaluation module (EVM) for Texas Instruments ideal diode controller, LM74700-
Q1. This document provides configuration information and test setup details for evaluating LM74700-Q1 device
in 8-pin DDF package. An EVM schematic, board layout images, and bill of materials (BOM) are included.
Table of Contents
1 Introduction.............................................................................................................................................................................2
2 Setup........................................................................................................................................................................................2
2.1 I/O Connector Description..................................................................................................................................................2
2.2 Board Setup....................................................................................................................................................................... 3
2.3 Schematic.......................................................................................................................................................................... 4
3 Operation.................................................................................................................................................................................5
3.1 Reverse Polarity Protection................................................................................................................................................5
3.2 ORing Application.............................................................................................................................................................. 6
4 EVM Board Assembly Drawings and Layout Guidelines....................................................................................................7
4.1 PCB Drawings....................................................................................................................................................................7
4.2 Bill of Materials...................................................................................................................................................................9
List of Figures
Figure 2-1. LM74700DDFEVM Typical Application Circuit.......................................................................................................... 2
Figure 2-2. LM74700DDFEVM.................................................................................................................................................... 3
Figure 2-3. LM74700DDFEVM Schematic.................................................................................................................................. 4
Figure 3-1. Reverse Polarity 12 V to –12 V................................................................................................................................. 5
Figure 3-2. Startup Reverse Polarity (–12 V)...............................................................................................................................5
Figure 3-3. ORing Application – Higher Supply Switchover........................................................................................................ 6
Figure 3-4. ORing Application 12-V – Lower Supply Test............................................................................................................6
Figure 4-1. LM74700DDFEVM Top Side Placement................................................................................................................... 7
Figure 4-2. LM74700DDFEVM Bottom Side Placement..............................................................................................................7
Figure 4-3. LM74700DDFEVM Top Layer Routing...................................................................................................................... 8
Figure 4-4. LM74700DDFEVM Bottom Layer Routing................................................................................................................ 8
List of Tables
Table 4-1. Bill of Materials............................................................................................................................................................9
Trademarks
All trademarks are the property of their respective owners.
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1 Introduction
The LM74700-Q1 evaluation module (LM74700DDFEVM) assists designers to evaluate the operation and
performance of the LM74700-Q1 ideal diode controller (8-pin DDF package). This evaluation module
demonstrates how an N-channel power MOSFET can emulate a very-low forward voltage diode with low IQ and
low-leakage current flowing through the IC. In this design scheme, the LM74700-Q1 is combined with a
MOSFET and used in series with a battery as a replacement for a Schottky diode and PFET, in reverse-polarity
protection circuitry as shown in Figure 2-1. For more information on the LM74700-Q1 functional and electrical
characteristics, see LM74700-Q1 Low IQ reverse battery protection ideal diode controller.
2 Setup
This section describes the jumpers and connectors on the EVM, and how to properly connect, setup, and use
the LM74700DDFEVM. Ensure the power supply is turned off while making connections on the board.
2.1 I/O Connector Description
VIN J1: Power input connector to the positive rail of the input power supply
GND1 J3: Ground connection for the power supply
VOUT J2: Power output connector to the positive side of the load
GND2 J4: Ground connection for the load
Test Points VIN, VOUT, GND1, and GND2 are test points
LM74700
GATE CATHODE
EN
ANODE
VCAP GND
VBAT
TVS
Voltage
Regulator
Figure 2-1. LM74700DDFEVM Typical Application Circuit
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2.2 Board Setup
Before applying power to the LM74700DDFEVM, verify all external connections. Turn off external power supplies
and connect them with the proper polarity to the VIN and GND1 connectors. An electronic or resistive load must
be connected at the output VOUT and GND2 connectors. The tests outlined in this document are conducted with
3-A constant current as the load and 12 V at the input. Make sure that the external power-supply source for the
input voltage is capable of providing enough current to the output load so that the output voltage can be
obtained.
When all connections to the LM74700DDFEVM are verified, apply power to VIN. Figure 2-2 captures EVM board
setup.
Figure 2-2. LM74700DDFEVM
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2.3 Schematic
Figure 2-3 illustrates the EVM schematic.
Figure 2-3. LM74700DDFEVM Schematic
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3 Operation
3.1 Reverse Polarity Protection
A dynamic voltage pulse from 12 V to –12 V is applied at the input of the LM74700DDFEVM. Figure 3-1 shows
the input voltage (CH1) drops down to –12 V and the output voltage (CH2) does not go negative. Therefore, the
load is protected from dynamic reverse pulses at the input. The LM74700-Q1 reacts to the negative voltage
within 2 μs and it shuts down the MOSFET by pulling the gate (CH3) voltage down. The output slowly decays
due to the large output capacitors and increased time constant.
Figure 3-1. Reverse Polarity 12 V to –12 V
A –12-V source is connected to the VIN input of the LM74700DDFEVM. Figure 3-2 shows that the output voltage
remains at a constant 0 V in this situation. This test simulates the event of connecting a 12-V battery in the
reverse direction; therefore, protecting the load from negative input voltages.
Figure 3-2. Startup Reverse Polarity (–12 V)
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3.2 ORing Application
When using the LM74700-Q1 as an ORing device, if the input supplies operate at slightly different voltages, the
voltage at the common load point will follow the higher voltage. The LM74700-Q1 prevents reverse current flow
from the common load point to the lower voltage supply rail. This test uses two LM74700DDFEVMs with 15 V at
the input of the first EVM and 12 V at the input of the second EVM and the output of both the EVMs are shorted.
As Figure 3-3 shows, the 15-V source at EVM1 is turned off for a period of time and the output (CH2) drops to
12-V source from EVM2. When the 15-V source is turned on again, the output rises to 15 V from EVM1. CH1
shows the input to EVM1, CH2 shows the output and CH3 shows input of EVM2.
Figure 3-3. ORing Application – Higher Supply Switchover
Next, the 12-V source at EVM2 is turned off for a period of time and turned on again, the output (CH2) does not
change. Figure 3-4 captures this test.
Figure 3-4. ORing Application 12-V – Lower Supply Test
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4 EVM Board Assembly Drawings and Layout Guidelines
4.1 PCB Drawings
Figure 4-1 through Figure 4-4 show component placement and layout of this EVM.
Figure 4-1. LM74700DDFEVM Top Side Placement
Figure 4-2. LM74700DDFEVM Bottom Side Placement
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Figure 4-3. LM74700DDFEVM Top Layer Routing
Figure 4-4. LM74700DDFEVM Bottom Layer Routing
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4.2 Bill of Materials
Section 4.2 lists the LM74700DDFEVM BOM.
Table 4-1. Bill of Materials
Fitted Description Designator Part Number QTY Manufacturer Package Reference Value
Fitted CAP, CERM, 1 µF, 25 V,+/- 10%, X7R,
AEC-Q200 Grade 1, 0603
C1 CGA3E1X7R1E105K080AD 1 TDK 0603 1 uF
Fitted CAP, CERM, 2.2 uF, 100 V, +/- 10%, X7R,
1210
C2 C1210C225K1RACTU 1 Kemet 1210 2.2 uF
Fitted CAP, AL, 220 µF, 63 V, +/- 20%, 0.16
ohm, AEC-Q200 Grade 2, SMD
C3 EEV-FK1J221Q 1 Panasonic SMT Radial H13 220 uF
Fitted CAP, CERM, 0.33 µF, 50 V,+/- 10%, X8R,
AEC-Q200 Grade 0, 1206
C4, C5 CGA5L2X8R1H334K160AA 2 TDK 1206 0.33 uF
Fitted Diode, TVS, Bi, 33 V, SMB D1 SMBJ33CA-13-F 1 Diodes Inc. SMB 33 V
Fitted Test Point, Miniature, SMT EN, GATE, VIN,
VOUT
5015 4 Keystone Testpoint_Keystone_Mi
niature
Fitted TEST POINT SLOTTED .118", TH GND1, GND2 1040 2 Keystone Test point, TH Slot Test
point
Fitted Machine Screw, Round, #4-40 x 1/4,
Nylon, Philips panhead
H1, H2, H3, H4 NY PMS 440 0025 PH 4 B&F Fastener Supply Screw
Fitted Standoff, Hex, 0.5"L #4-40 Nylon H5, H6, H7, H8 1902C 4 Keystone Standoff
Fitted Standard Banana Jack, Uninsulated,
8.9mm
J1, J2, J3, J4 575-8 4 Keystone Keystone575-8
Fitted MOSFET, N-CH, 60 V, 15 A, AEC-Q101,
8-PowerVDFN
Q1 DMT6007LFG-13 1 Diodes Inc. 8-PowerVDFN 60 V
Fitted RES, 0, 5%, 0.1 W, AEC-Q200 Grade 0,
0603
R1 CRCW06030000Z0EA 1 Vishay-Dale 0603 0
Fitted IC, Ideal Didoe U1 LM74700QDDFRQ1 1 Texas Instruments SOT23-8
Not Fitted Diode, TVS, Uni, 58 V, SMA D2 SMAJ58A 0 Diodes Inc. SMA 58 V
Not Fitted Diode, TVS, Uni, 58 V, 93.6 Vc, SMB D3 SMBJ58A-13-F 0 Diodes Inc. SMB 58 V
Not Fitted Diode, TVS, Uni, 24 V, 38.9 Vc, SMB D4 SMBJ24A-13-F 0 Diodes Inc. SMB 24 V
Not Fitted Fiducial mark. There is nothing to buy or
mount.
FID1, FID2, FID3,
FID4, FID5, FID6
N/A 0 N/A N/A
Not Fitted MOSFET, N-CH, 60 V, 17.9 A, AEC-
Q101, 8-PowerTDFN
Q2 DMT6005LPS-13 0 Diodes Inc. 8-PowerTDFN 60 V
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STANDARD TERMS FOR EVALUATION MODULES
1. Delivery: TI delivers TI evaluation boards, kits, or modules, including any accompanying demonstration software, components, and/or
documentation which may be provided together or separately (collectively, an “EVM” or “EVMs”) to the User (“User”) in accordance
with the terms set forth herein. User's acceptance of the EVM is expressly subject to the following terms.
1.1 EVMs are intended solely for product or software developers for use in a research and development setting to facilitate feasibility
evaluation, experimentation, or scientific analysis of TI semiconductors products. EVMs have no direct function and are not
finished products. EVMs shall not be directly or indirectly assembled as a part or subassembly in any finished product. For
clarification, any software or software tools provided with the EVM (“Software”) shall not be subject to the terms and conditions
set forth herein but rather shall be subject to the applicable terms that accompany such Software
1.2 EVMs are not intended for consumer or household use. EVMs may not be sold, sublicensed, leased, rented, loaned, assigned,
or otherwise distributed for commercial purposes by Users, in whole or in part, or used in any finished product or production
system.
2Limited Warranty and Related Remedies/Disclaimers:
2.1 These terms do not apply to Software. The warranty, if any, for Software is covered in the applicable Software License
Agreement.
2.2 TI warrants that the TI EVM will conform to TI's published specifications for ninety (90) days after the date TI delivers such EVM
to User. Notwithstanding the foregoing, TI shall not be liable for a nonconforming EVM if (a) the nonconformity was caused by
neglect, misuse or mistreatment by an entity other than TI, including improper installation or testing, or for any EVMs that have
been altered or modified in any way by an entity other than TI, (b) the nonconformity resulted from User's design, specifications
or instructions for such EVMs or improper system design, or (c) User has not paid on time. Testing and other quality control
techniques are used to the extent TI deems necessary. TI does not test all parameters of each EVM.
User's claims against TI under this Section 2 are void if User fails to notify TI of any apparent defects in the EVMs within ten (10)
business days after delivery, or of any hidden defects with ten (10) business days after the defect has been detected.
2.3 TI's sole liability shall be at its option to repair or replace EVMs that fail to conform to the warranty set forth above, or credit
User's account for such EVM. TI's liability under this warranty shall be limited to EVMs that are returned during the warranty
period to the address designated by TI and that are determined by TI not to conform to such warranty. If TI elects to repair or
replace such EVM, TI shall have a reasonable time to repair such EVM or provide replacements. Repaired EVMs shall be
warranted for the remainder of the original warranty period. Replaced EVMs shall be warranted for a new full ninety (90) day
warranty period.
WARNING
Evaluation Kits are intended solely for use by technically qualified,
professional electronics experts who are familiar with the dangers
and application risks associated with handling electrical mechanical
components, systems, and subsystems.
User shall operate the Evaluation Kit within TI’s recommended
guidelines and any applicable legal or environmental requirements
as well as reasonable and customary safeguards. Failure to set up
and/or operate the Evaluation Kit within TI’s recommended
guidelines may result in personal injury or death or property
damage. Proper set up entails following TI’s instructions for
electrical ratings of interface circuits such as input, output and
electrical loads.
NOTE:
EXPOSURE TO ELECTROSTATIC DISCHARGE (ESD) MAY CAUSE DEGREDATION OR FAILURE OF THE EVALUATION
KIT; TI RECOMMENDS STORAGE OF THE EVALUATION KIT IN A PROTECTIVE ESD BAG.