Texas Instruments TPS23525EVM-815 User manual

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TPS23525EVM-815 Evaluation Module
User's Guide
SLVUB36–October 2017
TPS23525EVM-815 Evaluation Module
This user’s guide describes the TPS23525 evaluation module (TPS23525EVM-815). TPS23525EVM-815
contains evaluation and reference circuitry for the TPS23525, which is a low-side hot swap and dual
ORing controller targeted at telecom applications.
Contents
1 Introduction ................................................................................................................... 1
1.1 Features.............................................................................................................. 1
1.2 Applications.......................................................................................................... 2
1.3 Electrical Specifications............................................................................................ 2
2 Schematic .................................................................................................................... 3
3 General Configuration and Description .................................................................................. 4
3.1 Physical Access .................................................................................................... 4
3.2 Equipment Setup ................................................................................................... 5
3.3 Scope Considerations ............................................................................................. 5
4 Test Results ................................................................................................................. 5
5 Bill of Material .............................................................................................................. 13
List of Tables
1 TPS23525 Electrical and Performance Specifications at 25°C........................................................ 2
2 Connector Functionality .................................................................................................... 4
3 Test Points.................................................................................................................... 4
4 Jumper Descriptions......................................................................................................... 4
5 TPS23525EVM-815 Bill of Materials..................................................................................... 13
Trademarks
All trademarks are the property of their respective owners.
1 Introduction
The TPS23525 EVM provides a jump-start to anyone designing a redundant feed –48-V system. The EVM
includes input clamping to support lightning surge (up to 2 kV), various FET placeholders to support
various power levels, and an output inductor to mimic any EMI filter before the DC/DC converter.
Additionally, the EVM includes circuitry that supports auxiliary bulk capacitors. This “auxiliary bulk
capacitor” approach is useful when designing for large hold-up times (example: 10 ms) making the hot-
swap design more manageable by reducing the initial charge on the capacitor.
1.1 Features
This EVM has the following features:
• Inrush current control
• Hot-swap output short-circuit protection
• Reverse current protection
• Dual supply ORing
• Reverse hookup protection

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1.2 Applications
This EVM is used in the following applications:
• Wireless infrastructure
• Telecom infrastructure
• –48-V interface
1.3 Electrical Specifications
Table 1 lists the TPS23525 electrical and performance specifications at 25°C.
Table 1. TPS23525 Electrical and Performance Specifications at 25°C
Characteristic TPS23525EVM-PWR815
Input voltage Range (Recommended) 38 V to 60 V
Input Voltage Range (Abs Max) 0 V to 150 V
Load Power 400 W
Load Output Cap 660 µF
Current Limit (Normal) 12.5 A
Current Limit (High FET VDS) 1.5 A
Typical Inrush Current 0.4 A
Hot-swap FET VDS when current transitions from high to low 20.2 V
Time Out (VDS,HS < 10 V) 2.25 ms
Time Out (10 V < VDS,HS < 20 V) 1.12 ms
Time Out (VDS,HS > 20 V) 0.23 ms
Undervoltage Threshold (Rising) 36.6 V
Undervoltage Threshold (Falling) 34.6 V
Overvoltage Threshold (Rising) 64.4 V
Overvoltage Threshold (Falling) 61.4 V

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2 Schematic
Figure 1 illustrates the EVM schematic.
Figure 1. TPS23525EVM-815 Schematic

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3 General Configuration and Description
3.1 Physical Access
Table 2 lists the TPS23525EVM connector and functionality, Table 3 describes the test point availability,
and Table 4 describes the default jumper configuration.
Table 2. Connector Functionality
Connector Label Description
J1, J2, J3 RTN Power bus input - Tie the high-side of power-supply inputs and outputs here
J7 Neg48V_B Power bus input - Tie the low-side of power-supply B input here
J8 Vout_FLTD Output bus - Apply the low-side load here (if applicable)
J9 CAUX Connect to auxiliary bulk capacitor (if applicable)
J10 Neg48V_A Power bus input - Tie the low-side of power-supply A input here
Table 3. Test Points
Connector Label Description
TP1 RTN High-side power-supply input and high-side output load voltage
TP2 VCC Clamped voltage supply
TP3 PGB Power Good Bar
TP4 SS Soft-start pin voltage
TP5 UVEN UV pin voltage
TP6 D D pin voltage
TP7 OV OV pin voltage
TP8 GATE Gate drive output voltage for hot-swap FET
TP9 SNS Sense pin test point
TP10 TMR Timer capacitor voltage
TP11 GATEB Gate drive output voltage for Gate B ORing FET
TP12 GATEA Gate drive output voltage for Gate A ORing FET
TP13, TP15 VEE IC ground - Place voltage probe ground at this pin
TP14 Neg48VB Low-side input for power-supply B
TP16 HS_DRAIN Drain voltage of the hot-swap FET
TP17 VOUT_FLTD Low-side output for load
TP18 Neg48VA Low-side input for power-supply A
TP19 - Open-drain output for power good signal. Attach to downstream EN pin.
Table 4. Jumper Descriptions
Connector Description
J5 Jump pins 1-2 to enable UV (default), or jump pins 2-3 to tie UV to VCC (disable)
J6 Leave open to enable OV (default), or jump pins 1-2 to tie OV to GND (disable)

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3.2 Equipment Setup
Use the following equipment list and setup steps to work with the EVM:
• 2× power supplies capable of ≥60 V and ≥15 A (preferred)
• Resistive or electronic load – only turn on the load after the hot swap is up
• Set the input power-supply voltage to the desired operating input voltage
• Turn the power supply off
• Jump pins 1-2 on J5
• Leave pins 1-2 on J6 open
• Connect the positive voltage lead from the power-supply A to J1 (RTN). Connect the ground lead from
the power-supply A to J10 (Neg48V_A).
• Connect the positive voltage lead from the power-supply B to J3 (RTN). Connect the ground lead from
the power-supply B to J7 (Neg48V_B).
• Make sure all voltmeter or oscilloscope GNDs are tied to VEE
• Turn the power supplies on
3.3 Scope Considerations
Observe the following scope considerations:
• Most scopes have a 10-MΩresistance between scope GND and probe.
• If scope GND is tied to RTN and a probe is placed on TMR, that creates approximately 5 μA of pullup
current which can overpower the pull down of the TMR pin and result in an undesired time out.
4 Test Results
This section provides typical performance waveforms for the TPS23525EVM-815 board. Actual
performance data is affected by measurement techniques and environmental variables; therefore, these
curves are presented for reference and may differ from actual results obtained. All curves are based on
VIN = 48 V, unless stated otherwise.
No Load, Scope GND = –48V_A
Figure 2. Start Up (VIN = 54 V)
No Load, Scope GND = –48V_A
Figure 3. Start Up (VIN = 54 V)

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No Load, Scope GND = –48V_A
Figure 4. Start Up (VIN = 38 V)
No Load, Scope GND = –48V_A
Figure 5. Start Up (VIN = 60 V)
VINA = 54 V, VINB = 54 V, No Load, Scope GND = RTN
Figure 6. Hot Plug Channel A and B Together
VINA = 54.5 V, VINB = 54 V, No Load, Scope GND = RTN
Figure 7. Hot Plug Channel A and B Together
VINA = 54 V; VINB = 38 V, Scope GND = RTN, Iload = 5 A
Figure 8. Hot Plug A After B
VINA = 54 V; VINB = 38 V, Scope GND = RTN, Iload = 5 A
Figure 9. Hot Plug A After B

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VINA = 54 V; VINB = 38 V, Scope GND = RTN, Iload = 5 A
Figure 10. Hot Plug A After B
VINA = 54.5 V; VINB = 54 V, Scope GND = RTN, No Load
Figure 11. Hot Plug A After B
Scope GND = –48V_B, No Load, After Inductor
Figure 12. Output Hot Short (VINB = 54 V)
Scope GND = –48V_B, 5-A Load, After Inductor
Figure 13. Output Hot Short (VINB = 54 V)
Scope GND = –48V_B, 5A Load, Zoomed in
Figure 14. Output Hot Short (VINB = 54 V)
Scope GND = –48V_B, 5-A Load
Figure 15. Output Hot Short (VINB = 60 V)

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Scope GND = –48V_B, 5-A Load, Zoomed In
Figure 16. Output Hot Short (VINB = 60 V)
Scope GND = –48V_A
Figure 17. Gradual Overcurrent (VINA = 54 V)
Scope GND = –48V_A
Figure 18. Load Step Overcurrent
Scope Gnd = –48V_A, VIN = 54 V
Figure 19. Start Into Short
Scope Gnd = –48V_A, VIN = 54 V
Figure 20. Start Into Short
Scope Gnd = –48V_A, VIN = 54 V
Figure 21. Apply Short and Remove Short

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Scope GND = –48V_A, Iload = 5 A
Figure 22. 1-ms Brown Out
Scope GND = –48V_A, Iload = 5 A
Figure 23. 1-ms Brown Out
VINB = 53 V, Iload = 5 A, Scope GND = RTN
Figure 24. Supply Switch Over (Raise VINA)
VINB = 53 V (Raise VINA), Scope GND = RTN, Iload = 5 A
Figure 25. Supply Switch Over (Zoomed in)
VINA = 54.5 V; VINB = 54 V, Iload = 5 A, Scope GND = RTN
Figure 26. VINA Short
VINA = 54.5 V; VINB = 54 V, Iload = 5 A, Scope GND = RTN
Figure 27. VINA Short

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VINA = 54.5 V; VINB = 54 V, Iload = 5 A, Scope GND = RTN
Figure 28. Unplug VIN A
VINB = 60 V
Figure 29. Plug in VIN A Backwards
VINB Floating
Figure 30. Plug in VIN A Backwards
Scope GND = –48V_A, No Load
Figure 31. Undervoltage and Overvoltage (Rising)
Scope GND = –48V_A, No Load
Figure 32. Undervoltage and Overvoltage (Falling)
Scope GND = RTN, 5-A Load, Per IEC61000-4-5
Figure 33. –2-kV (2 Ω) Lightning Surge