User’s Guide
TPS2350 −48-V Hot Swap/Supply
Selector Evaluation Module
User’s Guide
1
EVM IMPORTANT NOTICE (CATEGORY B)
IMPORTANT: TI is providing the enclosed HPA021A evaluation module under the following conditions:
This evaluation module (EVM) being provided by Texas Instruments (TI) is intended for use for ENGINEERING
DEVELOPMENT OR EVALUATION PURPOSES ONLY and is not considered by Texas Instruments to be fit
for commercial use. As such, this EVM may not be complete in terms of design and/or manufacturing related
protective considerations including product safety measures typically found in the end−product incorporating
the module. As a prototype, this product does not fall within the scope of the European Union Directive on
electromagnetic compatibility and on low voltage and therefore may not meet the technical requirements of the
directive. This EVM is not subject to the EU marking requirements.
D Should this EVM not meet the specifications indicated in the User’s Guide the EVM may be returned within
30 days from the date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE
WARRANTY MADE BY TI AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR
STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY
PARTICULAR PURPOSE.
D The user assumes all responsibility and liability for proper and safe handling of the EVM. The user
acknowledge that the use of the EVM could present serious hazards and that it is the user’s responsibility
to take all precautions for the handling and use of the EVMs in accordance with good laboratory practices.
Please be aware that the products received may not be regulatory compliant or agency certified (FCC, UL,
etc.). Due to the open construction of the product, it is the user’s responsibility to take any and all appropriate
precautions with regard to electrostatic discharge.
D NEITHER PARTY WILL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES.
D TI is currently dealing with various customers for products, and therefore our arrangement with the user will
not be exclusive.
D TI assumes no liability for applications assistance, customer product design, software performance,
or infringement of patents or services described herein.
D Please read the User’s Guide and specifically the section in the User’s Guide pertaining to warnings and
restrictions prior to handling the product. This section contains important information regarding high
temperature and voltages which TI recommends to be read before handling the EVMs. In case of any doubt
regarding safety, please contact the TI application engineer.
D Persons handling the product should have electronics training and observe good laboratory practice
standards.
D No license is granted under any patent right or other intellectual property right of TI covering or relating to
any combination, machine, or process in which such TI products or services might be or are used.
D This Agreement is subject to the laws of the State of Texas, excluding the body of conflicts of laws and the
United Nations Convention on the International Sale of Goods, and will be subject to the exclusive
jurisdiction of the courts of the State of Texas.
2
DYNAMIC WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the maximum input voltage ranges specified in Table 2.
Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM.
If there are questions concerning the input range, please contact a TI field representative prior to connecting
the input power.
Applying loads outside of the specified output range may result in unintended operation and/or possible
permanent damage to the EVM. Please consult the EVM User’s Guide prior to connecting any load to the EVM
output. If there is uncertainty as to the load specification, please contact a TI field representative.
During normal operation, some circuit components may have case temperatures greater than 50°C. The EVM
is designed to operate properly with certain components above 50°C as long as the input and output ranges are
maintained. These components include but are not limited to linear regulators, switching transistors, pass
transistors, and current sense resistors. These types of devices can be identified using the EVM schematic
located in the EVM User’s Guide. When placing measurement probes near these devices during operation,
please be aware that these devices may be very warm to the touch.
Mailing Address:
Texas Instruments
Post Office Box 655303
Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated
3
SLUU171A - September 2003
TPS2350 −48-V Hot Swap/Supply Selector Evaluation
Module
Portable Power
Andy Ripanti
ABSTRACT
This User’s Guide describes the use and features of the TPS2350 −48-V Hot Swap/Supply Selector
Evaluation Module (EVM). This EVM can be used to learn about the TPS2350 Hot Swap Power
Manager (HSPM) Integrated Circuit (IC) from Texas Instruments (TI).
Contents
1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2
The TPS2350 −48-V Hot Swap/Supply Selector EVM Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Module Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 EVM Schematic Diagram and List of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.3 TPS2350 −48−V Hot Swap/Supply Selector EVM Operating Specifications . . . . . . . . . . . . . . 11
3
Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.1 Equipment Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2 Verifying the EVM Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.1 Equipment Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.2 Functional Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4
List of Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 Supply Connections and Test Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.2 Load Capacitors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.3 Supply Selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.4 Changing the Current Limit Threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.5 Changing the Inrush Slew Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.6 Fault Timing with the TPS2350 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.7 Programming the UVLO and OVLO Thresholds and Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . 18
4.8 TPS2350 Powergood Output (PG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4
TPS2350 −48-V Hot Swap/Supply Selector Evaluation Module
SLUU171A - September 2003
1
Introduction
The TPS2350 is a negative voltage hot swap controller intended for use in systems needing to hot swap telecom
distribution-level voltages. It integrates inrush current control, peak current limiting, electronic circuit breaker,
and overvoltage and undervoltage protection. In addition, it monitors and selects from two power supplies the
larger magnitude supply, reducing OR-ing losses in redundant supply systems. The EVM is a PCB-based tool
featuring the TPS2350 in a hot swap circuit, and can be used to evaluate device operation in simulated live
insertion events.
1.1
Features
The following list highlights some of the features of the TPS2350 device.
D Wide input supply range of −12 V to −80 V
D Transient rating to −100 V
D Programmable current limit
D Programmable linear inrush slew rate
D Redundant supply selector function
D Programmable UV/OV thresholds/hysteresis
D Fault timer to eliminate nuisance trips
D Open-drain power good (PG) output
D Open-drain fault output (FLT)
D 14-pin TSSOP package
1.2
Description
The TPS2350 integrated circuit is a hot swap power manager optimized for use in nominal −48-V systems. It
operates over a supply voltage range of −12 V to −80 V, and is rated to withstand spikes to −100 V. In conjunction
with an external N-channel FET and sense resistor, it can be used to enable live insertion of plug-in cards and
modules into powered systems. It provides load current slew rate control and peak magnitude limiting.
Undervoltage and overvoltage shutdown thresholds are easily programmed via a three-resistor divider network.
A power good (PG) output enables downstream converters. The TPS2350 also provides the basic hot swap
functions of electrical isolation of faulty cards, filtered protection against nuisance overcurrent trips, and
single-line fault reporting.
The TPS2350 also provides a unique feature for redundant-supply systems. The supply selection function can
be used to reduce power losses of diode-OR systems. A selection comparator monitors the two input supplies,
and selects the supply with the larger magnitude. Internal driver circuits provide the gate drive needed to control
two external N-channel FETs, providing a low-loss switch closure for the active supply, while disconnecting the
lower voltage supply.
For input capacitor charging and load current faults, the TPS2350 provides an internal fault timer to filter out
spurious current glitch events. In the event of a persistent fault which exceeds the programmable timer setting,
the TPS2350 turns off the hot swap FET, disconnecting the load. A retry mode periodically tests for continued
existence of the fault at a low duty cycle, thus protecting the pass FET from excessive dissipation.
TPS2350 −48-V Hot Swap/Supply Selector Evaluation Module
5
SLUU171A - September 2003
2
The TPS2350 −48-V Hot Swap/Supply Selector EVM Kit
2.1
Module Description
The TPS2350 −48-V hot swap/supply selector EVM kit is a PCB-based platform that enables designers to
rapidly learn about the TPS2350 operation, and evaluate its performance during hot swap events. The assembly
(TI part number HPA021−001) features a TPS2350 device as it may be connected in the power interface section
of a hot swap-capable plug-in card. The assembly also provides additional controls and components to simplify
testing and for quick modifications of the circuit characteristics. Input power to the module is connected at three
banana jacks located on the left-hand side of the board. A toggle switch is provided to rapidly apply power to
and remove it from the circuit.
The hot swap circuit on the EVM board contains the TPS2350 HSPM device, a power MOSFET switch, sense
resistor and some configuration capacitors. Two through-hole patterns are provided on the load side for the
installation of large-value aluminum electrolytic capacitors. These capacitors simulate the input bulk
capacitance that may be found on the target module’s back-end supply plane. The EVM is supplied from the
factory with a 100-µF capacitor installed in one of the locations. The second pattern, connected in parallel with
the first, can be used to increase or otherwise modify the amount of load capacitance. With the TPS2350, both
inrush slew rate limiting and a fault time-out period are externally programmable using capacitors. On the EVM
board, several options are provided for slew rate limit setting, for quick comparison of the effect of capacitor
value on this function. The capacitors can be quickly switched in and out of the circuit via the DIP switch SW1.
Fault timing programming is set up in a similar manner; some amount of capacitance is hard-wired into the
circuit, with the option of switching in additional capacitance.
N-channel FETs are also provided on-board to exercise or demonstrate the supply selection operation of the
TPS2350 when two supplies are connected to the board.
The board also contains the component patterns and connections to exercise the undervoltage (UVLO) and
overvoltage (OVLO) lockout functions. A slide switch is also tied into the UV input pin to provide an alternate
means of enabling and disabling the output voltage. The powergood output can be monitored directly at the
device pin, or through the on-board opto-coupler.
Test points are provided throughout the circuit for easy voltage monitoring via oscilloscope or voltmeter. The
test point connections are listed in Table 6.
6
TPS2350 −48-V Hot Swap/Supply Selector Evaluation Module
SLUU171A - September 2003
The pictorial of the TPS2350 −48-V hot swap/supply selector EVM top assembly is shown in Figure 1.
Figure 1. Evaluation Module Top Assembly
TPS2350 −48-V Hot Swap/Supply Selector Evaluation Module
7
SLUU171A - September 2003
2.2
EVM Schematic Diagram and List of Materials
+
+
The EVM schematic diagram is shown in Figures 2 and 3.
Figure 2. TPS2350 −48-V Hot Swap/Supply Selector EVM Schematic (Sheet 1)
8
TPS2350 −48-V Hot Swap/Supply Selector Evaluation Module
SLUU171A - September 2003
Figure 3. TPS2350 −48-V Hot Swap/Supply Selector EVM Schematic (Sheet 2)
TPS2350 −48-V Hot Swap/Supply Selector Evaluation Module
9
SLUU171A - September 2003
The EVM list of materials is shown in Table 1.
Table 1. Evaluation Module List of Materials (HPA021A)
DESCRIPTION
MANUFACTURER
PART NUMBER
C1
REFERENCE
1
Capacitor, ceramic, 1000 pF, 25 V, 10%, X7R
Vitramon
VJ0805Y102KXXA
C2
1
Capacitor, ceramic, 0.01 µF, 16 V, 10%, X7R
Vitramon
VJ0805Y103KXJA
C3
1
Capacitor, ceramic, 0.047 µF, 16 V, 10%, X7R
Vitramon
VJ0805Y473KXJA
C4
1
Capacitor, ceramic, 0.1 µF, 16 V, 10%, X7R
Vitramon
VJ0805Y104KXJA
C5
−
Capacitor, ceramic, 0805
Standard
Standard
C6
1
Capacitor, ceramic, 0.082 µF, 16 V, 10%, X7R
Vitramon
VJ0805Y823KXJA
C7
1
Capacitor, ceramic, 1500 pF, 25 V, 20%, X7R
Vitramon
VJ0805Y152MXXA
C8
1
Capacitor, aluminum electrolytic, 100 µF, 100 V, 20%
Vishay
EKA00DE310L00
C9
−
Capacitor, aluminum electrolytic, 100 V, radial
Standard
Standard
D1
1
DIODE, LED, ultra bright red, GW type
Panasonic
LN1261CAL
D3, D4
−
DIODE, Switching, 75 V, 0.35 W, type 4148
Standard
Standard
Q1
1
MOSFET, N-channel, V(BR) > 100 V
Int’l Rectifier
IRF530S
Q2, Q3
2
MOSFET, N-channel, V(BR) > 100 V
Int’l Rectifier
IRF530NS
Q4, Q5, Q6, Q7
−
MOSFET, N-channel, V(BR) > 100 V
Int’l Rectifier
IRF530NS
R1
1
Resistor, 200 kΩ, 0.1 W, 1%
Vishay
CRCW0805−2003F
R2
1
Resistor, 4.99 kΩ, 0.1 W, 1%
Vishay
CRCW0805−4991F
R3
1
Resistor, 3.92 kΩ, 0.1 W, 1%
Vishay
CRCW0805−3921F
R4
1
Resistor, 12 kΩ, 1 W, 5%
Vishay
CRCW2512−123J
R5
1
Resistor, 0.02 Ω, 0.5 W, 1%
Vishay−Dale
WSL−2010 .020 VUV)
30.8
OVLO threshold, supply low (VIN < VOV)
72.6
VOV_H
OVLO threshold, supply high (VIN > VOV)
70.5
TPS2350 −48-V Hot Swap/Supply Selector Evaluation Module
SLUU171A - September 2003
The thresholds are easily modified by changing the resistor values. When the desired trip voltages and the UV
hysteresis have been established for the protected load, new values are determined as follows. Generally, the
process is simplest by first selecting the top leg of the divider (R1) needed to obtain the desired hysteresis. This
value is calculated from equation 4.
R1 +
V HYS_UV
10 mA
(4)
where VHYS_UV is the desired amount of undervoltage hysteresis.
Once a value for R1 is selected, it is used to calculate R2 and R3 using equations 5 and 6.
R2 +
R3 +
ȱ
V UV_L
1*
ȧ
ǒVUV_L * 1.4Ǔ Ȳ ǒVOV_L ) 10*5
1.4
R1
ȱ
V UV_L
ȧ
ǒVUV_L * 1.4Ǔ ȲǒVOV_L ) 10*5
1.4
R1
ȳ
ȧ
R1ȴ
ȳ
ȧ
R1ȴ
(5)
(6)
where:
4.8
−
VUV_L is the UVLO threshold when the input supply is low; i.e., less than VUV, and
−
VOV_L is the OVLO threshold when the input supply is low; i.e., less than VOV
TPS2350 Powergood Output (PG)
The supply selector EVM features two nodes to access the powergood status generated by the TPS2350. For
simply monitoring, for example with a scope probe, the actual output signal itself is available at test point TP12.
The MOD_EN output at J7 demonstrates an isolated signal interface using an opto device. An example
application of such a signal is to drive the enable input of downstream converters. As such, this output is
referenced to the VOUT− node, as this would be the low side of input power to the brick. The EVM schematic
shows the circuit details. The MOD_EN assertion level is active-high. The use of this signal requires a pull-up
source at the VS input, J6. See Tables 2 and 3 for the requirements of the VS supply.
TPS2350 −48-V Hot Swap/Supply Selector Evaluation Module
19
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,
enhancements, improvements, and other changes to its products and services at any time and to discontinue
any product or service without notice. Customers should obtain the latest relevant information before placing
orders and should verify that such information is current and complete. All products are sold subject to TI’s terms
and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in
accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI
deems necessary to support this warranty. Except where mandated by government requirements, testing of all
parameters of each product is not necessarily performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for
their products and applications using TI components. To minimize the risks associated with customer products
and applications, customers should provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,
copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process
in which TI products or services are used. Information published by TI regarding third-party products or services
does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.
Use of such information may require a license from a third party under the patents or other intellectual property
of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of information in TI data books or data sheets is permissible only if reproduction is without
alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction
of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for
such altered documentation.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that
product or service voids all express and any implied warranties for the associated TI product or service and
is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.
Following are URLs where you can obtain information on other Texas Instruments products and application
solutions:
Products
Amplifiers
Applications
amplifier.ti.com
Audio
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
www.ti.com/broadband
Interface
interface.ti.com
Digital Control
www.ti.com/digitalcontrol
Logic
logic.ti.com
Military
www.ti.com/military
Power Mgmt
power.ti.com
Optical Networking
www.ti.com/opticalnetwork
Microcontrollers
microcontroller.ti.com
Security
www.ti.com/security
Telephony
www.ti.com/telephony
Video & Imaging
www.ti.com/video
Wireless
www.ti.com/wireless
Mailing Address:
Texas Instruments
Post Office Box 655303 Dallas, Texas 75265
Copyright 2003, Texas Instruments Incorporated
