Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - hot swap controller Multi-purpose SO 8 Surface-mount

VOUT

VIN

FLT

ISET

GND

LOAD

Optional: To

System Monitor

4 5 6

VIN

VOUT

RSET

TPS2421-1

TPS2421-2

www.ti.com

SLUS907H –JANUARY 2009–REVISED JANUARY 2014

5-A, 20-V Integrated FET Hot Swap

Check for Samples: TPS2421-1, TPS2421-2

FEATURES

DESCRIPTION

The TPS2421 device provides highly integrated hot

• Integrated Pass MOSFET

swap power management and superior protection in

• Up to 20-V Bus Operation

applications where the load is powered by busses up

• Programmable Fault Current

to 20 V. The TPS2421 device is well suited to

standard bus voltages as low as 3.3 V because of the

• Current Limit Proportionally Larger than Fault

maximum-UV turn-on threshold of 2.9 V. These

Current

devices are very effective in systems where a voltage

• Programmable Fault Timer

bus must be protected to prevent shorts from

• Internal MOSFET Power Limiting

interrupting or damaging the unit. The TPS2421

device is an easy to use devices in an 8-pin

• Latch-Off on Fault (TPS2421-1) and Retry

PowerPad™ SO-8 package.

(TPS2421-2) Versions

The TPS2421 device has multiple programmable

• SO-8 PowerPad™ Package

protection features. Load protection is accomplished

• –40°C to 125°C Junction Temperature Range

by a non-current limiting fault threshold, a hard

• UL2367 Recognized - File Number E169910

current limit, and a fault timer. The current dual

thresholds allow the system to draw short high

APPLICATIONS

current pulses, while the fault timer is running, without

causing a voltage droop at the load. An example of

• RAID Arrays

this is a disk drive startup. This technique is ideal for

• Telecommunications

loads that experience brief high demand, but benefit

• Plug-In Circuit Boards

from protection levels in-line with their average

current draw.

• Disk Drives

Hotswap MOSFET protection is provided by power

• SSDs

limit circuitry which protects the internal MOSFET

• PCIE

against SOA related failures.

• Fan Control

The TPS2421 device is available in latch-off on fault

(TPS2421-1) and retry on fault (TPS2421-2).

Typical Application

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2PowerPad is a trademark of Texas Instruments.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (27 pages)

PAGE 1
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 5-A, 20-V Integrated FET Hot Swap Check for Samples: TPS2421-1, TPS2421-2 FEATURES DESCRIPTION • • • • The TPS2421 device provides highly integrated hot swap power management and superior protection in applications where the load is powered by busses up to 20 V. The TPS2421 device is well suited to standard bus voltages as low as 3.3 V because of the maximum-UV turn-on threshold of 2.9 V.
PAGE 2
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
PAGE 3
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 ELECTRICAL CHARACTERISTICS Unless otherwise noted: 3 V ≤ VVIN ≤ 18 V, EN = 0 V, PG = FLT = open, ROUT = open, RRSET = 49.9 kΩ, –40°C ≤ TJ ≤ 125°C, No external capacitor connected to VOUT PARAMETER TEST CONDITIONS MIN TYP MAX 2.6 2.85 2.9 UNIT VIN UVLO VIN rising Hysteresis Bias current 150 V mV EN = 2.4 V 25 100 μA EN = 0 V 3.9 5 mA 33 50 mΩ 5 7.5 0.
PAGE 4
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com ELECTRICAL CHARACTERISTICS (continued) Unless otherwise noted: 3 V ≤ VVIN ≤ 18 V, EN = 0 V, PG = FLT = open, ROUT = open, RRSET = 49.9 kΩ, –40°C ≤ TJ ≤ 125°C, No external capacitor connected to VOUT PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 0.2 0.4 V 1 μA FLT VOL Low level output voltage VCT = 1.8 V, I FLT = 1 mA Leakage current V FLT = 18 V PG PG threshold VOL V(VIN-VOUT) falling 0.4 0.5 0.
PAGE 5
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 BLOCK DIAGRAM I(D) Detector IVOUT VIN 3 7 VOUT V(DS) Detector + 6 t 10 µA Q Pump Internal Rail 8 + GND 4 LCA + Constant Power Engine ILIM VVIN ±500 mV PLIM 1 FLT 1.6 u ILIM + Fast Trip Comparator 1.5 u ISET + 1V ISET 5 + ISET 200 k 1 V RRSET EN PG 2.85 V / 2.7 V 2 + VVIN + 1.15 V / 1.00 V 10 0 THERMAL SHUTDOWN 16.8 0 S Q R Q VIN LATCH -1 RETRY -2 FACTORY SET 50 N 35 µA CT 1.
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TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com PINOUT DIAGRAM TPS2421-x 1 FLT PG 8 2 EN VOUT 7 CT 6 ISET 5 3 VIN 4 GND Table 1. TERMINAL FUNCTIONS FUNCTION PIN NO.
PAGE 7
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 ISET: A resistor from this pin to GND sets both the fault current (ISET) and current limit (ILIM) levels. The current limit is internally set at 150% of the fault current. The fault timer described in the CT section starts when IVOUT exceeds ISET. The internal MOSFET actively limits current if IVIN reaches the current limit set point. The fault timer operation is the same in this mode as described previously.
PAGE 8
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com TYPICAL CHARACTERISTICS FAULT TIMER THRESHOLD VOLTAGE vs JUNCTION TEMPERATURE FAULT CURRENT vs JUNCTION TEMPERATURE 1.50 RRSET = 100 k 2.15 IFAULT ± Fault Current ± A VTHRESH – Fault Timer Threshold Voltage -– V 2.20 2.10 2.50 2.00 1.95 1.90 1.85 1.80 ±50 0 TJ 50 100 1.45 1.40 1.35 1.30 –50 150 TJ ± Junction Temperature ± °C Figure 1. 50 – Junction 100 150 Temperature – °C Figure 2.
PAGE 9
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 TYPICAL CHARACTERISTICS (continued) PG PG EN VCT 12 V Startup into 15 W, 700 mF Load RRSET = 49.9 kW ILOAD Temperature capacitive overload, power limit tripped 12-V load at 1.5 A, then 140 mF added to load ILOAD RRSET = 49.9 kW VOUT VOUT Figure 5. 12-V Startup Into 15 Ω, 700-μF Load Figure 6.
PAGE 10
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com TYPICAL CHARACTERISTICS (continued) PG PG VCT VCT ILOAD ILOAD Overload, power limit tripped, 12-V load stepped from 3 A to 5.4 A, CLOAD = 700 µF, R RSET = 49.9 kΩ 12-V load at 3.6 A, then short applied to output, RRSET = 49.9 kΩ VOUT VOUT Figure 9. 12-V Firm Overload, 3 A to 5.4 A, Power Limit Tripped Figure 10. 12-V Hard Overload, 3.6-A Load Then Short 12-V PLIM during startup into 60 Ω, 800 µF RRSET = 49.
PAGE 11
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 TYPICAL CHARACTERISTICS (continued) PG PG VCT EN 3 V startup into 3.2 A load RRSET = 49.9 kΩ ILOAD 3.3 V overload step from 3.8 A to 5.5 A, RRSET = 49.9 kΩ ILOAD VOUT VOUT Figure 13. 3-V Startup into 1-Ω Load PG Figure 14. 3-V Firm Overload, Load Stepped From 3.8 A to 5.5 A FLT VCT VCT ILOAD ILOAD 3.3 V overload shorted while under 3.5 A load, RRSET = 49.9 kΩ 3.3 V overload step from 3.8 A to 7.1 A, RRSET = 49.
PAGE 12
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com TYPICAL CHARACTERISTICS (continued) 3.3 V attempting startup into 1 W, 2200 µF load, retry mode - CT = 0.1 µF PG EN RRSET = 49.9 kΩ VCT VCT ILOAD ILOAD 3.3 V, 1600 µF added while under 3.5 A load, RRSET = 49.9 kΩ VOUT VOUT Figure 17. 3 V, 1600 μF Added To 3.5-A Load Figure 18. 3-V Retry Startup into 1 Ω, 2200-μF Load Figure 19.
PAGE 13
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 APPLICATION INFORMATION Startup Large inrush current occurs when power is applied to discharged capacitors and load. During the inrush period, the TPS2421 device operates in power limit (or SOA protect mode) managing the current as VVOUT rises. In SOA protect mode, the internal MOSFET power dissipation ([VVIN – VVOUT] x IVOUT) is regulated at 5W typical while the fault timer starts and CCT ramps up.
PAGE 14
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com 2 4 ´ RMIN ´ PLIM _ MIN > VVIN RLOAD > RMIN = 2 VVIN 4 ´ PLIM _ MIN (9) = 2 VVIN 12 (10) Enable Pin Considerations For the case when EN is simply connected to GND, the TPS2421 device starts ramping the voltage on VOUT as VIN rises above UVLO (approximately 2.85 V typical). If IN does not ramp monotonically, the TPS2421 may momentarily turn off then on during startup if IN falls below approximately 2.7 V.
PAGE 15
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 2V/div FLT 0.5V/div CT 1A/div ILOAD 5V/div VOUT 5ms/div Figure 21. Fault Timer Operation During Startup CCT can be chosen for fault-free start up including expected CLOAD and CCT capacitance tolerance as shown in Equation 11. (1 + CLOAD_TOL + CCT_TOL ) ´ t ON CCT = 40000 (11) Normal Operation When load current exceeds ISET during normal operation the fault timer starts.
PAGE 16
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com Overcurrent Shutdown Overcurrent shutdown occurs when the output current exceeds ISET for the duration of the fault timer. Figure 8 shows a step rise in output current which exceeds the ISET threshold but not the ILIM threshold. The increased current is on for the duration of the timer. When the timer expires, the output is turned off.
PAGE 17
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 12-V Bus 3 VIN TPS2421 2 EN GND ISET CT 4 5 6 80.6 k VOUT 7 FLT 1 PG 8 Optional: To System Monitor CLOAD 0.56 µF Figure 22. Design Example Schematic 1. Calculate maximum RRSET to ensure that minimum ISET is above maximum operating load current using Equation 15 as shown below in Equation 18. RRSET,max = 0.99 ´ 185.58 = 82.39kW 2.1 + 0.13 (18) ● Choose a standard 1% value below RRSET,max for RRSET = 80.
PAGE 18
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com The following equation estimates the magnitude of these voltage spikes: VSPIKE(absolute ) = VNOM + ILOAD ´ L C where • • • • VNOM is the nominal supply voltage ILOAD is the load current C is the capacitance present at the input or output of the TPS2421 device L equals the effective inductance seen looking into the source or the load (20) Calculating the inductance due to a straight length of wire is shown in Equation 21.
PAGE 19
TPS2421-1 TPS2421-2 www.ti.com SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 REVISION HISTORY Changes from Revision A (March 2009) to Revision B Page • Changed MARKING .............................................................................................................................................................. 2 • Added For the most current package and ordering information, see the Package Option Addendum at the end of this document, or visit the device product folder on www.ti.com. .
PAGE 20
TPS2421-1 TPS2421-2 SLUS907H – JANUARY 2009 – REVISED JANUARY 2014 www.ti.com • Added note for TPS2421-1 to the VIN description in the PIN DESCRIPTION section ........................................................ 7 • Changed RSET = 100 kW to RRSET = 100 kΩ in the FAULT CURRENT vs JUNCTION TEMPERATURE graph ................. 8 • Changed VIN to VVIN in the functional block diagram, Equation 6, and Equation 7 ............................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 18-Oct-2013 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties.
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PACKAGE MATERIALS INFORMATION www.ti.com 28-Apr-2014 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant TPS2421-1DDAR SO Power PAD DDA 8 2500 330.0 12.8 6.4 5.2 2.1 8.0 12.0 Q1 TPS2421-2DDAR SO Power PAD DDA 8 2500 330.0 12.8 6.4 5.2 2.1 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 28-Apr-2014 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS2421-1DDAR SO PowerPAD DDA 8 2500 364.0 364.0 27.0 TPS2421-2DDAR SO PowerPAD DDA 8 2500 364.0 364.0 27.
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