PTH12050YAH - Texas Instruments

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6-A NON-ISOLATED DDR/QDR

FEATURES

NOMINAL SIZE =0.87 in x 0.5 in

(22,1 mm x 12,57 mm)

DESCRIPTION

VIN

Standby

GND

VTT

VREF

Low−ESR

(Required)

VTTTermination Island

1 k

1 %

1 k

1 %

VDDQ

SSTL−2

Bus

Ceramic

(Optional)

BSS138

(Optional)

hf−Ceramic

PTHxx050Y

(Top View)

CIN = Required Electrolytic Capacitor; 220µF (3.3 ± 5 V Input), 560 µF (12 V Input).

Co1 = Required Low-ESR Electrolyitic Capacitor; 470 µF (3.3 ± 5 V Input), 940 µF (12 V Input).

Co2 = Ceramic Capacitance for Response to a 3 A (+ 1.5 A) Load Transient; 200 µF (3.3 ± 5 V Input), 400 µF (12 V Input).

Con = Distributed hf-Ceramic Decoupling Capacitors for VTT bus; as Recommended for DDR Memory Applications.

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

MEMORY BUS TERMINATION MODULES

•50 W/in3Power Density

•VTT Bus Termination Output •Safety Agency Approvals:

(Output Tracks the System VREF) UL/cUL60950, EN60950, VDE

•6 A Output Current (8 A Peak) •Point-of-Load Alliance (POLA™) Compatible

•3.3-V, 5-V or 12-V Input Voltage

•DDR and QDR Compatible

•On/Off Inhibit (for VTT Standby)

•Undervoltage Lockout

•Operating Temperature: –40°Cto85°C

•Efficiencies up to 88%

•Output Overcurrent Protection (Non-Latching,

Auto-Reset)

The PTHxx050Y are a series of ready-to-use switching regulator modules from Texas Instruments designed

specifically for bus termination in DDR and QDR memory applications. Operating from either a 3.3-V, 5-V or 12-V

input, the modules generate a VTT output that will source or sink up to 6 A of current (8 A transient) to accurately

track their VREF input. VTT is the required bus termination supply voltage, and VREF is the reference voltage for

the memory and chipset bus receiver comparators. VREF is usually set to half the VDDQ power supply voltage.

Both the PTHxx050Y series employs an actively switched synchronous rectifier output to provide state-of-the-art

stepdown switching conversion. The products are small in size (0.87 in ×0.5 in), and are an ideal choice where

space, performance, and high efficiency are desired, along with the convenience of a ready-to-use module.

Operating features include an on/off inhibit and output over-current protection (source mode only). The on/off

inhibit feature allows the VTT bus to be turned off to save power in a standby mode of operation.

Package options include both throughhole and surface mount configurations.

STANDARD 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.

POLA is a trademark of Texas Instruments.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

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ENVIRONMENTAL AND ABSOLUTE MAXIMUM RATINGS

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

ORDERING INFORMATION

PTHXX050Y (Base Part Number)

Input Voltage Part Number (1) DESCRIPTION Pb – free and Mechanical Package

RoHS (2)

PTH03050YAH Horizontal T/H Yes (3) EUU

3.3 V PTH03050YAS Standard SMD No (4) EUV

PTH03050YAZ Optional SMD Yes (3) EUV

PTH05050YAH Horizontal T/H Yes (3) EUU

5 V PTH05050YAS Standard SMD No (4) EUV

PTH05050YAZ Optional SMD Yes (3) EUV

PTH12050YAH Horizontal T/H Yes (3) EUU

12 V PTH12050YAS Standard SMD No (4) EUV

PTH12050YAZ Optional SMD Yes (3) EUV

(1) Add Tto end of part number for tape and reel on SMD packages only.

(2) Reference the applicable package reference drawing for the dimensions and PC board layout.

(3) Lead (Pb) –free option specifies Sn/Ag pin solder material.

(4) Standard option specifies 63/37, Sn/Pb pin solder material.

voltages are with respect to GND

UNIT

VREF Control input voltage –0.3 V to Vi+0.3 V

TAOperating temperature Over VIN range –40°Cto85°C(1)

range

Twave Wave solder Surface temperature of module body or pins PTHXX050YAH 260°C(2)

temperature (5 seconds)

PTHXX050YAS 235°C(2)

Solder reflow

Treflow Surface temperature of module body or pins

temperature PTHXX050YAZ 260°C(2)

TsStorage temperature –40°C to 125°C

Mechanical shock Per Mil-STD-883D, Method 2002.3 1 msec, 1/2 Sine, mounted 500 G

Mechanical vibration Mil-STD-883D, Method 2007.2 20-2000 Hz 20 G

Weight 2.9 grams

Flammability Meets UL 94V-O

(1) For operation below 0°C the external capacitors m ust bave stable characteristics, use either a low ESR tantalum, Os-Con, or ceramic

capacitor.

(2) During soldering of package version, do not elevate peak temperature of the module, pins or internal components above the stated

maximum.

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ELECTRICAL SPECIFICATIONS

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

TA=25°C; nominal VIN;V

REF =1.25V;C

IN,C

O1, and CO2 = typical values; and Io=I

omax (unless otherwise stated)

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Continuous 0 ±6(1) A

IOOutput current Over VREF range Repetitive pulse ±8(2) A

PTH03050Y 2.95 3.65

VIN Input voltage range Over IOrange PTH05050Y 4.5 5.5 V

PTH12050Y 10.8 13.2

∆VREF Tracking range for VREF 0.55 1.8 V

|VTT–V

REF| Tracking tolerance to VREF Over line, load and temperature –10 10 mV

PTH03050Y 88%

ηEfficiency Io= 4 A PTH05050Y 87%

PTH12050Y 84%

VrVoRipple (pk-pk) 20 MHz bandwidth 20 mVpp

Iotrip Overcurrent threshold Reset, followed by auto recovery 12 A

ttr Recovery time 80 µsec

15 A/µs load step, from:

Load transient response –1.5Ato1.5A

(3)

Vtr VOover/undershoot 25 40 mV

PTH03050Y 2.45 2.8

VIN Increasing PTH05050Y 4.3 4.45 V

PTH12050Y 9.5 10.4

UVLO Under-voltage lockout PTH03050Y 2.0 2.40

VIN Dncreasing PTH05050Y 3.4 3.7 V

PTH12050Y 8.8 9

Inhibit control (pin 4) VIN–0.5 Open(4)

VIH V

Input high voltage Referenced to GND

Inhibit control (pin 4) –0.2 0.6

VIL V

Input low voltage

Inhibit control (pin 4)

IIL inhibit Pin to GND 130 µA

Input low curent

IIN inh Input standby current Inhibit control (pin 4) to GND 10 mA

PTH03050Y/PTH05050Y 550 600 650

fsSwitching frequency Over VIN and IOranges kHz

PTH12050Y 200 250 300

PTH03050Y/PTH05050Y 220(5)

CIN External input capacitance µF

PTH12050Y 560(5)

Capacitance value: Nonceramic PTH03050Y/PTH05050Y 470(3) 3300(6)

µF

PTH12050Y 940(3) 3300(6)

Co1,Co

2External output capacitance PTH03050Y/PTH05050Y 200(3) 300

Capacitance value: Ceramic µF

PTH12050Y 400(3) 600

Equiv. series resistance (non-ceramic) 4(7) mΩ

MTBF Reliability Per Bellcore TR-332 50 % stress, TA=40°C, ground benign 6 106Hrs

(1) Rating is conditional on the module being directly soldered to a 4-layer PCB with 1 oz. copper. See the SOA curves or contact the

factory for appropriate derating. The PTH03050Y and PTH05050Y require no derating up to 85°C operating temperature and natural

convection airflow.

(2) Up to 10 ms pulse period at 10% maximum duty.

(3) The minimum value of external output capacitance value ensures that VTT meets the specified transient performance requirements for

the memory bus terminations. Lower values of capacitance may be possible when the measured peak change in output current is

consistently less than 3 A.

(4) This control pin has an internal pull-up to the input voltage VIN. If it is left open-circuit the module will operate when input power is

applied. A small low-leakage (<100 nA) MOSFET is recommended for control. For further information, consult the related application

note.

(5) An input capacitor is required for proper operation. The capacitor must be rated for a minimum of 300 mA rms (750 mA rms for 12-V

input) of ripple current.

(6) This is the calculated maximum. The minimum ESR limitation will often result in a lower value. Consult the application notes for further

guidance.

(7) This is the typcial ESR for all the electrolytic (non-ceramic) output capacitance. Use 8 mΩas the minimum when using max-ESR values

to calculate.

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PTHXX050

(Top View)

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

Terminal Functions

TERMINAL DESCRIPTION

NAME NO.

VIN 3 The positive input voltage power node to the module, which is referenced to common GND.

This is the common ground connection for the VIN and VTT power connections. It is also the 0-VDC reference for

GND 1 the control inputs.

The module senses the voltage at this input to regulate the output voltage, VTT. The voltage at VREF is also the

reference voltage for the system bus receiver comparators. It is normally set to precisely half the bus driver supply

VREF 2voltage (VDDQ÷2), using a resistor divider. The Thevenin impedance of the network driving the VREF pin should

not exceed 500 Ω. See the Typical DDR Application Diagram in the Application Information section for reference.

This is the regulated power output from the module with respect to the GND node, and the tracking termination

supply for the application data and address buses. It is precisely regulated to the voltage applied to the module's

VTT 6VREF input, and is active active about 20 ms after a valid input source is applied to the module. Once active it will

track the voltage applied at VREF.

The Inhibit pin is an open-collector/drain negative logic input that is referenced to GND. Applying a low-level

ground signal to this input turns off the output voltage, VTT. Although the module is inhibited, a voltage, VDDQ will

be present at the output terminals, fed through the DDR memory. When the Inhibit is active, the input current

Inhibit 4 drawn by the regulator is significantly reduced. If the Inhibit pin is left open circuit, the module will produce an

output whenever a valid input source is applied. See the Typical DDR Application Diagram in the Application

Information section for reference.

N/C 5 No Connection

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TYPICAL CHARACTERISTICS (VREF =1.25 V)(1)(2)

10 0

Efficiency −%

1234560

IL − Load Current − A

VIN = 3.3 VVIN = 5 V

VIN = 12 V

0. 3

0. 6

0. 9

1. 2

1. 5

123450

IL − Load Current − A

VIN = 3.3 V

VIN = 5 V

VIN = 12 V

− Power Dissipation − W

123450

IL − Load Current − A

Output Ripple − mV

VIN = 3.3 V VIN = 5 V

VIN = 12 V

VTT − VREF

(50 mV/div)

+VTT (5

A/div)

100 ms/div

400 LFM

200 LFM

100 LFM

Nat Cinv

VIN = 12 V

123450

TA−Ambient Temperature −

IL − Load Current − A

Airflow = Nat Conv

1234506

TA−Ambient Temperature −

IL − Load Current − A

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

EFFICIENCY OUTPUT RIPPLE POWER DISSIPATION

vs vs vs

LOAD CURRENT LOAD CURRENT LOAD CURRENT

Figure 1. Figure 2. Figure 3.

PTH03050Y/PTH05050Y AT PTH12050Y ONLY; VIN = 12 V TRANSIENT PERFORMANCE, 4-A

NOMINAL VIN TEMPERTURE DERATING vs LOAD LOAD CHANGE

TEMPERTURE DERATING vs LOAD CURRENT PTH03050Y/PTH05050Y/PTH12050Y:

CURRENT SINK TO SOURCE TRANSIENT

Figure 4. Figure 5. Figure 6.

(1) The electrical characteristic data has been developed from actual products tested at 25°C. This data is considered typical for the

converter. Applies to Figure 1,Figure 2, and Figure 3.

(2) The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum

operating temperatures. Derating limits apply to modules soldered directly to a 4 mm x 4 mm double-sided PCB with 1 oz. copper. For

surface mount packages (AS and AZ suffix), multiple vias (plated through holes) are required to add thermal paths around the power

pins. Please refer to the mechanical specification for more information. Applies to Figure 4, and Figure 5.

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APPLICATION INFORMATION

Typical DDR Application Diagram

Inhibit ++

DDRII/

QDRII

PTH05010W

VDDQ I/O Memory

Inhibit +

PTH05050Y

DDR Termination

2×

330 µF

2×

22 µF

2×

330 µF

2×

22 µF

+SenseMargin ±

Auto-Track

+VADJ

1 kΩ

VI= 5V

220 µF47 µF

470 µF47 µF5.51 kΩ

+VREF

UDG−05096

VTT

VTT = 0.9 V

VDDQ = 1.8 V

CAPACITOR RECOMMENDATIONS FOR THE PTH03050Y & PTH05050Y DDR POWER MODULES

Input Capacitor

Output Capacitors

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

(3.3-V/5-V OPTION)

The recommended input capacitor(s) is determined by the 220 µF minimum capacitance and 500 mArms

minimum ripple current rating.

Ripple current and less than 100 mΩequivalent series resistance (ESR) values are the major considerations,

along with temperature, when designing with different types of capacitors. Unlike polymer tantalum, regular

tantalum capacitors have a recommended minimum voltage rating of 2 ×(maximum DC voltage + AC ripple).

This is standard practice to insure reliability.

For improved ripple reduction on the input bus, ceramic capacitors may be substituted for electrolytic types using

the minimum required capacitance.

For applications with load transients (sudden changes in load current), regulator response will benefit from

external output capacitance. The recommended output capacitance of 470 µF will allow the module to meet its

transient response specification (see Electrical Specifications table). For most applications, a high quality

computer-grade aluminum electrolytic capacitor is adequate. These capacitors provide decoupling over the

frequency range, 2 kHz to 150 kHz, and are suitable when ambient temperatures are above 0°C. For operation

below 0°C tantalum, ceramic or Os-Con type capacitors are recommended. When using one or more

non-ceramic capacitors, the calculated equivalent ESR should be no lower than 4 mΩ(8 mΩusing the

manufacturer's maximum ESR for a single capacitor). A list of preferred low-ESR type capacitors are identified in

Table 1.

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Ceramic Capacitors (Recommended)

Tantalum Capacitors

Capacitor Table

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

APPLICATION INFORMATION (continued)

Above 150 kHz the performance of aluminum electrolytic capacitors becomes less effective. To further improve

the reflected input ripple current or the output transient response. Multilayer ceramic capacitors have very low

ESR and their resonant frequency higher than the bandwidth of the regulator. They can be used to reduce the

reflected ripple current at the input as well as improve the transient response of the output. When used on the

output their combined ESR is not critical as long as the total value of ceramic capacitance does not exceed

300 µF. Also, to prevent the formation of local resonances, do not place more than five identical ceramic

capacitors in parallel with values of 10 µF or greater.

Tantalum type capacitors can be used at both the input and output, and are recommended for applications where

the ambient operating temperature can be less than 0°C. The AVX TPS, Sprague 593D/594/595 and Kemet

T495/T510 capacitor series are suggested over many other tantalum types due to their higher rated surge, power

dissipation, and ripple current capability. As a caution many general purpose tantalum capacitors have

considerably higher ESR, reduced power dissipation and lower ripple current capability. These capacitors are

also less reliable when determining their power dissipation and surge current rating. Tantalum capacitors that do

not have a stated ESR or surge current rating are not recommended for power applications.

When specifying Os-Con and polymer tantalum capacitors for the output, the minimum ESR limit will be

encountered well before the maximum capacitance value is reached.

Table 1 identifies the characteristics of capacitors from a number of vendors with acceptable ESR and ripple

current (rms) ratings. The recommended number of capacitors required at both the input and output buses is

identified for each capacitor type.

This is not an extensive capacitor list. Capacitors from other vendors are available with comparable

specifications. Those listed are for guidance. The RMS ripple current rating and ESR (at 100 kHz) are critical

parameters necessary to insure both optimum regulator performance and long capacitor life.

Table 1. Input/Output Capacitors(1)

Capacitor Characteristics Quantity

Capacitor Vendor, Vendor

Working Max ESR Max Ripple Physical

Value Input Output

Type/Series (Style) Part Number

Voltage at 100 kHz Current at 85°CSize

(µF) Bus Bus

(V) (Ω) (Irms) (mA) (mm)

Panasonic, Aluminum

FC (Radial) 10 470 0.117 555 8×10 1 1 EEUFC1A471

FK (SMD) 25 470 0.080 850 10×10.2 1 1 EEVFK1E471P

FC (SMD) 16 470 0.150 670 10×10.2 1 1 EEVFC1C471P

United Chemi-Con

PXA, Poly-Aluminum (SMD) 6.3 470 0.020 >4100 10×7.7 1 ≤2 PXA6.3VC471MJ80TP

PS, Poly-Aluminum (Radial) 6.3 390 0.012 4770 8×11.5 1 ≤1(2) 6PS390MH11

PSA, Poly-Aluminum (Radial) 10 470 0.008 5650 8×11,5 1 ≤1 PSA10VB470MJ11

LXZ, Aluminum (Radial) 16 470 0.090 760 10×12.5 1 1 LXZ16VB471M10X12LL

Panasonic, Poly-Aluminum

S/SE (SMD) 6.3 180 0.005 4000 7.3×4.3×4.2 2 N/R(3) EEFSE0J181R

(1) Capacitor Supplier Verification

Please verify availability of capacitors identified in this table. Capacitor suppliers may recommend alternative part numbers because of

limited availability or obsolete products. In some instances, the capacitor product life cycle may be in decline and have short-term

consideration for obsolescence.

RoHS, Lead-free and Material Details

Please consult capacitor suppliers regarding material composition, RoHS status, lead-free status, and manufacturing process

requirements. Component designators or part number deviations can occur when material composition or soldering requirements are

updated.

(2) The total capacitance can be slightly lower than recommended minimum, but is acceptable based on the combined ripple current rating.

(3) This capacitor is not recommended for the VObus. The capacitor ESR is below the specified minimum for non-ceramic capacitor.

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Designing for Very Fast Load Transients

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

APPLICATION INFORMATION (continued)

Table 1. Input/Output Capacitors (continued)

Capacitor Characteristics Quantity

Capacitor Vendor, Vendor

Working Max ESR Max Ripple Physical

Value Input Output

Type/Series (Style) Part Number

Voltage at 100 kHz Current at 85°CSize

(µF) Bus Bus

(V) (Ω) (Irms) (mA) (mm)

Nichicon Aluminum

WG (SMD) 10 470 0.150 670 10×10 1 1 UWG1A471MNR1GS

HD (Radial) 10 470 0.072 760 8×11.5 1 1 UHD1A471MPR

PM (Radial) 10 470 0.120 600 10×12.5 1 1 UPM1A471MPH6

Sanyo

SP, Os-con (Radial) 10 470 0.015 4500 10×10.5 1 ≤2 10SP470M

SVPA (SMD) 6.3 470 0.020 >4100 7,9×10 1 ≤2 6SVPA470M

TPE, Poscap (SMD) 6.3 220 0.025 2400 7.3×4.3 1 ≤3 6TPE220ML

AVX, Tantalum 10 330 0.045 1723 1 ≤5 TPSE337M010R0045

7.3L ×5.7W

×4.1H

TPS (SMD) 10 330 0.060 1826 1 ≤5 TPSV337M010R0060

Kemet, Poly-Tantalum

4.3W ×7.3L

T520 (SMD) 10 330 0.040 1800 1 ≤5 T520X337M010ASE045

×4.0H

T530 (SMD) 10 330 0.010 >5000 1 ≤1 T530X337M010ASE010

Vishay-Sprague

7.2L×6W

595D, Tantalum (SMD) 10 330 0.100 1040 1 ≤5 595D377x0010D2T

×4.1H

594D, Tantalum (SMD) 10 330 0.045 2360 1 ≤5 594D337X0016R2T

10x10.5

94SVP, Poly-Aluminum (Radial) 6.3 330 0.025 3500 1 ≤3 94SA337X06R3FBP

Kemet, Ceramic X5R (SMD) 16 10 0.002 – 1210 /3225 1 ≤5 C1210C106M4PAC

6.3 47 0.002 3225 mm 1 ≤5 C1210C476K9PAC

Murata, Ceramic X5R (SMD) 6.3 100 0.002 – 3225 mm 1(4) ≤3 GRM32ER60J107M

6.3 47 0.002 3225 mm 1(4) ≤5 GRM32ER60J476M

16 22 0.002 1(4) ≤5 GRM32ER61C226K

16 10 0.002 1(4) ≤5 GRM32DR61C106K

TDK, Ceramic X5R (SMD) 6.3 100 0.002 – 3225 mm 1(4) ≤3 C3225X5R0J107MT

6.3 47 0.002 3225 mm 1(4) ≤5 C3225X5R0J476MT

16 22 0.002 1(4) ≤5 C3225X5R1C226MT

16 10 0.002 1(4) ≤5 C3225X5R1C106MT

(4) A ceramic capacitor can be used to compliment electrolytic types at the input to further reduce high-frequency ripple current.

The transient response of the DC/DC converter has been characterized using a load transient with a di/dt of

1A/µs. The typical voltage deviation for this load transient is given in the data sheet specification table using the

optional value of output capacitance. As the di/dt of a transient is increased, the response of a converter's

regulation circuit ultimately depends on its output capacitor decoupling network. This is an inherent limitation with

any DC/DC converter once the speed of the transient exceeds its bandwidth capability. If the target application

specifies a higher di/dt or lower voltage deviation, the requirement can only be met with additional output

capacitor decoupling. In these cases special attention must be paid to the type, value and ESR of the capacitors

selected.

If the transient performance requirements exceed that specified in the data sheet, or the total amount of load

capacitance is above 3300 µF, the selection of output capacitors becomes more important.

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CAPACITOR RECOMMENDATIONS FOR THE PTH12050Y DDR POWER MODULES

Input Capacitor

Output Capacitors

Ceramic Capacitors

Tantalum Capacitors

Capacitor Table

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

PTH12050Y (12-V OPTION)

The recommended input capacitance is determined by the 560 µF minimum capacitance and 750 mArms

minimum ripple current rating. A ≥10-µF X5R/X7R ceramic capacitor can be added to reduce the reflected input

ripple current. The ceramic capacitor should be located between the input electrolytic and the module.

Ripple current, less than 100 mΩequivalent series resistance (ESR) and temperature, are major considerations

when selecting input capacitors. Unlike polymer-tantalum capacitors, regular tantalum capacitors have a

recommended minimum voltage rating of 2 ×(max. dc voltage + ac ripple). No tantalum capacitors were found

with sufficient voltage rating to meet this requirement. At temperatures below 0°C, the ESR of aluminum

electrolytic capacitors increases. For these applications, Os-Con, polymer-tantalum, and polymer-aluminum types

should be considered.

For applications with load transients (sudden changes in load current), regulator response will benefit from

external output capacitance. The recommended minimum output capacitance of 940 µF will allow the module to

meet its transient response specification (see Electrical Specifications table). For most applications, a high quality

computer-grade aluminum electrolytic capacitor is adequate. These capacitors provide decoupling over the

frequency range, 2 kHz to 150 kHz, and are suitable when ambient temperatures are above 0°C. For operation

below 0°C tantalum, ceramic or Os-Con type capacitors are recommended. When using one or more

non-ceramic capacitors, the calculated equivalent ESR should be no lower than 4 mΩ(8 mΩusing the

manufacturer's maximum ESR for a single capacitor)

A list of preferred low-ESR type capacitors are identified in Table 2.

In addition to electrolytic capacitance, adding a 10-µF to 22-µF X5R/X7R ceramic capacitor to the output reduces

the output ripple voltage and improves the regulator's transient response. The measurement of both the output

ripple and transient response is also best achieved across a 10-µF ceramic capacitor.

Above 150 kHz, the performance of aluminum electrolytic capacitors is less effective. Multilayer ceramic

capacitors have a low ESR and a resonant frequency higher than the bandwidth of the regulator. They can be

used to reduce the reflected ripple current at the input, and improve the transient response of the output. When

used on the output, their combined ESR is not critical as long as the total value of ceramic capacitance does not

exceed 300 µF. Also, to prevent the formation of local resonances, do not place more than five identical ceramic

capacitors in parallel with values of 10 µF or greater.

Tantalum type capacitors are most suited for use on the output bus, and are recommended for applications

where the ambient operating temperature can be less than 0°C. The AVX TPS, Sprague 593D/594/595, and

Kemet T495/T510 capacitor series are suggested over other tantalum types due to their higher rated surge,

power dissipation, and ripple current capability. As a caution, many general-purpose tantalum capacitors have

considerably higher ESR, reduced power dissipation, and lower ripple current capability. These capacitors are

also less reliable as they have lower power dissipation and surge current ratings. Tantalum capacitors that do not

have a stated ESR or surge current rating are not recommended for power applications.

When specifying Os-con and polymer tantalum capacitors for the output, the minimum ESR limit is encountered

well before the maximum capacitance value is reached.

Table 2 identifies the characteristics of capacitors from a number of vendors with acceptable ESR and ripple

current (rms) ratings. The recommended number of capacitors required at both the input and output buses is

identified for each capacitor type.

Note: This is not an extensive capacitor list. Capacitors from other vendors are available with comparable

specifications. Those listed are for guidance. The RMS ripple current rating and ESR (at 100 kHz) are critical

parameters necessary to insure both optimum regulator performance and long capacitor life.

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PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

Table 2. Input/Output Capacitors(1)

Capacitor Characteristics Quantity

Max Ripple

Max

Capacitor Vendor, Type/Series Working Current Vendor Number

Value ESR at Physical Size Input Output

(Style) Voltage at 85°C

(µF) 100 kHz (mm) Bus Bus

(V) (Irms)

(Ω)(mA)

Panasonic, Aluminum FC Radial 25 560 0.065 1205 12,5 ×15 1 1 EEUFC1E561S

FK (SMD) 16 680 0.080 850 10 ×10,2 1 2 EEVFK1C681P

United Chemi-Con

PXA, Poly-Aliminum (SMD) 16 330 0.014 5050 10 ×12,5 2 ≤2 PXA16VC331MJ12TP

PS, Poly-Aluminum (Radial) 16 330 0.0014 5050 10 ×12,5 2 ≤2 16PS330MJ12

LXZ, Aluminum (Radial) 16 680 0.068 1050 10 ×16 1 1 LXZ16VB681M10X16LL

Nichicon Aluminum 25 560 0.060 1060 12,5 ×15 1 1 UPM1E561MHH6

PM (Radial) 16 680 0.038 1430 10 ×16 1 2 UHD1C681MHR

HD (Radial) 35 560 0.048 1360 16 ×15 1 1 UPM1V561MHH6

Panasonic, Poly-Alum S/SE (SMD) 6.3 180 0.005 4000 7,3 ×4,3 ×4,2 N/R(2) ≤1 EEFSE0J181R

Sanyo

TPE, ps-Ccap (SMD) 10 330 0.025 3000 7,3 L ×5,7 W N/R(2) ≤3 10TPE330M

SEPC Os-con (Radial) 16 470 0.010 >6100 10 ×13 1(3) ≤1 16SEPC470M

SVP, Os-con (SMD) 16 330 0.016 4700 11 ×12 2 ≤2 16SVP330M

SVPC Os-con (SMD) 4 1200 0.010 4700 8 ×11,9 N/R(2) ≤1 4SVPC1200M

AVX, Tantalum TPS (SMD) 10 470 0.045 >1723 7,3 ×5,7 ×4,1 N/R(2) ≤5 TPSE477M019R0045

10 330 0.045 >1723 N/R(2) ≤5 TPSE337M019R0045

Kemet

T520, Poly-Tantalum (SMD) 6.3 470 0.040 1800 N/R(2) ≤5 T520X477M006ASE040

T530, Tantalum/Organic 4 680 0.010 >5100 4,3 ×7,3 ×4N/R

(2) ≤1 T530X687M004ASE010

T530, Tantalum/Organic 6.3 470 0.010 5200 N/R(2) ≤1 T530X477M006ASE010

Vishay-Sprague

594D, Tantalum (SMD) 10 470 0.100 1440 7,2 ×6×4,1 N/R(2) ≤5 595D477X0010R2T

94SVP, Os-con (SMD) 16 330 0.017 >4500 10 ×12,7 2 ≤2 94SVP337X0016F12

94SA, Organic (Radial) 16 1000 0.015 >9700 16 ×25 1 ≤2 94SA108X0016HBP

Kemet, Ceramic X5R (SMD) 16 10 0.002 3225 mm 1(4) ≤5 C1210C106M4PAC

6.3 47 0.002 3225 mm N/R(2) ≤5 C1210C476K9PAC

Murata, Ceramic X5R (SMD) 6.3 100 0.002 3225 mm N/R(2) ≤3 GRM32ER60J107M

6.3 47 3225 mm N/R(2) ≤5 GRM32ER60J476M

16 22 1(4) ≤5 GRM32ER61C226K

16 10 1(4) ≤5 GRM32DR61C106K

TDK, Ceramic X5R (SMD) 6.3 100 0.002 3225 mm N/R(2) ≤3 C3225X5R0J107MT

6.3 47 3225 mm N/R(2) ≤5 C3225X5R0J476MT

16 22 1(4) ≤5 C3225X5R1C226MT

16 10 1(4) ≤5 C3225X5R1C106MT

(1) Capacitor Supplier Verification

Please verify availability of capacitors identified in this table. Capacitor suppliers may recommend alternative part numbers because of

limited availability or obsolete products. In some instances, the capacitor product life cycle may be in decline and have short-term

consideration for obsolescence.

RoHS, Lead-free and Material Details

Please consult capacitor suppliers regarding material composition, RoHS status, lead-free status, and manufacturing process

requirements. Component designators or part number deviations can occur when material composition or soldering requirements are

updated.

(2) N/R – Not recommended. The capacitor voltage rating does not meet the minimum operating limits.

(3) A total capacitance of 470 µF is acceptable based on the combined ripple current rating.

(4) Ceramic capacitors are recommended to complement electrolytic types at the input and to reduce high-frequency ripple current.

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Designing for Very Fast Load Transients

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

The transient response of the DC/DC converter has been characterized using a load transient with a di/dt of

1A/µs. The typical voltage deviation for this load transient is given in the data sheet specification table using the

optional value of output capacitance. As the di/dt of a transient is increased, the response of a converter's

regulation circuit ultimately depends on its output capacitor decoupling network. This is an inherent limitation with

any DC/DC converter once the speed of the transient exceeds its bandwidth capability. If the target application

specifies a higher di/dt or lower voltage deviation, the requirement can only be met with additional output

capacitor decoupling. In these cases special attention must be paid to the type, value and ESR of the capacitors

selected.

If the transient performance requirements exceed that specified in the data sheet, or the total amount of load

capacitance is above 3300 µF, the selection of output capacitors becomes more important.

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TAPE AND REEL SPECIFICATION

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

www.ti.com

TRAY SPECIFICATION

PTH03050Y

PTH05050Y

PTH12050Y

SLTS221A–MARCH 2004–REVISED OCTOBER 2005

PACKAGE OPTION ADDENDUM

www.ti.com 20-May-2011

Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status (1) Package Type Package

Drawing Pins Package Qty Eco Plan (2) Lead/

Ball Finish MSL Peak Temp (3) Samples

(Requires Login)

PTH03050YAH ACTIVE Through-

Hole Module EUU 6 56 Pb-Free (RoHS) SN N / A for Pkg Type

PTH03050YAS ACTIVE Surface

Mount Module EUV 6 56 TBD SNPB Level-1-235C-UNLIM/

Level-3-260C-168HRS

PTH03050YAST ACTIVE Surface

Mount Module EUV 6 250 TBD SNPB Level-1-235C-UNLIM/

Level-3-260C-168HRS

PTH03050YAZ ACTIVE Surface

Mount Module EUV 6 56 Pb-Free (RoHS) SNAGCU Level-3-260C-168 HR

PTH03050YAZT ACTIVE Surface

Mount Module EUV 6 250 Pb-Free (RoHS) SNAGCU Level-3-260C-168 HR

PTH03050YBH ACTIVE Through-

Hole Module EUU 6 56 Pb-Free (RoHS) Call TI N / A for Pkg Type

PTH05050YAH ACTIVE Through-

Hole Module EUU 6 56 Pb-Free (RoHS) SN N / A for Pkg Type

PTH05050YAS ACTIVE Surface

Mount Module EUV 6 56 TBD SNPB Level-1-235C-UNLIM/

Level-3-260C-168HRS

PTH05050YAST ACTIVE Surface

Mount Module EUV 6 250 TBD SNPB Level-1-235C-UNLIM/

Level-3-260C-168HRS

PTH05050YAZ ACTIVE Surface

Mount Module EUV 6 56 Pb-Free (RoHS) SNAGCU Level-3-260C-168 HR

PTH05050YAZT ACTIVE Surface

Mount Module EUV 6 250 Pb-Free (RoHS) SNAGCU Level-3-260C-168 HR

PTH12050YAH ACTIVE Through-

Hole Module EUU 6 56 Pb-Free (RoHS) SN N / A for Pkg Type

PTH12050YAS ACTIVE Surface

Mount Module EUV 6 56 TBD SNPB Level-1-235C-UNLIM/

Level-3-260C-168HRS

PTH12050YAST ACTIVE Surface

Mount Module EUV 6 250 TBD SNPB Level-1-235C-UNLIM/

Level-3-260C-168HRS

PTH12050YAZ ACTIVE Surface

Mount Module EUV 6 56 Pb-Free (RoHS) SNAGCU Level-3-260C-168 HR

PTH12050YAZT ACTIVE Surface

Mount Module EUV 6 250 Pb-Free (RoHS) SNAGCU Level-3-260C-168 HR

(1) The marketing status values are defined as follows:

PACKAGE OPTION ADDENDUM

www.ti.com 20-May-2011

Addendum-Page 2

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability

information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.

Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that

lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.

Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between

the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.

Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight

in homogeneous material)

(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

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