Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - DC/DC voltage regulator Holder HTSSOP 14

V (50 mV / div)

OUT

I (2 A / div)

OUT

100 s / divµ

TPS54325

www.ti.com

SLVS932D –MAY 2009–REVISED AUGUST 2012

4.5-V to 18-V, 3-A OUTPUT SYNCHRONOUS STEP DOWN

SWITCHER WITH INTEGRATED FET

Check for Samples: TPS54325

FEATURES

DESCRIPTION

The TPS54325 is an adaptive on-time D-CAP2™

• D-CAP2™ Mode Enables Fast Transient

mode synchronous buck converter. The TPS54325

Response

enables system designers to complete the suite of

• Low Output Ripple and Allows Ceramic Output

various end equipment’s power bus regulators with a

Capacitor

cost effective, low component count, low standby

current solution. The main control loop for the

• Wide V

Input Voltage Range: 4.5 V to 18 V

TPS54325 uses the D-CAP2™ mode control which

• Wide V

Input Voltage Range: 2.0 V to 18 V

provides a very fast transient response with no

• Output Voltage Range: 0.76 V to 5.5 V

external components. The TPS54325 also has a

• Highly Efficient Integrated FET’s Optimized for

proprietary circuit that enables the device to adapt to

both low equivalent series resistance (ESR) output

Lower Duty Cycle Applications – 120 mΩ (High

capacitors, such as POSCAP or SP-CAP, and ultra-

Side) and 70 mΩ (Low Side)

low ESR ceramic capacitors. The device operates

• High Efficiency, less than 10 μA at shutdown

from 4.5-V to 18-V VCC input , and from 2.0-V to 18-

• High Initial Bandgap Reference Accuracy

V VIN input power supply voltage. The output voltage

can be programmed between 0.76 V and 5.5 V. The

• Adjustable Soft Start

device also features an adjustable slow start time and

• Pre-Biased Soft Start

a power good function. The TPS54325 is available in

• 700-kHz Switching Frequency (f

)

the 14 pin HTSSOP package, and designed to

operate from –40°C to 85°C.

• Cycle By Cycle Over Current Limit

• Power Good Output

APPLICATIONS

• Wide Range of Applications for Low Voltage

System

– Digital TV Power Supply

– High Definition Blue-ray Disc™ Players

– Networking Home Terminal

– Digital Set Top Box (STB)

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.

2D-CAP2, PowerPAD are trademarks of Texas Instruments.

3Blue-ray Disc is a trademark of Blu-ray Disc.

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 (25 pages)

PAGE 1
TPS54325 www.ti.com SLVS932D – MAY 2009 – REVISED AUGUST 2012 4.5-V to 18-V, 3-A OUTPUT SYNCHRONOUS STEP DOWN SWITCHER WITH INTEGRATED FET Check for Samples: TPS54325 FEATURES DESCRIPTION • The TPS54325 is an adaptive on-time D-CAP2™ mode synchronous buck converter. The TPS54325 enables system designers to complete the suite of various end equipment’s power bus regulators with a cost effective, low component count, low standby current solution.
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TPS54325 SLVS932D – MAY 2009 – REVISED AUGUST 2012 www.ti.com ORDERING INFORMATION (1) PACKAGE (2) TA –45°C to 85°C (1) (2) (3) (3) TRANSPORT MEDIA, QUANTITY ORDERABLE PART NUMBER PowerPAD™ (HTSSOP) – PWP TPS54325PWP Tube TPS54325PWPR Tape and Reel For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. Package drawings, thermal data, and symbolization are available at www.ti.com/packaging.
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TPS54325 www.ti.com SLVS932D – MAY 2009 – REVISED AUGUST 2012 RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) MIN MAX UNIT VCC Supply input voltage range 4.5 18 V VIN Power input voltage range 2 18 V VBST –0.1 24 VBST (vs SW1, SW2) –0.1 6 SS, PG –0.1 6 EN –0.1 18 VO, VFB –0.1 5.5 SW1, SW2 –1.8 18 VI Input voltage range SW1, SW2 (10 ns transient) –3 18 PGND1, PGND2 –0.1 0.1 V VO Output voltage range VREG5 –0.
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TPS54325 SLVS932D – MAY 2009 – REVISED AUGUST 2012 www.ti.com ELECTRICAL CHARACTERISTICS (continued) over operating free-air temperature range, VCC, VIN = 12 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT ON-TIME TIMER CONTROL tON On time VIN = 12 V, VO = 1.05 V 145 ns tOFF(MIN) Minimum off time TA = 25°C, VFB = 0.7 V 260 ns SOFT START ISSC SS charge current VSS = 0 V 1.4 2.0 ISSD SS discharge current VSS = 0.5 V 0.1 0.2 VFB rising (good) 85 90 2.
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TPS54325 www.ti.com SLVS932D – MAY 2009 – REVISED AUGUST 2012 DEVICE INFORMATION PWP PACKAGE (TOP VIEW) VO 1 14 VCC VFB 2 13 VIN VREG5 3 12 VBST 11 SW2 SW1 POWERPAD TPS54325 SS 4 GND 5 10 PG 6 9 PGND2 EN 7 8 PGND1 PWP HTSSOP14 TERMINAL FUNCTIONS TERMINAL NAME NO. DESCRIPTION VO 1 Connect to output of converter. This terminal is used for On-Time Adjustment. VFB 2 Converter feedback input. Connect with feedback resistor divider. VREG5 3 5.5 V power supply output.
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TPS54325 SLVS932D – MAY 2009 – REVISED AUGUST 2012 www.ti.
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TPS54325 www.ti.com SLVS932D – MAY 2009 – REVISED AUGUST 2012 OVERVIEW The TPS54325 is a 3-A synchronous step-down (buck) converter with two integrated N-channel MOSFETs. It operates using D-CAP2™ mode control. The fast transient response of D-CAP2™ control reduces the output capacitance required to meet a specific level of performance. Proprietary internal circuitry allows the use of low ESR output capacitors including ceramic and special polymer types.
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TPS54325 SLVS932D – MAY 2009 – REVISED AUGUST 2012 www.ti.com Output Discharge Control The TPS54325 discharges the output when EN is low, or the controller is turned off by the protection functions (OVP, UVP, UVLO and thermal shutdown). The device discharges outputs using an internal 50-Ω MOSFET which is connected to VO and PGND. The internal low-side MOSFET is not turned on during the output discharge operation to avoid the possibility of causing negative voltage at the output, except for OVP protection.
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TPS54325 www.ti.com SLVS932D – MAY 2009 – REVISED AUGUST 2012 TYPICAL CHARACTERISTICS VIN = 12 V, TA = 25°C (unless otherwise noted) break is for spacing 1200 8 IVCCSDN - Shutdown Current - µA IVCC - Supply Current - µA 1000 800 600 400 200 0 -50 0 50 100 4 2 0 -50 150 0 50 100 150 TJ - Junction Temperature - °C TJ - Junction Temperature - °C Figure 1. VCC TEMPERATURE vs. JUNCTION TEMPERATURE Figure 2. VCC SHUTDOWN CURRENT vs. JUNCTION TEMPERATURE 1.100 1.100 1.075 VI = 18 V 1.
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TPS54325 SLVS932D – MAY 2009 – REVISED AUGUST 2012 www.ti.com TYPICAL CHARACTERISTICS (continued) VIN = 12 V, TA = 25°C (unless otherwise noted) break is for spacing VOUT (50 mV / div) EN (10 V / div) VOUT (0.5 V / div) IOUT (2 A / div) PG (5 V / div) 400 µs / div 100 µs / div Figure 5. 1.05-V, 0-A TO 3-A LOAD TRANSIERESPONSE 100 80 70 60 50 40 0.0 VO = 2.5 V VO = 1.8 V 800 VO = 1.8 V 700 600 VO = 3.3 V 500 0.5 1.0 1.5 2.0 2.5 Iout - Output Current - A Figure 7. EFFICIENCY vs.
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TPS54325 www.ti.com SLVS932D – MAY 2009 – REVISED AUGUST 2012 TYPICAL CHARACTERISTICS (continued) VIN = 12 V, TA = 25°C (unless otherwise noted) break is for spacing 900 fSW - Switching Frequency - kHz VO = 1.05 V VO (10 mV / div) 800 VO = 1.8 V 700 VO = 2.5 V SW (5 V / div) 600 500 0.0 0.5 1.0 1.5 2.0 2.5 3.0 IO - Output Current - A Figure 9. SWICHING FREQUENCY vs. OUTPUT CURRENT VO = 1.05 V Figure 10. VOLTAGE RIPPLE AT OUTPUT VIN (50 mV / div) SW (5 V / div) Figure 11.
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TPS54325 SLVS932D – MAY 2009 – REVISED AUGUST 2012 www.ti.com DESIGN GUIDE Step By Step Design Procedure To • • • • • begin the design process, you must know a few application parameters: Input voltage range Output voltage Output current Output voltage ripple Input voltage ripple Figure 12. Schematic Diagram for this Design Example Output Voltage Resistors Selection The output voltage is set with a resistor divider from the output node to the VFB pin.
PAGE 13
TPS54325 www.ti.com SLVS932D – MAY 2009 – REVISED AUGUST 2012 At low frequencies, the overall loop gain is set by the output set-point resistor divider network and the internal gain of the TPS54325. The low frequency phase is 180 degrees. At the output filter pole frequency, the gain rolls off at a -40 dB per decade rate and the phase drops rapidly.
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TPS54325 SLVS932D – MAY 2009 – REVISED AUGUST 2012 www.ti.com Input Capacitor Selection The TPS54325 requires an input decoupling capacitor and a bulk capacitor is needed depending on the application. A ceramic capacitor over 10-mF is recommended for the decoupling capacitor. An additional 0.1-µF capacitor from pin 14 to ground is recommended to improve the stability of the over-current limit function. The capacitor voltage rating needs to be greater than the maximum input voltage.
PAGE 15
TPS54325 www.ti.com SLVS932D – MAY 2009 – REVISED AUGUST 2012 LAYOUT CONSIDERATIONS 1. Keep the input switching current loop as small as possible. 2. Keep the SW node as physically small and short as possible to minimize parasitic capacitance and inductance and to minimize radiated emissions. Kelvin connections should be brought from the output to the feedback pin of the device. 3. Keep analog and non-switching components away from switching components. 4.
PAGE 16
TPS54325 SLVS932D – MAY 2009 – REVISED AUGUST 2012 www.ti.com REVISION HISTORY Changes from Original (May 2009) to Revision A Page • Changed TA, for the current limit, Iocl, From: 25°C to –40°C To: 85°C and 3.5 A was added at the MIN value .................. 3 • Figure 7 title was change to Efficiency vs. Output Current (VIN = 12 V) ............................................................................. 10 Changes from Revision A (May 2009) to Revision B • Page Added Figure 14 ..............
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 2-Oct-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device TPS54325PWPR Package Package Pins Type Drawing SPQ HTSSOP 2000 PWP 14 Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 330.0 12.4 Pack Materials-Page 1 6.9 B0 (mm) K0 (mm) P1 (mm) 5.6 1.6 8.0 W Pin1 (mm) Quadrant 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 2-Oct-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS54325PWPR HTSSOP PWP 14 2000 367.0 367.0 35.
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