Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - DC/DC voltage regulator Holder SO 8

V = 50 mV / div (-950 mV dc offset)

I = 1 A / div (0.75 to 2.25 A load step,

slew rate = 1 A / µsec)

Time = 50 µsec / div

TPS54328

www.ti.com

SLVSAN2C –NOVEMBER 2010–REVISED NOVEMBER 2012

4.5V to 18V Input, 3-A Synchronous Step-Down Converter with Eco-mode™

Check for Samples: TPS54328

FEATURES

DESCRIPTION

The TPS54328 is an adaptive on-time D-CAP2™

• D-CAP2™ Mode Enables Fast Transient

mode synchronous buck converter. The TPS54328

Response

enables system designers to complete the suite of

• Low Output Ripple and Allows Ceramic Output

various end-equipment 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

TPS54328 uses the D-CAP2™ mode control that

• Output Voltage Range: 0.76 V to 7 V

provides a fast transient response with no external

• Highly Efficient Integrated FETs Optimized

compensation components. The adaptive on-time

for Lower Duty Cycle Applications

control supports seamless transition between PWM

– 100 mΩ (High Side) and 70 mΩ (Low Side)

mode at higher load conditions and Eco-mode™

operation at light loads. Eco-mode™ allows the

• High Efficiency, less than 10 μA at shutdown

TPS54328 to maintain high efficiency during lighter

• High Initial Bandgap Reference Accuracy

load conditions. The TPS54328 also has a proprietary

• Adjustable Soft Start

circuit that enables the device to adopt to both low

equivalent series resistance (ESR) output capacitors,

• Pre-Biased Soft Start

such as POSCAP or SP-CAP, and ultra-low ESR

• 700-kHz Switching Frequency (f

)

ceramic capacitors. The device operates from 4.5-V

• Cycle By Cycle Over Current Limit

to 18-V VIN input. The output voltage can be

programmed between 0.76 V and 7 V. The device

• Auto-Skip Eco-mode™ for High Efficiency at

also features an adjustable soft start time. The

Light Load

TPS54328 is available in 8-pin DDA and 10-pin DRC

packages, and is designed to operate over the

APPLICATIONS

ambient temperature range of –40°C to 85°C.

• Wide Range of Applications for Low Voltage

System

– Digital TV Power Supply

– High Definition Blu-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, Eco-mode are trademarks of Texas Instruments.

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

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)

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TPS54328 www.ti.com SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 4.5V to 18V Input, 3-A Synchronous Step-Down Converter with Eco-mode™ Check for Samples: TPS54328 FEATURES DESCRIPTION • The TPS54328 is an adaptive on-time D-CAP2™ mode synchronous buck converter. The TPS54328 enables system designers to complete the suite of various end-equipment power bus regulators with a cost effective, low component count, low standby current solution.
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TPS54328 SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure.
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TPS54328 www.ti.com SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 RECOMMENDED OPERATING CONDITIONS over operating free-air temperature range (unless otherwise noted) VIN Supply input voltage range VI Input voltage range MIN MAX 4.5 18 VBST –0.1 24 VBST (10 ns transient) –0.1 27 VBST(vs SW) –0.1 5.7 SS –0.1 5.7 EN –0.1 18 VFB –0.1 5.5 SW –1.8 18 SW (10 ns transient) UNIT V V –3 21 GND –0.1 0.1 –0.1 5.
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TPS54328 SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 www.ti.com ELECTRICAL CHARACTERISTICS (continued) over operating free-air temperature range , VIN = 12 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT THERMAL SHUTDOWN TSDN (2) Shutdown temperature Thermal shutdown threshold Hysteresis 165 (2) °C 30 ON-TIME TIMER CONTROL tON On time VIN = 12 V, VO = 1.05 V 150 tOFF(MIN) Minimum off time TA = 25°C, VFB = 0.7 V 260 310 ns 2.
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TPS54328 www.ti.com SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 PIN FUNCTIONS PIN NAME DESCRIPTION DDA DRC EN 1 1 Enable input control. Active high. VFB 2 2 Converter feedback input. Connect to output voltage with feedback resistor divider. VREG5 3 3 5.5 V power supply output. A capacitor (typical 1 µF) should be connected to GND. VREG5 is not active when EN is low. SS 4 4 Soft-start control. An external capacitor should be connected to GND. GND 5 Ground pin.
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TPS54328 SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 www.ti.com OVERVIEW The TPS54328 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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TPS54328 www.ti.com SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 Current Protection The output over-current protection (OCP) is implemented using a cycle-by-cycle valley detect control circuit. The switch current is monitored by measuring the low-side FET switch voltage between the SW pin and GND. This voltage is proportional to the switch current. To improve accuracy, the voltage sensing is temperature compensated.
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TPS54328 SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 www.ti.com TYPICAL CHARACTERISTICS VIN = 12 V, TA = 25°C (unless otherwise noted). 1200 10.0 IVINSDN - Supply Current - µA IVIN - Supply Current - µA 1000 800 600 400 8.0 6.0 4.0 2.0 200 0 -50 0 50 100 Tj - Junction Temperature - °C 0 -50 150 Figure 1. VIN CURRENT vs JUNCTION TEMPERATURE 0 50 100 Tj - Junction Temperature - °C 150 Figure 2. VIN SHUTDOWN CURRENT vs JUNCTION TEMPERATURE 1.
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TPS54328 www.ti.com SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 TYPICAL CHARACTERISTICS (continued) VIN = 12 V, TA = 25°C (unless otherwise noted). 100 90 Efficiency (%) EN = 10 V / div SS = 5 V / div 80 70 60 VO = 3.3V VO = 2.5 V VO = 1.8 V 50 VO = 500 mV / div 40 0 0.5 1 1.5 2 Iout−Output Current (A) Time = 2 msec / div Figure 7. START-UP WAVE FORM 850 FS - Switching Frequency - kHz 900 90 Efficiency (%) 80 70 60 VO = 3.3 V VO = 2.5 V VO = 1.8 V 40 30 20 10 0.01 0.
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TPS54328 SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 www.ti.com TYPICAL CHARACTERISTICS (continued) VIN = 12 V, TA = 25°C (unless otherwise noted). VO = 50 mV / div (-950 mV dc offset) VIN = 50 mV / div SW = 10 V / div SW = 5 V / div Time = 1 µsec / div Time = 1 µsec / div Figure 13. DCM VOLTAGE RIPPLE AT OUTPUT (IO = 30 mA) Figure 14.
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TPS54328 www.ti.com SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 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 15. Shows the 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.
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TPS54328 SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 www.ti.com Table 1. Recommended Component Values Output Voltage (V) R1 (kΩ) R2 (kΩ) L1 (µH) C8 + C9 (µF) 1 6.81 22.1 C4 (pF) 1.5 22 - 68 1.05 8.25 22.1 1.5 22 - 68 1.2 12.7 22.1 1.5 22 - 68 1.8 30.1 22.1 5 - 22 2.2 22 - 68 2.5 49.9 22.1 5 - 22 2.2 22 - 68 3.3 73.2 22.1 5 - 22 2.2 22 - 68 5 124 22.1 5 - 22 3.3 22 - 68 6.5 165 22.1 5 - 22 3.
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TPS54328 www.ti.com SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 THERMAL INFORMATION This 8-pin DDA package incorporates an exposed thermal pad that is designed to be directly to an external heartsick. The thermal pad must be soldered directly to the printed board (PCB). After soldering, the PCB can be used as a heartsick.
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TPS54328 SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 www.ti.com 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.
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TPS54328 www.ti.com SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 VIN FEEDBACK RESISTORS TO ENABLE CONTROL EN VIN HIGH FREQENCY BYPASS VIN CAPACITOR VFB VIN VREG5 BIAS CAP SLOW START CAP ANALOG GROUND TRACE VIN INPUT BYPASS CAPACITOR VBST SS SW GND SW BOOST CAPACITOR OUTPUT INDUCTOR EXPOSED THERMAL PAD AREA Connection to POWER GROUND on internal or bottom layer VOUT OUTPUT FILTER CAPACITOR POWER GROUND VIA to Ground Plane Figure 18.
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TPS54328 SLVSAN2C – NOVEMBER 2010 – REVISED NOVEMBER 2012 www.ti.com REVISION HISTORY Changes from Original (November 2010) to Revision A Page • Changed the Functional Block Diagram ............................................................................................................................... 5 • Added Condition to the TYPICAL CHARACTERISTICS title line, all pages ........................................................................
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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 5-Dec-2012 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 TPS54328DDAR SO Power PAD DDA 8 2500 330.0 12.8 6.4 5.2 2.1 8.0 12.0 Q1 TPS54328DRCR SON DRC 10 3000 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 TPS54328DRCT SON DRC 10 250 180.0 12.4 3.3 3.3 1.1 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 5-Dec-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TPS54328DDAR SO PowerPAD DDA 8 2500 366.0 364.0 50.0 TPS54328DRCR SON DRC 10 3000 367.0 367.0 35.0 TPS54328DRCT SON DRC 10 250 210.0 185.0 35.
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