Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsLMZ31520RLGT

100

0 4 8 12 16 20

Efficiency (%)

Output Current (A)

PVIN = 3.3 V, VIN = 5 V

PVIN = VIN = 5 V

PVIN = VIN = 12 V

C001

Vout = 1.8 V

Fsw = 500 kHz

VOUT

AGND

SENSE+

LMZ31520

FREQ_SEL

SS_SEL

V5V

VIN

VOUT

PGND

VADJ

SET

ILIM

INH

PWRGD

PVIN

LMZ31520

www.ti.com

SLVSBM9B –OCTOBER 2013–REVISED DECEMBER 2013

20A SIMPLE SWITCHER® Power Module with 3.0V-14.5V Input in QFN Package

Check for Samples: LMZ31520

FEATURES

DESCRIPTION

• Complete Integrated Power Solution;

The LMZ31520 SIMPLE SWITCHER® power module

Smaller than a Discrete Design

is an easy-to-use integrated power solution that

• 15 mm × 16 mm × 5.8 mm Package Size

combines a 20-A DC/DC converter with power

- Pin Compatible with LMZ31530

MOSFETs, a shielded inductor, and passives into a

• Ultra-Fast Load Step Response

low profile, QFN package. This total power solution

allows as few as three external components and

• Efficiencies Up To 96%

eliminates the loop compensation and magnetics part

• Wide-Output Voltage Adjust

selection process.

0.6 V to 3.6 V, with 1% Reference Accuracy

The 15x16x5.8 mm QFN package is easy to solder

• Optional Split Power Rails Allows

onto a printed circuit board and allows a compact

Input Voltage Down to 3.0 V

point-of-load design. Achieves greater than 95%

• Selectable Switching Frequency

efficiency, has ultra-fast load step response and

(300 kHz to 850 kHz)

excellent power dissipation capability with a thermal

impedance of 8.6°C/W. The LMZ31520 offers the

• Selectable Slow-Start

flexibility and the feature-set of a discrete point-of-

• Adjustable Overcurrent Limit

load design and is ideal for powering a wide range of

• Power Good Output

ICs and systems. Advanced packaging technology

affords a robust and reliable power solution

• Output Voltage Sequencing

compatible with standard QFN mounting and testing

• Over Temperature Protection

techniques.

• Pre-bias Output Start-up

SIMPLIFIED APPLICATION

• Operating Temperature Range: –40°C to 85°C

• Enhanced Thermal Performance: 8.6°C/W

• Meets EN55022 Class A Emissions

- Integrated Shielded Inductor

APPLICATIONS

• Broadband and Communications

Infrastructure

• DSP and FPGA Point of Load Applications

• High Density Power Systems

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.

2 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 (32 pages)

PAGE 1
LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 20A SIMPLE SWITCHER® Power Module with 3.0V-14.5V Input in QFN Package Check for Samples: LMZ31520 FEATURES 1 • 2 • • • • • • • • • • • • • • • Complete Integrated Power Solution; Smaller than a Discrete Design 15 mm × 16 mm × 5.8 mm Package Size - Pin Compatible with LMZ31530 Ultra-Fast Load Step Response Efficiencies Up To 96% Wide-Output Voltage Adjust 0.6 V to 3.
PAGE 2
LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 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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LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 THERMAL INFORMATION LMZ31520 THERMAL METRIC (1) RLG UNIT 72 PINS θJA Junction-to-ambient thermal resistance (2) Natural Convection 8.6 (3) 100 LFM 7.8 θJA(100LFM) Junction-to-ambient thermal resistance ψJT Junction-to-top characterization parameter (4) 1.6 ψJB Junction-to-board characterization parameter (5) 4.
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com ELECTRICAL CHARACTERISTICS TA = -40°C to 85°C, VIN = 12 V, VOUT = 1.8 V, IOUT = 20A CIN = 2x 22 µF ceramic & 330 µF bulk, COUT = 4x 100 µF ceramic (unless otherwise noted) PARAMETER TEST CONDITIONS IOUT Output current VIN Input bias voltage range PVIN Input switching voltage range A 4.5 14.5 V Over IOUT range 3.0 (1) 14.5 V 4.33 V 3.6 V VIN Increasing 4.
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LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 ELECTRICAL CHARACTERISTICS (continued) TA = -40°C to 85°C, VIN = 12 V, VOUT = 1.8 V, IOUT = 20A CIN = 2x 22 µF ceramic & 330 µF bulk, COUT = 4x 100 µF ceramic (unless otherwise noted) PARAMETER COUT (6) TEST CONDITIONS External output capacitance MIN TYP MAX UNIT (6) 400 5000 µF 100 A minimum of 100 µF of ceramic capacitance is required at the output. Locate the capacitance close to the device.
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com PIN DESCRIPTIONS TERMINAL NAME NO. AGND 9 DESCRIPTION This pin is connected internally to the power ground of the device. This pin should only be used as the zero volt ground reference for connecting the voltage setting resistor (RSET). Do not connect AGND to PGND. See Layout Recommendations. 4 8 12 DNC 20 Do Not Connect. Do not connect these pins to AGND, to another DNC pin, or to any other voltage.
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LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 PIN DESCRIPTIONS (continued) TERMINAL NAME DESCRIPTION NO. 11 22 23 24 PH 25 Phase switch node. Do not place any external component on these pins or tie them to a pin of another function. Connect these pins using a copper area beneath pad 71. 26 27 28 71 42 43 PVIN 44 Input switching voltage pin. This pin supplies voltage to the power switches of the converter. 66 69 PWRGD 19 Power Good flag pin.
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com FUNCTIONAL BLOCK DIAGRAM LMZ31520 VIN ILIM OCP PWRGD_PU PWRGD Logic SENSE+ V5V VIN Thermal Shutdown VIN UVLO 1.43kΩ PVIN SS/ FCCM/ Skip + + VREF Power Stage and Control Logic PH VOUT Frequency Select AGND 8 LDO Ramp Comp VADJ FREQ_SEL 10kΩ 6.
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LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 TYPICAL CHARACTERISTICS (PVIN = VIN = 12 V) 100 55 Output Ripple Voltage (mV) 90 Efficiency (%) 80 70 60 Vo = 3.3V, fsw = 500kHz Vo = 1.8V, fsw = 500kHz Vo = 1.2V, fsw = 500kHz Vo = 0.9V, fsw = 500kHz Vo = 0.6V, fsw = 500kHz 50 40 30 0 4 8 12 16 Vo = 3.3V, fsw = 500kHz Vo = 1.8V, fsw = 500kHz Vo = 1.2V, fsw = 500kHz Vo = 0.9V, fsw = 500kHz Vo = 0.
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com TYPICAL CHARACTERISTICS (PVIN = VIN = 5 V) 45 100 Output Voltage Ripple (mV) 90 Efficiency (%) 80 70 60 Vo = 3.3V, fsw = 500kHz Vo = 1.8V, fsw = 500kHz Vo = 1.2V, fsw = 500kHz Vo = 0.9V, fsw = 500kHz Vo = 0.6V, fsw = 500kHz 50 40 30 0 4 8 12 16 Output Current (A) Vo = 3.3V, fsw = 500kHz Vo = 1.8V, fsw = 500kHz Vo = 1.2V, fsw = 500kHz Vo = 0.9V, fsw = 500kHz Vo = 0.6V, fsw = 500kHz 35 25 15 5 0 20 2.0 0.
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LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 APPLICATION INFORMATION ADJUSTING THE OUTPUT VOLTAGE The VADJ control sets the output voltage of the LMZ31520. The output voltage adjustment range is from 0.6V to 3.6V. The adjustment method requires the addition of RSET, which sets the output voltage, and the connection of SENSE+ to VOUT. The RSET resistor must be connected directly between the VADJ (pin 13) and AGND (pin 9).
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com Frequency Select The LMZ31520 switching frequency can be selected from several values as shown in Table 2. To select a switching frequency, a resistor (RFREQ) must be connected between the FREQ_SEL pin and either PGND or V5V (pin 61) as shown in Table 2. For all output voltages, the recommended switching frequency is 500 kHz which can be configured by leaving the FREQ_SEL pin open.
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LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 Table 3. Recommended Input/Output Capacitors (1) CAPACITOR CHARACTERISTICS VENDOR SERIES PART NUMBER WORKING VOLTAGE (V) CAPACITANCE (µF) ESR (2) (mΩ) Murata X5R GRM32ER61E226K 25 22 2 TDK X5R C3216X5R1E476M 25 47 2 TDK X5R C3216X5R1C476M 16 47 2 Murata X5R GRM32ER61C476M 16 47 2 TDK X5R C3225X5R0J107M 6.3 100 2 Murata X5R GRM32ER60J107M 6.3 100 2 TDK X5R C3225X5R0J476K 6.
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 Transient Waveforms www.ti.com (1) Figure 10. PVIN = 5V, VOUT = 1.8V, 5A Load Step Figure 11. PVIN = 5V, VOUT = 1.2V, 10A Load Step Figure 12. PVIN = 12V, VOUT = 1.0V, 10A Load Step Figure 13. PVIN = 12V, VOUT = 1.8V, 10A Load Step (1) 14 Device configured for FCCM mode of operation, (pin 3 connected to pin 19).
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LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 Application Schematics LMZ31520 VIN VIN / PVIN 4.5 V to 14.5 V VOUT 1.2 V SENSE+ PVIN VOUT + + CIN1 CIN2 100 µF 22 µF COUT1 2x 100 µF CIN3 22 µF COUT2 220 µF INH FREQ_SEL PWRGD RSET 1.43 k VADJ SS_SEL AGND PGND Figure 14. Typical Schematic PVIN = VIN = 4.5 V to 14.5 V, VOUT = 1.2 V VIN 4.5 V to 14.5 V CIN3 4.7 µF LMZ31520 VOUT 0.9 V SENSE+ PVIN 3.
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com VIN and PVIN Input Voltage The LMZ31520 allows for a variety of applications by using the VIN and PVIN pins together or separately. The VIN voltage supplies the internal control circuits of the device. The PVIN voltage provides the input voltage to the power converter system. If tied together, the input voltage for the VIN pin and the PVIN pin can range from 4.5 V to 14.5 V.
PAGE 17
LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 Auto-Skip Eco-Mode ™ / Forced Continuous Conduction Mode Auto-skip Eco-mode or Forced Continuous Conduction Mode (FCCM) can be selected using the SS_SEL pin (pin 3). Connect the SS_SEL pin to PGND to select Auto-skip Eco-mode or to the PWRGD pin to select FCCM. In Auto-skip Eco-mode, the LMZ31520 automatically reduces the switching frequency at light load conditions to maintain high efficiency.
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com Output On/Off Inhibit (INH) The INH pin provides electrical on/off control of the device. Once the INH pin voltage exceeds the threshold voltage, the device starts operation. If the INH pin voltage is pulled below the threshold voltage, the regulator stops switching and enters low quiescent current state. The INH pin has an internal pull-up current source, allowing the user to float the INH pin for enabling the device.
PAGE 19
LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 Overcurrent Protection For protection against load faults, the LMZ31520 incorporates cycle-by-cycle overcurrent limiting control. The inductor current is monitored during the OFF state and the controller maintains the OFF state during the period in that the inductor current is larger than the overcurrent trip level.
PAGE 20
LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com Layout Considerations To achieve optimal electrical and thermal performance, an optimized PCB layout is required. Figure 25 thru Figure 30, shows a typical PCB layout. Some considerations for an optimized layout are: • Use large copper areas for power planes (PVIN, VOUT, and PGND) to minimize conduction loss and thermal stress. • Place ceramic input and output capacitors close to the device pins to minimize high frequency noise.
PAGE 21
LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 Figure 27. Typical Layer 3 Layout Figure 28. Typical Layer 4 Layout Figure 29. Typical Layer 5 Layout Figure 30.
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LMZ31520 SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 www.ti.com EMI The LMZ31520 is compliant with EN55022 Class A radiated emissions. Figure 31 and Figure 32 show typical examples of radiated emissions plots for the LMZ31520 operating from 5V and 12V respectively. Both graphs include the plots of the antenna in the horizontal and vertical positions. Figure 31. Radiated Emissions 5-V Input, 1.8-V Output, 20-A Load (EN55022 Class A) 22 Figure 32. Radiated Emissions 12-V Input, 3.
PAGE 23
LMZ31520 www.ti.com SLVSBM9B – OCTOBER 2013 – REVISED DECEMBER 2013 REVISION HISTORY Changes from Revision A (December 2013) to Revision B • Page Added additional capacitors to the recommended capacitor table ..................................................................................... 13 Changes from Original (October 2013) to Revision A • Page Changed status from Preview to Production ...........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.com 17-May-2014 PACKAGING INFORMATION Orderable Device Status (1) LMZ31520RLGT ACTIVE Package Type Package Pins Package Drawing Qty BQFN RLG 72 250 Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Green (RoHS & no Sb/Br) Call TI Level-3-260C-168 HR Op Temp (°C) Device Marking (4/5) -40 to 85 LMZ31520 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 19-Feb-2014 TAPE AND REEL INFORMATION *All dimensions are nominal Device LMZ31520RLGT Package Package Pins Type Drawing BQFN RLG 72 SPQ 250 Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 330.0 24.4 Pack Materials-Page 1 15.35 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 16.35 6.1 20.0 24.
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PACKAGE MATERIALS INFORMATION www.ti.com 19-Feb-2014 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMZ31520RLGT BQFN RLG 72 250 383.0 353.0 58.
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