Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsLMZ31503RUQT

100

0 0.5 1 1.5 2 2.5 3

Output Current (A)

Efficiency (%)

= PV

= 5 V, V

OUT

= 3.3V, f

= 630 kHz

= PV

= 12 V, V

OUT

= 3.3V, f

= 630 kHz

G000

VOUTVIN

LMZ31503

SENSE+

VADJ

AGNDPGND

OUT

PWRGD

RT/CLK

INH/UVLO

SS/TR

STSEL

SET

OUT

PVIN

LMZ31503

www.ti.com

SNVS992 –JULY 2013

3A SIMPLE SWITCHER

Power Module with 4.5V-14.5V Input in QFN Package

Check for Samples: LMZ31503

FEATURES

DESCRIPTION

The LMZ31503 SIMPLE SWITCHER® power module

• Complete Integrated Power Solution Allows

is an easy-to-use integrated power solution that

Small Footprint, Low-Profile Design

combines a 3-A DC/DC converter with power

• 9mm x 15mm x 2.8mm package

MOSFETs, a shielded inductor, and passives into a

- Pin Compatible with LMZ31506

low profile, QFN package. This total power solution

allows as few as 3 external components and

• Efficiencies Up To 95%

eliminates the loop compensation and magnetics

• Wide-Output Voltage Adjust

design process.

0.8 V to 5.5 V, with 1% Reference Accuracy

The 9×15×2.8 mm QFN package is easy to solder

• Optional Split Power Rail Allows

onto a printed circuit board and allows a compact

Input Voltage Down to 1.6 V

point-of-load design with up to 95% efficiency and

• Adjustable Switching Frequency

excellent power dissipation with a thermal impedance

(330 kHz to 780 kHz)

of 13°C/W junction to ambient. The device delivers

the full 3-A rated output current at 85°C ambient

• Synchronizes to an External Clock

temperature without airflow.

• Adjustable Slow-Start

The LMZ31503 offers the flexibility and the feature-

• Output Voltage Sequencing / Tracking

set of a discrete point-of-load design and is ideal for

• Power Good Output

powering performance DSPs and FPGAs. Advanced

• Programmable Undervoltage Lockout (UVLO)

packaging technology afford a robust and reliable

power solution compatible with standard QFN

• Overcurrent Protection (Hiccup-Mode)

mounting and testing techniques.

• Over Temperature Protection

• Pre-bias Output Start-up

SIMPLIFIED APPLICATION

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

• Enhanced Thermal Performance: 13°C/W

• Meets EN55022 Class B Emissions

- Integrated Shielded Inductor

APPLICATIONS

• Broadband & Communications Infrastructure

• Automated Test and Medical Equipment

• Compact PCI / PCI Express / PXI Express

• DSP and FPGA Point of Load Applications

• High Density Distributed 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.

2SIMPLE SWITCHER is a registered 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
LMZ31503 www.ti.com SNVS992 – JULY 2013 3A SIMPLE SWITCHER® Power Module with 4.5V-14.5V Input in QFN Package Check for Samples: LMZ31503 FEATURES DESCRIPTION • The LMZ31503 SIMPLE SWITCHER® power module is an easy-to-use integrated power solution that combines a 3-A DC/DC converter with power MOSFETs, a shielded inductor, and passives into a low profile, QFN package. This total power solution allows as few as 3 external components and eliminates the loop compensation and magnetics design process.
PAGE 2
LMZ31503 SNVS992 – JULY 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.
PAGE 3
LMZ31503 www.ti.com SNVS992 – JULY 2013 THERMAL INFORMATION LMZ31503 THERMAL METRIC (1) RUQ47 UNIT 47 PINS θJA Junction-to-ambient thermal resistance (2) 13 (3) ψJT Junction-to-top characterization parameter ψJB Junction-to-board characterization parameter (4) (1) (2) (3) (4) 2.5 °C/W 5 For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
PAGE 4
LMZ31503 SNVS992 – JULY 2013 www.ti.com ELECTRICAL CHARACTERISTICS Over -40°C to 85°C free-air temperature, PVIN = VIN = 12 V, VOUT = 1.8 V, IOUT = 3A, CIN1 = 2x 22 µF ceramic, CIN2 = 68 µF poly-tantalum, COUT1 = 4x 47 µF ceramic (unless otherwise noted) PARAMETER TEST CONDITIONS IOUT Output current TA = 85°C, natural convection VIN Input bias voltage range PVIN Input switching voltage range UVLO VIN Undervoltage lockout VOUT(adj) VOUT A 4.5 14.5 V Over IOUT range 1.6 (1) 14.
PAGE 5
LMZ31503 www.ti.com SNVS992 – JULY 2013 ELECTRICAL CHARACTERISTICS (continued) Over -40°C to 85°C free-air temperature, PVIN = VIN = 12 V, VOUT = 1.
PAGE 6
LMZ31503 SNVS992 – JULY 2013 www.ti.com PIN DESCRIPTIONS TERMINAL NAME DESCRIPTION NO. 1 2 AGND 34 Zero VDC reference for the analog control circuitry. Connect AGND to PGND at a single point. Connect near the output capacitors. See for a recommended layout. 45 8 INH/UVLO 9 Inhibit and UVLO adjust pin. Use an open drain or open collector output logic to control the INH function. A resistor divider between this pin, AGND and VIN adjusts the UVLO voltage.
PAGE 7
LMZ31503 www.ti.com SNVS992 – JULY 2013 PIN DESCRIPTIONS (continued) TERMINAL NAME DESCRIPTION NO. 21 24 25 VOUT 26 27 Output voltage. Connect output capacitors between these pins and PGND.
PAGE 8
LMZ31503 SNVS992 – JULY 2013 www.ti.com 100 95 90 85 80 75 70 65 60 55 50 45 40 VOUT = 5.0 V, fSW = 780 kHz VOUT = 3.3 V, fSW = 630 kHz VOUT = 2.5 V, fSW = 480 kHz VOUT = 1.8 V, fSW = 480 kHz VOUT = 1.2 V, fSW = 480 kHz VOUT = 0.8 V, fSW = 330 kHz 0 0.5 1 1.5 2 Output Current (A) 2.5 3 VOUT = 5.0 V, fSW = 780 kHz VOUT = 3.3 V, fSW = 630 kHz VOUT = 2.5 V, fSW = 480 kHz VOUT = 1.8 V, fSW = 480 kHz VOUT = 1.2 V, fSW = 480 kHz VOUT = 0.8 V, fSW = 330 kHz 70 60 50 40 30 20 10 0 0.
PAGE 9
LMZ31503 www.ti.com SNVS992 – JULY 2013 100 95 90 85 80 75 70 65 60 55 50 45 40 VOUT = 3.3 V, fSW = 630 kHz VOUT = 2.5 V, fSW = 480 kHz VOUT = 1.8 V, fSW = 480 kHz VOUT = 1.2 V, fSW = 480 kHz VOUT = 1.0 V, fSW = 330 kHz VOUT = 0.8 V, fSW = 330 kHz 0 0.5 1 1.5 2 Output Current (A) 2.5 50 40 30 20 10 3 VOUT = 3.3 V, fSW = 630 kHz VOUT = 2.5 V, fSW = 480 kHz VOUT = 1.8 V, fSW = 480 kHz VOUT = 1.2 V, fSW = 480 kHz VOUT = 0.8 V, fSW = 330 kHz 0 0.5 1 G000 Figure 6. Efficiency vs.
PAGE 10
LMZ31503 SNVS992 – JULY 2013 www.ti.com 100 95 90 85 80 75 70 65 60 55 50 45 40 VOUT = 5.0 V, fSW = 780 kHz VOUT = 3.3 V, fSW = 630 kHz VOUT = 2.5 V, fSW = 480 kHz VOUT = 1.8 V, fSW = 480 kHz VOUT = 1.2 V, fSW = 480 kHz VOUT = 0.8 V, fSW = 330 kHz 0 0.5 1 1.5 2 Output Current (A) 2.5 60 50 40 30 20 10 3 VOUT = 5.0 V, fSW = 780 kHz VOUT = 3.3 V, fSW = 630 kHz VOUT = 2.5 V, fSW = 480 kHz VOUT = 1.8 V, fSW = 480 kHz VOUT = 1.2 V, fSW = 480 kHz VOUT = 0.8 V, fSW = 330 kHz 70 0 0.
PAGE 11
LMZ31503 www.ti.com SNVS992 – JULY 2013 APPLICATION INFORMATION ADJUSTING THE OUTPUT VOLTAGE The VADJ control sets the output voltage of the LMZ31503. The output voltage adjustment range is from 0.8V to 5.5V. The adjustment method requires the addition of RSET, which sets the output voltage, the connection of SENSE+ to VOUT, and in some cases RRT which sets the switching frequency. The RSET resistor must be connected directly between the VADJ (pin 43) and AGND (pin 45).
PAGE 12
LMZ31503 SNVS992 – JULY 2013 www.ti.com CAPACITOR RECOMMENDATIONS FOR THE LMZ31503 POWER SUPPLY Capacitor Technologies Electrolytic, Polymer-Electrolytic Capacitors When using electrolytic capacitors, high-quality, computer-grade electrolytic capacitors are recommended. Polymer-electrolytic type capacitors are recommended for applications where the ambient operating temperature is less than 0°C.
PAGE 13
LMZ31503 www.ti.com SNVS992 – JULY 2013 Table 4. Output Voltage Transient Response CIN1 = 22 µF CERAMIC, CIN2 = 68 µF POSCAP, LOAD STEP = 1.5 A, 1 A/µs VOUT (V) PVIN (V) 5 0.8 12 5 1.0 12 5 1.2 12 5 1.8 12 5 3.3 12 5.
PAGE 14
LMZ31503 SNVS992 – JULY 2013 www.ti.com Transient Response 14 Figure 16. PVIN = 12V, VOUT = 0.8V, 1.5A Load Step Figure 17. PVIN = 5V, VOUT = 0.8V, 1.5A Load Step Figure 18. PVIN = 12V, VOUT = 1.2V, 1.5A Load Step Figure 19. PVIN = 5V, VOUT = 1.2V, 1.
PAGE 15
LMZ31503 www.ti.com SNVS992 – JULY 2013 Figure 20. PVIN = 12V, VOUT = 1.8V, 1.5A Load Step Figure 21. PVIN = 5V, VOUT = 1.8V, 1.5A Load Step Figure 22. PVIN = 12V, VOUT = 3.3V, 1.5A Load Step Figure 23. PVIN = 5V, VOUT = 3.3V, 1.
PAGE 16
LMZ31503 SNVS992 – JULY 2013 www.ti.com Application Schematics LMZ31503 VIN VIN / PVIN 4.5 V to 14.5 V PWRGD PVIN + CIN2 68 F CIN1 22 F VOUT 1.8 V SENSE+ INH/UVLO VOUT + COUT1 4x 47 F SS/TR COUT2 220 F RT/CLK VADJ RSET 324 k RSET 1.13 k STSEL AGND PGND Figure 24. Typical Schematic PVIN = VIN = 4.5 V to 14.5 V, VOUT = 1.8 V LMZ31503 VIN VIN / PVIN 4.5 V to 14.5 V PWRGD PVIN + CIN2 68 F CIN1 22 F VOUT 3.
PAGE 17
LMZ31503 www.ti.com SNVS992 – JULY 2013 VIN 4.5 V to 14.5 V CIN3 4.7 F VIN LMZ31503 PVIN 3.3 V + PWRGD PVIN CIN2 68 F CIN1 22 F VOUT 1.0 V SENSE+ INH/UVLO VOUT + SS/TR COUT1 6x 47 F COUT2 330 F RT/CLK VADJ RSET 5.76 k STSEL AGND PGND Figure 26. Typical Schematic PVIN = 3.3 V, VIN = 4.5 V to 14.5 V, VOUT = 1.0 V VIN and PVIN Input Voltage The LMZ31503 allows for a variety of applications by using the VIN and PVIN pins together or separately.
PAGE 18
LMZ31503 SNVS992 – JULY 2013 www.ti.com Power-Up Characteristics When configured as shown in the front page schematic, the LMZ31503 produces a regulated output voltage following the application of a valid input voltage. During the power-up, internal soft-start circuitry slows the rate that the output voltage rises, thereby limiting the amount of in-rush current that can be drawn from the input source.
PAGE 19
LMZ31503 www.ti.com SNVS992 – JULY 2013 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 20
LMZ31503 SNVS992 – JULY 2013 www.ti.com Slow Start (SS/TR) Connecting the STSEL pin to AGND and leaving SS/TR pin open enables the internal SS capacitor with a slow start interval of approximately 1.1 ms. Adding additional capacitance between the SS pin and AGND increases the slow start time. Table 6 shows an additional SS capacitor connected to the SS/TR pin and the STSEL pin connected to AGND. See Table 6 below for SS capacitor values and timing interval. SS/TR CSS (Optional) AGND STSEL Figure 32.
PAGE 21
LMZ31503 www.ti.com SNVS992 – JULY 2013 Synchronization (CLK) An internal phase locked loop (PLL) has been implemented to allow synchronization between 330 kHz and 780 kHz, and to easily switch from RT mode to CLK mode. To implement the synchronization feature, connect a square wave clock signal to the RT/CLK pin with a duty cycle between 20% to 80%. The clock signal amplitude must transition lower than 0.8 V and higher than 2.0 V.
PAGE 22
LMZ31503 SNVS992 – JULY 2013 www.ti.com Sequencing (SS/TR) Many of the common power supply sequencing methods can be implemented using the SS/TR, INH and PWRGD pins. The sequential method is illustrated in Figure 36 using two LMZ31503 devices. The PWRGD pin of the first device is coupled to the INH pin of the second device which enables the second power supply once the primary supply reaches regulation. Figure 37 shows sequential turn-on waveforms of two LMZ31503 devices.
PAGE 23
LMZ31503 www.ti.com SNVS992 – JULY 2013 Programmable Undervoltage Lockout (UVLO) The LMZ31503 implements internal UVLO circuitry on the VIN pin. The device is disabled when the VIN pin voltage falls below the internal VIN UVLO threshold. The internal VIN UVLO rising threshold is 4.5 V(max) with a typical hysteresis of 150 mV.
PAGE 24
LMZ31503 SNVS992 – JULY 2013 www.ti.com Thermal Shutdown The internal thermal shutdown circuitry forces the device to stop switching if the junction temperature exceeds 175°C typically. The device reinitiates the power up sequence when the junction temperature drops below 165°C typically. Layout Considerations To achieve optimal electrical and thermal performance, an optimized PCB layout is required. Figure 43 and Figure 44 show two layers of a typical PCB layout.
PAGE 25
LMZ31503 www.ti.com SNVS992 – JULY 2013 EMI The LMZ31503 is compliant with EN55022 Class B radiated emissions. Figure 45 and Figure 46 show typical examples of radiated emissions plots for the LMZ31503 operating from 5V and 12V respectively. Both graphs include the plots of the antenna in the horizontal and vertical positions. Figure 45. Radiated Emissions 5-V Input, 1.2-V Output, 3-A Load (EN55022 Class B) Figure 46. Radiated Emissions 12-V Input, 1.
PAGE 26
PACKAGE OPTION ADDENDUM www.ti.
PAGE 27
PACKAGE OPTION ADDENDUM www.ti.com 25-Oct-2014 In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
PAGE 28
PAGE 29
PAGE 30
PAGE 31
PAGE 32
IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.