TPS54388QRTERQ1

Manufacturer Part NumberTPS54388QRTERQ1
Description3A O/P Synchronous Step Down SWIFT
ManufacturerTexas Instruments
TPS54388QRTERQ1 datasheet
 


Specifications of TPS54388QRTERQ1

Lead Free Status / Rohs StatusLead free / RoHS Compliant  
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2.95-V to 6-V Input, 3-A Output, 2-MHz, Synchronous Step-Down
Switcher With Integrated FETs ( SWIFT™)
FEATURES
1
Qualified for Automotive Applications
2
Two 12-mΩ (typical) MOSFETs for High
Efficiency at 3-A Loads
200 kHz to 2 MHz Switching Frequency
0.8 V ± 1% Voltage Reference Over
Temperature (–40°C to 150°C)
Synchronizes to External Clock
Adjustable Slow Start/Sequencing
UV and OV Power Good Output
–40°C to 150°C Operating Junction
Temperature Range
Thermally Enhanced 3mm × 3mm 16-pin QFN
Pin Compatible to TPS54418
APPLICATIONS
Low-Voltage, High-Density Power Systems
Point of Load Regulation for High Performance
DSPs, FPGAs, ASICs and Microprocessors
Broadband, Networking and Optical
Communications Infrastructure
SIMPLIFIED SCHEMATIC
vertical spacer
vertical spacer
VIN
C
BOOT
VIN
BOOT
C I
R 4
TPS54388-Q1
EN
PH
R 5
PWRGD
VSENSE
SS/TR
RT /CLK
GND
COMP
AGND
C ss
POWERPAD
R T
R 3
C 1
1
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.
SWIFT, SwitcherPro, PowerPAD are trademarks of Texas Instruments.
2
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.
Check for Samples:
TPS54388-Q1
DESCRIPTION
The TPS54388-Q1 device is a full featured 6 V, 3 A,
synchronous step down current mode converter with
two integrated MOSFETs.
The
TPS54388-Q1
integrating the MOSFETs, implementing current
mode control to reduce external component count,
reducing inductor size by enabling up to 2 MHz
switching frequency, and minimizing the IC footprint
with a small 3 mm x 3 mm thermally enhanced QFN
package.
The TPS54388-Q1 provides accurate regulation for a
variety of loads with an accurate ±1% Voltage
Reference (VREF) over temperature.
Efficiency is maximized through the integrated 12 mΩ
MOSFETs and 515 μA typical supply current. Using
the enable pin, shutdown supply current is reduced to
5.5 µA by entering a shutdown mode.
Under voltage lockout is internally set at 2.45 V, but
can be increased by programming the threshold with
a resistor network on the enable pin. The output
voltage startup ramp is controlled by the slow start
pin. An open drain power good signal indicates the
output is within 93% to 107% of its nominal voltage.
Frequency fold back and thermal shutdown protects
the device during an over-current condition.
The TPS54388-Q1 is supported in the SwitcherPro™
Software Tool at www.ti.com/switcherpro.
For more SWIFT
website at www.ti.com/swift.
L O
VOUT
C O
100
R 1
95
90
R 2
85
80
75
70
65
60
55
50
0
TPS54388-Q1
SLVSAF1A – OCTOBER 2010 – REVISED JUNE 2011
enables
small
designs
TM
documentation, see the TI
3 Vin
5 Vin
f = 500kHz
s
Vout = 1.8V
1
2
3
4
5
I - Output Current - A
O
Copyright © 2010–2011, Texas Instruments Incorporated
by
6

TPS54388QRTERQ1 Summary of contents

  • Page 1

    ... 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. SWIFT, SwitcherPro, PowerPAD are trademarks of Texas Instruments. 2 PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty ...

  • Page 2

    ... ELECTRICAL SPECIFICATIONS is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. 2 ORDERING INFORMATION ORDERABLE PART NUMBER Reel of 2500 TPS54388QRTERQ1 (1) www.ti.com TOP-SIDE MARKING 5438Q VALUES ...

  • Page 3

    ... PCB (c) 2 oz. copper ground planes on the 2 internal layers and bottom layer (d) 4 thermal vias (10mil) located under the device package Copyright © 2010–2011, Texas Instruments Incorporated SLVSAF1A – OCTOBER 2010 – REVISED JUNE 2011 (1) (2) (3) ...

  • Page 4

    ... I < 2 μ (COMP) (COMP) Vsense = 0 100 mV overdrive (COMP 400 kΩ 400kΩ (RT/CLK) Measure at 500 kHz with RT resistor in series Measure at 500 kHz Copyright © 2010–2011, Texas Instruments Incorporated www.ti.com MIN TYP MAX UNIT 2.95 6.0 V 2.28 2.5 V 2.45 2 ...

  • Page 5

    ... SS discharge current (UVLO, EN, Thermal fault) POWER GOOD (PWRGD PIN) VSENSE threshold Hysteresis Output high leakage On resistance Output low Minimum VIN for valid output Copyright © 2010–2011, Texas Instruments Incorporated CONDITIONS Measured at 50% points on PH OUT Measured at 50% points on PH, VIN = OUT Prior to skipping off pulses, BOOT- ...

  • Page 6

    ... Slow start and tracking. An external capacitor connected to this pin sets the output voltage rise time. This pin can also be used for tracking. VIN Input supply voltage, 2. VSENSE 6 Inverting node of the transconductance (gm) error amplifier. 6 DEVICE INFORMATION QFN16 RTE PACKAGE (TOP VIEW PowerPAD (17 SS/ PIN FUNCTIONS DESCRIPTION Copyright © 2010–2011, Texas Instruments Incorporated www.ti.com ...

  • Page 7

    ... Shutdown 91% Logic 109% Voltage Reference ERROR AMPLIFIER VSENSE SS/TR Shutdown Logic COMP Maximum Overload Clamp Recovery AGND Copyright © 2010–2011, Texas Instruments Incorporated hys 1 Thermal Shutdown Enable Comparator Shutdown Enable Threshold Minimum COMP Clamp PWM Comparator Logic and PWM Latch ...

  • Page 8

    ... FREQUENCY vs TEMPERATURE W - 100 125 T - Junction Temperature - °C J Figure 2. - 100 125 T - Junction Temperature - °C J Figure 4. SWITCHING FREQUENCY vs VSENSE Vsense Falling Vsense Rising 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Vsense - V Figure 6. Copyright © 2010–2011, Texas Instruments Incorporated 150 150 0.8 ...

  • Page 9

    ... Vin = 5 V, -1.2 Ven = Threshold -50 mV -1.4 -1.6 -1.8 -2 -2.2 -2.4 -2.6 -2.8 -3 -50 - Junction Temperature - °C J Figure 11. Copyright © 2010–2011, Texas Instruments Incorporated TRANSCONDUCTANCE (SLOW START) vs 105 Vin = 3.3 V 100 100 125 150 -50 -25 EN PIN CURRENT vs TEMPERATURE -3 Vin = ...

  • Page 10

    ... T - Junction Temperature - °C J Figure 14 100 125 150 T - Junction Temperature - °C J Figure 16. Vsense Rising Vsense Falling Vsense Rising Vsense Falling 100 125 150 T - Junction Temperature - °C J Figure 18. Copyright © 2010–2011, Texas Instruments Incorporated ...

  • Page 11

    ... UVLO fault or disabled condition. The use of a frequency fold-back circuit reduces the switching frequency during startup and over current fault conditions to help limit the inductor current. Copyright © 2010–2011, Texas Instruments Incorporated SS/TR to VSENSE OFFSET vs TEMPERATURE 100 Vin = ...

  • Page 12

    ... VSENSE input current are noticeable. vertical spacer vertical spacer æ ö 0.799 V ´ ç ÷ 0.799 V è ø DETAILED DESCRIPTION Copyright © 2010–2011, Texas Instruments Incorporated www.ti.com Equation 1 (1) ...

  • Page 13

    ... R1 V ´ ENFALLING STOP ENFALLING Where I = 1.6 µ 1.6 µA, V hys 1 ENRISING Copyright © 2010–2011, Texas Instruments Incorporated TPS54388- VSENSE - R2 0 Figure 21. Voltage Divider Circuit Figure 22 ) should be set to provide enough hysteresis to allow for any input supply TPS54388-Q1 I hys VIN 1 ...

  • Page 14

    ... Equation 4. The ratio metric method is illustrated in PWRGD EN SS Figure 23. Sequential Start-Up Sequence 14 Equation 4 calculates the required slow start capacitor value Figure 25. TPS54388-Q1 EN EN1 SS EN2 PWRGD VO1 VO2 Figure 24. Sequential Startup using EN and Copyright © 2010–2011, Texas Instruments Incorporated www.ti.com (4) PWRGD ...

  • Page 15

    ... R1 2930 Vout1 145 V > ´ - ´ D vertical spacer Copyright © 2010–2011, Texas Instruments Incorporated EN SS VO1 VO2 Figure 26. Ratio-metric Startup with Vout1 Leading to the output of the power supply that needs to be tracked or another voltage and Equation 6, the tracking resistors can be calculated to initiate the Vout2 ...

  • Page 16

    ... MOSFET to be off long enough to decrease the current in the inductor. During start-up, the switching frequency increases as the voltage on VSENSE increases from 0 to 0.800 volts. See 16 VOUT1 EN1 SS2 VOUT 2 Figure 28. Ratio-metric Start-Up using Coupled SS/TR Pins Figure 6 Copyright © 2010–2011, Texas Instruments Incorporated www.ti.com Vout1 Vout2 (9) (10) for details. ...

  • Page 17

    ... The thermal shutdown forces the device to stop switching when the junction temperature exceeds the thermal trip threshold. Once the die temperature decreases below 148°C, the device reinitiates the power up sequence by discharging the SS pin to below 60 mV. The thermal shutdown hysteresis is 20°C. Copyright © 2010–2011, Texas Instruments Incorporated TPS54388-Q1 PLL RT/CLK Figure 30 ...

  • Page 18

    ... PH Power Stage 25 A/V R1 VSENSE 0.800 245 µA/V Copyright © 2010–2011, Texas Instruments Incorporated www.ti.com ESR OUT Figure 31) is the power stage Equation 12. As the load Equation 13] ...

  • Page 19

    ... The compensation circuits are shown in circuits are most likely implemented in high bandwidth power supply designs using low ESR output capacitors. In Type 2A, one additional high frequency pole is added to attenuate high frequency noise Figure 33. Types of Frequency Compensation Copyright © 2010–2011, Texas Instruments Incorporated VO Adc R ESR ...

  • Page 20

    ... Equation 17 or Equation 18 is the power stage gain (25 A/V ¦ C ´ R ´ OUT L www.ti.com Equation 15 and Equation Equation 17 Equation 17 is the geometric as the maximum crossover can be determined by Copyright © 2010–2011, Texas Instruments Incorporated 16. (15) (16) (17) (18) (19) (20) (21) ...

  • Page 21

    ... In general, the inductor ripple value is at the discretion of the designer; however, K Copyright © 2010–2011, Texas Instruments Incorporated APPLICATION INFORMATION 1.8 V Δ ...

  • Page 22

    ... For this design, a Vout sw ´ ¦ Vout Vinmax sw ´ ¦ 2 ö - (Vinmax Vo) ÷ ´ ´ ¦ ø Equation 26 shows the minimum output capacitance necessary www.ti.com Copyright © 2010–2011, Texas Instruments Incorporated (22) (23) (24) (25) (26) ...

  • Page 23

    ... Cin ´ ¦ sw SLOW START CAPACITOR The slow start capacitor determines the minimum amount of time it takes for the output voltage to reach its Copyright © 2010–2011, Texas Instruments Incorporated Vout) ´ ¦ sw Equation 31. Using the design example values, Ioutmax=3 A, Cin=10 μF, Fsw=1 ...

  • Page 24

    ... RL = series resistance of output inductor 24 Equation 32. For the example circuit, the slow start time is Equation 33 calculated as 80 kΩ. The nearest ) - ´ ´ - Ioutmin ) ( ) Vinmin Ioutmax 2 RDS Ioutmax ´ - ´ ´ - www.ti.com ( ) ´ RL RDS + (34 RDS ´ + (35) Copyright © 2010–2011, Texas Instruments Incorporated (32) (33) ...

  • Page 25

    ... additional pole can be added to attenuate high frequency noise. In this application not necessary to add it. From the procedures above, the compensation network includes a 7.68 kΩ resistor and a 3300 pF capacitor. Copyright © 2010–2011, Texas Instruments Incorporated SwitcherPro Equation 38 and Equation 39 Equation 39 yields 85.3 kHz and ...

  • Page 26

    ... Output Current - A Figure 36. EFFICIENCY vs LOAD CURRENT 1 MHz, 5 VIN 25°C A 2.5 V 1.8 V 1.5 V 1.2 V 1.05V 3.3 V 0.5 1 1 Output Current - A O Figure 38. POWER DOWN VOUT, VIN V/div V/div V/div V/div OUT Time = 500 s/div m Figure 40. Copyright © 2010–2011, Texas Instruments Incorporated 10 3 ...

  • Page 27

    ... Time = 5 msec / div Figure 43. INPUT RIPPLE Vin = 100 mV / div (ac coupled div Time = 500 nsec / div Figure 45. Copyright © 2010–2011, Texas Instruments Incorporated SLVSAF1A – OCTOBER 2010 – REVISED JUNE 2011 POWER UP VOUT, VIN Vin = div Vout = div div PWRGD = div Time = 5 msec / div Figure 42 ...

  • Page 28

    ... Rth is the thermal resistance of the package (°C/W). T MAX is maximum junction temperature (°C MAX is maximum ambient temperature (°C 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0 2.5 3 –9 www.ti.com REGULATION vs INPUT VOLTAGE Iout = 5.5 Input Voltage-V Figure 48. Copyright © 2010–2011, Texas Instruments Incorporated 6 ...

  • Page 29

    ... It may be possible to obtain acceptable performance with alternate PCB layouts, however this layout has been shown to produce good results and is meant as a guideline. Copyright © 2010–2011, Texas Instruments Incorporated SLVSAF1A – OCTOBER 2010 – REVISED JUNE 2011 Figure 49 for a PCB layout example ...

  • Page 30

    ... Ground Plane BOOT CAPACITOR PH PH EXPOSED POWERPAD PH AREA PH SS SLOW START CAPACITOR ANALOG GROUND TRACE FREQUENCY SET RESISTOR COMPENSATION NETWORK VIA to Ground Plane Figure 49. PCB Layout Example Copyright © 2010–2011, Texas Instruments Incorporated www.ti.com OUTPUT VOUT INDUCTOR OUTPUT FILTER CAPACITOR ...

  • Page 31

    ... PACKAGING INFORMATION Orderable Device (1) Package Type Package Status TPS54388QRTERQ1 ACTIVE WQFN (1) The marketing status values are defined as follows: 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. ...

  • Page 32

    ... TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Type Drawing TPS54388QRTERQ1 WQFN RTE PACKAGE MATERIALS INFORMATION Pins SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm 330.0 12.4 3.3 Pack Materials-Page 1 7-Jun-2011 Pin1 (mm) (mm) (mm) (mm) Quadrant 3.3 1.1 8.0 12 ...

  • Page 33

    ... Device Package Type TPS54388QRTERQ1 WQFN PACKAGE MATERIALS INFORMATION Package Drawing Pins SPQ Length (mm) RTE 16 1 Pack Materials-Page 2 7-Jun-2011 Width (mm) Height (mm) 346.0 346.0 29.0 ...

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    ... Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’ ...