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LTM4625

Rev D

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TYPICAL APPLICATION

FEATURES DESCRIPTION

20V

, 5A Step-Down DC/DC

µModule Regulator

The LTM

4625 is a complete 5A step-down switching

mode µModule (micromodule) regulator in a tiny 6.25mm

× 6.25mm × 5.01mm BGA package. Included in the pack

age are the switching controller, power FETs, inductor and

support components. Operating over an input voltage range

of 4V to 20V or 2.375V to 20V with an external bias supply,

the LTM4625 supports an output voltage range of 0.6V to

5.5V, set by a single external resistor. Its high efficiency

design delivers up to 5A continuous output current. Only

bulk input and output capacitors are needed.

The LTM4625 supports selectable discontinuous mode

operation and output voltage tracking for supply rail se

quencing. Its high switching frequency and current mode

control enable a very fast transient response to line and

load changes without sacrificing stability.

Fault protection features include overvoltage, overcurrent

and overtemperature protection.

The LTM4625 is available with SnPb or RoHS compliant

terminal finish.

5A, 1.5V Output DC/DC µModule

Step-Down Regulator

1.5V Output Efficiency vs Load Current

APPLICATIONS

Complete Solution in <1cm

(Single-Sided PCB) or

0.5cm

(Dual-Sided PCB)

Wide Input Voltage Range: 4V to 20V

Input Voltage Down to 2.375V with External Bias

0.6V to 5.5V Output Voltage

5A DC Output Current

±1.5% Maximum Total DC Output Voltage Error

Over Line, Load and Temperature

Current Mode Control, Fast Transient Response

External Frequency Synchronization

Multiphase Parallel Current Sharing with

MultipleLTM4625s

Output Voltage Tracking

Selectable Discontinuous Mode

Power Good Indicator

Overvoltage, Overcurrent and Overtemperature

Protection

6.25mm × 6.25mm × 5.01mm BGA Package

Telecom, Datacom, Networking and

Industrial Equipment

Medical Diagnostic Equipment

Data Storage Rack Units and Cards

Test and Debug Systems

All registered trademarks and trademarks are the property of their respective owners.

40.2k

4625 TA01a

10µF

4V TO 20V

OUT

1.5V

47µF

0.1µF

RUN

INTV

MODE

TRACK/SS

FREQ

OUT

CLKIN PHMODE CLKOUT

PGOOD

COMP

GND SGND

LTM4625

LOAD CURRENT (A)

EFFICIENCY (%)

4625 TA01b

3 4

= 5V

= 12V

Downloaded from Arrow.com.

Summary of content (26 pages)

PAGE 1
LTM4625 20VIN, 5A Step-Down DC/DC µModule Regulator FEATURES DESCRIPTION Complete Solution in <1cm2 (Single-Sided PCB) or 0.5cm2 (Dual-Sided PCB) nn Wide Input Voltage Range: 4V to 20V nn Input Voltage Down to 2.375V with External Bias nn 0.6V to 5.5V Output Voltage nn 5A DC Output Current nn ±1.
PAGE 2
LTM4625 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) (See Pin Functions, Pin Configuration Table) VIN, SVIN..................................................... –0.3V to 22V RUN............................................................ –0.3V to 22V PGOOD, MODE, TRACK/SS, FREQ, PHMODE, CLKIN..................................................... –0.3V to INTVCC Internal Operating Temperature Range (Notes 2, 5)............................................. –40°C to 125°C Storage Temperature Range...
PAGE 3
LTM4625 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the specified internal operating temperature range (Note 2), otherwise specifications are at TA = 25°C. VIN = SVIN = 12V per the typical application shown on the front page. SYMBOL PARAMETER CONDITIONS IOUT(DC) Output Continuous Current Range VIN = 12V, VOUT = 1.5V ΔVOUT (Line)/VOUT Line Regulation Accuracy VOUT = 1.5V, VIN = 4V to 20V, IOUT = 0A l 0.04 0.15 VOUT = 1.5V, IOUT = 0A to 5A l 0.5 1.
PAGE 4
LTM4625 TYPICAL PERFORMANCE CHARACTERISTICS 95 95 EFFICIENCY (%) EFFICIENCY (%) DCM Mode Efficiency, VOUT = 1.5V 100 90 90 90 85 80 75 3.3VOUT 1.8VOUT 1.2VOUT 0 1 2 3 LOAD CURRENT (A) 2.5VOUT 1.5VOUT 1VOUT 85 80 75 5 4 5VOUT 2.5VOUT 1.5VOUT 1VOUT 65 60 0 1 2 3.3VOUT 1.8VOUT 1.2VOUT 3 LOAD CURRENT (A) 1V Output Transient Response 70 50 40 30 10 0 0.001 10 4625 G03 1.5V Output Transient Response 2.
PAGE 5
LTM4625 TYPICAL PERFORMANCE CHARACTERISTICS Start-Up with No Load Current Short-Circuit with No Load Applied Start-Up with 5A Load Current VOUT 0.5V/DIV VOUT 0.5V/DIV VOUT 0.5V/DIV IIN 2A/DIV IIN 2A/DIV IIN 500mA/DIV 4625 G09 5ms/DIV VIN = 12V VOUT = 1.5V INPUT CAPACITOR = 22µF SANYO ELECTROLYTIC CAPACITOR + 22µF CERAMIC CAPACITOR OUTPUT CAPACITOR = 47µF CERAMIC CAPACITOR SOFT-START CAPACITOR = 0.1µF 4625 G10 5ms/DIV VIN = 12V VOUT = 1.
PAGE 6
LTM4625 PIN FUNCTIONS PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY. COMP (A1): Current Control Threshold and Error Amplifier Compensation Point. The current comparator’s trip threshold is linearly proportional to this voltage, whose normal range is from 0.3V to 1.8V. Tie the COMP pins together for parallel operation. The device is internally compensated. Strictly an output pin. Do not drive this pin.
PAGE 7
LTM4625 BLOCK DIAGRAM VOUT 60.4k FB RFB 40.2k 10k PGOOD INTVCC SVIN INTVCC VIN 1µF VIN CIN 4V TO 20V 10µF 25V 0.1µF CLKIN 20k 1µH VOUT CLKOUT COUT 47µF 6.3V 1µF POWER CONTROL PHMODE GND VOUT 1.5V 5A MODE TRACK/SS 0.1µF VIN RUN COMP INTERNAL COMP INTERNAL FILTER 162k FREQ SGND 4625 BD Figure 1. Simplified LTM4625 Block Diagram DECOUPLING REQUIREMENTS SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS CIN External Input Capacitor Requirement (VIN = 4V to 20V, VOUT = 1.
PAGE 8
LTM4625 OPERATION The LTM4625 is a standalone nonisolated switch mode DC/ DC power supply. It can deliver up to 5A DC output current with few external input and output capacitors. This module provides precisely regulated output voltage adjustable between 0.6V to 5.5V via one external resistor over a 4V to 20V input voltage range. With an external bias supply above 4V connected to SVIN, this module operates with an input voltage down to 2.375V. The typical application schematic is shown in Figure 20.
PAGE 9
LTM4625 APPLICATIONS INFORMATION The typical LTM4625 application circuit is shown in Figure 20. External component selection is primarily determined by the input voltage, the output voltage and the maximum load current. Refer to Table 7 for specific external capacitor requirements for a particular application.
PAGE 10
LTM4625 APPLICATIONS INFORMATION Discontinuous Current Mode (DCM) In applications where low output ripple and high efficiency at intermediate current are desired, discontinuous current mode (DCM) should be used by connecting the MODE pin to SGND. At light loads the internal current comparator may remain tripped for several cycles and force the top MOSFET to stay off for several cycles, thus skipping cycles. The inductor current does not reverse in this mode.
PAGE 11
LTM4625 APPLICATIONS INFORMATION 0 CLKIN CLKOUT +90 PHMODE CLKIN CLKOUT PHMODE PHASE 1 +120 +90 PHMODE PHASE 1 0 90 CLKIN CLKOUT 120 CLKIN CLKOUT PHMODE +120 INTVCC PHASE 3 180 CLKIN CLKOUT PHMODE PHASE 2 PHASE 3 240 (420) 60 CLKIN CLKOUT +90 +180 PHMODE PHASE 5 CLKIN CLKOUT 270 CLKIN CLKOUT PHMODE PHASE 4 +120 PHMODE PHASE 2 180 CLKIN CLKOUT PHMODE +120 INTVCC 300 CLKIN CLKOUT PHMODE PHASE 4 PHASE 6 4625 F02 Figure 2. 4-Phase, 6-Phase Operation 0.60 0.55 0.
PAGE 12
LTM4625 APPLICATIONS INFORMATION Soft-Start And Output Voltage Tracking The TRACK/SS pin provides a means to either soft start the regulator or track it to a different power supply. A capacitor on the TRACK/SS pin will program the ramp rate of the output voltage. An internal 2µA current source will charge up the external soft-start capacitor towards INTVCC voltage. When the TRACK/SS voltage is below 0.6V, it will take over the internal 0.6V reference voltage to control the output voltage.
PAGE 13
LTM4625 APPLICATIONS INFORMATION The RFB(SL) is the feedback resistor and the RTR(TOP)/ RTR(BOT) is the resistor divider on the TRACK/SS pin of the slave regulator, as shown in Figure 5. OUTPUT VOLTAGE Following the previous equation, the ratio of the master’s output slew rate (MR) to the slave’s output slew rate (SR) is determined by: MASTER OUTPUT SLAVE OUTPUT R FB(SL) MR SR = R FB(SL) + 60.4k R TR(BOT) TIME R TR(TOP) +R TR(BOT) Figure 6.
PAGE 14
LTM4625 APPLICATIONS INFORMATION Pre-Biased Output Start-Up Thermal Considerations and Output Current Derating There may be situations that require the power supply to start up with some charge on the output capacitors. The LTM4625 can safely power up into a pre-biased output without discharging it.
PAGE 15
LTM4625 APPLICATIONS INFORMATION may be useful for comparing packages, but the test conditions don’t generally match the user’s application. 3. θJCtop, the thermal resistance from junction to top of the product case, is determined with nearly all of the component power dissipation flowing through the top of the package.
PAGE 16
LTM4625 APPLICATIONS INFORMATION LTM4625 and the specified PCB with all of the correct material coefficients along with accurate power loss source definitions; (2) this model simulates a software-defined JEDEC environment consistent with JSED 51-12 to predict power loss heat flow and temperature readings at different interfaces that enable the calculation of the JEDEC-defined thermal resistance values; (3) the model and FEA software is used to evaluate the LTM4625 with heat sink and airflow; (4) having solv
PAGE 17
LTM4625 APPLICATIONS INFORMATION 2.5 2.0 1.5 1.0 0.5 0 3.0 VIN = 5V VIN = 12V 2.5 POWER LOSS (W) POWER LOSS (W) 3.0 VIN = 5V VIN = 12V 2.0 1.5 1.0 0.5 0 1 2 3 0 5 4 1 0 2 3 LOAD CURRENT (A) 4 0 1 3 2 LOAD CURRENT (A) 5 4 6 5 5 4 3 2 400LFM 200LFM 0LFM 0 30 40 5 LOAD CURRENT (A) LOAD CURRENT (A) 5 4 3 2 0 400LFM 200LFM 0LFM 30 40 2 400LFM 200LFM 0LFM 30 40 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 4645 F12 4645 F13 Figure 13.
PAGE 18
LTM4625 6 6 5 5 5 4 3 2 400LFM 200LFM 0LFM 1 0 30 40 LOAD CURRENT (A) 6 LOAD CURRENT (A) LOAD CURRENT (A) APPLICATIONS INFORMATION 4 3 2 400LFM 200LFM 0LFM 1 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 0 30 40 3 2 400LFM 200LFM 0LFM 1 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 0 30 40 50 60 70 80 90 100 110 120 AMBIENT TEMPERATURE (°C) 4645 F18 4645 F17 4645 F16 Figure 16. 5V to 3.3V Derating Curve, No Heat Sink 4 Figure 17. 12V to 3.
PAGE 19
LTM4625 APPLICATIONS INFORMATION Table 7. Output Voltage Response vs Component Matrix (Refer to Figure 20) CIN Murata PART NUMBER GRM21BR61E106KA73L Taiyo Yuden TMK212BBJ106KG-T Murata GRM31CR61E226ME15L Taiyo Yuden TMK316BBJ226ML-T VOUT (V) 1 1 1 1 1.2 1.2 1.2 1.2 1.5 1.5 1.5 1.5 1.8 1.8 1.8 1.8 2.5 2.5 2.5 2.5 3.3 3.3 3.3 3.
PAGE 20
LTM4625 APPLICATIONS INFORMATION Safety Considerations • Place a dedicated power ground layer underneath the unit. The LTM4625 modules do not provide galvanic isolation from VIN to VOUT. There is no internal fuse. If required, a slow blow fuse with a rating twice the maximum input current needs to be provided to protect each unit from catastrophic failure. The device does support thermal shutdown and over current protection.
PAGE 21
LTM4625 APPLICATIONS INFORMATION FREQ VIN 4V TO 20V CLKIN CLKOUT 10µF 25V VOUT 1.5V 47µF 5A 6.3V VOUT VIN SVIN RUN INTVCC 10µF 25V 5V LTM4625 SVIN 1µF 6.3V RUN INTVCC LTM4625 MODE PHMODE PHMODE TRACK/SS PGOOD FB TRACK/SS FB 0.1µF COMP GND GND SGND 4624 F21 Figure 20. 4VIN to 20VIN, 1.5V Output at 5A Design Figure 21. 2.375VIN to 5VIN, 1V at 5A Output Design 2MHz CLOCK 162k CLKIN CLKOUT FREQ VOUT 3.3V 47µF 5A 6.
PAGE 22
LTM4625 APPLICATIONS INFORMATION VIN 4V TO 20V FREQ CLKIN CLKOUT 10µF 25V ×2 VOUT VIN SVIN RUN INTVCC 47µF 6.3V VOUT 1.5V 5A LTM4625 MODE PHMODE FB TRACK/SS 0.1µF COMP 40.2k PGOOD GND SGND FREQ CLKIN CLKOUT VOUT VIN SVIN RUN INTVCC 47µF 6.3V VOUT2 1.2V 5A LTM4625 MODE 60.4k PHMODE TRACK/SS 60.4k FB COMP 60.4k PGOOD GND SGND 4625 F24 Figure 24. 4VIN to 20VIN, 1.2V and 1.5V with Coincident Tracking Rev D 22 Downloaded from Arrow.com. For more information www.analog.
PAGE 23
LTM4625 PACKAGE DESCRIPTION PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY.
PAGE 24
0.000 1.270 2.540 For more information www.analog.com 2.540 1.270 0.3175 0.3175 4 E PACKAGE TOP VIEW SUGGESTED PCB LAYOUT TOP VIEW 2.540 PIN “A1” CORNER 1.270 aaa Z 0.3175 0.000 0.3175 Downloaded from Arrow.com. 1.270 24 2.540 D X 0.630 ±0.025 Y DETAIL B H2 b1 NOM 5.01 0.60 4.41 0.75 0.63 6.25 6.25 1.27 5.08 5.08 0.41 4.00 MAX 5.21 0.70 4.51 0.90 0.
PAGE 25
LTM4625 REVISION HISTORY REV DATE DESCRIPTION PAGE NUMBER A 08/15 Added Footnote 7 B 06/17 Changed RUN Pin Absolute Maximum Ratings from SVIN to 22V. 2 Added Pin 1 Mark to Pin Configuration. C 04/18 Corrected connection of PHMODE to INTVCC/2 for 90° phase shift. 10 D 07/18 Changed Storage Temperature Range from “–55°C to 125°C” to “–60°C to 150°C”. 2 Rev D Information furnished by Analog Devices is believed to be accurate and reliable.
PAGE 26
LTM4625 PACKAGE PHOTO DESIGN RESOURCES SUBJECT DESCRIPTION µModule Design and Manufacturing Resources Design: • Selector Guides • Demo Boards and Gerber Files • Free Simulation Tools µModule Regulator Products Search Manufacturing: • Quick Start Guide • PCB Design, Assembly and Manufacturing Guidelines • Package and Board Level Reliability 1. Sort table of products by parameters and download the result as a spread sheet. 2. Search using the Quick Power Search parametric table.