Linear Technology LTM4612 User manual

LTM4612

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TYPICAL APPLICATION

FEATURES

APPLICATIONS

DESCRIPTION

EN55022B Compliant

36VIN, 15VOUT, 5A,

DC/DC

Module Regulator

The LT M

4612 is a EN55022 Class B certified high voltage

inputandoutput,5AswitchingmodeDC/DCpowersupply.

Includedin the package are the switching controller,power

FETs, inductor and all support components. Operating

over an input voltage range of 5V to 36V, the LTM4612

supports an output voltage range of 3.3V to 15V, set by a

single resistor. Only bulk input and output capacitors are

needed to finish the design.

High switching frequency and an adaptive on-time current

mode architecture enables a very fast transient response

to line and load changes without sacrificing stability.

The onboard input filter and noise cancellation circuits

achieve low noise coupling, thus effectively reducing the

electromagnetic interference (EMI)—see Figures 4 and 8.

Furthermore, the DC/DC µModule

regulator can be syn-

chronized with an external clock to reduce undesirable

frequency harmonics and allow PolyPhase

operation for

high load currents.

The LTM4612 is offered in a space saving and thermally

enhanced 15mm ×15mm ×2.8mm LGA package, which

enables utilization of unused space on the bottom of PC

boards for high density point-of-load regulation. The

LTM4612 is Pb-free and RoHS compliant.

L, LT, LTC, LTM, Linear Technology, the Linear logo, PolyPhase and µModule are registered

trademarks and LTpowerCAD is a trademark of Linear Technology Corporation. All other

trademarks are the property of their respective owners.

5V/5A Ultralow Noise µModule with 7V to 36V Input

nComplete Low EMI Switch Mode Power Supply

nEN55022 Class B Compliant

nWide Input Voltage Range: 5V to 36V

n3.3V to 15V Output Voltage Range

n5A DC, 7A Peak Output Current

nLow Input and Output Referred Noise

nOutput Voltage Tracking and Margining

nPower Good Tracks with Margining

nPLL Frequency Synchronization

n±1.5% Set Point Accuracy

nCurrent Foldback Protection (Disabled at Start-Up)

nParallel/Current Sharing

nUltrafast Transient Response

nCurrent Mode Control

nProgrammable Soft-Start

nOutput Overvoltage Protection

n–55°C to 125°C Operating Temperature Range

(LTM4612MPV)

nSmall Surface Mount Footprint, Low Profile

(15mm ×15mm ×2.8mm) LGA Package

nTelecom and Networking Equipment

nIndustrial and Avionic Equipment

nRF Systems

Radiated Emission Scan at 24VIN, 5VOUT/5A

FREQUENCY (MHz)

dBµV/m

128.1

226.2

324.3

–10

422.4

520.5

618.6

716.7

814.8

912.9

1010

EN55022 CLASS B LIMIT

4612 TA01b

PGOOD

RUN

COMP

INTVCC

DRVCC

fSET

TRACK/SS

FCB

MARG0

MARG1

MPGM

VOUT

VFB

VIN

0.01µF

10µF

100pF COUT

VOUT

CIN

VIN

TO 36V PLLIN

CLOCK SYNC

LTM4612

SGND

PGND

MARGIN

CONTROL

100k

13.7k

392k

5% MARGIN

4612 TA01

LTM4612

4612fc

For more information www.linear.com/LTM4612

PIN CONFIGURATIONABSOLUTE MAXIMUM RATINGS

INTVCC, DRVCC............................................. –0.3V to 6V

VOUT........................................................... –0.3V to 16V

PLLIN, FCB, TRACK/SS, MPGM, MARG0,

MARG1, PGOOD ....................–0.3V to INTVCC + 0.3V

RUN ............................................................. –0.3V to 5V

VFB, COMP ................................................ –0.3V to 2.7V

VIN, VD....................................................... –0.3V to 36V

Internal Operating Temperature Range (Note 2)

E and I Grades ................................... –40°C to 125°C

MP Grade........................................... –55°C to 125°C

Junction Temperature ........................................... 125°C

Storage Temperature Range .................. –55°C to 125°C

(Note 1)

MARG1

DRVCC

VFB

PGOOD

SGND

FCB

VIN

BANK 1 VD

PGND

BANK 2

VOUT

BANK 3

fSET

MARG0

RUN

COMP

MPGM

PLLIN

INTVCC

TRACK/SS

LGA PACKAGE

133-LEAD (15mm × 15mm × 2.8mm)

TOP VIEW

SGND

1221 43 5 6 98 10 117

TJMAX = 125°C, θJA = 15°C/W, θJC = 6°C/W

θJA DERIVED FROM 95mm ×76mm PCB WITH 4 LAYERS

WEIGHT = 1.7g

ORDER INFORMATION

LEAD FREE FINISH TRAY PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE

LTM4612EV#PBF LTM4612EV#PBF LTM4612V 133-Lead (15mm ×15mm ×2.8mm) LGA –40°C to 125°C

LTM4612IV#PBF LTM4612IV#PBF LTM4612V 133-Lead (15mm ×15mm ×2.8mm) LGA –40°C to 125°C

LTM4612MPV#PBF LTM4612MPV#PBF LTM4612MPV 133-Lead (15mm ×15mm ×2.8mm) LGA –55°C to 125°C

Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.

For more information on lead free part marking, go to: http://www.linear.com/leadfree/

This product is only offered in trays. For more information go to: http://www.linear.com/packaging/

ELECTRICAL CHARACTERISTICS

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

VIN(DC) Input DC Voltage l5 36 V

VOUT(DC) Output Voltage CIN = 10µF ×3, COUT = 300µF; FCB = 0

VIN = 24V, VOUT = 12V, IOUT = 0A

VIN = 36V, VOUT=12V, IOUT = 0A

11.83

12.07

12.31

Input Specifications

VIN(UVLO) Undervoltage Lockout Threshold IOUT = 0A 3.2 4.8 V

IINRUSH(VIN) Input Inrush Current at Start-Up IOUT = 0A; CIN = 10µF ×2, COUT = 200µF;

VOUT = 12V

VIN = 24V

VIN = 36V

0.6

0.7

The ldenotes the specifications which apply over the specified internal

operating temperature range, otherwise specifications are at TA= 25°C, VIN = 24V, unless otherwise noted (Note 2). Per Typical

Application (front page) configuration.

http://www.linear.com/product/LTM4612#orderinfo

LTM4612

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For more information www.linear.com/LTM4612

ELECTRICAL CHARACTERISTICS

The ldenotes the specifications which apply over the specified internal

operating temperature range, otherwise specifications are at TA= 25°C, VIN = 24V, unless otherwise noted (Note 2). Per Typical

Application (front page) configuration.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

IQ(VIN) Input Supply Bias Current VIN = 36V, VOUT = 12V, Switching Continuous

VIN = 24V, VOUT = 12V, Switching Continuous

Shutdown, RUN = 0, VIN = 36V

µA

IS(VIN) Input Supply Current VIN = 36V, VOUT = 12V, IOUT = 5A

VIN = 24V, VOUT = 12V, IOUT = 5A

1.85

2.72

VINTVCC Internal VCC Voltage VIN = 36V, RUN > 2V, IOUT = 0A 4.7 5 5.5 V

Output Specifications

IOUT(DC) Output Continuous Current Range VIN = 24V, VOUT = 12V (Note 4) 0 5 A

DVOUT(LINE)

VOUT

Line Regulation Accuracy VOUT = 12V, FCB = 0V, VIN = 22V to 36V,

IOUT = 0A

0.05

0.3

DVOUT(LOAD)

VOUT

Load Regulation Accuracy VOUT = 12V, FCB = 0V, IOUT = 0A to 5A (Note 4)

VIN = 36V

VIN = 24V

0.3

0.6

VIN(AC) Input Ripple Voltage IOUT = 0A,

CIN = 2 ×10µF X5R Ceramic and 1 ×100µF

Electrolytic, 1 ×10µF X5R Ceramic on VDPins

VIN = 24V, VOUT = 5V

VIN = 24V, VOUT = 12V

7.2

3.4

mVP-P

VOUT(AC) Output Ripple Voltage IOUT = 0A,

COUT = 2 ×22µF, 2 ×47µF X5R Ceramic

VIN = 24V, VOUT = 5V

VIN = 24V, VOUT = 12V

17.5

12.5

mVP-P

fSOutput Ripple Voltage Frequency IOUT = 1A, VIN = 24V, VOUT = 12V 940 kHz

DVOUT(START) Turn-On Overshoot,

TRACK/SS = 10nF

COUT = 200µF, VOUT = 12V, IOUT = 0A

VIN = 36V

VIN = 24V

tSTART Turn-On Time, TRACK/SS = Open COUT = 300µF, VOUT = 12V, IOUT = 1A

Resistive Load

VIN = 36V

VIN = 24V

0.5

DVOUT(LS) Peak Deviation for Dynamic Load Load: 0% to 50% to 0% of Full Load

COUT = 2 ×22µF Ceramic, 150µF Bulk

VIN = 24V, VOUT = 12V

153

tSETTLE Settling Time for Dynamic Load Step Load: 0% to 50% to 0% of Full Load, VIN = 24V 37 µs

IOUT(PK) Output Current Limit COUT = 200µF

VIN = 36V, VOUT = 12V

VIN = 24V, VOUT = 12V

Control Section

VFB Voltage at VFB Pin IOUT = 0A, VOUT = 12V l0.591 0.6 0.609 V

VRUN RUN Pin On/Off Threshold 1 1.5 1.9 V

ISS / TRACK Soft-Start Charging Current VSS/TRACK = 0V –1 –1.5 –2 µA

VFCB Forced Continuous Threshold 0.57 0.6 0.63 V

IFCB Forced Continuous Pin Current VFCB = 0V –1 –2 µA

tON(MIN) Minimum On-Time (Note 3) 50 100 ns

tOFF(MIN) Minimum Off-Time (Note 3) 250 400 ns

RPLLIN PLLIN Input Resistor 50 kW

LTM4612

4612fc

For more information www.linear.com/LTM4612

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 2: The LTM4612E is guaranteed to meet performance specifications

over the 0°C to 125°C internal operating temperature range. Specifications

over the –40°C to 125°C internal operating temperature range are assured

by design, characterization and correlation with statistical process

controls. The LTM4612I is guaranteed to meet specifications over the

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

IDRVCC Current into DRVCC Pin VOUT = 12V, IOUT = 1A 22 30 mA

RFBHI Resistor Between VOUT and VFB Pins 99.5 100 100.5 kW

VMPGM Margin Reference Voltage 1.18 V

VMARG0, VMARG1 MARG0, MARG1 Voltage Thresholds 1.4 V

PGOOD

DVFBH PGOOD Upper Threshold VFB Rising 7 10 13 %

DVFBL PGOOD Lower Threshold VFB Falling –7 –10 –13 %

DVFB(HYS) PGOOD Hysteresis VFB Returning 1.5 %

VPGL PGOOD Low Voltage IPGOOD = 5mA 0.15 0.4 V

ELECTRICAL CHARACTERISTICS

The ldenotes the specifications which apply over the specified internal

operating temperature range, otherwise specifications are at TA= 25°C, VIN = 24V, unless otherwise noted (Note 2). Per Typical

Application (front page) configuration.

–40°C to 125°C internal operating temperature range. The LTM4612MP

is guaranteed and tested over the full –55°C to 125°C internal operating

temperature range. Note that the maximum ambient temperature

consistent with these specifications is determined by specific operating

conditions in conjunction with board layout, the rated package thermal

resistance and other environmental factors.

Note 3: 100% tested at die level only.

Note 4: See the Output Current Derating curves for different VIN, VOUT

and TA.

LTM4612

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For more information www.linear.com/LTM4612

TYPICAL PERFORMANCE CHARACTERISTICS

Efficiency vs Load Current with

3.3VOUT (FCB = 0)

Efficiency vs Load Current with

5VOUT (FCB = 0)

Efficiency vs Load Current with

12VOUT (FCB = 0)

Efficiency vs Load Current with

15VOUT (FCB = 0, Refer to Figure 20)

Transient Response from 12VIN

to 3.3VOUT

Transient Response from 12VIN

to 5VOUT

Transient Response from 24VIN

to 12VOUT

Start-Up with 24VIN to 12VOUT

at IOUT = 0A

Start-Up with 24VIN to 12VOUT at

IOUT = 5A

(Refer to Figure 18)

LOAD CURRENT (A)

EFFICIENCY (%)

100

123

4612 G01

5VIN 3.3VOUT

12VIN 3.3VOUT

24VIN 3.3VOUT

36VIN 3.3VOUT

LOAD CURRENT (A)

EFFICIENCY (%)

123

4612 G02

12VIN 5VOUT

24VIN 5VOUT

36VIN 5VOUT

LOAD CURRENT (A)

EFFICIENCY (%)

100

123

4612 G03

20VIN 12VOUT

24VIN 12VOUT

28VIN 12VOUT

36VIN 12VOUT

LOAD CURRENT (A)

EFFICIENCY (%)

100

123

4612 G04

28VIN 15VOUT

32VIN 15VOUT

36VIN 15VOUT

50µs/DIV

2A/DIV

100mV/DIV

4612 G05

LOAD STEP: 0A to 3A

COUT = 2 ×22µF CERAMIC CAPACITORS AND

2 ×47µF CERAMIC CAPACITORS

50µs/DIV

2A/DIV

100mV/DIV

4612 G06

LOAD STEP: 0A to 3A

COUT = 2 ×22µF CERAMIC CAPACITORS AND

2 ×47µF CERAMIC CAPACITORS

50µs/DIV

2A/DIV

200mV/

DIV

4612 G07

LOAD STEP: 0A to 3A

COUT = 2 ×22µF CERAMIC CAPACITORS AND

2 ×47µF CERAMIC CAPACITORS

500µs/DIV

IIN

0.2A/DIV

VOUT

5V/DIV

4612 G08

SOFT-START CAPACITOR: 3.9nF

CIN = 3 ×10µF CERAMIC CAPACITORS AND

1 ×47µF OSCON CAPACITOR

500µs/DIV

IIN

1A/DIV

VOUT

5V/DIV

4612 G09

SOFT-START CAPACITOR: 3.9nF

CIN = 3 ×10µF CERAMIC CAPACITORS AND

1 ×47µF OSCON CAPACITOR

LTM4612

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For more information www.linear.com/LTM4612

TYPICAL PERFORMANCE CHARACTERISTICS

Start-Up with 24VIN to 12VOUT at

IOUT = 5A, TA= –55°C

Short-Circuit with 24VIN to 12VOUT

at IOUT = 0A

Short-Circuit with 24VIN to 12VOUT

at IOUT = 5A

VIN to VOUT Step-Down Ratio

Input Ripple

Output Ripple

500µs/DIV

IIN

1A/DIV

VOUT

5V/DIV

4612 G10

SOFT-START CAPACITOR: 3.9nF

CIN = 3 ×10µF CERAMIC CAPACITORS AND

1 ×47µF OSCON CAPACITOR

50µs/DIV

IIN

0.2A/DIV

VOUT

5V/DIV

4612 G11

COUT = 2 ×22µF CERAMIC CAPACITORS AND

2 ×47µF CERAMIC CAPACITORS

20µs/DIV

IIN

2A/DIV

VOUT

5V/DIV

4612 G12

COUT = 2 ×22µF CERAMIC CAPACITORS AND

2 ×47µF CERAMIC CAPACITORS

3.3

6 10

8 12 14 15

4612 G13

SEE FREQUENCY ADJUSTMENT SECTION

FOR OPERATIONS OUTSIDE THIS REGION

OPERATING REGION

WITH DEFAULT FREQUENCY

VOUT (V)

(V)

1µs/DIV

50mV/DIV

4612 G14

VIN = 24V

VOUT = 12V AT 5A RESISTIVE LOAD

CIN = 3 ×10µF 50V CERAMIC 1 ×100µF BULK

1µs/DIV

10mV/DIV

4612 G15

VIN = 24V

VOUT = 12V AT 5A RESISTIVE LOAD

COUT = 2 ×22µF 16V CERAMIC AND

2 ×47µF 16V CERAMIC

LTM4612

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For more information www.linear.com/LTM4612

PIN FUNCTIONS

VIN (Bank 1): Power Input Pins. Apply input voltage be-

tween these pins and PGND pins. Recommend placing

input decoupling capacitance directly between VIN pins

and PGND pins.

PGND (Bank 2): Power Ground Pins for Both Input and

Output Returns.

VOUT (Bank 3): Power Output Pins. Apply output load

betweenthesepinsandPGNDpins.Recommendplacingout-

put decoupling capacitance directly between these pins and

GND pins (see the L

TM4612 Pin Configuration below).

VD(Pins B7, C7): Top FET Drain Pins. Add more capa-

citors between VDand ground to handle the input RMS

current and reduce the input ripple further.

DRVCC (Pins C10, E11, E12): These pins normally connect

to INTVCC for powering the internal MOSFET drivers. They

can be biased up to 6V from an external supply with about

50mA capability. This improves efficiency at higher input

voltages by reducing power dissipation in the module.

INTVCC (Pin A7): This pin is for additional decoupling of

the 5V internal regulator.

PLLIN(PinA8):ExternalClock Synchronization Inputtothe

Phase Detector. This pin is internally terminated to SGND

with a 50k resistor. Apply a clock above 2V and below

INTVCC. See the Applications Information section.

FCB (Pin M12): Forced Continuous Input. Connect this pin

to SGND to force continuous synchronization operation at

low load, to INTVCC to enable discontinuous mode opera-

tion at low load or to a resistive divider from a secondary

output when using a secondary winding.

TRACK/SS(PinA9):OutputVoltageTrackingand Soft-Start

Pin. When the module is configured as a master output,

then a soft-start capacitor is placed on this pin to ground

to control the master ramp rate. A soft-start capacitor can

be used for soft-start turn-on as a standalone regulator.

Slave operation is performed by putting a resistor divider

from the master output to the ground, and connecting the

center point of the divider to this pin. See the Applications

Information section.

MPGM (Pins A12, B11): Programmable Margining In-

put. A resistor from these pins to ground sets a current

that is equal to 1.18V/R. This current multiplied by 10k

will equal a value in millivolts that is a percentage of the

0.6V reference voltage. May be left open if margining is

not desired. See the Applications Information section. To

parallel LTM4612s, each requires an individual MPGM

resistor. Do not tie MPGM pins together.

fSET (Pin B12): Frequency Set Internally to ~850kHz to

900kHz at 12V Output. An external resistor can be placed

from this pin to ground to increase frequency. See the

ApplicationsInformationsectionforfrequency adjustment.

LTM4612 Pin Configuration

(See Package Description for Pin Assignments)

MARG1

DRVCC

VFB

PGOOD

SGND

FCB

VIN

BANK 1 VD

PGND

BANK 2

VOUT

BANK 3

fSET

MARG0

RUN

COMP

MPGM

PLLIN

INTVCC

TRACK/SS

LGA PACKAGE

133-LEAD (15mm × 15mm × 2.8mm)

TOP VIEW

SGND

1221 43 5 6 98 10 117

LTM4612

4612fc

For more information www.linear.com/LTM4612

VFB (Pin F12): The Negative Input of the Error Ampli-

fier. Internally, this pin is connected to VOUT with a 100k

0.5% precision resistor. Different output voltages can be

programmed with an additional resistor between the VFB

and SGND pins. See the Applications Information section.

MARG0 (Pin C12): LSB Logic Input for the Margining

Function. Together with the MARG1 pin, the MARG0 pin

will determine if a margin high, margin low, or no margin

state is applied. The pin has an internal pull-down resistor

of 50k. See the Applications Information section.

MARG1 (Pins C11, D12): MSB Logic Input for the Margin-

ingFunction. Togetherwith theMARG0pin, theMARG1pin

will determine if a margin high, margin low, or no margin

stateis applied.Thepins have aninternalpull-down resistor

of 50k. See the Applications Information section.

SGND (Pins D9, H12): Signal Ground Pins. These pins

connect to PGND at output capacitor point.

COMP (Pins A11, D11): Current Control Threshold and

Error Amplifier Compensation Point. The current com-

parator threshold increases with this control voltage. The

voltage ranges from 0V to 2.4V with 0.7V corresponding

to zero sense voltage (zero current).

PGOOD (Pin G12): Output Voltage Power Good Indicator.

Open-drain logic output that is pulled to ground when the

output voltage is not within ±10% of the regulation point,

after a 25µs power bad mask timer expires.

RUN (Pins A10, B9): Run Control Pins. A voltage above

1.9V will turn on the module, and below 1V will turn off

the module. A programmable UVLO function can be ac-

complished with a resistor from VIN to this pin that is has

a 5.1V zener to ground. Maximum pin voltage is 5V.

NC (Pins J12, K12, L12): No Connect Pins. Leave floating.

PIN FUNCTIONS

LTM4612

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BLOCK DIAGRAM

DECOUPLING REQUIREMENTS

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

CIN External Input Capacitor Requirement

(VIN = 20V to 36V, VOUT = 12V)

IOUT = 4A 20 µF

COUT External Output Capacitor Requirement

(VIN = 20V to 36V, VOUT = 12V)

IOUT = 4A 100 150 µF

Specifications are at TA= 25°C. Use Figure 1 configuration.

INTERNAL

COMP

SGND

COMP

PGOOD

RUN

> 1.9V = ON

< 1V = OFF

MAX = 5V

MARG1

MARG0

MPGM

FCB

PLLIN

CSS

INTVCC

DRVCC

TRACK/SS

VFB

fSET

50k

93.1k

RFB

5.23k

50k

100k

VOUT

5.1V

ZENER

POWER CONTROL M1

VIN

20V TO 36V

VOUT

12V

AT 4A

50k

10µF

1µF CIN

COUT

PGND

4612 F01

10k

4.7µF

INPUT

FILTER

2.7µH

NOISE

CANCEL-

LATION

Figure 1. Simplified Block Diagram

LTM4612

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For more information www.linear.com/LTM4612

OPERATION

Power Module Description

The LTM4612 is a standalone nonisolated switching mode

DC/DC power supply. It can deliver 5A of DC output

current with some external input and output capacitors.

This module provides precisely regulated output voltage

programmable via one external resistor from 3.3VDC to

15VDC over a 5V to 36V wide input voltage. The typical

application schematic is shown in Figure 18.

The LTM4612 has an integrated constant on-time current

mode regulator, ultralow RDS(ON) FETs with fast switching

speedandintegratedSchottky diodes.The typicalswitching

frequencyis850kHzat full load at 12V output. With current

mode control and internal feedback loop compensation,

the LTM4612 module has sufficient stability margins and

good transient performance under a wide range of operat-

ing conditions and with a wide range of output capacitors,

even all ceramic output capacitors.

Current mode control provides cycle-by-cycle fast current

limiting. Moreover, foldback current limiting is provided in

an overcurrent condition while VFB drops. Internal over-

voltageandundervoltage comparators pull the open-drain

PGOOD output low if the output feedback voltage exits a

±10% window around the regulation point. Furthermore,

in an overvoltage condition, internal top FET M1 is turned

off and bottom FET M2 is turned on and held on until the

overvoltage condition clears.

Inputfilter and noise cancellation circuitry reduce thenoise

coupling to I/O sides, and ensure the electromagnetic

interference (EMI) meets the limits of EN55022 Class B.

Pulling the RUN pin below 1V forces the controller into

its shutdown state, turning off both M1 and M2. At light

load currents, discontinuous mode (DCM) operation can

be enabled to achieve higher efficiency compared to con-

tinuous mode (CCM) by setting FCB pin higher than 0.6V.

When the DRVCC pin is connected to INTVCC, an integrated

5V linear regulator powers the internal gate drivers. If a

5V external bias supply is applied on DRVCC pin, then an

efficiencyimprovement willoccurdue tothereduced power

loss in the internal linear regulator. This is especially true

at higher input voltages.

The MPGM, MARG0, and MARG1 pins are used to sup-

port output voltage margining, where the percentage of

margin is programmed by the MPGM pin, and the MARG0

and MARG1 select margining. The PLLIN pin provides

frequency synchronization of the device to an external

clock. The TRACK/SS pin is used for power supply track-

ing and soft-start programming.

The typical L

TM4612 application circuit is shown in Figure

18. External component selection is primarily determined

by the maximum load current and output voltage. Refer

to Table 2 for specific external capacitor requirements for

a particular application.

APPLICATIONS INFORMATION

VIN to VOUT Stepdown Ratios

There are restrictions in the maximum VIN and VOUT step

down ratio that can be achieved for a given input voltage.

These constraints are shown in the Typical Performance

Characteristic curve labeled “VIN to VOUT Step-Down

Ratio.” Note that additional thermal derating may be ap-

plied. See the Thermal Considerations and Output Current

Derating section in this data sheet.

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