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LTM4622A

15

Rev B

For more information 

www.analog.com

APPLICATIONS INFORMATION

software, the thermal resistances reported in the Pin Con-

figuration section are in-and-of themselves not relevant to 

providing guidance of thermal performance; instead, the 

derating curves provided in the data sheet can be used in 

a manner that yields insight and guidance pertaining to 

one’s application usage, and can be adapted to correlate 

thermal performance to one’s own application.
The Pin Configuration section typically gives four thermal 

coefficients explicitly defined in JESD51-12; these coef-

ficients are quoted or paraphrased below:
1. 

θ

JA

, the thermal resistance from junction to ambi-

ent, is the natural convection junction-to-ambient 

air thermal resistance measured in a one cubic foot 

sealed enclosure. This environment is sometimes 

referred to as still air although natural convection 

causes the air to move. This value is determined with 

the part mounted to a JESD51-9 defined test board, 

which does not reflect an actual application or viable 

operating condition.

2. 

θ

JCbottom

, the thermal resistance from junction to 

ambient, is the natural convection junction-to-ambient 

air thermal resistance measured in a one cubic foot 

sealed enclosure. This environment is sometimes 

referred to as still air although natural convection 

causes the air to move. This value is determined with 

the part mounted to a JESD51-9 defined test board, 

which does not reflect an actual application or viable 

operating condition.

3. 

θ

JCtop

, 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. As the electrical connections of the 

typical µModule are on the bottom of the package, it 

is rare for an application to operate such that most of 

the heat flows from the junction to the top of the part. 

As in the case of 

θ

JCbottom

, this value may be useful 

for comparing packages but the test conditions don’t 

generally match the user’s application.

4. 

θ

JB

, the thermal resistance from junction to the 

printed circuit board, is the junction-to-board thermal 

resistance where almost all of the heat flows through 

the bottom of the µModule and into the board, and 

is really the sum of the 

θ

JCbottom

 and the thermal re-

sistance of the bottom of the part through the solder 

joints and through a portion of the board. The board 

temperature is measured a specified distance from 

the package, using a two sided, two layer board. This 

board is described in JESD51-9.

A graphical representation of the aforementioned ther-

mal resistances is given in Figure 7; blue resistances are 

contained within the μModule regulator, whereas green 

resistances are external to the µModule.

Figure 7. Graphical Representation of JESD51-12 Thermal Coefficients

4622A F07

µMODULE DEVICE

JUNCTION-TO-CASE (TOP)

RESISTANCE

JUNCTION-TO-BOARD RESISTANCE

JUNCTION-TO-AMBIENT THERMAL RESISTANCE COMPONENTS

CASE (TOP)-TO-AMBIENT

RESISTANCE

BOARD-TO-AMBIENT

RESISTANCE

JUNCTION-TO-CASE

(BOTTOM) RESISTANCE

JUNCTION

AMBIENT

CASE (BOTTOM)-TO-BOARD

RESISTANCE

Summary of Contents for Analog Devices LTM4622A

Page 1: ...6V to 20V 0 6V to 5 5V Dual 2 5A or Single 5A LTM4622A 1 5V to 12V Dual 2A or Single 4A 3 3V and 5V Dual Output DC DC Step Down Module Regulator 12V Input 3 3V and 5V Output Efficiency vs Load Current...

Page 2: ...e0 BGA 4 40 C to 125 C Consult Marketing for parts specified with wider operating temperature ranges Device temperature grade is indicated by a label on the shipping container Pad or ball finish code...

Page 3: ...2 A VOUT Line VOUT Line Regulation Accuracy VOUT 1 5V VIN1 VIN2 3 6V to 20V IOUT 0A l 0 01 0 1 V VOUT Load VOUT Load Regulation Accuracy VOUT 1 5V IOUT 0A to 2A l 0 2 1 0 VOUT AC Output Ripple Voltage...

Page 4: ...s is determined by specific operating conditions in conjunction with board layout the rated package thermal resistance and other environmental factors SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VIN...

Page 5: ...Hz 5V OUTPUT 1 5MHz LOAD CURRENT mA 0 001 0 01 0 1 1 10 0 10 20 30 40 50 60 70 80 90 100 EFFICIENCY 4622A G04 Burst Mode OPERATION CMM 12V Output Transient Response 50 s DIV LOAD STEP 1A DIV VOUT AC C...

Page 6: ...TPUT CAPACITOR 10 F CERAMIC 47 F POSCAP SOFT START CAP 0 1 F 20 s DIV 4622A G14 IIN 1A DIV VOUT 2V DIV VIN 12V VOUT 3 3V fSW 1MHz OUTPUT CAPACITOR 10 F 47 F POSCAP 10ms DIV VOUT 2V DIV RUN 10V DIV IIN...

Page 7: ...adjustment PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG Module PRODUCTS REVIEW EACH PACKAGE LAYOUT CAREFULLY RUN1 D2 RUN2 B2 RunControlInputofEachSwitch ing Mode Regulator Channel Enables chip oper...

Page 8: ...itor Requirement VIN 3 6V to 20V VOUT 1 5V IOUT 2A 22 47 F Figure 1 Simplified LTM4622A Block Diagram POWER CONTROL FB2 60 4k 2 2 F 0 1 F 8 25k 0 22 F 10 F INTVCC VOUT2 TRACK SS2 0 1 F TRACK SS1 RUN1...

Page 9: ...s above 22 5V to protect internal devices Multiphaseoperationcanbeeasilyemployedbyconnecting SYNC pin to an external oscillator Up to 6 phases can be paralleled to run simultaneously a good current sh...

Page 10: ...above the zero current level to initiate another cycle Force Continuous Current Mode CCM Operation In applications where fixed frequency operation is more critical than low current efficiency and wher...

Page 11: ...ule has a phase locked loop comprised of an internal voltage controlled oscillator and a phase detector This allows the internal top MOSFET turn on to be locked to the rising edge of the external cloc...

Page 12: ...theramprate of the output voltage An internal 1 4 A 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...

Page 13: ...th the same ratios as the resistor values calculated from the above equation can be used For example where the 60 4k is used then a 6 04k can be used to reduce the TRACK pin offset to a negligible val...

Page 14: ...scontinuous mode DCM operation until the TRACK SS pin voltage reaches 0 6V reference voltage This will prevent the BG from turning on during the pre biased output start up which would discharge the ou...

Page 15: ...flect an actual application or viable operating condition 3 JCtop the thermal resistance from junction to top of the product case is determined with nearly all of the componentpowerdissipationflowingt...

Page 16: ...other sections of this data sheet After these laboratory test have been performed and correlated to the Modulemodel thenthe JBand BAaresummedtogether to correlate quite well with the Module model wit...

Page 17: ...F12 VIN 16V AMBIENT TEMPERATURE C 30 40 50 60 70 80 90 100 110 120 0 0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 LOAD CURRENT A 4622A F13 0LFM 200LFM 400LFM AMBIENT TEMPERATURE C 30 40 50 60 70 80 90 100 110...

Page 18: ...5 LOAD CURRENT A 4622A F19 0LFM 200LFM 400LFM AMBIENT TEMPERATURE C 30 40 50 60 70 80 90 100 110 120 0 0 5 1 0 1 5 2 0 2 5 3 0 3 5 4 0 4 5 LOAD CURRENT A 4622A F20 0LFM 200LFM 400LFM AMBIENT TEMPERATU...

Page 19: ...16 Figure 9 400 None 17 18 Table 4 5V Output DERATING CURVE VIN V POWER LOSS CURVE AIRFLOW LFM HEAT SINK JA C W Figures 19 20 12 16 Figure 10 0 None 19 20 Figures 19 20 12 16 Figure 10 200 None 17 18...

Page 20: ...T 4 7 F 25V 0805 X5R Taiyo Yuden JMK212BJ476MG T 47 F 6 3V 0805 X5R VOUT V CIN CERAMIC F CIN BULK COUT1 CERAMIC F COUT2 BULK F CFF pF VIN V DROOP mV P P DERIVATION mV RECOVERY TIME s LOAD STEP A LOAD...

Page 21: ...rovided to protect each unit from catastrophic failure The device does support thermal shutdown and over current protection and without airflow The derived thermal resistances in Tables 2 to 6 for the...

Page 22: ...information www analog com APPLICATIONS INFORMATION Figure 24 Thermal Image 12V Input 3 3V and 5V Output 2A Each No Airflow and No Heat Sink Figure 25 Thermal Image 12V Input 5V and 8V Output 2A Each...

Page 23: ...ce a dedicated power ground layer underneath the unit Thetwodedicatedinputdecouplingcapacitors onefor each VIN closely placed on each side of the module Tominimizetheviaconductionlossandreducemodule t...

Page 24: ...65k 4622A F28 VOUT 3 3V 4A 47 F 2 F 0 1 F VOUT1 VOUT2 FB1 COMP1 COMP2 FREQ GND LTM4622A PGOOD1 PGOOD2 INTVCC PGOOD SYNC MODE TRACK SS1 TRACK SS2 FB2 VIN 4V TO 20V VIN2 VIN1 RUN2 RUN1 10 F 10 F 3 16k 4...

Page 25: ...RACK SS1 TRACK SS2 13 3k FB2 VIN 4V TO 20V VIN2 VIN1 RUN2 RUN1 10 F 10 F 10k 10 F 4 VIN 4V TO 20V VOUT 1 5V 8A 1 F 47 F 4 0 1 F VOUT1 VOUT2 FB1 COMP1 COMP2 FREQ GND LTM4622A PGOOD1 PGOOD2 PGOOD VIN2 R...

Page 26: ...ION PIN ID FUNCTION PIN ID FUNCTION A1 VOUT2 A2 VIN2 A3 TRACK SS2 A4 FB2 A5 COMP2 B1 VOUT2 B2 RUN2 B3 VIN2 B4 PGOOD2 B5 GND C1 GND C2 GND C3 INTVCC C4 FREQ C5 SYNC MODE D1 VOUT1 D2 RUN1 D3 VIN1 D4 PGO...

Page 27: ...25mm 1 82mm Reference LTC DWG 05 08 1949 Rev 7 SEE NOTES NOTES 1 DIMENSIONING AND TOLERANCING PER ASME Y14 5M 1994 2 ALL DIMENSIONS ARE IN MILLIMETERS LAND DESIGNATION PER JESD MO 222 SPP 010 5 PRIMA...

Page 28: ...R MAY BE EITHER A MOLD OR MARKED FEATURE b 25 PLACES A DETAIL B PACKAGE SIDE VIEW M X Y Z ddd M Z eee A2 D E e b F G DETAIL A 0 3175 0 3175 BGA 25 0517 REV A LTMXXXXXX Module TRAY PIN 1 BEVEL PACKAGE...

Page 29: ...use nor for any infringements of patents or other rights of third parties that may result from its use Specifications subject to change without notice No license is granted by implication or otherwise...

Page 30: ...m 1 91mm LGA LTM4642 20VIN Dual 4A Step Down Module Regulator 4 5V VIN 20V 0 6V VOUT 5 5V 9mm 11 25mm 4 92mm BGA LTM4643 Ultrathin Quad 3A Step Down Module Regulator 4V VIN 20V 0 6V VOUT 3 3V 9mm 15mm...

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