LINEAR Dual μModule DC-DC Regulator Achieves High Efficiency, Producing 4A Outputs from a 4.5V to 26.5V Input Range Design Note 474 by Alan Chern Owner's Manual, Specification Sheet

Dual µModule DC/DC Regulator Produces High Effi ciency 4A Outputs from a 4.5V to 26.5V Input Design Note 474 Alan Chern Dual System-in-a-Package Regulator power MOSFETs, inductors, compensation and other sup-

Systems and PC boards that use FPGAs and ASICs are port components are all integrated within the compact often very densely populated with components and ICs. surface mount 15mm × 15mm × 2.82mm LGA package. This dense real estate (especially the supporting circuitry Such easy layout saves board space and design time by for FPGAs, such as DC/DC regulators) puts a burden on implementing high density point-of-load regulators.

system designers who aim to simplify layout, improve

The LTM®4619 switching DC/DC μModule converter

performance and reduce component count. A new fam-

regulates two 4A outputs from a single wide 4.5V to

ily of DC/DC μModule® regulator systems with multiple

26.5V input voltage range. Each output can be set be-

outputs is designed to dramatically reduce the number

tween 0.8V and 5V with a single resistor. In fact, only a

of components and their associated costs. These regula-

few components are needed to build a complete circuit

tors are designed to eliminate layout errors and to offer

(see Figure 2).

a ready-made complete solution. Only a few external

Figure 2 shows the LTM4619 μModule regulator in an

components are needed since the switching controllers,

application with 3.3V and 1.2V outputs. The output volt- ages can be adjusted with a value change in RSET1 and RSET2. Thus, the fi nal design requires nothing more than a few resistors and capacitors. Flexibility is achieved by pairing outputs, allowing the regulator to form different combinations such as single input/dual independent outputs or single input/parallel single output for higher dn474 F01 maximum current output. L, LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode and μModule are

Figure 1. The LTM4619 LGA Package Is Only registered trademarks of Linear Technology Corporation. All other trademarks are the

property of their respective owners.

15mm × 15mm × 2.82mm and Houses Dual DC/DC Switching Circuitry, Inductors, MOSFETs and Support Components

4.5V TO VIN INTVCCMODE/ FREQ/

RSET1 RSET2

PLLIN PLLFLTR

VFB1 VFB2

22p F COMP1 COMP2 22p F

LTM4619

VOUT1 VOUT2

VOUT1 VOUT2

TK/SS1 TK/SS2

RUN1 RUN2 PGOOD SGND PGND EXTVCC

dn474 F02

Figure 2. 4.5V to 26.5V Input to Dual 3.3V and 1.2V Outputs with 4A Maximum Output Current Each