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LINEAR TECHNOLOGY LTM4604 User Guide Specifications and Instructions for Use

Summary

The LTM4604 is a high-efficiency, standalone 4A DC/DC µModule designed for compact power delivery in demanding applications. It supports wide input voltage ranges (2.375V–5.5V) and features output tracking from 0.8V to 5V with ultra-fast transient response. This manual provides detailed specifications on its electrical characteristics, protection modes, and integration guidelines. It is ideal for engineers designing networking gear, telecom equipment, servers, and industrial devices requiring reliable, high-density power solutions.

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LTM4604

Low Voltage, 4A DC/DC µModule TM with Tracking

FEATURES DESCRIPTION ■ Complete Standalone Power Supply

The LTM®4604 is a complete 4A switch mode DC/DC power

■ Wide Input Voltage Range: 2.375V to 5.5V

supply. Included in the package are the switching control-

■ 4A DC, 5A Peak Output Current

ler, power FETs, inductor and all support components.

■ 0.8V to 5V Output

Operating over an input voltage range of 2.375V to 5.5V,

■ Output Voltage Tracking

the LTM4604 supports an output voltage range of 0.8V

■ ±2% Total DC Error

to 5V, set by a single resistor. This high effi ciency design

■ Ultra Fast TM Transient Response

delivers up to 4A continuous current (5A peak). Only bulk

■ Power Good Indicator

output capacitors are needed to complete the design.

■ Current Mode Control

The low profi le package (2.3mm) enables utilization of

■ Current Foldback Protection, Parallel/Current Sharing

unused space on the bottom of PC boards for high density

■ Up to 95% Effi ciency

point of load regulation. High switching frequency and

■ Programmable Soft-Start

a current mode architecture enable a very fast transient

■ Micropower Shutdown: IQ ≤ 7μA

response to line and load changes without sacrifi cing

■ Overtemperature Protection EF FI CI EN CY

stability. The device supports output voltage tracking for

■ Small and Very Low Profi le Package:

supply rail sequencing.

15mm × 9mm × 2.3mm LGA

Fault protection features include foldback current protec- APPLICATIONS tion, thermal shutdown and a programmable soft-start function. The LTM4604 is offered in a space saving and

■ Telecom and Networking Equipment

thermally enhanced 15mm × 9mm × 2.3mm LGA package

■ Servers

and is Pb free and Ro HS compliant.

■ Storage Cards

, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.

■ ATCA Cards

μModule and Ultra Fast are trademarks of Linear Technology Corporation. ■ Industrial Equipment All other trademarks are the property of their respective owners.

TYPICAL APPLICATION

Effi ciency vs Output Current

3.3V to 2.5V/4A μModule Regulator

VIN = 3.3V

VIN VOUT = 2.5V 3.3V

VOUT PGOOD VOUT 2.5V 4A

LTM4604

COMP FB

RUN/SS TRACK VIN

4604 TA01a

OUTPUT CURRENT (A)

Page Summary Contents For LINEAR TECHNOLOGY LTM4604 User Guide Specifications and Instructions for Use

Page 1 LTM4604 Low Voltage, 4A DC/DC µModule TM with Tracking FEATURES DESCRIPTION ■ Complete Standalone Power Supply The LTM®4604 is a complete 4A switch mode DC/DC power ■ Wide Input Voltage Range: 2.375V ...
Page 2 LTM4604 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) VIN, PGOOD ................................................. –0.3V to 6V TOP VIEW TRACK PGOOD COMP, RUN/SS, FB, TRACK .........................
Page 3 LTM4604 ELECTRICAL CHARACTERISTICS The ● denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 5V unless otherwise noted....
Page 4 (V EF FI CI EN CY LTM4604 TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency vs Output Current Effi ciency vs Output Current Effi ciency vs Output Current VIN = 2.5V VIN = 3.3V VIN = 5V VOUT = 3.3V EF FI...
Page 5 LTM4604 TYPICAL PERFORMANCE CHARACTERISTICS Start-Up Start-Up VOUT VOUT 1V/DIV 1V/DIV 1A/DIV 1A/DIV VIN = 5V 200μs/DIV VIN = 5V 200μs/DIV VOUT = 2.5V VOUT = 2.5V COUT = 4 × 22μF COUT = 4 × 22μF NO LOA...
Page 6 LTM4604 PIN FUNCTIONS VIN (B1, C1, C3-C7, D7, E6 and E7): Power Input Pins. resistor. Different output voltages can be programmed Apply input voltage between these pins and GND pins. with an additiona...
Page 7 LTM4604 BLOCK DIAGRAM PGOOD VIN VIN 2.375V TO 5.5V10μF RSS 6.3V RUN/SS 1M ×2 CSSEXT VOUT VOUT CONTROL, TRACKTRACK DRIVE SUPPLY C2 10μF COMP 0.5% ×3 INTERNAL COMP 4604 BD FB SW RFB 5.76k Figure 1. Simp...
Page 8 LTM4604 OPERATION Power Module Description drain PGOOD output low if the output feedback voltage exits a ±7.5% window around the regulation point. Furthermore, The LTM4604 is a standalone non-isolated...
Page 9 LTM4604 APPLICATIONS INFORMATION A typical LTM4604 application circuit is shown in Figure 15. Without considering the inductor current ripple, the RMS External component selection is primarily determi...
Page 10 LTM4604 APPLICATIONS INFORMATION Run Enable and Soft-Start VIN 5V The RUN/SS pin provides dual functions of enable and CIN1 10μF soft-start control. The RUN/SS pin is used to control 6.3V X5R OR X7R t...
Page 11 LTM4604 AT TS APPLICATIONS INFORMATION Ratio metric modes of tracking can be achieved by selecting Parallel Operation different resistor values to change the output tracking ratio. The LTM4604 device ...
Page 12 LTM4604 LO AD UR RE NT (A LO AD UR RE NT (A LO AD UR RE NT (A APPLICATIONS INFORMATION 4.0 4.0 0LFM 0LFM 0.5 200LFM 0.5 200LFM 400LFM 400LFM AMBIENT TEMPERATURE (°C) AMBIENT TEMPERATURE (°C) Figure 6....
Page 13 LTM4604 LO AD UR RE NT (A APPLICATIONS INFORMATION 4.0 4.0 0LFM 0LFM 0.5 200LFM 0.5 200LFM 400LFM 400LFM AMBIENT TEMPERATURE (°C) AMBIENT TEMPERATURE (°C) Figure 12. 3.3VIN to 2.5VOUT No Heat Sink Fig...
Page 14 LTM4604 APPLICATIONS INFORMATION Table 2. 1.2V Output DERATING CURVE VIN (V) POWER LOSS CURVE AIR FLOW (LFM) HEAT SINK θJA (°C/W) Figures 6, 8 3.3, 5 Figure 4 None Figures 6, 8 3.3, 5 Figure 4 200 Non...
Page 15 LTM4604 APPLICATIONS INFORMATION Safety Considerations • Do not put vias directly on the pads unless they are capped. The LTM4604 modules do not provide isolation from VIN to VOUT. There is no interna...
Page 16 LTM4604 TYPICAL APPLICATIONS VIN 2.375V TO 5V CIN1 10μF 6.3V X5R OR X7R VOUT = 0.8V × ((4.99k/N) + RFB)/RFB VIN WHERE N IS THE NUMBER OF PARALLEL DEVICES OPEN-DRAIN PULL UP PGOOD VOUT LTM4604 COUT1 22...
Page 17 LTM4604 TYPICAL APPLICATIONS VIN 3.3V TO 5V CIN 50k 10μF 6.3V X5R OR X7R OPEN-DRAIN PGOOD VOUT 2.5V PULL UP 4A LTM4604 COUT 22μF ×3 COMP FB 6.3V RUN/SS TRACK X5R OR X7R RFB REFER TO CSSEXT 2.37k TABLE...
Page 18 LTM4604 aaa Z PACKAGE DESCRIPTION 5.080 LG ac ka ge -L ea (1 5m .3 2m (R ef er en ce TC 5- -1 ev 3.810 FG SU BS TR AT 7. 9. CA BS BS PA “A 1” CO RN ER DE TA IL 1. BS PA CK AG TO VI EW DS PA SE NO TE D...
Page 19 LTM4604 PACKAGE DESCRIPTION Pin Assignment Table (Arranged by Pin Number) PIN NAME PIN NAME PIN NAME PIN NAME PIN NAME PIN NAME PIN NAME A1 GND B1 VIN C1 VIN D1 RUN/SS E1 TRACK F1 PGOOD G1 COMP A2 GND...
Page 20 LTM4604 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC2900 Quad Supply Monitor with Adjustable Reset Timer Monitors Four Supplies; Adjustable Reset Timer LTC2923 Power Supply Tracking Controller T...

Manual Details

Brand Linear
Pages 20
File Size 314.28 KB
Published June 05, 2026
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Frequently Asked Questions

What is the input voltage range for the LTM4604 regulator?

It operates over an input voltage range of 2.375V to 5.5V.

How does the device manage changes in load current?

It provides UltraFast Transient Response and includes Current Foldback Protection, allowing it to deliver up to 4A continuous (5A peak) current.

Is output voltage tracking supported by this module?

Yes, the LTM4604 supports output voltage tracking for supply rail sequencing.

What are the operating temperature limits and features?

The device operates from –40°C to 85°C and includes Overtemperature Protection, thermal shutdown, and programmabe soft-start functionality.