LINEAR TECHNOLOGY LTM4604 Technical data
LTM4604
Low Voltage, 4A DC/DC
µModule
TM
with Tracking
FEATURES
■
Complete Standalone Power Supply
■
Wide Input Voltage Range: 2.375V to 5.5V
■
4A DC, 5A Peak Output Current
■
0.8V to 5V Output
■
Output Voltage Tracking
■
±2% Total DC Error
■
UltraFastTM Transient Response
■
Power Good Indicator
■
Current Mode Control
■
Current Foldback Protection, Parallel/Current Sharing
■
Up to 95% Effi ciency
■
Programmable Soft-Start
■
Micropower Shutdown: IQ ≤ 7μA
■
Overtemperature Protection
■
Small and Very Low Profi le Package:
15mm × 9mm × 2.3mm LGA
APPLICATIONS
■
Telecom and Networking Equipment
■
Servers
■
Storage Cards
■
ATCA Cards
■
Industrial Equipment
DESCRIPTION
The LTM®4604 is a complete 4A switch mode DC/DC power
supply. Included in the package are the switching controller, power FETs, inductor and all support components.
Operating over an input voltage range of 2.375V to 5.5V,
the LTM4604 supports an output voltage range of 0.8V
to 5V, set by a single resistor. This high effi ciency design
delivers up to 4A continuous current (5A peak). Only bulk
output capacitors are needed to complete the design.
The low profi le package (2.3mm) enables utilization of
unused space on the bottom of PC boards for high density
point of load regulation. High switching frequency and
a current mode architecture enable a very fast transient
response to line and load changes without sacrifi cing
stability. The device supports output voltage tracking for
supply rail sequencing.
Fault protection features include foldback current protection, thermal shutdown and a programmable soft-start
function. The LTM4604 is offered in a space saving and
thermally enhanced 15mm × 9mm × 2.3mm LGA package
and is Pb free and RoHS compliant.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
μModule and UltraFast are trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
3.3V to 2.5V/4A μModule Regulator
V
IN
3.3V
10μF
6.3V
PGOOD
LTM4604
COMP
RUN/SS
V
GND
IN
TRACK
V
OUT
FB
V
IN
2.37k
22μF
6.3V
×2
4604 TA01a
V
OUT
2.5V
4A
Effi ciency vs Output Current
100
95
90
85
80
EFFICIENCY (%)
75
70
65
0
VIN = 3.3V
= 2.5V
V
OUT
12 4
OUTPUT CURRENT (A)
3
"$" /
4604f
1
LTM4604
ABSOLUTE MAXIMUM RATINGS
(Note 1)
VIN, PGOOD ................................................. –0.3V to 6V
COMP, RUN/SS, FB, TRACK .........................–0.3V to V
SW, V
........................................–0.3V to (VIN + 0.3V)
OUT
Operating Temperature Range (Note 2) ... –40°C to 85°C
Junction Temperature ........................................... 125°C
Storage Temperature Range ................... –55°C to 125°C
IN
PIN CONFIGURATION
TOP VIEW
TRACK
A
BCDEFG
V
IN
RUN/
SW
GND
66-PIN (15mm ´ 9mm ´ 2.3mm)
= 125°C, θJA = 25°C/W, WEIGHT = 0.86g
SS
GND
LGA PACKAGE
V
OUT
10
11
T
1
2
3
4
5
6
7
8
9
JMAX
PGOOD
COMP
FB
ORDER INFORMATION
LEAD FREE FINISH TRAY PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTM4604EV#PBF
LTM4604IV#PBF
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based fi nish parts.
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://linear.com/packaging/
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. See Figure 15.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN(DC)
V
OUT(DC)
Input Specifi cations
V
IN(UVLO)
I
INRUSH(VIN)
I
Q(VIN NOLOAD)
LTM4604EV#PBF
LTM4604IV#PBF
LTM4604V
LTM4604V
Input DC Voltage
Output Voltage, Total Variation
with Line and Load
Undervoltage Lockout
CIN = 10μF × 1, C
V
= 2.375V to 5.5V, I
IN
V
= 2.375V to 5.5V, I
IN
I
= 0A 1.75 2 2.3 V
OUT
Threshold
Peak Input Inrush Current at
Start-Up
I
= 0A, CIN = 10μF, C
OUT
RUN/SS = 0.01μF, V
V
= 3.3V
IN
V
= 5V
IN
Input Supply Bias Current VIN = 3.3V, V
V
= 3.3V, V
IN
V
= 5V, V
IN
V
= 5V, V
IN
Shutdown, RUN = 0, V
15mm × 9mm × 2.3mm LGA
15mm × 9mm × 2.3mm LGA
= 22μF ×3, RFB = 5.69k 0.5%
OUT
= 1.5V, No Switching
OUT
= 1.5V, Switching Continuous
OUT
= 1.5V, No Switching
OUT
= 1.5V, Switching Continuous
OUT
= 0A to 4A, 0°C ≤ TA ≤ 85°C
OUT
= 0A to 4A
OUT
= 22μF ×3,
OUT
= 1.5V
OUT
= 5V
IN
–40°C to 85°C
–40°C to 85°C
●
2.375 5.5 V
1.478
●
1.470
1.5
1.5
1.522
1.522
0.7
0.7
60
28
100
35
7
μA
mA
μA
mA
μA
4604f
V
V
A
A
2
LTM4604
ELECTRICAL CHARACTERISTICS
The ● denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
S(VIN)
Output Specifi cations
I
OUT(DC)
ΔV
OUT(LINE)
V
OUT
ΔV
OUT(LOAD)
V
OUT
V
OUT(AC)
f
S
ΔV
OUT(START)
t
START
ΔV
OUT(LS)
t
SETTLE
I
OUT(PK)
Control Section
V
FB
I
FB
V
RUN
I
TRACK
V
TRACK(OFFSET)
V
TRACK(RANGE)
R
FBHI
PGOOD
ΔV
PGOOD
R
PGOOD
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.
Input Supply Current VIN = 2.5V, V
Output Continuous Current
Range (See Output Current
Derating Curves for Different
V
, V
and TA)
IN
OUT
Line Regulation Accuracy V
Load Regulation Accuracy V
Output Ripple Voltage I
Output Ripple Voltage
Frequency
Turn-On Overshoot C
Turn-on Time C
Peak Deviation for Dynamic
Load Step
Settling Time for Dynamic
Load Step
Output Current Limit C
Voltage at FB Pin I
RUN Pin On/Off Threshold 0.5 0.65 0.8 V
TRACK Pin Current 0.2 μA
Offset Voltage TRACK = 0.4V 30 mV
Tracking Input Range 0 0.8 V
Resistor Between V
OUT
and
FB Pins
PGOOD Range ±7.5 %
PGOOD Resistance Open-Drain Pull-Down 90 150
= 25°C. VIN = 5V unless otherwise noted. See Figure 15.
A
= 1.5V, I
V
= 3.3V, V
IN
V
= 5V, V
IN
= 3.3V, V
V
IN
OUT
OUT
V
IN
V
IN
OUT
V
IN
V
IN
I
OUT
OUT
I
OUT
V
IN
V
IN
OUT
TRACK = V
V
IN
V
IN
OUT
= 1.5V, I
OUT
= 1.5V, I
OUT
= 1.5V 4 A
OUT
= 1.5V, VIN from 2.375V to 5.5V, I
= 1.5V, 0A to 4A
= 3.3V
= 5V
= 0A, C
= 3.3V, V
= 5V, V
= 22μF/X5R/Ceramic ×3
OUT
= 1.5V
OUT
= 1.5V
OUT
= 4A, VIN = 5V, V
= 22μF ×3, V
OUT
= 0A
= 3.3V
= 5V
= 22μF ×3, V
OUT
and RUN/SS = Float
IN
= 3.3V
= 5V
= 4A
OUT
= 4A
OUT
= 4A
OUT
= 0A
OUT
= 1.5V 1.25 MHz
OUT
= 1.5V, RUN/SS = 10nF,
= 1.5V, I
= 1A Resistive Load,
OUT
Load: 0% to 50% to 0% of Full Load,
C
= 22μF ×3 Ceramic
OUT
V
= 5V, V
IN
= 1.5V 25 mV
OUT
Load: 0% to 50% to 0% of Full Load
V
V
V
I
IN
OUT
IN
IN
OUT
OUT
= 5V, V
= 22μF ×3
= 3.3V, V
= 5V, V
= 0A, V
= 0A, V
= 1.5V 10 μs
OUT
= 1.5V
OUT
= 1.5V
OUT
= 1.5V, 0°C ≤ TA ≤ 85°C
OUT
= 1.5V
OUT
Note 2: The LTM4604E is guaranteed to meet performance specifi cations
from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTM4604I is guaranteed over the full
–40°C to 85°C temperature range.
2.9
2.2
1.45
●
●
●
0.1 0.2 %
0.3
0.3
0.6
0.6
10
12
20
20
1.5
1.0
8
8
0.792
●
0.788
0.8
0.8
0.808
0.812
0.2 μA
4.975 4.99 5.025 kΩ
mV
mV
P-P
P-P
mV
mV
ms
ms
A
A
A
%
%
A
A
V
V
Ω
4604f
3
LTM4604
TYPICAL PERFORMANCE CHARACTERISTICS
Effi ciency vs Output Current
V
= 2.5V
IN
100
95
90
85
80
EFFICIENCY (%)
75
70
65
V
= 1.8V
OUT
= 1.5V
V
OUT
= 1.2V
V
OUT
= 0.8V
V
OUT
0
12 4
OUTPUT CURRENT (A)
Minimum Input Voltage
at 4A Load
(V)
OUT
V
3.5
3.0
2.5
2.0
1.5
V
= 3.3V
OUT
= 2.5V
V
OUT
= 1.8V
V
OUT
= 1.5V
V
OUT
= 1.2V
V
OUT
= 0.8V
V
OUT
Effi ciency vs Output Current
VIN = 3.3V
100
95
90
85
80
EFFICIENCY (%)
75
70
3
"$" /
65
V
= 2.5V
OUT
= 1.8V
V
OUT
= 1.5V
V
OUT
= 1.2V
V
OUT
= 0.8V
V
OUT
0
12 4
OUTPUT CURRENT (A)
3
"$" /
Load Transient Response
I
LOAD
2A/DIV
V
OUT
20mV/DIV
Effi ciency vs Output Current
VIN = 5V
95
90
85
80
EFFICIENCY (%)
75
70
65
0
V
V
V
V
V
V
12 34
OUTPUT CURRENT (A)
Load Transient Response
I
LOAD
2A/DIV
V
OUT
20mV/DIV
OUT
OUT
OUT
OUT
OUT
OUT
= 3.3V
= 2.5V
= 1.8V
= 1.5V
= 1.2V
= 0.8V
"$" /!
1.0
0.5
I
LOAD
2A/DIV
V
OUT
20mV/DIV
0
0
0.5
1.5
2.5
34
2
1
VIN (V)
Load Transient Response
= 5V
V
IN
= 1.8V
V
OUT
= 3 × 22μF, 6.3V CERAMICS
C
OUT
20μs/DIV
3.5
4.5
4604 G04
4604 G07
V
= 5V
V
= 5V
IN
= 1.2V
V
OUT
= 4 × 22μF, 6.3V CERAMICS
C
OUT
5.55
20μs/DIV
4604 G05
IN
= 1.5V
V
OUT
= 4 × 22μF, 6.3V CERAMICS
C
OUT
20μs/DIV
4604 G06
Load Transient Response Load Transient Response
I
LOAD
2A/DIV
V
OUT
20mV/DIV
V
= 5V
IN
= 2.5V
V
OUT
= 3 ´ 22mF, 6.3V CERAMICS
C
OUT
20ms/DIV
4604 G08
I
LOAD
2A/DIV
V
OUT
20mV/DIV
V
= 5V
IN
= 3.3V
V
OUT
= 2 × 22μF, 6.3V CERAMICS
C
OUT
20μs/DIV
4604 G09
4604f
4
TYPICAL PERFORMANCE CHARACTERISTICS
Start-Up Start-Up
LTM4604
V
OUT
1V/DIV
I
IN
1A/DIV
= 5V
V
IN
= 2.5V
V
OUT
= 4 × 22μF
C
OUT
NO LOAD
(0.01μF SOFT-START CAPACITOR)
VFB vs Temperature
806
804
802
800
(mV)
FB
V
798
796
794
-50
-25 500 25 10075
Temperature (C)
200μs/DIV
4604 G10
"$" /#
V
OUT
1V/DIV
I
IN
1A/DIV
= 5V
V
IN
= 2.5V
V
OUT
= 4 × 22μF
C
OUT
4A LOAD
(0.01μF SOFT-START CAPACITOR)
Current Limit Foldback
1.6
1.4
1.2
1.0
(V)
0.8
OUT
V
0.6
V
0.2
= 1.5V
OUT
VIN = 5V
= 3.3V
V
IN
= 2.5V
V
0
IN
45 7
3
OUTPUT CURRENT (A)
0.4
200μs/DIV
4604 G11
6
8
4604 G12
Short-Circuit Protection
1.5V Short, No Load
V
OUT
0.5V/DIV
I
IN
4A/DIV
20μs/DIV
4604 G13
Short-Circuit Protection
1.5V Short, 4A Load
V
OUT
0.5V/DIV
I
IN
1A/DIV
100μs/DIV
4604 G14
4604f
5
LTM4604
PIN FUNCTIONS
VIN (B1, C1, C3-C7, D7, E6 and E7): Power Input Pins.
Apply input voltage between these pins and GND pins.
Recommend placing input decoupling capacitance directly
between V
(D8-D11, E8-E11, F6-F11, G6-G11): Power Output
V
OUT
pins and GND pins.
IN
Pins. Apply output load between these pins and GND pins.
Recommend placing output decoupling capacitance directly
between these pins and GND pins. Review Table 4.
GND (G3-G5, F3-F5, E4-E5, A1-A11, B6-B11, C8-C11):
Power Ground Pins for Both Input and Output Returns.
TRACK (E1): Output Voltage Tracking Pin. When the module
is confi gured as a master output, then a soft-start capacitor is placed on the RUN/SS pin to ground to control the
master ramp rate. Slave operation is performed by putting
a resistor divider from the master output to ground, and
connecting the center point of the divider to this pin on
the slave regulator. If tracking is not desired, then connect
the TRACK pin to V
. Load current must be present for
IN
tracking. See Applications Information section.
FB (G2): The Negative Input of the Error Amplifi er. Internally, this pin is connected to V
with a 4.99k precision
OUT
resistor. Different output voltages can be programmed
with an additional resistor between FB and GND pins.
Two power modules can current share when this pin is
connected in parallel with the adjacent module’s FB pin.
See Applications Information section.
COMP (G1): Current Control Threshold and Error Amplifi er
Compensation Point. The current comparator threshold
increases with this control voltage. Two power modules
can current share when this pin is connected in parallel
with the adjacent module’s COMP pin.
PGOOD (F1): Output Voltage Power Good Indicator. Opendrain logic output that is pulled to ground when the output
voltage is not within ±7.5% of the regulation point.
RUN/SS (D1): Run Control and Soft-Start Pin. A voltage
above 0.8V will turn on the module, and below 0.5V will
turn off the module. This pin has a 1M resistor to V
IN
and
a 1000pF capacitor to GND. See Application Infomation
section for soft-start information.
SW (B3 and B4): Switching Node of the circuit is used for
testing purposes. This can be connected to copper on the
board to improve thermal performance. Make sure not to
connect it to other output pins.
TOP VIEW
TRACK
A
BCDEFG
V
SW
GND
IN
RUN/
1
2
3
4
5
6
7
8
9
10
11
PGOOD
COMP
SS
GND
V
OUT
FB
4604f
6
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