spectrum operation, output voltage tracking for supply
rail sequencing and voltage margining.
Fault protection features include overvoltage protection,
overcurrent protection and thermal shutdown. The power
module is offered in a compact and thermally enhanced
15mm × 9mm × 2.8mm surface mount LGA package. The
LTM4608A is Pb-free and RoHS compliant.
Complete Standalone Power Supply
±1.75%
Total DC Output Error (–55°C to 125°C)
2.7V to 5.5V Input Voltage Range
8A DC, 10A Peak Output Current
0.6V Up to 5V Output
Output Voltage Tracking and Margining
Power Good Tracks Margining
Multiphase Operation
Parallel Current Sharing
Onboard Frequency Synchronization
Spread Spectrum Frequency Modulation
Overcurrent/Thermal Shutdown Protection
Current Mode Control/Fast Transient Response
Selectable Burst Mode
®
Operation
Up to 95% Efficiency
Output Overvoltage Protection
Small, Low Profile 9mm × 15mm × 2.8mm
LGA Package (0.630mm Pads)
APPLICATIONS
■
■
■
Telecom, Networking and Industrial Equipment
Storage Systems
Point of Load Regulation
, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology
Corporation. μModule is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S.
Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131.
TYPICAL APPLICATION
3V to 5.5V Input to 1.8V Output DC/DC μModule™
CLKIN
V
IN
3V TO 5.5V
10μF
V
OUT
1.8V
100μF
4.87k
EFFICIENCY (%)
CLKIN
100
95
Efficiency vs Load Current
V
OUT
= 1.8V
V
IN
= 3.3V
V
IN
SV
IN
SW
RUN
LTM4608A
V
OUT
FB
I
TH
I
THM
PGOOD
V
OUT
4608A TA01a
90
V
IN
= 5V
85
80
75
70
0
2
4
6
LOAD CURRENT (A)
8
10
4608A TA01b
PLLLPF
TRACK
PGOOD
MGN
CLKOUT GND SGND
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1
LTM4608A
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
TOP VIEW
A
1
2
3
4
5
6
7
8
9
10
11
GND
V
OUT
CNTRL
SW
B
C
D
V
IN
E
F
G
GND
CNTRL GND
V
IN
, SV
IN
...................................................... –0.3V to 6V
CLKOUT ....................................................... –0.3V to 2V
PGOOD, PLLLPF, CLKIN, PHMODE, MODE . –0.3V to V
IN
I
TH
, I
THM
, RUN, FB, TRACK,MGN, BSEL ..... –0.3V to V
IN
V
OUT
, SW ...................................... –0.3V to (V
IN
+ 0.3V)
Internal Operating Temperature Range (Note 2)
E and I Grades........................................ –40°C to 125°C
MP Grade ............................................... –55°C to 125°C
Storage Temperature Range .................. –55°C to 125°C
LGA PACKAGE
68-PIN (15mm × 9mm × 2.8mm)
T
JMAX
= 125°C,
θ
JA
= 25°C/W,
θ
JP
= 7°C/W,
θ
JC
= 50°C/W, WEIGHT = 1.0g
ORDER INFORMATION
LEAD FREE FINISH
LTM4608AEV#PBF
LTM4608AIV#PBF
TRAY
LTM4608AEV#PBF
LTM4608AIV#PBF
PART
MARKING*
LTM4608AV
LTM4608AV
PACKAGE DESCRIPTION
INTERNAL TEMPERATURE RANGE (NOTE 2)
68-Lead (15mm × 9mm × 2.8mm) LGA –40°C to 125°C
68-Lead (15mm × 9mm × 2.8mm) LGA –40°C to 125°C
68-Lead (15mm × 9mm × 2.8mm) LGA –55°C to 125°C
LTM4608AMPV#PBF LTM4608AMPV#PBF LTM4608AMPV
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
V
IN(DC)
V
OUT(DC)
PARAMETER
Input DC Voltage
Output Voltage, Total Variation
with Line and Load
The
●
denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 5V unless otherwise noted. See Figure 1.
CONDITIONS
●
MIN
2.7
TYP
MAX
5.5
UNITS
V
C
IN
= 10μF × 1, C
OUT
= 100μF Ceramic,
100μF POSCAP, R
FB
= 6.65k
V
IN
= 2.7V to 5.5V, I
OUT
= I
OUT(DC)MIN
to
I
OUT(DC)MAX
(Note 3)
●
1.472
1.464
2.05
1.85
1.49
1.49
2.2
2.0
1.508
1.516
2.35
2.15
V
V
V
V
Input Specifications
V
IN(UVLO)
Undervoltage Lockout Threshold SV
IN
Rising
SV
IN
Falling
4608afa
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LTM4608A
ELECTRICAL CHARACTERISTICS
SYMBOL
I
Q(VIN)
PARAMETER
Input Supply Bias Current
The
●
denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 5V unless otherwise noted. See Figure 1.
CONDITIONS
V
IN
= 3.3V, No Switching, Mode = V
IN
V
IN
= 3.3V, No Switching, Mode = 0V
V
IN
= 3.3V, V
OUT
= 1.5V, Switching Continuous
V
IN
= 5V, No Switching, Mode = V
IN
V
IN
= 5V, No Switching, Mode = 0V
V
IN
= 5V, V
OUT
= 1.5V, Switching Continuous
Shutdown, RUN = 0, V
IN
= 5V
MIN
TYP
400
1.15
55
450
1.3
75
1
4.5
2.93
MAX
UNITS
μA
mA
mA
μA
mA
mA
μA
A
A
I
S(VIN)
Input Supply Current
V
IN
= 3.3V, V
OUT
= 1.5V, I
OUT
= 8A
V
IN
= 5V, V
OUT
= 1.5V, I
OUT
= 8A
V
OUT
= 1.5V
V
IN
= 3.3V, 5.5V
V
IN
= 2.7V
V
OUT
= 1.5V, V
IN
from 2.7V to 5.5V, I
OUT
= 0A
V
OUT
= 1.5V (Note 3)
V
IN
= 3.3V, 5.5V, I
LOAD
= 0A to 8A
V
IN
= 2.7V, I
LOAD
= 0A to 5A
I
OUT
= 0A, C
OUT
= 100μF X5R Ceramic, V
IN
= 5V,
V
OUT
= 1.5V
I
OUT
= 8A, V
IN
= 5V, V
OUT
= 1.5V
C
OUT
= 100μF, V
OUT
= 1.5V, I
OUT
= 0A
V
IN
= 3.3V
V
IN
= 5V
C
OUT
= 100μF, V
OUT
= 1.5V, V
IN
= 5V,
I
OUT
= 1A Resistive Load, Track = V
IN
,
Load: 0% to 50% to 0% of Full Load,
C
OUT
= 100μF Ceramic, 100μF POSCAP,
V
IN
= 5V, V
OUT
= 1.5V
Load: 0% to 50% to 0% of Full Load, V
IN
= 5V,
V
OUT
= 1.5V, C
OUT
= 100μF
C
OUT
= 100μF
V
IN
= 2.7V, V
OUT
= 1.5V
V
IN
= 3.3V, V
OUT
= 1.5V
V
IN
= 5V, V
OUT
= 1.5V
I
OUT
= 0A, V
OUT
= 1.5V, V
IN
= 2.7V to 5.5V
0.590
0.587
1.25
0.75
●
Output Specifications
I
OUT(DC)
Output Continuous Current
Range (Note 3)
Line Regulation Accuracy
Load Regulation Accuracy
0
0
0.1
8
5
0.25
A
A
%/V
ΔV
OUT(LINE)
V
OUT
ΔV
OUT(LOAD)
V
OUT
V
OUT(AC)
f
S
f
SYNC
ΔV
OUT(START)
●
●
0.3
0.3
10
1.5
0.75
0.75
%
%
mV
P-P
Output Ripple Voltage
Switching Frequency
SYNC Capture Range
Turn-On Overshoot
1.75
2.25
MHz
MHz
mV
mV
μs
mV
10
10
100
15
t
START
ΔV
OUT(LS)
Turn-On Time
Peak Deviation for Dynamic
Load
Settling Time for Dynamic Load
Step
Output Current Limit
t
SETTLE
I
OUT(PK)
10
μs
8
11
13
0.596
0.596
90
0.2
0.602
0.606
A
A
A
V
V
μs
μA
1.7
1.5
V
V
Control Section
V
FB
SS Delay
I
FB
V
RUN
RUN Pin On/Off Threshold
RUN Rising
RUN Falling
1.4
1.3
Voltage at FB Pin
Internal Soft-Start Delay
●
1.55
1.4
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LTM4608A
ELECTRICAL CHARACTERISTICS
SYMBOL
TRACK
PARAMETER
Tracking Threshold (Rising)
Tracking Threshold (Falling)
Tracking Disable Threshold
Resistor Between V
OUT
and FB
Pins
PGOOD Range
Output Voltage Margining
Percentage
MGN = V
IN
, BSEL = 0V
MGN = V
IN
, BSEL = V
IN
MGN = V
IN
, BSEL = Float
MGN = 0V, BSEL = 0V
MGN = 0V, BSEL = V
IN
MGN = 0V, BSEL = Float
4
9
14
–4
–9
–14
The
●
denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 5V unless otherwise noted. See Figure 1.
CONDITIONS
RUN = V
IN
RUN = 0V
9.95
MIN
TYP
0.57
0.18
V
IN
– 0.5
10
±10
5
10
15
–5
–10
–15
6
11
16
–6
–11
–16
10.05
MAX
UNITS
V
V
V
kΩ
%
%
%
%
%
%
%
R
FBHI
ΔV
PGOOD
%Margining
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 LTM4608AE is guaranteed to meet performance
specifications over the 0°C to 125°C internal operating temperature
range. Specifications over the full –40°C to 125°C internal operating
temperature range are assured by design, characterization and
correlation with statistical process controls. The LTM4608AI is
guaranteed to meet specifications over the full internal operating
temperature range. The LTM4608AMP is guaranteed and tested
over the –55°C to 125°C temperature range. Note that the maximum
ambient temperature is determined by specific operating conditions in
conjunction with board layout, the rated package thermal resistance and
other environmental factors.
Note 3:
See output current derating curves for different V
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