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
9mm × 15mm × 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)
Telecom, Networking and Industrial Equipment
Storage Systems
Point of Load Regulation
APPLICATIONS
n
n
n
L,
LT, LTC, LTM, Linear Technology, the Linear logo, Burst Mode, µModule and PolyPhase
are registered trademarks and LTpowerCAD 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
2.7V to 5.5V Input to 1.8V Output DC/DC µModule
®
Regulator
CLKIN
V
IN
2.7V TO 5.5V
10µF
CLKIN
V
OUT
1.8V
100µF
4.87k
PGOOD
V
OUT
4608A TA01a
Efficiency vs Load Current
100
95
V
IN
= 3.3V
EFFICIENCY (%)
90
V
IN
= 5V
85
80
75
70
V
OUT
FB
I
TH
I
THM
MGN
V
OUT
= 1.8V
V
IN
SV
IN
SW
RUN
TRACK
LTM4608A
PLLLPF
PGOOD
CLKOUT GND SGND
0
2
4
6
LOAD CURRENT (A)
8
10
4608A TA01b
4608afc
1
LTM4608A
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PIN CONFIGURATION
A
1
2
CLKIN
PHMODE
MODE
3
4
5
FB
GND
B
TOP VIEW
C
D
E
V
IN
F
G
GND
RUN
SGND
SW
CLKOUT
PLLLPF
SV
IN
I
THM
TRACK
I
TH
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) .................................................. –55°C to 125°C
Storage Temperature Range .................. –55°C to 125°C
PGOOD 6
BSEL
7
MGN
8
9
10
11
GND
V
OUT
LGA PACKAGE
68-LEAD (15mm
×
9mm
×
2.8mm)
T
JMAX
= 125°C,
θ
JA
= 25°C/W,
θ
JCbottom
= 7°C/W,
θ
JCtop
= 50°C/W, WEIGHT = 1.0g
ORDER INFORMATION
LEAD FREE FINISH
LTM4608AEV#PBF
LTM4608AIV#PBF
LTM4608AMPV#PBF
TRAY
LTM4608AEV#PBF
LTM4608AIV#PBF
PART MARKING* PACKAGE DESCRIPTION
LTM4608AV
LTM4608AV
68-Lead (15mm × 9mm × 2.8mm) LGA
68-Lead (15mm × 9mm × 2.8mm) LGA
68-Lead (15mm × 9mm × 2.8mm) LGA
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–55°C to 125°C
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/
The
l
denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at T
A
= 25°C (Note 2). V
IN
= 5V unless otherwise noted. See Figure 1.
SYMBOL
V
IN(DC)
V
OUT(DC)
PARAMETER
Input DC Voltage
Output Voltage, Total Variation
with Line and Load
C
IN
= 10µF × 1, C
OUT
= 100µF Ceramic,
100µF POSCAP R
FB
= 6.65k, MODE = 0V
,
V
IN
= 2.7V to 5.5V, I
OUT
= I
OUT(DC)MIN
to
I
OUT(DC)MAX
(Note 3)
SV
IN
Rising
SV
IN
Falling
CONDITIONS
l
ELECTRICAL CHARACTERISTICS
MIN
2.7
TYP
MAX
5.5
UNITS
V
l
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
4608afc
2
LTM4608A
ELECTRICAL CHARACTERISTICS
SYMBOL
I
Q(VIN)
PARAMETER
Input Supply Bias Current
The
l
denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at T
A
= 25°C (Note 2). 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
Output Specifications
I
OUT(DC)
∆V
OUT(LINE)
V
OUT
∆V
OUT(LOAD)
V
OUT
V
OUT(AC)
f
S
f
SYNC
∆V
OUT(START)
t
START
∆V
OUT(LS)
t
SETTLE
I
OUT(PK)
Output Ripple Voltage
Switching Frequency
SYNC Capture Range
Turn-On Overshoot
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 Regulation Accuracy
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
1.25
0.75
10
10
100
15
l
l
Output Continuous Current Range V
OUT
= 1.5V
(Note 3)
V
IN
= 3.3V, 5.5V
V
IN
= 2.7V
Line Regulation Accuracy
V
OUT
= 1.5V, V
IN
from 2.7V to 5.5V, I
OUT
= 0A
l
0
0
0.1
8
5
0.25
A
A
%/V
0.3
0.3
10
1.5
0.75
0.75
%
%
mV
P-P
1.75
2.25
MHz
MHz
mV
mV
µs
mV
Turn-On Time
Peak Deviation for Dynamic Load Load: 0% to 50% to 0% of Full Load,
C
OUT
= 100µF Ceramic, 100µF POSCAP
,
V
IN
= 5V, V
OUT
= 1.5V
Settling Time for Dynamic Load
Step
Output Current Limit
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
l
10
µs
8
11
13
0.590
0.587
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
4608afc
3
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
l
denotes the specifications which apply over the full internal
operating temperature range, otherwise specifications are at T
A
= 25°C (Note 2). 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
∆V
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 LTM4608A is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTM4608AE is guaranteed to meet specifications from
0°C to 125°C internal temperature. Specifications over the –40°C to
125°C internal operating temperature range are assured by design,
characterization and correlation with statistical process controls.
The LTM4608AI is guaranteed over the –40°C to 125°C internal operating
temperature range and the LTM4608AMP is tested and guaranteed over
the full –55°C to 125°C internal operating temperature range. Note that
the maximum ambient temperature consistent with these specifications
is determined by specific operating conditions in conjunction with board
layout, the rated package thermal impedance and other environmental
factors.
Note 3:
See output current derating curves for different V
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