Features
n
n
n
n
n
n
n
n
n
n
n
n
LTM4605
High Efficiency
Buck-Boost DC/DC
µModule Regulator
Description
The
LTM
®
4605
is a high efficiency switching mode buck-
boost power supply. Included in the package are the
switching controller, power FETs, and support components.
Operating over an input voltage range of 4.5V to 20V, the
LTM4605 supports an output voltage range of 0.8V to
16V, set by a resistor. This high efficiency design delivers
up to 5A continuous current in boost mode (12A in buck
mode). Only the inductor, sense resistor, bulk input and
output capacitors are needed to finish the design.
The low profile package enables utilization of unused space
on the bottom of PC boards for high density point of load
regulation. The high switching frequency and current
mode architecture enable a very fast transient response
to line and load changes. The LTM4605 can be frequency
synchronized with an external clock to reduce undesirable
frequency harmonics.
Fault protection features include overvoltage and foldback
current protection. The DC/DC µModule
®
regulator is of-
fered in a small and thermally enhanced 15mm
×
15mm
×
2.8mm LGA package. The LTM4605 is Pb-free and
RoHS compliant.
Single Inductor Architecture Allows V
IN
Above,
Below or Equal to V
OUT
Wide V
IN
Range: 4.5V to 20V
Wide V
OUT
Range: 0.8V to 16V
5A DC Typical (12A DC Typical at Buck Mode)
High Efficiency Up to 98%
Current Mode Control
Power Good Output Signal
Phase-Lockable Fixed Frequency: 200kHz to 400kHz
Ultrafast Transient Response
Current Foldback Protection
Output Overvoltage Protection
Small, Low Profile Surface Mount LGA Package
(15mm
×
15mm
×
2.8mm)
applications
n
n
n
Telecom, Servers and Networking Equipment
Industrial and Automotive Equipment
High Power Battery-Operated Devices
L,
LT, LTC, LTM, Linear Technology, the Linear logo, µModule ad PolyPhase are registered
trademarks and No R
SENSE
is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
typical application
12V/5A Buck-Boost DC/DC µModule Regulator with 4.5V to 20V Input
V
IN
4.5V TO 20V
10µF
35V
ON/OFF
RUN
CLOCK SYNC
V
IN
PLLIN V
OUT
FCB
4.7µH
SW1
SW2
SENSE
+
0.1µF
SS
SGND
PGND
SENSE
–
V
FB
7.15k
4605 TA01
Efficiency and Power Loss
vs Input Voltage
V
OUT
12V
5A
EFFICIENCY (%)
99
98
97
96
95
94
93
92
91
90
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
V
IN
(V)
4605 TA01b
LTM4605
10µF
35V
+
330µF
25V
V
OUT
= 12V
I
LOAD
= 5A
f = 200kHz
8
7
6
POWER LOSS (W)
5
4
3
2
1
0
R
SENSE
6m
4605fd
For more information
www.linear.com/LTM4605
1
LTM4605
absolute MaxiMuM ratings
(Note 1)
pin conFiguration
(See Table 6. Pin Assignment)
TOP VIEW
BANK 2
M
L
V
IN
............................................................. –0.3V to 20V
V
OUT
..............................................................0.8V to 16V
INTV
CC
, EXTV
CC
, RUN, SS, PGOOD ............. –0.3V to 7V
SW1, SW2 (Note 6) ....................................... –5V to 20V
V
FB
, COMP ................................................ –0.3V to 2.4V
FCB, STBYMD .......................................–0.3V to INTV
CC
PLLIN ........................................................ –0.3V to 5.5V
PLLFLTR ................................................... –0.3V to 2.7V
Operating Temperature Range
(Note 2) ...............................................–40°C to 85°C
Storage Temperature Range .................. –55°C to 125°C
BANK 4
K
J
H
G
F
E
D
C
B
A
1
2
3
4
5
6
7
8
9
10
11
12
BANK 1
BANK 5
BANK 3
BANK 6
LGA PACKAGE
141-LEAD (15mm
×
15mm
×
2.8mm)
T
JMAX
= 125°C,
θ
JP
= 4°C/W
WEIGHT = 1.5g
orDer inForMation
PART MARKING*
PART NUMBER
LTM4605EV#PBF
LTM4605IV#PBF
PAD OR BALL FINISH
Au (RoHS)
Au (RoHS)
DEVICE
LTM4605V
LTM4605V
FINISH CODE
e4
e4
PACKAGE
TYPE
LGA
LGA
MSL
RATING
3
3
TEMPERATURE RANGE
(SEE NOTE 2)
–40°C to 85°C
–40°C to 85°C
Consult Marketing for parts specified with wider operating temperature
ranges. *Device temperature grade is indicated by a label on the shipping
container. Pad or ball finish code is per IPC/JEDEC J-STD-609.
•
Terminal Finish Part Marking:
www.linear.com/leadfree
•
Recommended LGA and BGA PCB Assembly and Manufacturing
Procedures:
www.linear.com/umodule/pcbassembly
•
LGA and BGA Package and Tray Drawings:
www.linear.com/packaging
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C (Note 2), V
IN
= 12V. Per typical application (front page) configuration.
SYMBOL
Input Specifications
V
IN(DC)
V
IN(UVLO)
I
Q(VIN)
Input DC Voltage
Undervoltage Lockout Threshold
Input Supply Bias Current
Normal
Standby
Shutdown Supply Current
V
IN
Falling
V
RUN
= 0V, V
STBYMD
> 2V
V
RUN
= 0V, V
STBYMD
= Open
l
l
electrical characteristics
PARAMETER
CONDITIONS
MIN
4.5
TYP
MAX
20
UNITS
V
V
mA
mA
µA
4605fd
3.4
2.8
1.6
35
4
60
2
For more information
www.linear.com/LTM4605
LTM4605
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C (Note 2), V
IN
= 12V. Per typical application (front page) configuration.
SYMBOL
I
OUTDC
ΔV
FB
/V
FB(NOM)
ΔV
FB
/V
FB(LOAD)
Switch Section
M1 t
r
M1 t
f
M3 t
r
M3 t
f
M2, M4 t
r
M2, M4 t
f
t
1d
t
2d
t
3d
t
4d
Mode Transition 1
Mode Transition 2
M1 R
DS(ON)
M2 R
DS(ON)
M3 R
DS(ON)
M4 R
DS(ON)
f
NOM
f
LOW
f
HIGH
R
PLLIN
I
PLLFLTR
Turn-On Time (Note 4)
Turn-Off Time
Turn-On Time
Turn-Off Time
Turn-On Time
Turn-Off Time
M1 Off to M2 On Delay (Note 4)
M2 Off to M1 On Delay
M3 Off to M4 On Delay
M4 Off to M3 On Delay
M2 Off to M4 On Delay
M4 Off to M2 On Delay
Static Drain-to-Source On-Resistance
Static Drain-to-Source On-Resistance
Static Drain-to-Source On-Resistance
Static Drain-to-Source On-Resistance
Nominal Frequency
Lowest Frequency
Highest Frequency
PLLIN Input Resistance
Phase Detector Output Current
f
PLLIN
< f
OSC
f
PLLIN
> f
OSC
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Drain to Source Voltage V
DS
= 12V,
Bias Current I
SW
= 10mA
Bias Current I
SW
= 3A
Bias Current I
SW
= 3A
Bias Current I
SW
= 3A
Bias Current I
SW
= 3A
V
PLLFLTR
= 1.2V
V
PLLFLTR
= 0V
V
PLLFLTR
= 2.4V
260
170
340
50
40
25
20
20
20
50
50
50
50
220
220
6.5
8
8
8
300
200
400
50
–15
15
12
12
12
330
220
440
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
mΩ
mΩ
mΩ
mΩ
kHz
kHz
kHz
kΩ
µA
µA
PARAMETER
Output Continuous Current Range
(See Output Current Derating Curves
for Different V
IN
, V
OUT
and T
A
)
Reference Voltage Line Regulation
Accuracy
Load Regulation Accuracy
CONDITIONS
V
IN
= 12V, V
OUT
= 5V
V
IN
= 6V, V
OUT
= 12V
V
IN
= 4.5V to 20V, V
COMP
= 1.2V (Note 3)
V
COMP
= 1.2V to 0.7V
V
COMP
= 1.2V to 1.8V (Note 3)
l
l
electrical characteristics
Output Specifications
MIN
TYP
12
5
0.002
0.15
–0.15
MAX
UNITS
A
A
0.02
0.5
–0.5
%/V
%
%
Oscillator and Phase-Locked Loop
4605fd
For more information
www.linear.com/LTM4605
3
LTM4605
The
l
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C (Note 2), V
IN
= 12V. Per typical application (front page) configuration.
SYMBOL
Control Section
V
FB
V
RUN
I
SS
V
STBYMD(START)
V
STBYMD(KA)
V
FCB
I
FCB
V
BURST
DF
(BOOST, MAX)
DF
(BUCK, MAX)
t
ON(MIN, BUCK)
RFBHI
INTV
CC
ΔV
LDO
/V
LDO
V
EXTVCC
ΔV
EXTVCC(HYS)
ΔV
EXTVCC
V
SENSE(MAX)
V
SENSE(MIN, BUCK)
I
SENSE
PGOOD
ΔV
FBH
ΔV
FBL
ΔV
FB(HYS)
V
PGL
I
PGOOD
PGOOD Upper Threshold
PGOOD Lower Threshold
PGOOD Hysteresis
PGOOD Low Voltage
PGOOD Leakage Current
V
FB
Rising
V
FB
Falling
V
FB
Returning
I
PGOOD
= 2mA
V
PGOOD
= 5V
5.5
–5.5
7.5
–7.5
2.5
0.2
0.3
1
10
–10
%
%
%
V
µA
Feedback Reference Voltage
RUN Pin ON/OFF Threshold
Soft-Start Charging Current
Start-Up Threshold
Keep-Active Power On Threshold
Forced Continuous Threshold
Forced Continuous Pin Current
Burst Inhibit (Constant Frequency)
Threshold
Maximum Duty Factor
Maximum Duty Factor
Minimum On-Time for Synchronous
Switch in Buck Operation
Resistor Between V
OUT
and V
FB
Pins
Internal V
CC
Voltage
Internal V
CC
Load Regulation
EXTV
CC
Switchover Voltage
EXTV
CC
Switchover Hysteresis
EXTV
CC
Switch Drop Voltage
Maximum Current Sense Threshold
Minimum Current Sense Threshold
Sense Pins Total Source Current
I
CC
= 20mA, V
EXTVCC
= 6V
Boost Mode
Buck Mode
Discontinuous Mode
V
SENSE–
= V
SENSE+
= 0V
l
l
electrical characteristics
PARAMETER
CONDITIONS
V
COMP
= 1.2V
V
RUN
= 2.2V
V
STBYMD
Rising
V
STBYMD
Rising, V
RUN
= 0V
l
MIN
0.792
1
1
0.4
0.76
TYP
0.8
1.6
1.7
0.7
1.25
0.8
–0.2
5.3
99
99
200
MAX
0.808
2.2
UNITS
V
V
µA
V
V
0.84
–0.1
5.5
V
µA
V
%
%
V
FCB
= 0.85V
Measured at FCB Pin
% Switch M4 On
% Switch M1 On
Switch M1 (Note 5)
–0.3
250
100.5
6.3
2
ns
kΩ
V
%
V
mV
99.5
V
IN
> 7V, V
EXTVCC
= 5V
I
CC
= 0mA to 20mA, V
EXTVCC
= 5V
I
CC
= 20mA, V
EXTVCC
Rising
l
l
100
6
0.3
5.6
300
60
160
–130
–6
–380
Internal V
CC
Regulator
5.7
5.4
150
190
–150
mV
mV
mV
mV
µA
Current Sensing Section
–95
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 LTM4605E is guaranteed to meet specifications from the 0°C
to 85°C operating temperature range. Specifications over the –40°C to
85°C operating temperature range are assured by design, characterization
and correlation with statistical process controls. The LTM4605I is
guaranteed over the –40°C to 85°C operating temperature range.
Note 3:
The LTM4605 is tested in a feedback loop that servos V
COMP
to a
specified voltage and measures the resultant V
FB
.
Note 4:
Turn-on and turn-off time are measured using 10% and 90%
levels. Transition delay time is measured using 50% levels.
Note 5:
100% tested at wafer level only.
Note 6:
Absolute Maximum Rating of –5V on SW1 and SW2 is under
transient condition only.
4
4605fd
For more information
www.linear.com/LTM4605
LTM4605
typical perForMance characteristics
Efficiency vs Load Current
6V
IN
to 12V
OUT
100
90
80
EFFICIENCY (%)
60
50
40
30
20
10
0
0.01
0.1
1
LOAD CURRENT (A)
CCM
DCM
BURST
10
4605 G01
(Refer to Figure 16)
Efficiency vs Load Current
18V
IN
to 12V
OUT
95
85
75
EFFICIENCY (%)
65
55
45
35
CCM
DCM
BURST
25
15
0.01
CCM
DCM
SKIP CYCLE
0.1
1
10
LOAD CURRENT (A)
100
4605 G03
Efficiency vs Load Current
12V
IN
to 12V
OUT
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.01
0.1
1
LOAD CURRENT (A)
70
10
4605 G02
Efficiency vs Load Current
3.3µH Inductor (CCM)
100
95
90
EFFICIENCY (%)
EFFICIENCY (%)
85
80
75
70
65
60
0
3
18V
IN
TO 5V
OUT
12V
IN
TO 5V
OUT
5V
IN
TO 5V
OUT
6
9
LOAD CURRENT (A)
12
4605 G04
Efficiency vs Load Current
1.5µH Inductor (CCM)
100
95
90
EFFICIENCY (%)
18V
IN
TO 3.3V
OUT
12V
IN
TO 3.3V
OUT
5V
IN
TO 3.3V
OUT
0
3
6
9
LOAD CURRENT (A)
12
4605 G05
Efficiency vs Load Current
1.5µH Inductor (CCM)
100
95
90
85
80
75
70
65
60
55
50
0
3
18V
IN
TO 2.5V
OUT
12V
IN
TO 2.5V
OUT
5V
IN
TO 2.5V
OUT
6
9
LOAD CURRENT (A)
12
4605 G06
85
80
75
70
65
60
55
50
Transient Response from
6V
IN
to 12V
OUT
I
OUT
2A/DIV
I
OUT
2A/DIV
Transient Response from
12V
IN
to 12V
OUT
I
OUT
2A/DIV
Transient Response from
18V
IN
to 12V
OUT
V
OUT
200mV/DIV
200µs/DIV
4605 G07
V
OUT
200mV/DIV
200µs/DIV
4605 G08
V
OUT
100mV/DIV
200µs/DIV
4605 G09
LOAD STEP: 0A TO 3A AT CCM
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 15m SENSING RESISTORS
LOAD STEP: 0A TO 3A AT CCM
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 15m SENSING RESISTORS
LOAD STEP: 0A TO 4A AT CCM
OUTPUT CAPS: 4x 22µF CERAMIC CAPS AND
2x 180µF ELECTROLYTIC CAPS
2x 15m SENSING RESISTORS
4605fd
For more information
www.linear.com/LTM4605
5
京公网安备 11010802033920号
EEWORLD
