LINER LTM4601_12

LTM4601/LTM4601-1
12A µModule Regulators
with PLL, Output Tracking
and Margining
DESCRIPTION
FEATURES
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Complete Switch Mode Power Supply
Wide Input Voltage Range: 4.5V to 20V
12A DC Typical, 14A Peak Output Current
0.6V to 5V Output Voltage
Output Voltage Tracking and Margining
Parallel Multiple µModule Regulators for Current
Sharing
Differential Remote Sensing for Precision
Regulation (LTM4601 Only)
PLL Frequency Synchronization
±1.5% Regulation
Current Foldback Protection (Disabled at Start-Up)
RoHS Compliant with Pb-Free Finish
Gold Finish LGA (e4) or SAC 305 BGA (e1)
UltraFast™ Transient Response
Current Mode Control
Up to 95% Efficiency at 5VIN, 3.3VOUT
Programmable Soft-Start
Output Overvoltage Protection
Small Footprint, Low Profile
(15mm × 15mm × 2.82mm) Surface Mount LGA and
(15mm × 15mm × 3.42mm) BGA Packages
The LTM®4601 is a complete 12A step-down switch mode
DC/DC power supply with onboard switching controller,
MOSFETs, inductor and all support components. The
µModule® regulator is housed in small surface mount
15mm × 15mm × 2.82mm LGA and 15mm × 15mm ×
3.42mm BGA packages. Operating over an input voltage
range of 4.5V to 20V, the LTM4601 supports an output
voltage range of 0.6V to 5V as well as output voltage
tracking and margining. The high efficiency design delivers 12A continuous current (14A peak). Only bulk input
and output capacitors are needed to complete the design.
The low profile and light weight package easily mounts
in unused space on the back side of PC boards for high
density point of load regulation. The µModule regulator
can be synchronized with an external clock for reducing
undesirable frequency harmonics and allows PolyPhase®
operation for high load currents.
A high switching frequency and adaptive on-time current
mode architecture deliver a very fast transient response
to line and load changes without sacrificing stability. An
onboard differential remote sense amplifier can be used
to accurately regulate an output voltage independent of
load current. The onboard remote sense amplifier is not
available in the LTM4601-1.
APPLICATIONS
Telecom and Networking Equipment
Servers
n Industrial Equipment
n Point of Load Regulation
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L, LT, LTC, LTM, Linear Technology, the Linear logo, µModule and PolyPhase are registered
trademarks and UltraFast and LTpowerCAD are trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents
including 5481178, 5847554, 6580258, 6304066, 6476589, 6774611, 6677210.
TYPICAL APPLICATION
Efficiency and Power Loss
vs Load Current
1.5V/12A Power Supply with 4.5V to 20V Input
95
CLOCK SYNC
TRACK/SS CONTROL
ON/OFF
CIN
R1
392k
5% MARGIN
RUN
COMP
INTVCC
DRVCC
MPGM
SGND
PLLIN TRACK/SS
VOUT
LTM4601
PGND
VFB
MARG0
MARG1
VOUT
1.5V
12A
100pF
MARGIN
CONTROL
COUT
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
fSET
3.5
85
12VIN
80
12VIN
70
1.5
POWER LOSS
55
4601 TA01a
2.0
5VIN
65
50
3.0
2.5
75
60
RSET
40.2k
4.0
5VIN
0
2
4
6
8
10
LOAD CURRENT (A)
POWER LOSS (W)
VIN
PGOOD
EFFICIENCY
90
EFFICIENCY (%)
VIN
4.5V TO 20V
1.0
12
14
4601 TA01b
0.5
4601fc
1
LTM4601/LTM4601-1
ABSOLUTE MAXIMUM RATINGS
(Note 1)
INTVCC, DRVCC, VOUT_LCL, VOUT (VOUT ≤ 3.3V with
DIFFVOUT )..................................................... –0.3V to 6V
PLLIN, TRACK/SS, MPGM, MARG0, MARG1,
PGOOD, fSET...............................–0.3V to INTVCC + 0.3V
RUN (Note 5)................................................ –0.3V to 5V
VFB, COMP................................................. –0.3V to 2.7V
VIN.............................................................. –0.3V to 20V
VOSNS+, VOSNS –...........................–0.3V to INTVCC + 0.3V
Operating Temperature Range (Note 2)....–40°C to 85°C
Junction Temperature............................................ 125°C
Storage Temperature Range................... –55°C to 125°C
fSET
VIN
VIN
fSET
MARG0
MARG0
MARG1
MARG1
DRVCC
DRVCC
VFB
PGND
PGOOD
VFB
PGND
PGOOD
SGND
SGND
VOSNS+/NC2*
VOSNS+
DIFFVOUT/NC3*
VOUT
VOUT_LCL
DIFFVOUT
VOUT
VOUT_LCL
VOSNS–/NC1*
VOSNS–
LGA PACKAGE
118-LEAD (15mm × 15mm × 2.82mm)
TJMAX = 125°C, θJA = 15°C/W, θJC = 6°C/W,
θJA DERIVED FROM 95mm × 76mm PCB WITH 4 LAYERS
WEIGHT = 1.7g
*LTM4601-1 ONLY
MPGM
COMP
RUN
PLLIN
INTVCC
MPGM
RUN
COMP
TOP VIEW
TRACK/SS
PLLIN
INTVCC
TOP VIEW
TRACK/SS
PIN CONFIGURATION
BGA PACKAGE
118-LEAD (15mm × 15mm × 3.42mm)
TJMAX = 125°C, θJA = 15.5°C/W, θJC = 6.5°C/W,
θJA DERIVED FROM 95mm × 76mm PCB WITH 4 LAYERS
WEIGHT = 1.9g
ORDER INFORMATION
LEAD FREE FINISH
TRAY
PART MARKING* PACKAGE DESCRIPTION
TEMPERATURE RANGE (NOTE 2)
LTM4601EV#PBF
LTM4601EV#PBF
LTM4601V
118-Lead (15mm × 15mm × 2.82mm) LGA
–40°C to 85°C
LTM4601IV#PBF
LTM4601IV#PBF
LTM4601V
118-Lead (15mm × 15mm × 2.82mm) LGA
–40°C to 85°C
LTM4601EV-1#PBF
LTM4601EV-1#PBF
LTM4601V-1
118-Lead (15mm × 15mm × 2.82mm) LGA
–40°C to 85°C
LTM4601IV-1#PBF
LTM4601IV-1#PBF
LTM4601V-1
118-Lead (15mm × 15mm × 2.82mm) LGA
–40°C to 85°C
118-Lead (15mm × 15mm × 3.42mm) BGA
–40°C to 85°C
118-Lead (15mm × 15mm × 3.42mm) BGA
–40°C to 85°C
LTM4601EY#PBF
LTM4601EY#PBF
LTM4601Y
LTM4601IY#PBF
LTM4601IY#PBF
LTM4601Y
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/
2
4601fc
LTM4601/LTM4601-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the –40°C to 85°C
temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration.
SYMBOL
PARAMETER
VIN(DC)
Input DC Voltage
VOUT(DC)
Output Voltage
CONDITIONS
CIN = 10µF ×3, COUT = 200µF, RSET = 40.2k
VIN = 5V, VOUT = 1.5V, IOUT = 0A
VIN = 12V, VOUT = 1.5V, IOUT = 0A
MIN
l
4.5
l
l
1.478
1.478
TYP
MAX
UNITS
20
V
1.5
1.5
1.522
1.522
V
V
4
V
Input Specifications
VIN(UVLO)
Undervoltage Lockout Threshold
IOUT = 0A
3.2
IINRUSH(VIN)
Input Inrush Current at Start-Up
IOUT = 0A. VOUT = 1.5V
VIN = 5V
VIN = 12V
0.6
0.7
A
A
IQ(VIN,NOLOAD)
Input Supply Bias Current
VIN = 12V, No Switching
VIN = 12V, VOUT = 1.5V, Switching Continuous
VIN = 5V, No Switching
VIN = 5V, VOUT = 1.5V, Switching Continuous
Shutdown, RUN = 0, VIN = 12V
3.8
38
2.5
42
22
mA
mA
mA
mA
µA
IS(VIN)
Input Supply Current
VIN = 12V, VOUT = 1.5V, IOUT = 12A
VIN = 12V, VOUT = 3.3V, IOUT = 12A
VIN = 5V, VOUT = 1.5V, IOUT = 12A
1.81
3.63
4.29
A
A
A
INTVCC
VIN = 12V, RUN > 2V
No Load
4.7
5
5.3
V
12
A
Output Specifications
IOUTDC
Output Continuous Current Range
VIN = 12V, VOUT = 1.5V (Note 6)
0
ΔVOUT(LINE)
Line Regulation Accuracy
VOUT = 1.5V, IOUT = 0A, VIN from 4.5V to 20V
l
0.3
%
Load Regulation Accuracy
VOUT = 1.5V, 0A to 12A (Note 6)
VIN = 12V, with Remote Sense Amplifier
VIN = 12V (LTM4601-1)
l
l
0.25
1
%
%
VOUT
ΔVOUT(LOAD)
VOUT
VOUT(AC)
Output Ripple Voltage
IOUT = 0A, COUT = 2× 100µF X5R Ceramic
VIN = 12V, VOUT = 1.5V
VIN = 5V, VOUT = 1.5V
20
18
mVP-P
mVP-P
fS
Output Ripple Voltage Frequency
IOUT = 5A, VIN = 12V, VOUT = 1.5V
850
kHz
ΔVOUT(START)
Turn-On Overshoot
COUT = 200µF, VOUT = 1.5V, IOUT = 0A,
TRACK/SS = 10nF
VIN = 12V
VIN = 5V
20
20
mV
mV
COUT = 200µF, VOUT = 1.5V, TRACK/SS = Open,
IOUT = 1A Resistive Load
VIN = 12V
VIN = 5V
0.5
0.5
ms
ms
Load: 0% to 50% to 0% of Full Load,
COUT = 2 × 22µF Ceramic, 470µF 4V Sanyo
POSCAP
VIN = 12V
VIN = 5V
35
35
mV
mV
25
µs
17
17
A
A
tSTART
ΔVOUTLS
Turn-On Time
Peak Deviation for Dynamic Load
tSETTLE
Settling Time for Dynamic Load Step Load: 0% to 50%, or 50% to 0% of Full Load
VIN = 12V
IOUTPK
Output Current Limit
COUT = 200µF Ceramic
VIN = 12V, VOUT = 1.5V
VIN = 5V, VOUT = 1.5V
4601fc
3
LTM4601/LTM4601-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the –40°C to 85°C
temperature range (Note 2), otherwise specifications are at TA = 25°C, VIN = 12V, per typical application (front page) configuration.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Remote Sense Amp (Note 3) (LTM4601 Only, Not Supported in the LTM4601-1)
VOSNS+, VOSNS–
CM Range
Common Mode Input Voltage Range VIN = 12V, RUN > 2V
0
INTVCC – 1
V
DIFFVOUT Range
Output Voltage Range
0
INTVCC – 1
V
VOS
Input Offset Voltage Magnitude
AV
Differential Gain
1
V/V
GBP
Gain Bandwidth Product
3
MHz
SR
Slew Rate
2
V/µs
20
kW
100
dB
RIN
Input Resistance
CMRR
Common Mode Rejection Mode
VIN = 12V, DIFFVOUT Load = 100k
1.25
+ to GND
VOSNS
mV
Control Stage
VFB
Error Amplifier Input Voltage
Accuracy
IOUT = 0A, VOUT = 1.5V
0.594
0.6
0.606
V
VRUN
RUN Pin On/Off Threshold
1
1.5
1.9
V
ITRACK/SS
Soft-Start Charging Current
VTRACK/SS = 0V
–1.0
–1.5
–2.0
µA
tON(MIN)
Minimum On Time
(Note 4)
50
100
ns
tOFF(MIN)
Minimum Off Time
(Note 4)
250
400
ns
RPLLIN
PLLIN Input Resistance
IDRVCC
Current into DRVCC Pin
18
25
mA
RFBHI
Resistor Between VOUT_LCL and VFB
60.4
60.702
kΩ
VMPGM
Margin Reference Voltage
1.18
V
VMARG0, VMARG1
MARG0, MARG1 Voltage Thresholds
1.4
V
l
50
VOUT = 1.5V, IOUT = 1A, DRVCC = 5V
60.098
kΩ
PGOOD Output
ΔVFBH
PGOOD Upper Threshold
VFB Rising
7
10
13
%
ΔVFBL
PGOOD Lower Threshold
VFB Falling
–7
–10
–13
%
ΔVFB(HYS)
PGOOD Hysteresis
VFB Returning
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 LTM4601 is tested under pulsed load conditions such that
TJ ≈ TA. The LTM4601E/LTM4601E-1 are guaranteed to meet performance
specifications from 0°C to 85°C. Specifications over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls. The LTM4601I/LTM4601I-1
are guaranteed over the –40°C to 85°C operating temperature range.
4
1.5
%
Note 3: Remote sense amplifier recommended for ≤3.3V output.
Note 4: 100% tested at wafer level only.
Note 5: Limit current into RUN pin to less than 1mA.
Note 6: See output current derating curves for different VIN, VOUT and TA.
4601fc
LTM4601/LTM4601-1
TYPICAL PERFORMANCE CHARACTERISTICS (See Figure 18 for all curves)
Efficiency vs Load Current
with 5VIN
100
95
100
95
95
85
80
75
0.6VOUT
1.2VOUT
1.5VOUT
2.5VOUT
3.3VOUT
70
65
0
5
90
85
80
75
70
0.6VOUT
1.2VOUT
1.5VOUT
2.5VOUT
3.3VOUT
5VOUT
65
60
55
10
50
15
EFFICIENCY (%)
EFFICIENCY (%)
EFFICIENCY (%)
100
90
90
60
Efficiency vs Load Current
with 20VIN
Efficiency vs Load Current
with 12VIN
0
LOAD CURRENT (A)
10
5
LOAD CURRENT (A)
4601 G01
85
80
75
65
15
60
0
10
5
LOAD CURRENT (A)
1.5V Transient Response
1.8V Transient Response
VOUT
50mV/DIV
VOUT
50mV/DIV
VOUT
50mV/DIV
0A TO 6A
LOAD STEP
0A TO 6A
LOAD STEP
0A TO 6A
LOAD STEP
4601 G04
20µs/DIV
1.5V AT 6A/µs LOAD STEP
COUT = 3 • 22µF 6.3V CERAMICS
470µF 4V SANYO POSCAP
C3 = 100pF
2.5V Transient Response
4601 G05
20µs/DIV
1.8V AT 6A/µs LOAD STEP
COUT = 3 • 22µF 6.3V CERAMICS
470µF 4V SANYO POSCAP
C3 = 100pF
4601 G06
3.3V Transient Response
VOUT
50mV/DIV
VOUT
50mV/DIV
0A TO 6A
LOAD STEP
0A TO 6A
LOAD STEP
20µs/DIV
2.5V AT 6A/µs LOAD STEP
COUT = 3 • 22µF 6.3V CERAMICS
470µF 4V SANYO POSCAP
C3 = 100pF
15
4601 G03
4601 G02
1.2V Transient Response
20µs/DIV
1.2V AT 6A/µs LOAD STEP
COUT = 3 • 22µF 6.3V CERAMICS
470µF 4V SANYO POSCAP
C3 = 100pF
1.2VOUT
1.5VOUT
2.5VOUT
3.3VOUT
5.0VOUT
70
4601 G07
20µs/DIV
3.3V AT 6A/µs LOAD STEP
COUT = 3 • 22µF 6.3V CERAMICS
470µF 4V SANYO POSCAP
C3 = 100pF
4601 G08
4601fc
5
LTM4601/LTM4601-1
TYPICAL PERFORMANCE CHARACTERISTICS (See Figure 18 for all curves)
Start-Up, IOUT = 12A
(Resistive Load)
Start-Up, IOUT = 0A
VOUT
0.5V/DIV
VOUT
0.5V/DIV
IIN
1A/DIV
IIN
0.5A/DIV
5ms/DIV
VIN = 12V
VOUT = 1.5V
COUT = 470µF, 3 × 22µF
SOFT-START = 10nF
5.5
3.3V OUTPUT WITH
130k FROM VOUT
TO ION
4.5
5V OUTPUT WITH
100k RESISTOR
ADDED FROM fSET
TO GND
4.0
3.5
3.0
2.0
5V OUTPUT WITH
NO RESISTOR ADDED
FROM fSET TO GND
1.5
2.5V OUTPUT
1.0
1.8V OUTPUT
0.5
1.5V OUTPUT
2.5
0
TRACK/SS
0.5V/DIV
VFB
0.5V/DIV
VOUT
1V/DIV
2ms/DIV
VIN = 12V
VOUT = 1.5V
COUT = 470µF, 3 × 22µF
SOFT-START = 10nF
1.2V OUTPUT
0
2
4
4601 G10
Track, IOUT = 12A
VIN to VOUT Step-Down Ratio
5.0
OUTPUT VOLTAGE (V)
2ms/DIV
VIN = 12V
VOUT = 1.5V
COUT = 470µF, 3 × 22µF
SOFT-START = 10nF
4601 G09
4601 G12
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
4601 G11
Short-Circuit Protection, IOUT = 0A
VOUT
0.5V/DIV
VOUT
0.5V/DIV
IIN
1A/DIV
IIN
1A/DIV
50µs/DIV
VIN = 12V
VOUT = 1.5V
COUT = 470µF, 3 × 22µF
SOFT-START = 10nF
6
Short-Circuit Protection, IOUT = 12A
4601 G13
50µs/DIV
VIN = 12V
VOUT = 1.5V
COUT = 470µF, 3 × 22µF
SOFT-START = 10nF
4601 G14
4601fc
LTM4601/LTM4601-1
PIN FUNCTIONS
(See Package Description for Pin Assignment)
VIN (Bank 1): Power Input Pins. Apply input voltage between these pins and PGND pins. Recommend placing
input decoupling capacitance directly between VIN pins
and PGND pins.
VOUT (Bank 3): Power Output Pins. Apply output load
between these pins and PGND pins. Recommend placing
output decoupling capacitance directly between these pins
and PGND pins. See Figure 15.
PGND (Bank 2): Power ground pins for both input and
output returns.
TRACK/SS (Pin A9): Output Voltage Tracking and SoftStart Pin. When the module is configured as a master
output, then a soft-start capacitor is placed from this pin
to ground to control the master ramp rate. A soft-start
capacitor can also be used for soft-start turn-on of a stand
alone regulator. Slave operation is performed by putting
a resistor divider from the master output to the ground,
and connecting the center point of the divider to this pin.
See the Applications Information section.
NC1 (Pin M12): No internal connection on the LTM4601-1.
MPGM (Pin A12): Programmable Margining Input. A resistor from this pin to ground sets a current that is equal
to 1.18V/R. This current multiplied by 10kΩ will equal a
value in millivolts that is a percentage of the 0.6V reference voltage. See the Applications Information section.
To parallel LTM4601s, each requires an individual MPGM
resistor. Do not tie MPGM pins together.
VOSNS+ (Pin J12): (+) Input to the Remote Sense Amplifier. This pin connects to the output remote sense point.
The remote sense amplifier is used for VOUT ≤3.3V. Tie to
ground if not used.
fSET (Pin B12): Frequency Set Internally to 850kHz. An
external resistor can be placed from this pin to ground
to increase frequency. See the Applications Information
section for frequency adjustment.
NC2 (Pin J12): No internal connection on the LTM4601-1.
VFB (Pin F12): The Negative Input of the Error Amplifier.
Internally, this pin is connected to VOUT_LCL pin with a
60.4k precision resistor. Different output voltages can be
programmed with an additional resistor between VFB and
SGND pins. See the Applications Information section.
VOSNS– (Pin M12): (–) Input to the Remote Sense Amplifier. This pin connects to the ground remote sense point.
The remote sense amplifier is used for VOUT ≤3.3V. Tie to
INTVCC if not used.
DIFFVOUT (Pin K12): Output of the Remote Sense Amplifier. This pin connects to the VOUT_LCL pin. Leave floating
if not used.
NC3 (Pin K12): No internal connection on the LTM4601-1.
DRVCC (Pin E12): This pin normally connects to INTVCC
for powering the internal MOSFET drivers. This pin can be
biased up to 6V from an external supply with about 50mA
capability, or an external circuit as shown in Figure 16.
This improves efficiency at the higher input voltages by
reducing power dissipation in the module.
INTVCC (Pin A7): This pin is for additional decoupling of
the 5V internal regulator.
PLLIN (Pin A8): External Clock Synchronization Input
to the Phase Detector. This pin is internally terminated
to SGND with a 50k resistor. Apply a clock with a high
level above 2V and below INTVCC. See the Applications
Information section.
MARG0 (Pin C12): This pin is the LSB logic input for the
margining function. Together with the MARG1 pin it will
determine if margin high, margin low or no margin state
is applied. The pin has an internal pull-down resistor of
50k. See the Applications Information section.
MARG1 (Pin D12): This pin is the MSB logic input for the
margining function. Together with the MARG0 pin it will
determine if margin high, margin low or no margin state
is applied. The pin has an internal pull-down resistor of
50k. See the Applications Information section.
4601fc
7
LTM4601/LTM4601-1
PIN FUNCTIONS
(See Package Description for Pin Assignment)
SGND (Pin H12): Signal Ground. This pin connects to
PGND at output capacitor point. See Figure 15.
COMP (Pin A11): Current Control Threshold and Error
Amplifier Compensation Point. The current comparator
threshold increases with this control voltage. The voltage
ranges from 0V to 2.4V with 0.7V corresponding to zero
sense voltage (zero current).
PGOOD (Pin G12): Output Voltage Power Good Indicator.
Open-drain logic output that is pulled to ground when the
output voltage is not within ±10% of the regulation point,
after a 25µs power bad mask timer expires.
8
RUN (Pin A10): Run Control Pin. A voltage above 1.9V
will turn on the module, and when below 1V, will turn
off the module. A programmable UVLO function can be
accomplished by connecting to a resistor divider from
VIN to ground. See Figure 1. This pin has a 5.1V Zener to
ground. Maximum pin voltage is 5V. Limit current into the
RUN pin to less than 1mA.
VOUT_LCL (Pin L12): VOUT connects directly to this pin
to bypass the remote sense amplifier, or DIFFVOUT connects to this pin when the remote sense amplifier is used.
VOUT_LCL can be connected to VOUT on the LTM4601-1,
VOUT is internally connected to VOUT_LCL with 50Ω in the
LTM4601-1.
4601fc
LTM4601/LTM4601-1
SIMPLIFIED BLOCK DIAGRAM
VOUT_LCL
VIN
R1
UVLO
FUNCTION
>1.9V = ON
<1V = OFF
MAX = 5V
1M
(50Ω, LTM4601-1)
VOUT
RUN
PGOOD
R2
5.1V
ZENER
COMP
VIN
4.5V TO 20V
+
1.5µF
CIN
60.4k
INTERNAL
COMP
Q1
POWER CONTROL
SGND
0.47µH
VOUT
1.5V
12A
MARG1
MARG0
22µF
VFB
50k
50k
fSET
RSET
40.2k
39.2k
2.2k
MPGM
10k
TRACK/SS
INTVCC
50k
INTVCC
+
–
4.7µF
+
PGND
PLLIN
CSS
COUT
Q2
VOSNS–
10k
10k
VOSNS+
10k
DRVCC
NOT INCLUDED
IN THE LTM4601-1
VOSNS– = NC1
VOSNS+ = NC2
DIFFVOUT = NC3
DIFFVOUT
4601 F01
= SGND
= PGND
Figure 1. Simplified LTM4601/LTM4601-1 Block Diagram
DECOUPLING
REQUIREMENTS A = 25°C, VIN = 12V. Use Figure 1 configuration.
T
SYMBOL
PARAMETER
CIN
COUT
CONDITIONS
MIN
TYP
MAX
UNITS
External Input Capacitor Requirement (VIN = IOUT = 12A, 3× 10µF Ceramics
4.5V to 20V, VOUT = 1.5V)
20
30
µF
External Output Capacitor Requirement (VIN IOUT = 12A
= 4.5V to 20V, VOUT = 1.5V)
100
200
µF
4601fc
9
LTM4601/LTM4601-1
OPERATION
Power Module Description
The LTM4601 is a standalone nonisolated switching mode
DC/DC power supply. It can deliver up to 12A of DC output
current with some external input and output capacitors.
This module provides a precisely regulated output voltage
programmable via one external resistor from 0.6VDC to
5.0VDC over a 4.5V to 20V wide input voltage. The typical
application schematic is shown in Figure 18.
The LTM4601 has an integrated constant on-time current
mode regulator, ultralow RDS(ON) FETs with fast switching speed and integrated Schottky diodes. The typical
switching frequency is 850kHz at full load. With current
mode control and internal feedback loop compensation,
the LTM4601 module has sufficient stability margins and
good transient performance under a wide range of operating conditions and with a wide range of output capacitors,
even all ceramic output capacitors.
Current mode control provides cycle-by-cycle fast current
limit. Besides, foldback current limiting is provided in an
overcurrent condition while VFB drops. Internal overvoltage and undervoltage comparators pull the open-drain
PGOOD output low if the output feedback voltage exits a
±10% window around the regulation point. Furthermore,
in an overvoltage condition, internal top FET Q1 is turned
off and bottom FET Q2 is turned on and held on until the
overvoltage condition clears.
10
Pulling the RUN pin below 1V forces the controller into its
shutdown state, turning off both Q1 and Q2. At low load
current, the module works in continuous current mode by
default to achieve minimum output ripple voltage.
When DRVCC pin is connected to INTVCC an integrated
5V linear regulator powers the internal gate drivers. If a
5V external bias supply is applied on the DRVCC pin, then
an efficiency improvement will occur due to the reduced
power loss in the internal linear regulator. This is especially
true at the high end of the input voltage range.
The LTM4601 has a very accurate differential remote
sense amplifier with very low offset. This provides for
very accurate output voltage sensing at the load. The
MPGM pin, MARG0 pin and MARG1 pin are used to support voltage margining, where the percentage of margin
is programmed by the MPGM pin, and the MARG0 and
MARG1 select margining.
The PLLIN pin provides frequency synchronization of the
device to an external clock. The TRACK/SS pin is used
for power supply tracking and soft-start programming.
4601fc
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
The typical LTM4601 application circuit is shown in Figure 18. External component selection is primarily determined by the maximum load current and output voltage.
Refer to Table 2 for specific external capacitor requirements
for a particular application.
VIN to VOUT Step-Down Ratios
There are restrictions in the maximum VIN to VOUT step
down ratio that can be achieved for a given input voltage.
These constraints are shown in the Typical Performance
Characteristics curves labeled VIN to VOUT Step-Down
Ratio. Note that additional thermal derating may apply. See
the Thermal Considerations and Output Current Derating
section of this data sheet.
Output Voltage Programming and Margining
The PWM controller has an internal 0.6V reference voltage.
As shown in the Block Diagram, a 1M and a 60.4k 0.5%
internal feedback resistor connects VOUT and VFB pins
together. The VOUT_LCL pin is connected between the 1M
and the 60.4k resistor. The 1M resistor is used to protect
against an output overvoltage condition if the VOUT_LCL
pin is not connected to the output, or if the remote sense
amplifier output is not connected to VOUT_LCL. In these
cases, the output voltage will default to 0.6V. Adding a
resistor RSET from the VFB pin to SGND pin programs
the output voltage:
VOUT = 0.6V •
60.4k +RSET
RSET
Table 1. RSET Standard 1% Resistor Values vs VOUT
RSET
(kΩ)
Open
60.4
40.2
30.1
25.5
19.1
13.3
8.25
VOUT
(V)
0.6
1.2
1.5
1.8
2
2.5
3.3
5
The MPGM pin programs a current that when multiplied
by an internal 10k resistor sets up the 0.6V reference ±
offset for margining. A 1.18V reference divided by the
RPGM resistor on the MPGM pin programs the current.
Calculate VOUT(MARGIN):
VOUT(MARGIN) =
%VOUT
• VOUT
100
where %VOUT is the percentage of VOUT you want to
margin, and VOUT(MARGIN) is the margin quantity in volts:
RPGM =
VOUT
1.18V
•
•10k
0.6V VOUT(MARGIN)
where RPGM is the resistor value to place on the MPGM
pin to ground.
The margining voltage, VOUT(MARGIN), will be added or
subtracted from the nominal output voltage as determined
by the state of the MARG0 and MARG1 pins. See the truth
table below:
MARG1
MARG0
MODE
LOW
LOW
NO MARGIN
LOW
HIGH
MARGIN UP
HIGH
LOW
MARGIN DOWN
HIGH
HIGH
NO MARGIN
Input Capacitors
LTM4601 module should be connected to a low AC impedance DC source. Input capacitors are required to be placed
adjacent to the module. In Figure 18, the 10µF ceramic input
capacitors are selected for their ability to handle the large
RMS current into the converter. An input bulk capacitor
of 100µF is optional. This 100µF capacitor is only needed
if the input source impedance is compromised by long
inductive leads or traces.
4601fc
11
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
D=
VOUT
VIN
Without considering the inductor ripple current, the RMS
current of the input capacitor can be estimated as:
ICIN(RMS) =
IOUT(MAX)
η%
• D • (1–D)
In the above equation, η% is the estimated efficiency of
the power module. CIN can be a switcher-rated electrolytic
aluminum capacitor, OS-CON capacitor or high value ceramic capacitor. Note the capacitor ripple current ratings
are often based on temperature and hours of life. This
makes it advisable to properly derate the input capacitor,
or choose a capacitor rated at a higher temperature than
required. Always contact the capacitor manufacturer for
derating requirements.
In Figure 18, the 10µF ceramic capacitors are together
used as a high frequency input decoupling capacitor. In a
typical 12A output application, three very low ESR, X5R or
X7R, 10µF ceramic capacitors are recommended. These
decoupling capacitors should be placed directly adjacent
to the module input pins in the PCB layout to minimize
the trace inductance and high frequency AC noise. Each
10µF ceramic is typically good for 2A to 3A of RMS ripple
current. Refer to your ceramics capacitor catalog for the
RMS current ratings.
Multiphase operation with multiple LTM4601 devices in
parallel will lower the effective input RMS ripple current
due to the interleaving operation of the regulators. Application Note 77 provides a detailed explanation. Refer to
Figure 2 for the input capacitor ripple current reduction as
a function of the number of phases. The figure provides
a ratio of RMS ripple current to DC load current as function of duty cycle and the number of paralleled phases.
12
Pick the corresponding duty cycle and the number of phases
to arrive at the correct ripple current value. For example,
the 2-phase parallel LTM4601 design provides 24A at 2.5V
output from a 12V input. The duty cycle is DC = 2.5V/12V
= 0.21. The 2-phase curve has a ratio of ~0.25 for a duty
cycle of 0.21. This 0.25 ratio of RMS ripple current to a
DC load current of 24A equals ~6A of input RMS ripple
current for the external input capacitors.
Output Capacitors
The LTM4601 is designed for low output ripple voltage.
The bulk output capacitors defined as COUT are chosen
with low enough effective series resistance (ESR) to meet
the output voltage ripple and transient requirements. COUT
can be a low ESR tantalum capacitor, a low ESR polymer
capacitor or a ceramic capacitor. The typical capacitance is
200µF if all ceramic output capacitors are used. Additional
output filtering may be required by the system designer
if further reduction of output ripple or dynamic transient
spikes is required. Table 2 shows a matrix of different
output voltages and output capacitors to minimize the
voltage droop and overshoot during a 5A/µs transient.
The table optimizes total equivalent ESR and total bulk
capacitance to maximize transient performance.
0.6
RMS INPUT RIPPLE CURRENT
DC LOAD CURRENT
For a buck converter, the switching duty-cycle can be
estimated as:
0.5
1-PHASE
2-PHASE
3-PHASE
4-PHASE
6-PHASE
12-PHASE
0.4
0.3
0.2
0.1
0
0.1
0.2
0.3 0.4 0.5 0.6 0.7
DUTY CYCLE (VOUT/VIN)
0.8
0.9
4601 F02
Figure 2. Normalized Input RMS Ripple Current
vs Duty Cycle for One to Six Modules (Phases)
4601fc
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
Multiphase operation with multiple LTM4601 devices in
parallel will lower the effective output ripple current due to
the interleaving operation of the regulators. For example,
each LTM4601’s inductor current in a 12V to 2.5V multiphase design can be read from the Inductor Ripple Current
vs Duty Cycle graph (Figure 3). The large ripple current
12
2.5V OUTPUT
10
5V OUTPUT
1.8V OUTPUT
1.5V OUTPUT
1.2V OUTPUT
6
3.3V OUTPUT WITH
130k ADDED FROM
VOUT TO fSET
4
5V OUTPUT WITH
100k ADDED FROM
fSET TO GND
2
0
0.2
0.4
0.6
DUTY CYCLE (VOUT/VIN)
0.8
4601 F03
Figure 4 provides a ratio of peak-to-peak output ripple current to the inductor current as a function of duty cycle and
the number of paralleled phases. Pick the corresponding
duty cycle and the number of phases to arrive at the correct
output ripple current ratio value. If a 2-phase operation is
chosen at a duty cycle of 21%, then 0.6 is the ratio. This
0.6 ratio of output ripple current to inductor ripple of 6A
equals 3.6A of effective output ripple current. Refer to
Application Note 77 for a detailed explanation of output
ripple current reduction as a function of paralleled phases.
The output ripple voltage has two components that are
related to the amount of bulk capacitance and effective
series resistance (ESR) of the output bulk capacitance.
Figure 3. Inductor Ripple Current vs Duty Cycle
1.00
0.95
1-PHASE
2-PHASE
3-PHASE
4-PHASE
6-PHASE
0.90
0.85
0.80
PEAK-TO-PEAK OUTPUT RIPPLE CURRENT
DIr
0
RATIO =
IL (A)
8
at low duty cycle and high output voltage can be reduced
by adding an external resistor from fSET to ground which
increases the frequency. If the duty cycle is DC = 2.5V/12V
= 0.21, the inductor ripple current for 2.5V output at 21%
duty cycle is ~6A in Figure 3.
0.75
0.70
0.65
0.60
0.55
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9
DUTY CYCLE (VO/VIN)
4601 F04
Figure 4. Normalized Output Ripple Current vs Duty Cycle, Dlr = VOT/LI, Dlr = Each Phase’s Inductor Current
4601fc
13
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
Therefore, the output ripple voltage can be calculated with
the known effective output ripple current. The equation:
ΔVOUT(P-P) ≈ (ΔIL/(8 • f • m • COUT) + ESR • ΔIL), where f
is frequency and m is the number of parallel phases. This
calculation process can be easily accomplished by using
LTpowerCAD™.
Fault Conditions: Current Limit and Overcurrent
Foldback
LTM4601 has a current mode controller, which inherently limits the cycle-by-cycle inductor current not only in
steady-state operation, but also in response to transients.
To further limit current in the event of an overload condition, the LTM4601 provides foldback current limiting. If the
output voltage falls by more than 50%, then the maximum
output current is progressively lowered to about one sixth
of its full current limit value.
Output Voltage Tracking
Output voltage tracking can be programmed externally
using the TRACK/SS pin. The output can be tracked up and
down with another regulator. The master regulator’s output
is divided down with an external resistor divider that is the
same as the slave regulator’s feedback divider. Figure 5
shows an example of coincident tracking. Ratiometric
modes of tracking can be achieved by selecting different
resistor values to change the output tracking ratio. The
master output must be greater than the slave output for
the tracking to work. Figure 6 shows the coincident output
tracking characteristics.
MASTER
OUTPUT
TRACK CONTROL
VIN
100k
Soft-Start and Tracking
The TRACK/SS pin provides a means to either soft-start
the regulator or track it to a different power supply. A
capacitor on this pin will program the ramp rate of the
output voltage. A 1.5µA current source will charge up the
external soft-start capacitor to 80% of the 0.6V internal
voltage reference plus or minus any margin delta. This will
control the ramp of the internal reference and the output
voltage. The total soft-start time can be calculated as:
(
t SOFTSTART = 0.8 • 0.6V ± VOUT(MARGIN)
)
C
• SS
1.5µA
When the RUN pin falls below 1.5V, then the TRACK/SS
pin is reset to allow for proper soft-start control when the
regulator is enabled again. Current foldback and forced
continuous mode are disabled during the soft-start process. The soft-start function can also be used to control
the output ramp up time, so that another regulator can
be easily tracked to it.
R1
40.2k
VIN
PGOOD
MPGM
RUN
COMP
INTVCC
DRVCC
CIN
R2
60.4k
SGND
PLLIN TRACK/SS
VOUT
LTM4601
PGND
SLAVE OUTPUT
VFB
MARG0
MARG1
COUT
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
fSET
RSET
40.2k
4601 F05
Figure 5. Coincident Tracking Schematic
MASTER OUTPUT
SLAVE OUTPUT
OUTPUT
VOLTAGE
TIME
4601 F06
Figure 6. Coincident Output Tracking Characteristics
14
4601fc
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
Run Enable
INTVCC and DRVCC Connection
The RUN pin is used to enable the power module. The
pin has an internal 5.1V Zener to ground. The pin can be
driven with a logic input not to exceed 5V.
An internal low dropout regulator produces an internal
5V supply that powers the control circuitry and DRVCC
for driving the internal power MOSFETs. Therefore, if
the system does not have a 5V power rail, the LTM4601
can be directly powered by VIN. The gate driver current
through the LDO is about 20mA. The internal LDO power
dissipation can be calculated as:
The RUN pin can also be used as an undervoltage lock out
(UVLO) function by connecting a resistor divider from the
input supply to the RUN pin:
VUVLO =
R1+R2
•1.5V
R2
See Figure 1, Simplified Block Diagram.
Power Good
The PGOOD pin is an open-drain pin that can be used to
monitor valid output voltage regulation. This pin monitors
a ±10% window around the regulation point and tracks
with margining.
COMP Pin
This pin is the external compensation pin. The module
has already been internally compensated for most output
voltages. Table 2 is provided for most application requirements. LTpowerCAD is available for other control loop
optimization.
PLLIN
The power module has a phase-locked loop comprised
of an internal voltage controlled oscillator and a phase
detector. This allows the internal top MOSFET turn-on
to be locked to the rising edge of an external clock. The
frequency range is ±30% around the operating frequency
of 850kHz. A pulse detection circuit is used to detect a
clock on the PLLIN pin to turn on the phase-locked loop.
The pulse width of the clock has to be at least 400ns and
at least 2V in amplitude. The PLLIN pin must be driven
from a low impedance source such as a logic gate located
close to the pin. During the start-up of the regulator, the
phase-locked loop function is disabled.
PLDO_LOSS = 20mA • (VIN – 5V)
The LTM4601 also provides the external gate driver voltage pin DRVCC. If there is a 5V rail in the system, it is
recommended to connect DRVCC pin to the external 5V
rail. This is especially true for higher input voltages. Do
not apply more than 6V to the DRVCC pin. A 5V output can
be used to power the DRVCC pin with an external circuit
as shown in Figure 16.
Parallel Operation of the Module
The LTM4601 device is an inherently current mode controlled device. Parallel modules will have very good current
sharing. This will balance the thermals on the design. The
voltage feedback equation changes with the variable N as
modules are paralleled:
60.4k
+ R SET
VOUT = 0.6V N
R SET
N is the number of paralleled modules.
Figure 19 shows an LTM4601 and an LTM4601-1 used in a
parallel design. The 2nd LTM4601 device does not require
the remote sense amplifier, therefore, the LTM4601-1 device
is used. An LTM4601 device can be used without the diff
amp. VOSNS+ can be tied to ground and the VOSNS– can be
tied to INTVCC. DIFFVOUT can float. When using multiple
LTM4601-1 devices in parallel with an LTM4601, limit the
number to five for a total of six modules in parallel.
4601fc
15
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
Thermal Considerations and Output Current Derating
The power loss curves in Figures 7 and 8 can be used
in coordination with the load current derating curves in
Figures 9 to 14 for calculating an approximate θJA for the
module with various heat sinking methods. Thermal models
are derived from several temperature measurements at
the bench and thermal modeling analysis. Thermal Application Note 103 provides a detailed explanation of the
analysis for the thermal models and the derating curves.
Tables 3 and 4 provide a summary of the equivalent θJA
for the noted conditions. These equivalent θJA parameters
are correlated to the measured values, and are improved
with air flow. The case temperature is maintained at 100°C
or below for the derating curves. The maximum case
temperature of 100°C is to allow for a rise of about 13°C
to 25°C inside the µModule with a thermal resistance θJC
from junction to case between 6°C/W to 9°C/W. This will
maintain the maximum junction temperature inside the
µModule regulator below 125°C.
Safety Considerations
The LTM4601 modules do not provide isolation from
VIN to VOUT. There is no internal fuse. If required, a
slow blow fuse with a rating twice the maximum input
current needs to be provided to protect each unit from
catastrophic failure.
6
5.0
4.5
5
3.5
POWER LOSS (W)
POWER LOSS (W)
4.0
20VIN
3.0
12VIN
2.5
2.0
1.5
4
20VIN
3
12VIN
2
5VIN
1.0
1
0.5
0
0
2
6
8
4
LOAD CURRENT (A)
0
12
10
0
2
4
6
8
LOAD CURRENT (A)
10
4601 F08
4601 F07
Figure 8. 3.3V Power Loss
12
12
10
10
MAXIMUM LOAD CURRENT (A)
MAXIMUM LOAD CURRENT (A)
Figure 7. 1.5V Power Loss
8
6
4
5VIN, 1.5VOUT 0LFM
5VIN, 1.5VOUT 200LFM
5VIN, 1.5VOUT 400LFM
2
0
50
60
70
80
90
AMBIENT TEMPERATURE (°C)
100
4600 F09
Figure 9. No Heat Sink 5VIN
16
12
8
6
4
5VIN, 1.5VOUT 0LFM
5VIN, 1.5VOUT 200LFM
5VIN, 1.5VOUT 400LFM
2
0
50
100
60
70
80
90
AMBIENT TEMPERATURE (°C)
4601 F10
Figure 10. BGA Heat Sink 5VIN
4601fc
LTM4601/LTM4601-1
12
12
10
10
MAXIMUM LOAD CURRENT (A)
MAXIMUM LOAD CURRENT (A)
APPLICATIONS INFORMATION
8
6
4
5VIN, 1.5VOUT 0LFM
5VIN, 1.5VOUT 200LFM
5VIN, 1.5VOUT 400LFM
2
0
50
6
4
5VIN, 1.5VOUT 0LFM
5VIN, 1.5VOUT 200LFM
5VIN, 1.5VOUT 400LFM
2
0
100
60
70
80
90
AMBIENT TEMPERATURE (°C)
8
50
4601 F11
4601 F12
Figure 12. BGA Heat Sink 12VIN
12
12
10
10
MAXIMUM LOAD CURRENT (A)
MAXIMUM LOAD CURRENT (A)
Figure 11. No Heat Sink 12VIN
8
6
4
0LFM
200LFM
400LFM
2
0
40
60
80
AMBIENT TEMPERATURE (°C)
100
60
70
80
90
AMBIENT TEMPERATURE (°C)
100
4601 F13
Figure 13. 12VIN, 3.3VOUT, No Heat Sink
8
6
4
0LFM
200LFM
400LFM
2
0
40
60
80
AMBIENT TEMPERATURE (°C)
100
4601 F14
Figure 14. 12VIN, 3.3VOUT, BGA Heat Sink
4601fc
17
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
Table 2. Output Voltage Response Versus Component Matrix (Refer to Figure 18), 0A to 6A Load Step
TYPICAL MEASURED VALUES
COUT1 VENDORS
TDK
TAIYO YUDEN
TAIYO YUDEN
VOUT
(V)
1.2
CIN
(CERAMIC)
2 × 10µF 25V
PART NUMBER
C4532X5R0J107MZ (100µF, 6.3V)
JMK432BJ107MU-T ( 100µF, 6.3V)
JMK316BJ226ML-T501 ( 22µF, 6.3V)
CIN
(BULK)
150µF 35V
COUT1
(CERAMIC)
3 × 22µF 6.3V
COUT2
(BULK)
470µF 4V
COUT2 VENDORS
SANYO POS CAP
SANYO POS CAP
SANYO POS CAP
CCOMP
NONE
C3
47pF
VIN
(V)
5
DROOP
(mV)
70
PART NUMBER
6TPE330MIL (330µF, 6.3V)
2R5TPE470M9 (470µF, 2.5V)
4TPE470MCL (470µF, 4V)
PEAK TO
PEAK (mV)
140
RECOVERY
TIME (µs)
30
LOAD STEP
(A/µs)
6
RSET
(kΩ)
60.4
1.2
2 × 10µF 25V
150µF 35V
1 × 100µF 6.3V
470µF 2.5V
NONE
100pF
5
35
70
20
6
60.4
1.2
2 × 10µF 25V
150µF 35V
2 × 100µF 6.3V
330µF 6.3V
NONE
22pF
5
70
140
20
6
60.4
1.2
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
2 × 10µF 25V
150µF 35V
4 × 100µF 6.3V
NONE
NONE
100pF
5
40
93
30
6
60.4
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
150µF 35V
3 × 22µF 6.3V
1 × 100µF 6.3V
2 × 100µF 6.3V
4 × 100µF 6.3V
3 × 22µF 6.3V
1 × 100µF 6.3V
2 × 100µF 6.3V
4 × 100µF 6.3V
3 × 22µF 6.3V
1 × 100µF 6.3V
2 × 100µF 6.3V
4 × 100µF 6.3V
3 × 22µF 6.3V
1 × 100µF 6.3V
2 × 100µF 6.3V
4 × 100µF 6.3V
3 × 22µF 6.3V
1 × 100µF 6.3V
2 × 100µF 6.3V
4 × 100µF 6.3V
1 × 100µF 6.3V
2 × 100µF 6.3V
3 × 22µF 6.3V
4 × 100µF 6.3V
1 × 100µF 6.3V
3 × 22µF 6.3V
2 × 100µF 6.3V
4 × 100µF 6.3V
2 × 100µF 6.3V
1 × 100µF 6.3V
3 × 22µF 6.3V
4 × 100µF 6.3V
1 × 100µF 6.3V
3 × 22µF 6.3V
2 × 100µF 6.3V
4 × 100µF 6.3V
4 × 100µF 6.3V
4 × 100µF 6.3V
470µF 4V
470µF 2.5V
330µF 6.3V
NONE
470µF 4V
470µF 2.5V
330µF 6.3V
NONE
470µF 4V
470µF 2.5V
330µF 6.3V
NONE
470µF 4V
470µF 2.5V
330µF 6.3V
NONE
470µF 4V
470µF 2.5V
330µF 6.3V
NONE
470µF 4V
330µF 6.3V
470µF 4V
NONE
470µF 4V
470µF 4V
330µF 6.3V
NONE
330µF 6.3V
470µF 4V
470µF 4V
NONE
470µF 4V
470µF 4V
330µF 6.3V
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
NONE
100pF
100pF
22pF
100pF
100pF
33pF
100pF
100pF
100pF
33pF
100pF
100pF
47pF
100pF
100pF
100pF
100pF
100pF
100pF
100pF
100pF
220pF
NONE
100pF
100pF
NONE
220pF
220pF
100pF
100pF
100pF
100pF
100pF
150pF
100pF
100pF
22pF
22pF
12
12
12
12
5
5
5
5
12
12
12
12
5
5
5
5
12
12
12
12
5
5
5
5
12
12
12
12
7
7
7
7
12
12
12
12
15
20
70
35
70
49
48
54
44
61
48
54
44
54
48
44
68
65
60
60
68
65
48
56
57
60
48
51
56
70
120
110
110
114
110
110
110
114
188
159
140
70
140
98
100
109
84
118
100
109
89
108
100
90
140
130
120
120
140
130
103
113
116
115
103
102
113
140
240
214
214
230
214
214
214
230
375
320
30
20
20
20
35
30
30
30
35
30
25
25
30
20
30
30
30
30
30
20
30
30
30
25
30
30
30
25
30
30
30
30
30
35
35
30
25
25
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
60.4
60.4
60.4
60.4
40.2
40.2
40.2
40.2
40.2
40.2
40.2
40.2
30.1
30.1
30.1
30.1
30.1
30.1
30.1
30.1
19.1
19.1
19.1
19.1
19.1
19.1
19.1
19.1
13.3
13.3
13.3
13.3
13.3
13.3
13.3
13.3
8.25
8.25
1.2
1.2
1.2
1.2
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.8
1.8
1.8
1.8
1.8
1.8
1.8
1.8
2.5
2.5
2.5
2.5
2.5
2.5
2.5
2.5
3.3
3.3
3.3
3.3
3.3
3.3
3.3
3.3
5
5
18
4601fc
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
Table 3. 1.5V Output at 12A
DERATING CURVE
VIN (V)
POWER LOSS CURVE
AIR FLOW (LFM)
HEAT SINK
qJA (°C/W) LGA
qJA (°C/W) BGA
Figures 9, 11
5, 12
Figure 7
0
None
15.2
15.7
Figures 9, 11
5, 12
Figure 7
200
None
14
14.5
Figures 9, 11
5, 12
Figure 7
400
None
12
12.5
Figures 10, 12
5, 12
Figure 7
0
BGA Heat Sink
13.9
14.4
Figures 10, 12
5, 12
Figure 7
200
BGA Heat Sink
11.3
11.8
Figures 10, 12
5, 12
Figure 7
400
BGA Heat Sink
10.25
10.75
Table 4. 3.3V Output at 12A
DERATING CURVE
VIN (V)
POWER LOSS CURVE
AIR FLOW (LFM)
HEAT SINK
qJA (°C/W) LGA
qJA (°C/W) BGA
Figure 13
12
Figure 8
0
None
15.2
15.7
Figure 13
12
Figure 8
200
None
14.6
15.0
Figure 13
12
Figure 8
400
None
13.4
13.9
Figure 14
12
Figure 8
0
BGA Heat Sink
13.9
14.4
Figure 14
12
Figure 8
200
BGA Heat Sink
11.1
11.6
Figure 14
12
Figure 8
400
BGA Heat Sink
10.5
11.0
Heat Sink Manufacturer
Aavid Thermalloy
Part No: 375424B00034G
Phone: 603-224-9988
4601fc
19
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
Layout Checklist/Example
The high integration of LTM4601 makes the PCB board
layout very simple and easy. However, to optimize its electrical and thermal performance, some layout considerations
are still necessary.
• Use large PCB copper areas for high current path, including VIN, PGND and VOUT. It helps to minimize the
PCB conduction loss and thermal stress.
• Place high frequency ceramic input and output capacitors next to the VIN, PGND and VOUT pins to minimize
high frequency noise.
• Place a dedicated power ground layer underneath the
unit. Refer frequency synchronization source to power
ground.
• To minimize the via conduction loss and reduce module
thermal stress, use multiple vias for interconnection
between top layer and other power layers.
• Do not put vias directly on pads unless they are capped.
• Use a separated SGND copper area for components
connected to signal pins. Connect the SGND to PGND
underneath the unit.
Figure 15 gives a good example of the recommended layout.
Frequency Adjustment
The LTM4601 is designed to typically operate at 850kHz
across most input conditions. The fSET pin is normally
left open. The switching frequency has been optimized
for maintaining constant output ripple noise over most
operating ranges. The 850kHz switching frequency and
the 400ns minimum off time can limit operation at higher
duty cycles like 5V to 3.3V, and produce excessive inductor ripple currents for lower duty cycle applications like
20V to 5V. The 5VOUT and 3.3VOUT drop out curves are
modified by adding an external resistor on the fSET pin to
allow for lower input voltage operation, or higher input
voltage operation.
VIN
CIN
CIN
GND
SIGNAL
GND
COUT
COUT
VOUT
4601 F15
Figure 15. Recommended Layout (LGA and BGA PCB Layouts Are Identical
with the Exception of Circle Pads for BGA, See Package Description.)
20
4601fc
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
Example for 5V Output
Example for 3.3V Output
LTM4601 minimum on-time = 100ns
tON = ((VOUT • 10pF)/IfSET), for VOUT > 4.8V use 4.8V.
LTM4601 minimum on-time = 100ns
tON = ((VOUT • 10pF)/IfSET)
LTM4601 minimum off-time = 400ns
tOFF = t – tON, where t = 1/Frequency
LTM4601 minimum off-time = 400ns
tOFF = t – tON, where t = 1/Frequency
Duty Cycle = tON/t or VOUT/VIN
Duty Cycle (DC) = tON/t or VOUT/VIN
Equations for setting frequency:
Equations for setting frequency:
IfSET = (VIN/(3 • RfSET)), for 20V operation, IfSET = 170µA,
tON = ((4.8 • 10pF)/IfSET), tON = 282ns, where the internal
RfSET is 39.2k. Frequency = (VOUT/(VIN • tON)) = (5V/(20
• 282ns)) ~ 886kHz. The inductor ripple current begins
to get high at the higher input voltages due to a larger
voltage across the inductor. This is noted in the Inductor
Ripple Current vs Duty Cycle graph (Figure 3) where IL ≈
10A at 25% duty cycle. The inductor ripple current can be
lowered at the higher input voltages by adding an external
resistor from fSET to ground to increase the switching
frequency. An 8A ripple current is chosen, and the total
peak current is equal to 1/2 of the 8A ripple current plus
the output current. The 5V output current is limited to 8A,
so the total peak current is less than 12A. This is below the
14A peak specified value. A 100k resistor is placed from
fSET to ground, and the parallel combination of 100k and
39.2k equates to 28k. The IfSET calculation with 28k and
20V input voltage equals 238µA. This equates to a tON of
200ns. This will increase the switching frequency from
~886kHz to ~1.25MHz for the 20V to 5V conversion. The
minimum on-time is above 100ns at 20V input. Since
the switching frequency is approximately constant over
input and output conditions, then the lower input voltage
range is limited to 10V for the 1.25MHz operation due to
the 400ns minimum off-time. Equation: tON = (VOUT/VIN)
• (1/Frequency) equates to a 400ns on-time, and a 400ns
off-time. The VIN to VOUT Step-Down Ratio curve reflects
an operating range of 10V to 20V for 1.25MHz operation
with a 100k resistor to ground, and an 8V to 16V operation
for fSET floating. These modifications are made to provide
wider input voltage ranges for the 5V output designs while
limiting the inductor ripple current, and maintaining the
400ns minimum off-time.
IfSET = (VIN /(3 • RfSET)), for 20V operation, IfSET = 170µA,
tON = ((3.3 • 10pf)/IfSET), tON = 195ns, where the internal
RfSET is 39.2k. Frequency = (VOUT/(VIN • tON)) = (3.3V/
(20 • 195ns)) ~ 846kHz. The minimum on-time and minimum off-time are within specification at 195ns and 980ns.
The 4.5V minimum input for converting 3.3V output will
not meet the minimum off-time specification of 400ns.
tON = 868ns, Frequency = 850kHz, tOFF = 315ns.
Solution
Lower the switching frequency at lower input voltages to
allow for higher duty cycles, and meet the 400ns minimum
off-time at 4.5V input voltage. The off-time should be about
500ns, which includes a 100ns guard band. The duty cycle
for (3.3V/4.5V) = ~73%. Frequency = (1 – DC)/tOFF or
(1 – 0.73)/500ns = 540kHz. The switching frequency
needs to be lowered to 540kHz at 4.5V input. tON = DC/
frequency, or 1.35µs. The fSET pin voltage is 1/3 of VIN, and
the IfSET current equates to 38µA with the internal 39.2k.
The IfSET current needs to be 24µA for 540kHz operation. A resistor can be placed from VOUT to fSET to lower
the effective IfSET current out of the fSET pin to 24µA.
The fSET pin is 4.5V/3 =1.5V and VOUT = 3.3V, therefore
130k will source 14µA into the fSET node and lower the
IfSET current to 24µA. This enables the 540kHz operation
and the 4.5V to 20V input operation for down converting to
3.3V output. The frequency will scale from 540kHz to 1.1
MHz over this input range. This provides for an effective
output current of 8A over the input range.
4601fc
21
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
VOUT
VIN
10V TO 20V
R2
100k
TRACK/SS CONTROL
R4
100k
VIN
PGOOD
MPGM
RUN
COMP
INTVCC
DRVCC
5% MARGIN
CIN
10µF
25V
×2
R1
392k
1%
SGND
REVIEW TEMPERATURE
DERATING CURVE
PLLIN TRACK/SS
VOUT
LTM4601-1
+
C3 100pF
VFB
MARG0
MARG1
VOUT
5V
8A
COUT1
100µF
REFER TO
6.3V
SANYO POSCAP TABLE 2
VOUT_LCL
NC3
NC1
NC2
fSET
PGND
RfSET
100k
RSET
8.25k
MARGIN CONTROL
IMPROVE
EFFICIENCY
FOR ≥12V INPUT
SOT-323
DUAL
CMSSH-3C3
4601 F16
Figure 16. 5V at 8A Design Without Differential Amplifier
VIN
4.5V TO 16V
VOUT
R2
100k
TRACK/SS CONTROL
R4
100k
VIN
PGOOD
PGOOD
CIN
10µF
25V
×3
MPGM
RUN
COMP
INTVCC
DRVCC
PLLIN TRACK/SS
VOUT
LTM4601
R1
392k
SGND
5% MARGIN
PGND
REVIEW TEMPERATURE
DERATING CURVE
VFB
MARG0
MARG1
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
fSET
MARGIN CONTROL
C3 100pF
+
RfSET
130k
VOUT
3.3V
10A
COUT1
100µF
6.3V
SANYO POSCAP
RSET
13.3k
4601 F17
Figure 17. 3.3V at 10A Design
22
4601fc
LTM4601/LTM4601-1
APPLICATIONS INFORMATION
CLOCK SYNC
C5
0.01µF
VOUT
VIN
4.5V TO 20V
R2
100k
R4
100k
PGOOD
CIN
BULK
OPT
+
CIN
10µF
25V
×3 CER
PLLIN TRACK/SS
VOUT
VIN
PGOOD
MPGM
RUN
ON/OFF
COMP
INTVCC
DRVCC
R1
392k
LTM4601
SGND
PGND
REVIEW TEMPERATURE
DERATING CURVE
VFB
MARG0
MARG1
C3 100pF
COUT1
100µF
6.3V
MARGIN
CONTROL
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
fSET
RSET
40.2k
4601 F18
5% MARGIN
+
COUT2
470µF
6.3V
VOUT
1.5V
12A
REFER TO
TABLE 2 FOR
DIFFERENT
OUTPUT
VOLTAGE
Figure 18. Typical 4.5V to 20V, 1.5V at 12A Design
VOUT
VIN
4.5V TO 20V
118k
1%
R2
100k
+
C1
0.1µF
LTC6908-1
1
2
3
V+
OUT1
GND
OUT2
SET
MOD
6
5
4
CLOCK SYNC
0° PHASE
C5*
100µF
25V
C2
10µF
25V
×2
R4
100k
VIN
PGOOD
MPGM
RUN
COMP
INTVCC
DRVCC
R1
392k
SGND
PLLIN TRACK/SS
VOUT
LTM4601
PGND
5%
MARGIN
2-PHASE
OSCILLATOR
VFB
MARG0
MARG1
60.4k + R
SET
N
RSET
N = NUMBER OF PHASES
VOUT = 0.6V
TRACK/SS CONTROL
C6 220pF
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
C3
22µF
6.3V
C4
470µF
6.3V
VOUT
1.5V
24A
+
REFER TO
TABLE 2
fSET
RSET
20k
100pF
MARGIN
CONTROL
CLOCK SYNC
180° PHASE
TRACK/SS CONTROL
4.5V TO 20V
C7
0.033µF
VIN
PGOOD
PGOOD
MPGM
RUN
COMP
INTVCC
DRVCC
C8
10µF
25V
×2
PLLIN TRACK/SS
VOUT
LTM4601-1
392k
SGND
PGND
C3
22µF
6.3V
VFB
MARG0
MARG1
C4
470µF
6.3V
REFER TO
TABLE 2
VOUT_LCL
NC3
NC2
NC1
fSET
+
4601 F19
*C5 OPTIONAL TO REDUCE ANY LC RINGING.
NOT NEEDED FOR LOW INDUCTANCE PLANE CONNECTION
Figure 19. 2-Phase Parallel, 1.5V at 24A Design
4601fc
23
24
+
C11
100µF
35V
OPT
C2
10µF
25V
×3
VIN
PGOOD
SGND
SGND
MPGM
RUN
ON/OFF
COMP
INTVCC
DRVCC
R1
392k
R3
100k
8V TO 16V
5% MARGIN
PGOOD
R2
100k
3.3V
VIN
PGOOD
MPGM
RUN
ON/OFF
COMP
INTVCC
DRVCC
R27
392k
5% MARGIN
C8
10µF
25V
×3
PGOOD
R7
100k
8V TO 16V
INTERMEDIATE
BUS
3.3V
R6
100k
–48V
INPUT
fSET
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
PGND
LTM4601
fSET
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
VFB
MARG0
MARG1
PLLIN TRACK/SS
VOUT
CLOCK SYNC 3
PGND
LTM4601
VFB
MARG0
MARG1
PLLIN TRACK/SS
VOUT
MARGIN
CONTROL
C8 100pF
R19
30.1k
MARGIN
CONTROL
R8
13.3k
R12
30.1k
R21
60.4k
C7
0.15µF
C12 100pF
TRACK/SS
CONTROL
CLOCK SYNC 1
3.3V
+
REFER TO
TABLE 2
C3
22µF
6.3V
+
1.8V AT 12A
REFER TO
TABLE 2
C9
22µF
6.3V
R17
59k
LTC6902
C4
470µF
6.3V
C10
470µF
6.3V
V+
SET
DIV
MOD
PH
GND
OUT1 OUT4
OUT2 OUT3
3.3V AT 10A
4-PHASE
OSCILLATOR
8V TO 16V
C26
0.1µF
C14
10µF
25V
×3
PGND
LTM4601
VIN
PGOOD
SGND
PGND
LTM4601
fSET
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
VFB
MARG0
MARG1
PLLIN TRACK/SS
VOUT
fSET
VOUT_LCL
DIFFVOUT
VOSNS+
VOSNS–
VFB
MARG0
MARG1
PLLIN TRACK/SS
VOUT
CLOCK SYNC 4
SGND
MPGM
RUN
ON/OFF
COMP
INTVCC
DRVCC
R14
392k
R16
100k
8V TO 16V
5% MARGIN
PGOOD
R15
100k
VIN
PGOOD
CLOCK SYNC 2
MPGM
RUN
ON/OFF
COMP
INTVCC
DRVCC
R9
392k
5% MARGIN
3.3V
C14
10µF
25V
×3
8V TO 16V
R11
100k
PGOOD
R10
100k
3.3V
4-Phase, Four Outputs (3.3V, 2.5V, 1.8V and 1.5V) with Coincident Tracking
R18
19.1k
R13
40.2k
R25
60.4k
4601 TA02
MARGIN
CONTROL
C24 100pF
R26
40.2k
MARGIN
CONTROL
C18 100pF
R24
19.1k
R23
60.4k
3.3V
3.3V
+
REFER TO
TABLE 2
C16
22µF
6.3V
+
1.5V AT 12A
REFER TO
TABLE 2
C16
22µF
6.3V
2.5V AT 12A
C15
470µF
6.3V
C15
470µF
6.3V
LTM4601/LTM4601-1
TYPICAL APPLICATIONS
4601fc
aaa Z
0.630 ±0.025 Ø 118x
3.1750
3.1750
SUGGESTED PCB LAYOUT
TOP VIEW
1.9050
PACKAGE TOP VIEW
E
0.6350
0.0000
0.6350
4
1.9050
PIN “A1”
CORNER
6.9850
5.7150
4.4450
4.4450
5.7150
6.9850
Y
6.9850
5.7150
4.4450
3.1750
1.9050
0.6350
0.0000
0.6350
1.9050
3.1750
4.4450
5.7150
6.9850
X
D
aaa Z
bbb Z
0.27
2.45
MIN
2.72
0.60
NOM
2.82
0.63
15.00
15.00
1.27
13.97
13.97
0.32
2.50
DIMENSIONS
0.37
2.55
0.15
0.10
0.05
MAX
2.92
0.66
NOTES
DETAIL B
PACKAGE SIDE VIEW
A
TOTAL NUMBER OF LGA PADS: 118
SYMBOL
A
b
D
E
e
F
G
H1
H2
aaa
bbb
eee
H1
SUBSTRATE
eee S X Y
DETAIL A
0.630 ±0.025 SQ. 118x
DETAIL B
H2
MOLD
CAP
Z
(Reference LTC DWG # 05-08-1801 Rev A)
LGA Package
118-Lead (15mm × 15mm × 2.82mm)
e
b
L
K
J
G
G
F
e
E
PACKAGE BOTTOM VIEW
H
D
C
B
A
DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE
BALL DESIGNATION PER JESD MS-028 AND JEP95
TRAY PIN 1
BEVEL
LGA 118 1011 REV A
PACKAGE IN TRAY LOADING ORIENTATION
LTMXXXXXX
µModule
5. PRIMARY DATUM -Z- IS SEATING PLANE
4
3
2. ALL DIMENSIONS ARE IN MILLIMETERS
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
COMPONENT
PIN “A1”
3
SEE NOTES
F
b
M
DETAIL A
1
2
3
4
5
6
7
8
9
C(0.30)
PAD 1
10
11
12
LTM4601/LTM4601-1
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
25
4601fc
aaa Z
0.630 ±0.025 Ø 118x
4
E
PACKAGE TOP VIEW
3.1750
3.1750
SUGGESTED PCB LAYOUT
TOP VIEW
1.9050
PIN “A1”
CORNER
0.6350
0.0000
0.6350
Y
6.9850
5.7150
4.4450
3.1750
1.9050
0.6350
0.0000
0.6350
1.9050
3.1750
4.4450
5.7150
6.9850
X
D
2.45 – 2.55
aaa Z
SYMBOL
A
A1
A2
b
b1
D
E
e
F
G
aaa
bbb
ccc
ddd
eee
NOM
3.42
0.60
2.82
0.75
0.63
15.0
15.0
1.27
13.97
13.97
DIMENSIONS
0.15
0.10
0.20
0.30
0.15
MAX
3.62
0.70
2.92
0.90
0.66
NOTES
DETAIL B
PACKAGE SIDE VIEW
TOTAL NUMBER OF BALLS: 118
MIN
3.22
0.50
2.72
0.60
0.60
b1
0.27 – 0.37
SUBSTRATE
A1
ddd M Z X Y
eee M Z
DETAIL A
Øb (118 PLACES)
DETAIL B
MOLD
CAP
ccc Z
A2
A
(Reference LTC DWG # 05-08-1903 Rev A)
// bbb Z
26
1.9050
BGA Package
118-Lead (15mm × 15mm × 3.42mm)
Z
e
b
L
K
J
G
G
F
e
E
PACKAGE BOTTOM VIEW
H
D
C
B
A
DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE ZONE INDICATED.
THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR
MARKED FEATURE
BALL DESIGNATION PER JESD MS-028 AND JEP95
TRAY PIN 1
BEVEL
BGA 118 0112 REV A
PACKAGE IN TRAY LOADING ORIENTATION
LTMXXXXXX
µModule
6. SOLDER BALL COMPOSITION IS 96.5% Sn/3.0% Ag/0.5% Cu
5. PRIMARY DATUM -Z- IS SEATING PLANE
4
3
2. ALL DIMENSIONS ARE IN MILLIMETERS
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994
COMPONENT
PIN “A1”
3
SEE NOTES
F
b
M
DETAIL A
1
2
3
4
5
6
7
8
9
10
11
12
PIN 1
LTM4601/LTM4601-1
PACKAGE DESCRIPTION
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
4601fc
6.9850
5.7150
4.4450
4.4450
5.7150
6.9850
LTM4601/LTM4601-1
PACKAGE DESCRIPTION
Table 5. Pin Assignment (Arranged by Pin Number)
PIN ID
FUNCTION
PIN ID
FUNCTION
PIN ID
FUNCTION
PIN ID
FUNCTION
PIN ID
FUNCTION
PIN ID
FUNCTION
A1
VIN
B1
VIN
C1
VIN
D1
PGND
E1
PGND
F1
PGND
A2
VIN
B2
VIN
C2
VIN
D2
PGND
E2
PGND
F2
PGND
A3
VIN
B3
VIN
C3
VIN
D3
PGND
E3
PGND
F3
PGND
A4
VIN
B4
VIN
C4
VIN
D4
PGND
E4
PGND
F4
PGND
A5
VIN
B5
VIN
C5
VIN
D5
PGND
E5
PGND
F5
PGND
A6
VIN
B6
VIN
C6
VIN
D6
PGND
E6
PGND
F6
PGND
A7
INTVCC
B7
–
C7
–
D7
–
E7
PGND
F7
PGND
A8
PLLIN
B8
–
C8
–
D8
–
E8
–
F8
PGND
A9
TRACK/SS
B9
–
C9
–
D9
–
E9
–
F9
PGND
A10
RUN
B10
–
C10
–
D10
–
E10
–
F10
–
A11
COMP
B11
–
C11
–
D11
–
E11
–
F11
–
A12
MPGM
B12
fSET
C12
MARG0
D12
MARG1
E12
DRVCC
F12
VFB
PIN ID
FUNCTION
PIN ID
FUNCTION
PIN ID
FUNCTION
PIN ID
FUNCTION
PIN ID
FUNCTION
PIN ID
FUNCTION
G1
PGND
H1
PGND
J1
VOUT
K1
VOUT
L1
VOUT
M1
VOUT
G2
PGND
H2
PGND
J2
VOUT
K2
VOUT
L2
VOUT
M2
VOUT
G3
PGND
H3
PGND
J3
VOUT
K3
VOUT
L3
VOUT
M3
VOUT
G4
PGND
H4
PGND
J4
VOUT
K4
VOUT
L4
VOUT
M4
VOUT
G5
PGND
H5
PGND
J5
VOUT
K5
VOUT
L5
VOUT
M5
VOUT
G6
PGND
H6
PGND
J6
VOUT
K6
VOUT
L6
VOUT
M6
VOUT
G7
PGND
H7
PGND
J7
VOUT
K7
VOUT
L7
VOUT
M7
VOUT
G8
PGND
H8
PGND
J8
VOUT
K8
VOUT
L8
VOUT
M8
VOUT
G9
PGND
H9
PGND
J9
VOUT
K9
VOUT
L9
VOUT
M9
VOUT
G10
–
H10
–
J10
VOUT
K10
VOUT
L10
VOUT
M10
VOUT
G11
–
H11
–
J11
–
K11
VOUT
L11
VOUT
M11
VOUT
G12
PGOOD
H12
SGND
J12
VOSNS+
K12
DIFFVOUT
L12
VOUT_LCL
M12
VOSNS–
4601fc
27
LTM4601/LTM4601-1
PACKAGE DESCRIPTION
Table 6. Pin Assignment (Arranged by Pin Function)
PIN NAME
PIN NAME
A1
A2
A3
A4
A5
A6
VIN
VIN
VIN
VIN
VIN
VIN
D1
D2
D3
D4
D5
D6
PGND
PGND
PGND
PGND
PGND
PGND
B1
B2
B3
B4
B5
B6
VIN
VIN
VIN
VIN
VIN
VIN
C1
C2
C3
C4
C5
C6
VIN
VIN
VIN
VIN
VIN
VIN
E1
E2
E3
E4
E5
E6
E7
PGND
PGND
PGND
PGND
PGND
PGND
PGND
F1
F2
F3
F4
F5
F6
F7
F8
F9
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
G1
G2
G3
G4
G5
G6
G7
G8
G9
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
H1
H2
H3
H4
H5
H6
H7
H8
H9
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND
28
PIN NAME
PIN NAME
J1
J2
J3
J4
J5
J6
J7
J8
J9
J10
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
A7
A8
A9
A10
A11
A12
INTVCC
PLLIN
TRACK/SS
RUN
COMP
MPGM
B12
fSET
C12
MARG0
K1
K2
K3
K4
K5
K6
K7
K8
K9
K10
K11
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
D12
MARG1
E12
DRVCC
F12
VFB
G12
PGOOD
H12
SGND
J12
VOSNS+
K12
DIFFVOUT
L12
VOUT_LCL
L1
L2
L3
L4
L5
L6
L7
L8
L9
L10
L11
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
M12
VOSNS–
M1
M2
M3
M4
M5
M6
M7
M8
M9
M10
M11
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
VOUT
PIN NAME
B7
B8
B9
B10
B11
-
C7
C8
C9
C10
C11
-
D7
D8
D9
D10
D11
-
E8
E9
E10
E11
-
F10
F11
-
G10
G11
-
H10
H11
-
J11
-
4601fc
LTM4601/LTM4601-1
REVISION HISTORY
(Revision history begins at Rev B)
REV
DATE
DESCRIPTION
PAGE NUMBER
B
01/10
Added Note 5
2, 4
C
03/12
Revised entire data sheet to include the BGA package.
1–30
4601fc
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
29
LTM4601/LTM4601-1
PACKAGE PHOTO
2.82mm
15mm
3.42mm
15mm
15mm
15mm
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LTM8061
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Programmable Input Current Limit
Compatible with Single Cell or Dual Cell Li-Ion or Li-Poly Battery Stacks
(4.1V, 4.2V, 8.2V, or 8.4V), 4.95V ≤ VIN ≤ 32V, C/10 or Adjustable Timer Charge
Termination, NTC Resistor Monitor Input, 9mm × 15mm × 4.32mm LGA
This product contains technology licensed from Silicon Semiconductor Corporation.
30
Linear Technology Corporation
®
4601fc
LT 0312 REV C • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2007