mode boost and SEPIC controller that drives N-channel
power MOSFETs. Two-phase operation reduces system
filtering capacitance and inductance requirements.
The operating frequency can be set with an external resistor
over a 75kHz to 500kHz range and can be synchronized
to an external clock using the internal PLL. Multiphase
operation is possible using the SYNC input, the CLKOUT
output and the PHASEMODE control pin allowing 2-, 3-,
4-, 6- or 12-phase operation.
Other features include an internal 10V LDO with under-
voltage lockout protection for the gate drivers, a preci-
sion RUN pin threshold with programmable hysteresis,
soft-start and programmable leading edge blanking and
maximum duty cycle.
PART NUMBER
LTC3862
LTC3862-1
LTC3862-2
INTV
CC
5V
10V
10V
V
IN
ON
3.3V
7.5V
4.4V
V
IN
OFF
2.9V
7.0V
3.9V
n
n
n
n
n
n
n
n
n
n
n
n
n
Wide V
IN
Range: 5.5V to 36V Operation
2-Phase Operation Reduces Input and Output
Capacitance
Fixed Frequency, Peak Current Mode Control
Internal 10V LDO Regulator
Lower UVLO Thresholds Allows the Use of
MOSFETs Rated at 6V V
GS
Adjustable Slope Compensation Gain
Adjustable Max Duty Cycle (Up to 96%)
Adjustable Leading Edge Blanking
±1% Internal Voltage Reference
Programmable Operating Frequency with One
External Resistor (75kHz to 500kHz)
Phase-Lockable Fixed Frequency 50kHz to 650kHz
SYNC Input and CLKOUT for 2-, 3-, 4-, 6- or
12-Phase Operation (PHASEMODE Programmable)
24-Lead Narrow SSOP Package
5mm
×
5mm QFN Package with 0.65mm Lead Pitch
24-Lead Thermally Enhanced TSSOP Package
applicaTions
n
Automotive, Telecom and Industrial Power Supplies
L,
LT, LTC, LTM, Linear Technology, the Linear logo and PolyPhase are registered trademarks
and No R
SENSE
and ThinSOT are trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners. Protected by U.S. Patents, including
6144194, 6498466, 6611131.
Typical applicaTion
100k
24.9k
V
IN
16µH
16µH
22µF
50V
V
IN
6V TO 32V
V
OUT
80V
7A (MAX)
210µF
100V
Efficiency vs Output Current
97 V
OUT
= 80V
95
93
91
89
87
85
83
81
79
77
10
100
1000
LOAD CURRENT (mA)
V
IN
= 6V
V
IN
= 9V
V
IN
= 12V
V
IN
= 24V
10000
38622 TA01b
RUN
INTV
CC
GATE1
SENSE1
+
0.0033
4.7µF
110k
LTC3862-2
BLANK
SENSE1
–
FREQ
GATE2
SYNC
SENSE2
+
PLLFLTR
0.1µF
1nF
0.0033
SS
3V8
FB
ITH
SENSE2
–
PGND
CLKOUT
SLOPE
D
MAX
PHASEMODE
SGND
10nF
796k
12.4k
12.1k
220pF
38622 TA01a
EFFICIENCY (%)
38622fa
For more information
www.linear.com/LTC3862-2
1
LTC3862-2
absoluTe MaxiMuM raTings
(Notes 1, 2)
Input Supply Voltage (V
IN
) ......................... –0.3V to 40V
INTV
CC
Voltage ..........................................–0.3V to 11V
INTV
CC
LDO RMS Output Current .........................50mA
RUN Voltage................................................. –0.3V to 8V
SYNC Voltage............................................... –0.3V to 6V
SLOPE, PHASEMODE, D
MAX
,
BLANK Voltage ......................................... –0.3V to V
3V8
SENSE1
+
, SENSE1
–
, SENSE2
+
,
SENSE2
–
Voltage ...................................... –0.3V to V
3V8
SS, PLLFLTR Voltage ................................ –0.3V to V
3V8
ITH Voltage ............................................... –0.3V to 2.7V
FB Voltage ................................................. –0.3V to V
3V8
FREQ Voltage ............................................ –0.3V to 1.5V
Operating Junction Temperature Range (Notes 3, 4)
LTC3862-2E .........................................–40°C to 85°C
LTC3862-2I ........................................ –40°C to 125°C
LTC3862-2H....................................... –40°C to 150°C
Storage Temperature Range .................. –65°C to 150°C
Reflow Peak Body Temperature ........................... 260°C
pin conFiguraTion
TOP VIEW
D
MAX
SLOPE
BLANK
PHASEMODE
FREQ
SS
ITH
FB
SGND
1
2
3
4
5
6
7
8
9
25
PGND
24 3V8
23 SENSE1
+
22 SENSE1
–
21 RUN
20 V
IN
19 INTV
CC
18 GATE1
17 PGND
16 GATE2
15 NC
14 SENSE2
–
13 SENSE2
+
TOP VIEW
D
MAX
SLOPE
BLANK
PHASEMODE
FREQ
SS
ITH
FB
SGND
1
2
3
4
5
6
7
8
9
24 3V8
23 SENSE1
+
22 SENSE1
–
21 RUN
20 V
IN
19 INTV
CC
18 GATE1
17 PGND
16 GATE2
15 NC
14 SENSE2
–
13 SENSE2
+
BLANK 1
PHASEMODE 2
FREQ 3
SS 4
ITH 5
FB 6
7
SGND
8
SLOPE
TOP VIEW
SENSE1
+
SENSE1
–
DMAX
RUN
18 V
IN
17 INTV
CC
25
PGND
16 GATE1
15 PGND
14 GATE2
13 NC
9 10 11 12
SENSE2
+
SENSE2
–
SYNC
PLLFLTR
3V8
24 23 22 21 20 19
CLKOUT 10
SYNC 11
PLLFLTR 12
SYNC 11
PLLFLTR 12
FE PACKAGE
24-LEAD PLASTIC TSSOP
T
JMAX
= 150°C,
θ
JA
= 38°C/W
EXPOSED PAD (PIN 25) IS PGND, MUST BE SOLDERED TO PCB
GN PACKAGE
24-LEAD NARROW PLASTIC SSOP
T
JMAX
= 150°C,
θ
JA
= 85°C/W
UH PACKAGE
24-LEAD (5mm
×
5mm) PLASTIC QFN
T
JMAX
= 150°C,
θ
JA
= 44°C/W
EXPOSED PAD (PIN 25) IS PGND, MUST BE SOLDERED TO PCB
CLKOUT
CLKOUT 10
2
38622fa
For more information
www.linear.com/LTC3862-2
LTC3862-2
orDer inForMaTion
LEAD FREE FINISH
LTC3862EFE-2#PBF
LTC3862IFE-2#PBF
LTC3862HFE-2#PBF
LTC3862EGN-2#PBF
LTC3862IGN-2#PBF
LTC3862HGN-2#PBF
LTC3862EUH-2#PBF
LTC3862IUH-2#PBF
LTC3862HUH-2#PBF
TAPE AND REEL
LTC3862EFE-2#TRPBF
LTC3862IFE-2#TRPBF
LTC3862HFE-2#TRPBF
LTC3862EGN-2#TRPBF
LTC3862IGN-2#TRPBF
LTC3862HGN-2#TRPBF
LTC3862EUH-2#TRPBF
LTC3862IUH-2#TRPBF
LTC3862HUH-2#TRPBF
PART MARKING*
LTC3862FE-2
LTC3862FE-2
LTC3862FE-2
LTC3862GN-2
LTC3862GN-2
LTC3862GN-2
38622
38622
38622
PACKAGE DESCRIPTION
24-Lead Plastic TSSOP
24-Lead Plastic TSSOP
24-Lead Plastic TSSOP
24-Lead Plastic SSOP
24-Lead Plastic SSOP
24-Lead Plastic SSOP
24-Lead (5mm
×
5mm) Plastic QFN
24-Lead (5mm
×
5mm) Plastic QFN
24-Lead (5mm
×
5mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 85°C
–40°C to 125°C
–40°C to 150°C
–40°C to 85°C
–40°C to 125°C
–40°C to 150°C
–40°C to 85°C
–40°C to 125°C
–40°C to 150°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/
elecTrical characTerisTics
SYMBOL
V
IN
I
VIN
INTV
CC
dV
INTVCC(LINE)
V
UVLO
3V8
V
FB
dV
FB
/dV
IN
dV
FB
/dV
ITH
g
m
f
0dB
PARAMETER
V
IN
Supply Voltage Range
V
IN
Supply Current
Normal Mode, No Switching
Shutdown
LDO Regulator Output Voltage
Line Regulation
INTV
CC
UV
+
Voltage
INTV
CC
UV
–
Voltage
LDO Regulator Output Voltage
Reference Voltage
Feedback Voltage V
IN
Line Regulation
Feedback Voltage Load Regulation
Transconductance Amplifier Gain
Error Amplifier Unity-Gain Crossover
Frequency
Switcher Control Loop
Supply Input and INTV
CC
Linear Regulator
(Notes 2, 3) The
l
denotes the specifications which apply over the
specified operating junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, RUN = 2V and SS = open, unless
otherwise noted.
CONDITIONS
l
MIN
5.5
TYP
MAX
36
UNITS
V
mA
µA
V
%/V
%
V
V
V
(Note 5)
V
RUN
= 0V
12V < V
IN
< 36V
Load = 0mA to 20mA
Rising INTV
CC
Falling INTV
CC
l
l
1.8
30
9.5
–2
4.4
3.9
3.8
10.0
0.002
3.0
80
10.5
0.02
dV
INTVCC(LOAD)
Load Regulation
V
ITH
= 0.8V (Note 6)
E-Grade (Note 3)
I-Grade and H-Grade (Note 3)
V
IN
= 5.5V to 36V (Note 6)
V
ITH
= 0.5V to 1.2V (Note 6)
V
ITH
= 0.8V (Note 6), ITH Pin Load = ±5µA
(Note 7)
l
l
1.210
1.199
1.223
1.223
±0.002
0.01
660
1.8
1.235
1.248
0.01
0.1
V
V
%/V
%
µMho
MHz
38622fa
For more information
www.linear.com/LTC3862-2
3
LTC3862-2
elecTrical characTerisTics
SYMBOL
V
ITH
PARAMETER
Error Amplifier Maximum Output Voltage
(Internally Clamped)
Error Amplifier Minimum Output Voltage
I
ITH
I
FB
V
ITH(PSKIP)
I
SENSE(ON)
V
SENSE(MAX)
V
SENSE(MATCH)
RUN/Soft-Start
I
RUN
V
RUN
V
RUNHYS
I
SS
R
SS
Oscillator
f
OSC
Oscillator Frequency
Oscillator Frequency Range
V
FREQ
f
SYNC
V
SYNC
I
PLLFLTR
CH1-CH2
Nominal FREQ Pin Voltage
SYNC Minimum Input Frequency
SYNC Maximum Input Frequency
SYNC Input Threshold
Phase Detector Sourcing Output Current
Phase Detector Sinking Output Current
Channel 1 to Channel 2 Phase Relationship
R
FREQ
= 45.6k
V
SYNC
= External Clock
V
SYNC
= External Clock
Rising Threshold
f
SYNC
> f
OSC
f
SYNC
< f
OSC
V
PHASEMODE
= 0V
V
PHASEMODE
= Float
V
PHASEMODE
= 3V8
V
PHASEMODE
= 0V
V
PHASEMODE
= Float
V
PHASEMODE
= 3V8
V
DMAX
= 0V (Note 9)
V
DMAX
= Float
V
DMAX
= 3V8
l
l
(Notes 2, 3) The
l
denotes the specifications which apply over the
specified operating junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, RUN = 2V and SS = open, unless
otherwise noted.
CONDITIONS
V
FB
= 1V, No Load
V
FB
= 1.5V, No Load
MIN
TYP
2.7
50
–30
30
(Note 6)
Rising ITH Voltage (Note 6)
Hysteresis
V
SLOPE
= Float, Low Duty Cycle
(Note 3)
V
SLOPE
= Float, Low Duty Cycle (Note 3)
(V
SENSE1
– V
SENSE2
)
V
RUN
= 0V
V
RUN
= 1.5V
68
65
–7
–50
0.275
25
0.01
l
l
MAX
UNITS
V
mV
µA
µA
Error Amplifier Output Source Current
Error Amplifier Output Sink Current
Error Amplifier Input Bias Currents
Pulse Skip Mode Operation ITH Pin Voltage
SENSE Pin Current
Maximum Current Sense Input Threshold
CH1 to CH2 Maximum Current Sense
Threshold Matching
RUN Source Current
High Level RUN Channel Enable Threshold
RUN Threshold Hysteresis
SS Pull-Up Current
SS Pull-Down Resistance
V
SS
= 0V
V
RUN
= 0V
R
FREQ
= 45.6k
R
FREQ
= 45.6k
280
260
75
–200
nA
V
mV
2
82
85
7
µA
mV
mV
mV
75
75
–0.5
–5
1.22
80
–5
10
300
300
1.223
50
650
1.5
–15
15
180
180
120
90
60
240
96
84
75
320
340
500
µA
µA
V
mV
µA
kΩ
kHz kHz
kHz
V
kHz
kHz
V
µA
µA
Deg
Deg
Deg
Deg
Deg
Deg
%
%
%
l
l
CH1-CLKOUT
Channel 1 to CLKOUT Phase Relationship
D
MAX
Maximum Duty Cycle
4
38622fa
For more information
www.linear.com/LTC3862-2
LTC3862-2
elecTrical characTerisTics
SYMBOL
t
ON(MIN)1
t
ON(MIN)2
t
ON(MIN)3
Gate Driver
R
DS(ON)
Overvoltage
V
FB(OV)
V
FB
, Overvoltage Lockout Threshold
V
FB(OV)
– V
FB(NOM)
in Percent
8
10
12
%
Driver Pull-Up R
DS(ON)
Driver Pull-Down R
DS(ON)
3
0.9
Ω
Ω
PARAMETER
Minimum On-Time
Minimum On-Time
Minimum On-Time
(Notes 2, 3) The
l
denotes the specifications which apply over the
specified operating junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 12V, RUN = 2V and SS = open, unless
otherwise noted.
CONDITIONS
V
BLANK
= 0V (Note 8)
V
BLANK
= Float (Note 8)
V
BLANK
= 3V8 (Note 8)
MIN
TYP
210
290
375
MAX
UNITS
ns
ns
ns
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:
All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
Note 3:
The LTC3862E-2 is 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 LTC3862I-2 is guaranteed over the
full –40°C to 125°C operating temperature range and the LTC3862H-2 is
guaranteed over the full –40°C to 150°C operating temperature range.
High junction temperatures degrade operating lifetimes. Operating lifetime
is derated at junction temperatures greater than 125°C.
Note 4:
This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Continuous
operation above the specified maximum operating junction temperature
may impair device reliability.
Note 5:
Supply current in normal operation is dominated by the current
needed to charge the external MOSFET gates. This current will vary with
supply voltage and the external MOSFETs used.
Note 6:
The IC is tested in a feedback loop that adjusts V
FB
to achieve a
specified error amplifier output voltage.
Note 7:
Guaranteed by design, not subject to test.
Note 8:
The minimum on-time condition is specified for an inductor peak-
to-peak ripple current = 30% (see Minimum On-Time Considerations in the
Applications Information section).
Note 9:
The maximum duty cycle limit is derived from an internal
clock that runs at 12× the programmed switching frequency. See the
Applications Information section for additional information.
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