1
LTC4440-5
44405fa
High Speed, High Voltage,
High Side Gate Driver
■
Wide Operating V
IN
Range: Up to 60V
■
Rugged Architecture Tolerant of 80V V
IN
Transients
■
Powerful 1.85Ω Driver Pull-Down (with 6V Supply)
■
Powerful 1.1A Peak Current Driver Pull-Up
(with 6V Supply)
■
7ns Fall Time Driving 1000pF Load
■
10ns Rise Time Driving 1000pF Load
■
Drives Standard Threshold MOSFETs
■
TTL/CMOS Compatible Inputs with Hysteresis
■
Input Thresholds are Independent of Supply
■
Undervoltage Lockout
■
Low Profile (1mm) SOT-23 (ThinSOT
TM
) and
Thermally Enhanced 8-Pin MSOP Packages
■
Telecommunications Power Systems
■
Distributed Power Architectures
■
Server Power Supplies
■
High Density Power Modules
■
General Purpose Low-Side Driver
The LTC
®
4440-5 is a high frequency high side N-channel
MOSFET gate driver that is designed to operate in applica-
tions with V
IN
voltages up to 60V. The LTC4440-5 can also
withstand and continue to function during 80V V
IN
tran-
sients. The powerful driver capability reduces switching
losses in MOSFETs with high gate capacitances. The
LTC4440-5’s pull-up has a peak output current of 1.1A and
its pull-down has an output impedance of 1.85Ω.
The LTC4440-5 features supply independent TTL/CMOS
compatible input thresholds with 350mV of hysteresis.
The input logic signal is internally level-shifted to the
bootstrapped supply, which may function at up to 95V
above ground.
The LTC4440-5 is optimized for driving (5V) logic level
FETs and contains an undervoltage lockout circuit that
disables the external MOSFET when activated.
The LTC4440-5 is available in the low profile (1mm)
SOT-23 or a thermally enhanced 8-lead MSOP package.
PARAMETER LTC4440-5 LTC4440
Max Operating TS 60V 80V
Absolute Max TS 80V 100V
MOSFET Gate Drive 4V to 15V 8V to 15V
V
CC
UV
+
3.2V 6.3V
V
CC
UV
–
3.04V 6.0V
V
CC
INP
GND
BOOST
TG
TS
LTC4440-5
V
IN
36V TO 60V
V
CC
4V TO 15V
V
CC
INP
GND
BOOST
TG
TS
LTC4440-5
LTC3722-1 ••
4440 TA01
Synchronous Phase-Modulated Full-Bridge Converter
TG-TS
2V/DIV
INP
2V/DIV
50ns/DIV
VCC = BOOST-TS = 5V
4440-5 TA02
LTC4440-5 Driving a 1000pF Capacitive Load
FEATURES
DESCRIPTIO
U
APPLICATIO S
U
TYPICAL APPLICATIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a
trademark of Linear Technology Corporation. All other trademarks are the property of their
respective owners. Protected by U.S. Patents including 6677210.
2
LTC4440-5
44405fa
Supply Voltage
V
CC
....................................................... –0.3V to 15V
BOOST – TS ......................................... –0.3V to 15V
INP Voltage............................................... –0.3V to 15V
BOOST Voltage (Continuous) ................... –0.3V to 85V
BOOST Voltage (100ms) .......................... –0.3V to 95V
TS Voltage (Continuous) ............................. –5V to 70V
ABSOLUTE MAXIMUM RATINGS
W
WW
U
PACKAGE/ORDER INFORMATION
W
UU
(Note 1)
TS Voltage (100ms)..................................... –5V to 80V
Peak Output Current < 1µs (TG) ............................... 4A
Operating Ambient Temperature Range
(Note 2) .............................................. –40°C to 85°C
Junction Temperature (Note 3)............................ 125°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
V
CC
1
GND 2
INP 3
6 BOOST
5 TG
4 TS
TOP VIEW
S6 PACKAGE
6-LEAD PLASTIC SOT-23
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = VBOOST = 6V, VTS = GND = 0V, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Supply (V
CC
)
I
VCC
DC Supply Current
Normal Operation INP = 0V 200 325 µA
UVLO V
CC
< UVLO Threshold (Falling) – 0.1V 18 40 µA
UVLO Undervoltage Lockout Threshold V
CC
Rising ●2.75 3.20 3.65 V
V
CC
Falling ●2.60 3.04 3.50 V
Hysteresis 160 mV
Bootstrapped Supply (BOOST – TS)
I
BOOST
DC Supply Current
Normal Operation INP = 0V 0 µA
INP = 6V 310 450 µA
Input Signal (INP)
V
IH
High Input Threshold INP Ramping High ●1.2 1.6 2 V
V
IL
Low Input Threshold INP Ramping Low ●0.8 1.25 1.6 V
V
IH
– V
IL
Input Voltage Hysteresis 0.350 V
I
INP
Input Pin Bias Current ±0.01 ±2µA
T
JMAX
= 125°C, θ
JA
= 40°C/W (NOTE 4)
EXPOSED PAD IS GND (PIN 9), MUST BE SOLDERED TO PCB
MS8E PART MARKING
Consult LTC Marketing for parts specified with wider operating temperature ranges.
LTBRG
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: http://www.linear.com/leadfree/
1
2
3
4
INP
GND
V
CC
GND
8
7
6
5
TS
TG
BOOST
NC
TOP VIEW
9
MS8E PACKAGE
8-LEAD PLASTIC MSOP
ORDER PART NUMBER
LTC4440EMS8E-5
T
JMAX
= 125°C, θ
JA
= 230°C/W
S6 PART MARKING
LTBRF
ORDER PART NUMBER
LTC4440ES6-5
3
LTC4440-5
44405fa
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VCC = VBOOST = 6V, VTS = GND = 0V, unless otherwise noted.
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC4440-5 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.
Note 3: T
J
is calculated from the ambient temperature T
A
and power
dissipation PD according to the following formula:
T
J
= T
A
+ (PD • θ
JA
°C/W)
Note 4: Failure to solder the exposed back side of the MS8E package to
the PC board will result in a thermal resistance much higher than 40°C/W.
TYPICAL PERFOR A CE CHARACTERISTICS
UW
VCC Supply Quiescent Current
vs Voltage
BOOST-TS Supply Quiescent
Current vs Voltage
Output Low Voltage (VOL)
vs Supply Voltage
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Output Gate Driver (TG)
V
OH
High Output Voltage I
TG
= –10mA, V
OH
= V
BOOST
– V
TG
0.7 V
V
OL
Low Output Voltage I
TG
= 100mA ●185 275 mV
I
PU
Peak Pull-Up Current ●0.75 1.1 A
R
DS
Output Pull-Down Resistance ●1.85 2.75 Ω
Switching Timing
t
r
Output Rise Time 10% – 90%, C
L
= 1nF 10 ns
10% – 90%, C
L
= 10nF 100 ns
t
f
Output Fall Time 10% – 90%, C
L
= 1nF 7 ns
10% – 90%, C
L
= 10nF 70 ns
t
PLH
Output Low-High Propagation Delay ●35 65 ns
t
PHL
Output High-Low Propagation Delay ●33 65 ns
V
CC
SUPPLY VOLTAGE (V)
0
350
300
250
200
150
100
50
0
4440-5 G01
510 15
QUIESCENT CURRENT (µA)
INP = GND
INP = V
CC
BOOST-TS SUPPLY VOLTAGE (V)
0
QUIESCENT CURRENT (µA)
150
200
250
15
4440-5 G02
100
50
0510
300
350
400 INP = V
CC
BOOST-TS SUPPLY VOLTAGE (V)
3
0
OUTPUT (TG-TS) VOLTAGE (mV)
50
100
150
200
300
57911
4440-5 G03
134 68 10121415
250
4
LTC4440-5
44405fa
Output High Voltage (VOH)
vs Supply Voltage
Input (INP) Thresholds
vs Supply Voltage 2MHz Operation
TYPICAL PERFOR A CE CHARACTERISTICS
UW
VCC Supply Current
vs Temperature
VCC Undervoltage Lockout
Thresholds vs Temperature
BOOST-TS Quiescent Current
vs Temperature
Input (INP) Threshold
vs Temperature
BOOST-TS SUPPLY VOLTAGE (V)
4
HIGH OUTPUT VOLTAGE (V)
10
12
14
15
4440-5 G04
6
05678910
11 12 13 14
16
8
4
2
I
TG
= 1mA
I
TG
= 100mA
I
TG
= 10mA
V
CC
SUPPLY VOLTAGE (V)
5
INPUT THRESHOLD (V)
1.2
1.6
2.0
13
4440-5 G05
0.8
0.4
1.0
1.4
1.8
0.6
0.2
07911
6414
810 12 15
V
IH
V
IL
INPUT
(INP)
5V/DIV
OUTPUT
(TG)
5V/DIV
V
CC
= BOOST-TS = 12V
250ns/DIV
4440-5 G07
TEMPERATURE (°C)
–55
0
QUIESCENT CURRENT (µA)
50
150
200
250
–15 25 45 125
4440-5 G08
100
–35 5 65 85 105
INP = VCC
INP = GND
TEMPERATURE (°C)
–55
2.5
UVLO THRESHOLD VOLTAGE (V)
2.6
2.8
2.9
3.0
3.5
3.2
–15 25 45 125
4440-5 G09
2.7
3.3
3.4
3.1
–35 5 65 85 105
RISING
FALLING
TEMPERATURE (°C)
–55
QUIESCENT CURRENT (µA)
200
250
300
105
4440-5 G10
150
100
0–15 25 65
–35 125
545 85
50
400
350
TEMPERATURE (°C)
–55
0.8
INPUT THRESHOLD (V)
1.0
1.4
1.6
1.8
–15 25
VIH
VIL
45 125
4440-5 G11
1.2
–35 5 65 85 105
2.0
Input Threshold Hysteresis
vs Temperature
TEMPERATURE (°C)
–55
HYSTERESIS (V
IH
-V
IL
) (mV)
340
350
360
105
4440-5 G12
330
320
300 –15 25 65
–35 125
545 85
310
380
370
Peak Driver (TG) Pull-Up Current
vs Temperature
TEMPERATURE (°C)
–55 –35 –15 5 25 45 65 85 105 125
0
PEAK CURRENT (A)
0.5
1.0
1.5
3.5
4440-5 G13
2.0
2.5
3.0
BOOST-TS = 15V
BOOST-TS = 12V
BOOST-TS = 6V
BOOST-TS = 4V
5
LTC4440-5
44405fa
UU
U
PI FU CTIO S
SOT-23 Package
V
CC
(Pin 1): Chip Supply. This pin powers the internal low
side circuitry. A low ESR ceramic bypass capacitor should
be tied between this pin and the GND pin (Pin 2).
GND (Pin 2): Chip Ground.
INP (Pin 3): Input Signal. TTL/CMOS compatible input
referenced to GND (Pin 2).
TS (Pin 4): Top (High Side) source connection or GND if
used in ground referenced applications.
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Output Driver Pull-Down
Resistance vs Temperature Propagation Delay vs Temperature
TG (Pin 5): High Current Gate Driver Output (Top Gate).
This pin swings between TS and BOOST.
BOOST (Pin 6): High Side Bootstrapped Supply. An exter-
nal capacitor should be tied between this pin and TS
(Pin 4). Normally, a bootstrap diode is connected between
V
CC
(Pin 1) and this pin. Voltage swing at this pin is from
V
CC
– V
D
to V
IN
+ V
CC
– V
D
, where V
D
is the forward voltage
drop of the bootstrap diode.
TEMPERATURE (°C)
–55
0
R
DS
(Ω)
0.5
1.5
2.0
2.5
–15 25 45 125
4440-5 G14
1.0
–35 5 65 85 105
3.0
BOOST-TS = 4V
BOOST-TS = 15V
BOOST-TS = 12V
BOOST-TS = 6V
TEMPERATURE (°C)
–55
20
PROPAGATION DELAY (ns)
25
35
40
45
–15 25 45 125
4440-5 G15
30
–35 5 65 85 105
50 VCC = BOOST = 6V
tPLH
tPHL
Driving a 3300pF Capacitive Load
TG-TS
2V/DIV
INP
2V/DIV
50ns/DIV
V
CC
= BOOST-TS = 5V
4440-5 G16
TG-TS
5V/DIV
INP
2V/DIV
50ns/DIV
V
CC
= BOOST-TS = 12V
4440-5 G17
Driving a 3300pF Capacitive Load
6
LTC4440-5
44405fa
TI I G DIAGRA
UWW
VIH
90%
10%
tr
INPUT (INP)
OUTPUT (TG)
INPUT RISE/FALL TIME <10ns
VIL
tf
tPLH
4440 TD
tPHL
BLOCK DIAGRA
W
BOOST
TS
GND
TG
BOOST
44405 BD
V
IN
UP TO 60V,
TRANSIENT
UP TO 80V
TS
UNDERVOLTAGE
LOCKOUT
LEVEL SHIFTER
V
CC
4V TO 15V
GND
INP
Exposed Pad MS8E Package
INP (Pin 1): Input Signal. TTL/CMOS compatible input
referenced to GND (Pin 2).
GND (Pins 2, 4): Chip Ground.
V
CC
(Pin 3): Chip Supply. This pin powers the internal low
side circuitry. A low ESR ceramic bypass capacitor should
be tied between this pin and the GND pin (Pin 2).
NC (Pin 5): No Connect. No connection required. For
convenience, this pin may be tied to Pin 6 (BOOST) on the
application board.
BOOST (Pin 6): High Side Bootstrapped Supply. An exter-
nal capacitor should be tied between this pin and TS
(Pin 8). Normally, a bootstrap diode is connected between
V
CC
(Pin 3) and this pin. Voltage swing at this pin is from
V
CC
– V
D
to V
IN
+ V
CC
– V
D
, where V
D
is the forward voltage
drop of the bootstrap diode.
TG (Pin 7): High Current Gate Driver Output (Top Gate).
This pin swings between TS and BOOST.
TS (Pin 8): Top (High Side) source connection or GND if
used in ground referenced applications.
Exposed Pad (Pin 9): Ground. Must be electrically con-
nected to Pins 2 and 4 and soldered to PCB ground for
optimum thermal performance.
UU
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PI FU CTIO S
7
LTC4440-5
44405fa
APPLICATIO S I FOR ATIO
WUUU
Figure 1. Capacitance Seen by TG During Switching
Overview
The LTC4440-5 receives a ground-referenced, low voltage
digital input signal to drive a high side N-channel power
MOSFET whose drain can float up to 80V above ground,
eliminating the need for a transformer between the low
voltage control signal and the high side gate driver. The
LTC4440-5 normally operates in applications with input
supply voltages (V
IN
) up to 60V, but is able to withstand
and continue to function during 80V, 100ms transients on
the input supply.
The powerful output driver of the LTC4440-5 reduces the
switching losses of the power MOSFET, which increase
with transition time. The LTC4440-5 is capable of driving
a 1nF load with 10ns rise and 7ns fall times using a
bootstrapped supply voltage V
BOOST–TS
of 6V.
Input Stage
The LTC4440-5 employs TTL/CMOS compatible input logic
level or thresholds that allow a low voltage digital signal to
drive standard threshold power MOSFETs. The LTC4440-
5 contains an internal voltage regulator that biases the input
buffer, allowing the input thresholds (V
IH
= 1.6V, V
IL
=
1.25V) to be relatively independent of variations in V
CC
. The
350mV hysteresis between V
IH
and V
IL
eliminates false
triggering due to noise during switching transitions. How-
ever, care should be taken to keep this pin from any noise
pickup, especially in high frequency, high voltage applica-
tions. The LTC4440-5 input buffer has a high input imped-
ance and draws negligible input current, simplifying the
drive circuitry required for the input.
Output Stage
A simplified version of the LTC4440-5’s output stage is
shown in Figure 1 . The pull-down device is an N-channel
MOSFET (N1) and the pull-up device is an NPN bipolar
junction transistor (Q1). The output swings from the lower
rail (TS) to within an NPN V
BE
(~0.7V) of the positive rail
(BOOST). This large voltage swing is important in driving
external power MOSFETs, whose R
DS(ON)
is inversely
proportional to its gate overdrive voltage (V
GS
– V
TH
).
The LTC4440-5’s peak pull-up (Q1) current is 1.1A while
the pull-down (N1) resistance is 1.85Ω, with a BOOST-TS
supply of 6V. The low impedance of N1 is required to
discharge the power MOSFET’s gate capacitance during
high-to-low signal transitions. When the power MOSFET’s
gate is pulled low (gate shorted to source through N1) by
the LTC4440-5, its source (TS) is pulled low by its load
(e.g., an inductor or resistor). The slew rate of the source/
gate voltage causes current to flow back to the MOSFET’s
gate through the gate-to-drain capacitance (C
GD
). If the
MOSFET driver does not have sufficient sink current
capability (low output impedance), the current through
the power MOSFET’s C
GD
can momentarily pull the gate
high, turning the MOSFET back on.
A similar scenario exists when the LTC4440-5 is used to
drive a low side MOSFET. When the low side power
MOSFET’s gate is pulled low by the LTC4440-5, its drain
voltage is pulled high by its load (e.g., inductor or resis-
tor). The slew rate of the drain voltage causes current to
flow back to the MOSFET’s gate through its gate-to-drain
capacitance. If the MOSFET driver does not have sufficient
sink current capability (low output impedance), the cur-
rent through the power MOSFET’s C
GD
can momentarily
pull the gate high, turning the MOSFET back on.
Rise/Fall Time
Since the power MOSFET generally accounts for the
majority of the power loss in a converter, it is important to
quickly turn it on or off, thereby minimizing the transition
time in its linear region. The LTC4440-5 can drive a 1nF
load with a 10ns rise time and 7ns fall time.
The LTC4440-5’s rise and fall times are determined by the
peak current capabilities of Q1 and N1. The predriver that
drives Q1 and N1 uses a nonoverlapping transition scheme
to minimize cross-conduction currents. N1 is fully turned
off before Q1 is turned on and vice versa.
BOOST V
IN
UP TO 100V
TS V
–
TG
C
GD
POWER
MOSFET
LOAD
INDUCTOR
C
GS
4440 F01
LTC4440-5
Q1
N1
8
LTC4440-5
44405fa
Power Dissipation
To ensure proper operation and long-term reliability, the
LTC4440-5 must not operate beyond its maximum tem-
perature rating. Package junction temperature can be
calculated by:
T
J
= T
A
+ PD (θ
JA
)
where:
T
J
= Junction Temperature
T
A
= Ambient Temperature
PD = Power Dissipation
θ
JA
= Junction-to-Ambient Thermal Resistance
Power dissipation consists of standby and switching
power losses:
PD = P
STDBY
+ P
AC
where:
P
STDBY
= Standby Power Losses
P
AC
= AC Switching Losses
The LTC4440-5 consumes very little current during
standby. The DC power loss at V
CC
= 6V and V
BOOST–TS
=
6V is only (250µA)(5V) = 1.2mW with INP = 0V.
AC switching losses are made up of the output capacitive
load losses and the transition state losses. The capacitive
load losses are primarily due to the large AC currents
needed to charge and discharge the load capacitance
during switching. Load losses for the output driver driving
a pure capacitive load C
OUT
would be:
Load Capacitive Power = (C
OUT
)(f)(V
BOOST–TS
)
2
The power MOSFET’s gate capacitance seen by the driver
output varies with its V
GS
voltage level during switching.
A power MOSFET’s capacitive load power dissipation can
be calculated using its gate charge, Q
G
. The Q
G
value
corresponding to the MOSFET’s V
GS
value (V
CC
in this
case) can be readily obtained from the manufacturer’s Q
G
vs V
GS
curves:
Load Capacitive Power (MOS) = (V
BOOST–TS
)(Q
G
)(f)
Transition state power losses are due to both AC currents
required to charge and discharge the driver’s internal
nodal capacitances and cross-conduction currents in the
internal gates.
Undervoltage Lockout (UVLO)
The LTC4440-5 contains an undervoltage lockout detector
that monitors V
CC
. When V
CC
falls below 3.04V, the
internal buffer is disabled and the output pin TG is pulled
down to TS.
Bypassing and Grounding
The LTC4440-5 requires proper bypassing on the V
CC
and
V
BOOST–TS
supplies due to its high speed switching (nano-
seconds) and large AC currents (Amperes). Careless
component placement and PCB trace routing may cause
excessive ringing and under/overshoot.
To obtain the optimum performance from the LTC4440-5:
A. Mount the bypass capacitors as close as possible
between the V
CC
and GND pins and the BOOST and TS
pins. The leads should be shortened as much as pos-
sible to reduce lead inductance.
B. Use a low inductance, low impedance ground plane to
reduce any ground drop and stray capacitance. Remem-
ber that the LTC4440-5 switches >2A peak currents and
any significant ground drop will degrade signal integrity.
C. Plan the power/ground routing carefully. Know where
the large load switching current is coming from and
going to. Maintain separate ground return paths for the
input pin and the output power stage.
D. Keep the copper trace between the driver output pin and
the load short and wide.
E. When using the MS8E package, be sure to solder the
exposed pad on the back side of the LTC4440-5 pack-
age to the board. Correctly soldered to a 2500mm
2
double-sided 1oz copper board, the LTC4440-5 has a
thermal resistance of approximately 40°C/W. Failure to
make good thermal contact between the exposed back
side and the copper board will result in thermal resis-
tances far greater than 40°C/W.
APPLICATIO S I FOR ATIO
WUUU
9
LTC4440-5
44405fa
LTC3722/LTC4440-5 420W 36V-60V
IN
to 12V/35A Isolated Full-Bridge Supply
TYPICAL APPLICATIO S
U
18
10
911
12V
V
IN
12
LTC3722EGN-1
PDLY OUTF OUTE
COMPSSPGNDGND
CS
V
IN
SBUS
UVLO
1µF
ADLY
330pF
MMBT3904
2.2nF
100k D12
5.1V
T3
1(1.5mH):0.5
T1
5(105µH):1:1
T2
5:5(105µH):1:1
2.49k
9.53k
10k
2.7k
470Ω
1/4W
L4
1mH
C3
68µF
20V
V
H
•
•
16
15
8
19
5
4
150Ω
0.02Ω
1.5W
30.1k
220pF
100Ω
330Ω
1.10k 909Ω
4.87k
1/4W
4.87k
1/4W
51Ω
2W
220pF
182k
20k
1/4W
220pF
4.99k
20k
180pF
68nF
220pF0.47µF
150k
SYNC PV
CC
CSE
+
LTC3901EGN
CSE
–
8
65
1
41013 7 1µF
1µF
4440 TA03
–V
OUT
V
OUT
–V
OUT
D10
10V
V
OUT
ME ME2
GND PGND GND2 PGND2 TIMER
V
CC
330pF
23
1.10k 909Ω
39.2k 100Ω1k
CSF
+
–V
OUT
V
OUT
V
OUT
–V
OUT
V
OUT
12V/35A
–V
OUT
CSF
–
11 12
MF MF2
14 15 16
22nF
Si7852DP
×4
Si7852DP
×4
Si7852DP
×2
L1
1.3µH
114
2
12V D7
D8
4
2
1
6
•
••••
••
•
10
8
7
+
1
0.22µF
Si7852DP
×2
3
6
7
824
A
D2
LTC4440-5EMS8E
BOOSTINP
TG
TSGNDGND
V
CC
12V
1
0.22µF
Si7852DP
×2
3
6
7
8
12VD
24
C
D3
D4 D5
51Ω
2W
0.47µF
100V
LTC4440-5EMS8E
BOOSTINP
TG
TSGNDGND
V
CC
12V
1µF
100V
×4
V
IN
V
IN
–V
IN
36V TO 60V 1µF
100V
17
D
OUTD
19
10Ω10Ω
C
OUTC
20
B
OUTB
21
A
OUTA
C1, C2
180µF
16V
×2
+
1µF
0.47µF, 100V TDK C3216X7R2A474M
1µF, 100V TDK C4532X7R2A105M
C1,C2: SANYO 16SP180M
C3: AVX TPSE686M020R0150
C4: MURATA DE2E3KH222MB3B
D1, D4-D6: MURS120T3
D2, D3, D7, D8: BAS21
D9: MMBZ5226B
D10: MMBZ5240B
D11: BAT54
D12: MMBZ231B
L1: SUMIDA CDEP105-1R3MC-50
L2: PULSE PA0651
L3: PA1294.910
L4: COILCRAFT DO1608C-105
Q1, Q2: ZETEX FMMT619
Q3, Q4: ZETEX FMMT718
T1, T2: PULSE PA0526
T3: PULSE PA0785
6
3
422236
33k
57
D11
8.25k
I
SNS
5V
REF
I
SNS
0.1µF
58
1
21
MOC207
C4
2.2nF
250V
0.047µF3
65
8
GND-F
V
+
GND-S
COLL REF
LT1431CS8
1.1k
22Ω
200k
750Ω
100Ω
D9 3.3V
0.02Ω
1.5W
V
H
D1
D6
13k
1/2W
0.47µF
100V
820pF
200V
L3
0.85µH
15Ω
1W
0.47µF
100V
Si7852DP
×2
12VB
Q1
Q3
Q2
Q4
11
10
8
7
MMBT3904
FBSPRG R
LEB
10k
13
SYNC
5.1k
1
NC
8
DPRG
2
V
REF
5V
REF
14
C
T
24
L2
150nH
•
10
LTC4440-5
44405fa
LTC3723-1 240W 42-56V
IN
to 12V/20A Isolated 1/4Brick (2.3" × 1.45")
TYPICAL APPLICATIO S
U
5
46
AB
12V
V
IN
15
LTC3723EGN-1
DRVB SDRB SDRA
COMP
CS
V
CC
UVLO
9
150k
1
0.47µF
1µF
DRVA
DPRG V
REF
SPRGGND SSFB C
T
330pF
22nF
100k D8
10V
68nF
270pF
T2
1(1.5mH):0.5
T1
4T:6T(65µHMIN):6T:2T:2T
243k
2.49k
9.53k
10k
750Ω
1k
100Ω
1/4W
813
3
Si7370DP
×2
L4
1mH
C3
68µF
20V
V
F
D2
•
•
3
2
8
19
5
4
16
10k
33k
200Ω
1/4W
R1
0.03Ω
1.5W
66.5k
RLEB
12
714
220pF
22nF
100Ω
665Ω
1k 866Ω
6.19k
1/4W
1.5nF
464k
30k
1/4W
SYNC PV
CC
CSF
+
V
F
LTC3901EGN
CSF
–
8
11 12
1
41013 7
22nF
1µF
4.7µF
4440 TA05
–V
OUT
V
OUT
–V
OUT
D7
10V
V
OUT
MF MF2
GND PGND GND2 PGND2 TIMER
V
CC
470pF
14 15
1k 866Ω
42.2k 1k
100Ω
6.19k
1/4W
CSE
+
V
E
–V
OUT
V
OUT
V
F
V
OUT
12V/20A
–V
OUT
CSE
–
65
ME ME2
23 16
Si7370DP
×2
Si7852DPSi7852DP
L5
0.56µH
112
4
12V D5
D6
3
5
1
6
•
••
•
•
9
7
V
E
+
0.1µF
Si7852DP
1
6
5
4
B
2
A
D3
LTC4440-5ES6
BOOSTINP
TG
TSGND
V
CC
12V
3
0.1µF
Si7852DP
1
6
5
42
B
D4
LTC4440-5ES6
BOOSTINP
TG
TSGND
V
CC
12V
1µF
100V
×3
V
IN
V
IN
–V
IN
42V TO 56V 1µF
100V
C1, C2
47µF
16V
×2
+
1µF
1µF
100V
1k
1/4W
1µF, 100V TDK C3225X7R2A105M
C1,C2: SANYO 16TQC47M
C3: AVX TPSE686M020R0150
C4: MURATA GHM3045X7R222K-GC
D2: DIODES INC. ES1B
D3-D6: BAS21
D7, D8: MMBZ5240B
L4: COILCRAFT DO1608C-105
L5: COILCRAFT DO1813P-561HC
L6: PULSE PA1294.132 OR
PANASONIC ETQP1H1R0BFA
R1, R2: IRC LRC2512-R03G
T1: PULSE PA0805.004
T2: PULSE PA0785
6
10
I
SNS
I
SNS
0.1µF
11
58
1
21
MOC207
C4
2.2nF
250V
0.1µF3
65
8
GND-F
V
+
GND-S
COLL REF
LT1431CS8
A
1.5k
22Ω
4.7Ω
4.7Ω
R2
0.03Ω
1.5W
V
E
470pF
100V
L6
1.25µH
10Ω
1W
6
93
EFFICIENCY (%)
94
95
96
97
81012
LOAD CURRENT (A)
14 16 18 20
42V
IN
48V
IN
56V
IN
MMBT3904
•
11
LTC4440-5
44405fa
PACKAGE DESCRIPTION
U
MS8E Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1662)
MSOP (MS8E) 0603
0.53 ± 0.152
(.021 ± .006)
SEATING
PLANE
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
0.18
(.007)
0.254
(.010)
1.10
(.043)
MAX
0.22 – 0.38
(.009 – .015)
TYP
0.127 ± 0.076
(.005 ± .003)
0.86
(.034)
REF
0.65
(.0256)
BSC
0° – 6° TYP
DETAIL “A”
DETAIL “A”
GAUGE
PLANE
12
34
4.90 ± 0.152
(.193 ± .006)
8
8
1
BOTTOM VIEW OF
EXPOSED PAD OPTION
765
3.00 ± 0.102
(.118 ± .004)
(NOTE 3)
3.00 ± 0.102
(.118 ± .004)
(NOTE 4)
0.52
(.0205)
REF 1.83 ± 0.102
(.072 ± .004)
2.06 ± 0.102
(.081 ± .004)
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
2.083 ± 0.102
(.082 ± .004)
2.794 ± 0.102
(.110 ± .004)
0.889 ± 0.127
(.035 ± .005)
RECOMMENDED SOLDER PAD LAYOUT
0.42 ± 0.038
(.0165 ± .0015)
TYP
0.65
(.0256)
BSC
1.50 – 1.75
(NOTE 4)
2.80 BSC
0.30 – 0.45
6 PLCS (NOTE 3)
DATUM ‘A’
0.09 – 0.20
(NOTE 3)
S6 TSOT-23 0302 REV B
2.90 BSC
(NOTE 4)
0.95 BSC
1.90 BSC
0.80 – 0.90
1.00 MAX 0.01 – 0.10
0.20 BSC
0.30 – 0.50 REF
PIN ONE ID
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
3.85 MAX
0.62
MAX
0.95
REF
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
1.4 MIN
2.62 REF
1.22 REF
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 represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
S6 Package
6-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1636)
12
LTC4440-5
44405fa
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2005
LT 1205 REV A • PRINTED IN USA
RELATED PARTS
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= 200µs, t
OFF
= 28µs
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IN
≤ 13.2V
LT1952 Single Switch Synchronous Forward Controller 25W to 500W DC/DC Controller
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Architecture, 16-Pin Exposed Pad TSSOP Package
LTC3705 Family Isolated Power Supply Chipset Primary and Secondary Side Controllers; Simple as Buck Circuit;
Polyphase® Operation
LTC3722-1/ Synchronous Dual Mode Phase Modulated Full-Bridge Adaptive Zero Voltage Switching, High Output Power Levels
LTC3722-2 Controllers (Up to Kilowatts)
LTC3723-1/ Synchronous Push-Pull PWM Controllers Current Mode or Voltage Mode Push-Pull Controllers
LTC3723-2
LT3781/LTC1698 36V to 72V Input Isolated DC/DC Converter Chip Set Synchronous Rectification; Overcurrent, Overvoltage, UVLO Protection;
Power Good Output Signal; Voltage Margining; Compact Solution
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Second Output Synchronous Driver Controller
LTC3900 Synchronous Rectifier Driver for Forward Converters Programmable Time Out, Reverse Inductor Current Sense
LTC3901 Secondary Side Synchronous Driver for Push-Pull and Programmable Time Out, Reverse Inductor Current Sense
Full-Bridge Converters
LTC4440 High Speed, High Voltage, High Side Gate Driver High Side Source up to 100V, 8V to 15V Gate Drive Supply,
Undervoltage Lockout, 6-Lead ThinSOT or 8-Lead Exposed MSOP Package
LTC4441 6A MOSFET Driver Adjustable Gate Drive from 5V to 8V, 5V ≤ V
IN
≤ 28V
PolyPhase is a registered trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
U
240W 42V-56VIN to Unregulated 12V Half-Bridge Converter
5
46
A
B
11V12VVIN
MMBT3904
15
LTC3723EGN-2
DRVB SDRB
SDRA
COMP
VCC
UVLO
12
62k
330pF
12V
MMBZ5242B
150pF
1
0.47µF
1µF
DRVA
DPRG VREF RAMP SPRG GND SSCS FBCT
470pF 0.47µF4.7k
0.22µF
2N7002
BCS+
T3
1(1.5mH):0.5
T1
5:4:4:2:2
1µF8913
1k
22Ω0.1µF
C1
2.2nF
250V
1µF
100V
1µF
100V
1µF
100V
1µF
100V
0.22µF
Si7370DP
×2
Si7852DP
×2
1
6
5
42
3
A
Si7370DP
×2
1500pF
100V
L2 0.22µH
L3
1mH
C3
68µF
VF
•
•
11
3
2
8
19
5
4
16
10k
120Ω
30.1k
7 10 14
7.5Ω
D4 D5
7.5Ω
220pF
100Ω
10k 3k
4.7k
1/4W
100pF
215k
15k
1/4W SYNC PVCC
CSF+
VF
LTC3901EGN
CSF–
8
11 12
1
41013 7 1µF
1µF
4440 TA04
–VOUT
10V
MMBZ5240B
1k
VOUT
MF MF2
GND PGND GND2 PGND2 TIMER
VCC
330pF
14 15
10k 3k
33.2k 100Ω
4.7k
1/4W
CSE+
VE
20Ω 1W
–VOUT
VOUT
VOUT
–VOUT
CSE–
65
ME ME2
23 16
MMBT3904
Si7852DP
×2
L1
0.56µH
72
4
CS+
T2
70(980µH):1
8
7
1
3
12V D2
D1
D3
3
5
1
6
•
••
•
•
•
•
9
11
VE
+
LTC4440-5ES6
BOOSTINP
TG
TSGND
VCC
11V
1µF
100V
VIN
VIN
–VIN
48VIN 1µF
100V
C2
180µF
16V
+
1µF
1µF, 100V TDK C4532X7R2A105M
C1: MURATA DE2E3KH222MB3B
C2: SANYO 16SP180M
C3: AVX TPSE686M020R0150
D1-D3: BAS21
D4, D5: MMBD914
L1: COILCRAFT DO1813P-561HC
L2: SUMIDA CDEP105-0R2NC-50
L3: COILCRAFT DO1608C-105
T1: PULSE PA0801.005
T2: PULSE P8207
T3: PULSE PA0785
