LTC3810-5
60V Current Mode
Synchronous Switching
Regulator Controller
FeaTures
DescripTion
The LTC®3810-5 is a synchronous step-down switching
regulator controller that can directly step-down voltages
from up to 60V, making it ideal for telecom and automo-
tive applications. The LTC3810-5 uses a constant on-time
valley current control architecture to deliver very low duty
cycles with accurate cycle-by-cycle current limit, without
requiring a sense resistor.
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High Voltage Operation: Up to 60V
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Large 1Ω Gate Drivers
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No Current Sense Resistor Required
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Dual N-Channel MOSFET Synchronous Drive
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Extremely Fast Transient Response
0.5% 0.8V Voltage Reference
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Programmable Output Voltage Tracking/Soft-Start
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Generates 5.5V Driver Supply from Input Supply
A precise internal reference provides 0.5% DC accuracy. A
highbandwidth(25MHz)erroramplifierprovidesveryfast
line and load transient response. Large 1Ω gate drivers
allow the LTC3810-5 to drive multiple MOSFETs for higher
current applications. The operating frequency is selected
by an external resistor and is compensated for variations
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Synchronizable to External Clock
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Selectable Pulse Skip Mode Operation
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Power Good Output Voltage Monitor
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Adjustable On-Time/Frequency: t
< 100ns
ON(MIN)
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Adjustable Cycle-by-Cycle Current Limit
Programmable Undervoltage Lockout
Output Overvoltage Protection
in V and can also be synchronized to an external clock
IN
for switching-noise sensitive applications. A shutdown
pin allows the LTC3810-5 to be turned off, reducing the
supply current to 240µA.
5mm × 5mm QFN Package
applicaTions
Integrated bias control generates gate drive power from
the input supply during start-up or when an output short-
circuit occurs, with the addition of a small external SOT23
MOSFET. When in regulation, power is derived from the
output for higher efficiency.
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48V Telecom and Base Station Power Supplies
Networking Equipment, Servers
Automotive and Industrial Control Systems
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L, LT, LTC, LTM, Linear Technology, the Linear logo and No R
are registered trademarks
SENSE
of Linear Technology Corporation. All other trademarks are the property of their respective
owners. Protected by U.S. Patents including 5481178, 5847554, 6304066, 6476589, 6580258,
6677210, 6774611.
Typical applicaTion
High Efficiency High Voltage Step-Down Converter
Efficiency vs Load Current
V
100
IN
13V TO 60V
+
274k
100k
22µF
V
V
= 24V
= 42V
IN
IN
I
ON
NDRV
ZXMN10A07F
95
90
85
PGOOD
BOOST
LTC3810-5
V
RNG
Si7450DP
TG
10µH
0.1µF
V
MODE/SYNC
SS/TRACK
SHDN
OUT
SW
1000pF
12V/6A
EXTV
DRV
INTV
CC
CC
14k
CC
+
+
0
2
3
4
5
6
270µF
1
MBR1100
SENSE
I
TH
LOAD CURRENT (A)
47pF
5pF
200k
Si7450DP
BG
38105 TA01b
V
FB
–
SENSE
BGRTN
SGND
1µF
1k
38105 TA01
38105fd
1