LTC3813
100V Current Mode
Synchronous Step-Up Controller
FEATURES
DESCRIPTION
n
High Output Voltages: Up to 100V
TheLTC3813isasynchronousstep-upswitchingregulator
controller that can generate output voltages up to 100V.
TheLTC3813usesaconstantoff-timepeakcurrentcontrol
architecture with accurate cycle-by-cycle current limit,
without requiring a sense resistor.
n
Large 1Ω Gate Drivers
n
No Current Sense Resistor Required
n
Dual N-Channel MOSFET Synchronous Drive
0.ꢀ5 0.8V Voltage Reference
n
n
Fast Transient Response
Programmable Soft-Start
A precise internal reference provides 0.ꢀ5 ꢁC accuracy.
A high bandwidth (2ꢀMHz) error amplifier provides very
fastlineandloadtransientresponse.Large1Ωgatedrivers
allow the LTC3813 to drive multiple MOSFETs for higher
current applications. The operating frequency is selected
n
n
Generates 10V ꢁriver Supply from Input Supply
n
Synchronizable to External Clock
n
Power Good Output Voltage Monitor
n
Adjustable Off-Time/Frequency: t
< 100ns
OFF(MIN)
by an external resistor and is compensated for variations
n
n
n
n
Adjustable Cycle-by-Cycle Current Limit
Programmable Undervoltage Lockout
Output Overvoltage Protection
28-Pin SSOP Package
in V and can also be synchronized to an external clock
IN
forswitching-noisesensitiveapplications.Ashutdownpin
allows the LTC3813 to be turned off, reducing the supply
current to 240μA.
PARAMETER
Maximum V
LTC3813
100V
LTC3814-5
60V
APPLICATIONS
OUT
n
24V Fan Supplies
MOSFET Gate ꢁrive
6.3ꢀV to 14V
6.2V
4.ꢀV to 14V
4.2V
n
+
48V Telecom and Base Station Power Supplies
Networking Equipment, Servers
INTV UV
CC
n
–
INTV UV
6V
4V
CC
n
Automotive and Industrial Control Systems
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners. Protected by U.S. Patents,
including ꢀ481178, ꢀ847ꢀꢀ4, 6304066, 6476ꢀ89, 6ꢀ802ꢀ8, 6677210, 6774611.
TYPICAL APPLICATION
Efficiency vs Load Current
High Efficiency High Voltage Step-Up Converter
ꢀ0k
100
V
= 36V
= 24V
IN
IN
ꢀ00k
V
V
OUT
NꢁRV
BOOST
TG
I
IN
OFF
10V TO 40V
V
+
9ꢀ
90
8ꢀ
80
PGOOꢁ
10μH
22μF
V
IN
= 12V
LTC3813
V
RNG
M1
0.1μF
Si78ꢀ0ꢁP
V
SYNC
SS
OUT
SW
1000pF
ꢀ0V/ꢀA
EXTV
CC
CC
ꢁRV
INTV
SHDN
ꢁ1
MBR1100
CC
+
30.9k
499Ω
+
SENSE
I
TH
270μF
2x
M2
Si78ꢀ0ꢁP
2x
0.01μF
100pF
100k
BG
V
0
1
2
3
4
ꢀ
FB
–
SENSE
BGRTN
LOAꢁ (A)
3813 TA01b
SGNꢁ
1μF
3813 TA01
3813fb
1