LTC3810-5 Datasheet, PDF (1/36 Pages) Linear Technology – 60V Current Mode Synchronous Switching Regulator Controller

FEATURES
n _{High Voltage Operation: Up to 60V}
n _{Large 1Ω Gate Drivers}
n _{No Current Sense Resistor Required}
n _{Dual N-Channel MOSFET Synchronous Drive}
n _{Extremely Fast Transient Response}
n _{±0.5% 0.8V Voltage Reference}
n _{Programmable Output Voltage Tracking/Soft-Start}
n _{Generates 5.5V Driver Supply from Input Supply}
n _{Synchronizable to External Clock}
n _{Selectable Pulse Skip Mode Operation}
n _{Power Good Output Voltage Monitor}
n _{Adjustable On-Time/Frequency: tON(MIN) < 100ns}
n _{Adjustable Cycle-by-Cycle Current Limit}
n _{Programmable Undervoltage Lockout}
n _{Output Overvoltage Protection}
n _{Thermally Enhanced 32-Pin QFN Package}
APPLICATIONS
n _{48V Telecom and Base Station Power Supplies}
n _{Networking Equipment, Servers}
n _{Automotive and Industrial Control Systems}
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including 5481178, 5847554, 6304066, 6476589, 6580258, 6677210, 6774611.
LTC3810-5
60V Current Mode
Synchronous Switching
Regulator Controller
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.
A precise internal reference provides 0.5% DC accuracy. A
high bandwidth (25MHz) error amplifier provides very fast
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
in V_IN and can also be synchronized to an external clock
for switching-noise sensitive applications. A shutdown
pin allows the LTC3810-5 to be turned off, reducing the
supply current to 240μA.
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.
TYPICAL APPLICATION
High Efficiency High Voltage Step-Down Converter
274k
I_ON
NDRV
V_IN
+
13V TO 60V
100k
22μF
ZXMN10A07F
1000pF
5pF
200k
47pF
PGOOD
BOOST
LTC3810-5
V_RNG
TG
MODE/SYNC
SW
SS/TRACK
SHDN
EXTV_CC
DRV_CC
INTV_CC
I_TH
SENSE⁺
BG
V_FB
SENSE^–
SGND BGRTN
0.1μF
1μF
Si7450DP
10μH
Si7450DP
MBR1100
14k
+
1k
V_OUT
12V/6A
270μF
38105 TA01
Efficiency vs Load Current
100
V_IN = 24V
95
V_IN = 42V
90
85
0
1
2
3
4
LOAD CURRENT (A)
56
38105 TA01b
38105fc
1