LTC7103-1
105V, 2.3A Low EMI
Synchronous Step-Down Regulator
with Fast Current Programming
DESCRIPTION
FEATURES
The LTC®7103-1 is a high efficiency, monolithic synchro-
nous step-down DC/DC converter utilizing a constant
frequency, average current mode control architecture. It
operates from an input voltage range of 4.4V to 105V and
provides an adjustable regulated output voltage from 1V
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Wide V Range: 4.4V to 105V (110V Abs Max)
Ultralow EMI/EMC Emissions: CISPR 25 Compliant
IN
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2µA I When Regulating 48V to 3.3V
Q
IN
OUT
Fast and Accurate Output Current Programming and
Monitoring with No External R
Brick Wall Current Limit
SENSE
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to V while delivering up to 2.3A of output current.
IN
Low Minimum On-Time: 40ns
The LTC7103-1 features high frequency operation and a
low minimum on-time that reduce inductor size and enable
constant-frequency operation even at very high step-down
ratios. In addition, the LTC7103-1 achieves the lowest
possible dropout voltage with 100% maximum duty cycle
operation. During light load operation, converter efficiency
and output ripple can be optimized by selecting Burst
Mode, pulse-skipping or forced continuous operation.
Wide V
Range: 1V to V
OUT
IN
PassThru™/100% Duty Cycle Capable
Programmable Fixed Frequency: 200kHz to 2MHz
Eight, Pin-Selectable Fixed (1.2V to 15V) or
Adjustable Output Voltages
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Selectable Continuous, Pulse-Skipping, or Low
Ripple Burst Mode® Operation at Light Loads
PLL Synchronization to External Clock
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The LTC7103-1 includes accurate, high speed average
current programming and monitoring without the need
for an external sense resistor. Additional features include
a bypass LDO to maximize efficiency, fixed or adjustable
output voltage and loop compensation, and a wide array
of protection features to enhance reliability.
EXTV LDO Powers Chip from V
= 3.3V to 40V
CC
OUT
OPTI-LOOP® or Fixed Internal Compensation
Input and Output Overvoltage Protection
Thermally Enhanced (5mm × 6mm) QFN Package
AEC-Q100 Qualification in Process
APPLICATIONS
Compared to the LTC7103, the LTC7103-1 is pin com-
patible, except that it also offers continuous inductor
current mode.
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Battery Chargers and CC/CV Supplies
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Automotive and Military Systems
Industrial, Avionics and Heavy Equipment
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All registered trademarks and trademarks are the property of their respective owners.
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Medical Instruments and Telecommunication
TYPICAL APPLICATION
Efficiency vs Load Current
5V to 105V Input to 5V, 2.3A Output Step-Down Regulator
100
V
= 5V
OUT
95
90
85
80
75
70
65
60
55
50
V
IN
V
BOOST
IN
5V TO 105V
0.1µF
4.7µF
18µH
V
LTC7103-1
OUT
5V
RUN
SW
2.3A
I
V
FB
CTRL
OVLO
EXTV
100µF
CC
CURRENT
MONITOR
I
V
PRG2
MON
f
= 300kHz
SW
FIGURE 14 CIRCUIT
PLLIN/MODE
FREQ
I
TH
V
V
V
V
= 12V
= 24V
= 48V
= 72V
IN
IN
IN
IN
INTV
CC
SGND
PGND
1µF
71031 TA01a
0.1
1
10
100
1000
LOAD CURRENT (mA)
71031 TA01b
Rev. 0
1
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