LTC3713 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
LTC3713
Linear Technology
'LTC3713' PDF : 24 Pages View PDF
LTC3713
Low Input Voltage,
High Power, No RSENSETM
Synchronous Buck DC/DC Controller
FEATURES
s Very Low VIN(MIN): 1.5V
s True Current Mode Control
s 5V Drive for N-Channel MOSFETs Eliminates
Auxillary 5V Supply
s No Sense Resistor Required
s Uses Standard 5V Logic-Level N-Channel MOSFETs
s Adjustable Current Limit
s Adjustable Frequency
s Switch tON(MIN) < 100ns
s 2% to 90% Duty Cycle at 200kHz
s 0.8V ±1% Reference
s Power Good Output Voltage Monitor
s Programmable Soft-Start
s Output Overvoltage Protection
s Optional Short-Circuit Shutdown Timer
s Small 24-Lead SSOP Package
U
APPLICATIO S
s Telecom Card 3.3V, 2.5V, 1.8V Step-Down
s Bus Termination (DDR memory, SSTL)
s Synchronous Buck with General Purpose Boost
s Low VIN Synchronous Boost
DESCRIPTIO
The LTC®3713 is a high current, high efficiency synchro-
nous buck switching regulator controller optimized for
use with very low input supply voltages. It operates from
inputs as low as 1.5V and provides a regulated output
voltage from 0.8V up to (0.9)VIN. The controller uses
a valley current control architecture to enable high operat-
ing frequencies without requiring a sense resistor.
Operating frequency is selected by an external resistor and
is compensated for variations in VIN and VOUT. The LTC3713
uses a pair of standard 5V logic-level N-channel external
MOSFETs, eliminating the need for expensive P-channel
or low threshold devices.
Discontinuous mode operation provides high efficiency
operation at light loads. A forced continuous control
pin reduces noise and RF interference, and can assist
secondary winding regulation by disabling discontinuous
operation when the main output is lightly loaded. Fault
protection is provided by internal foldback current limit-
ing, an output overvoltage comparator and an optional
short-circuit shutdown timer.
, LTC and LT are registered trademarks of Linear Technology Corporation.
No RSENSE is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
330k
5.6k
10k
680pF
20k
0.1µF
SHDN BOOST
ION
TG
LTC3713
VFB1
SW1
SENSE+
BG
ITH
PGND
SENSE–
RUN/SS INTVCC
PGOOD
VIN1
SGND
VIN2
12.1k
VFB2
SW2
CMDSH-3
0.33µF
M1
M2
10µF
22µF
×2
VIN
1.8V TO 3.3V
L1
1.8µH
+
B340A
COUT
270µF
×2
VOUT
1.25V
10A
4.7µF
37.4k
3713 F01a
MBR0520
4.7µH
COUT: PANASONIC EEFUEOD271R
L1: (A) PANASONIC ETQP6FIR8BFA
(B) TOKO D104C-1.8µH
M1, M2: (A) IRF7822, (B) IRF7811A
Figure 1. High Efficiency Step-Down Converter from 1.8V to 3.3V Input
Efficiency vs Load Current
100
VIN = 2.5V
90
A
80
B
70
60
50
40
30
20
10
0
0.01 0.04 0.10 0.40 1 3 7
LOAD CURRENT (A)
12 15
3713 F01b
3713fa
1
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