LTC3832_15 Datasheet, PDF (1/24 Pages) Linear Technology – High Power Step-Down Synchronous DC/DC Controllers for Low Voltage Operation

LTC3832/LTC3832-1
High Power Step-Down
Synchronous DC/DC Controllers
for Low Voltage Operation
FEATURES
s _{VOUT as Low as 0.6V}
s _{High Power Switching Regulator Controller}
for 3.3V-5V to 0.6V-3.xV Step-Down Applications
s _{No Current Sense Resistor Required}
s _{Low Input Supply Voltage Range: 3V to 8V}
s _{Maximum Duty Cycle > 91% Over Temperature}
s _{All N-Channel External MOSFETs}
s _{Excellent Output Regulation: ±1% Over Line, Load}
and Temperature Variations
s _{High Efficiency: Over 95% Possible}
s _{Adjustable or Fixed 2.5V Output (LTC3832)}
s _{Programmable Fixed Frequency Operation: 100kHz to}
500kHz
s _{External Clock Synchronization}
s _Soft-Start
s _{Low Shutdown Current: <10µA}
s _{Overtemperature Protection}
s _{Available in SO-8 and SSOP-16 Packages}
U
APPLICATIO S
s _{CPU Power Supplies}
s _{Multiple Logic Supply Generator}
s _{Distributed Power Applications}
s _{High Efficiency Power Conversion}
DESCRIPTIO
The LTC^®3832/LTC3832-1 are high power, high effi-
ciency switching regulator controllers optimized for
3.3V-5V to 0.6V-3.xV step-down applications. A preci-
sion internal reference and feedback system provide
±1% output regulation over temperature, load current
and line voltage variations. The LTC3832/LTC3832-1 use
a synchronous switching architecture with N-channel
MOSFETs. Additionally, the chip senses output current
through the drain-source resistance of the upper
N-channel MOSFET, providing an adjustable current limit
without a current sense resistor.
The LTC3832/LTC3832-1 operate with an input supply
voltage as low as 3V and with a maximum duty cycle of
>91% over temperature. They include a fixed frequency
PWM oscillator for low output ripple operation. The 300kHz
free-running clock frequency can be externally adjusted or
synchronized with an external signal from 100kHz to 500kHz.
In shutdown mode, the LTC3832 supply current drops to
<10µA. The LTC3832-1 is the SO-8 version without current
limit, frequency adjustment and shutdown functions.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
4.7µF
0.1µF
0.01µF
LTC3832-1
SS V_CC/PV_CC2
COMP
G1
15k
6.49k
GND PV_CC1
FB
G2
5.1Ω
V_IN
3V TO 7V
+
MBR0520T1
0.1µF
Si9426DY _L1
3.2µH
Si9426DY
+
4.32k
680pF
L1: SUMIDA CDEP105-3R2MC-88
C_OUT: PANASONIC EEFUEOD271R
V_OUT
1V
9A
C_OUT
270µF
2V
3832 F01
Figure 1. High Efficiency 3.3V to 1V Power Converter
Efficiency
100
90
V_OUT = 2.5V
80
V_OUT = 1V
70
60
50
V_IN = 3.3V
40
0 1 2 3 4 5 6 7 8 9 10
LOAD CURRENT (A)
3832 F01b
sn3832 3832fs
1