LTC3830/LTC3830-1
High Power Step-Down
Synchronous DC/DC Controllers
for Low Voltage Operation
FEATURES
■ High Power Switching Regulator Controller
for 3.3V-5V to 1.xV-3.xV Step-Down Applications
■ No Current Sense Resistor Required
■ Low Input Supply Voltage Range: 3V to 8V
■ Maximum Duty Cycle > 91% Over Temperature
■ All N-Channel External MOSFETs
■ Excellent Output Regulation: ±1% Over Line, Load
and Temperature Variations
■ High Efficiency: Over 95% Possible
■ Adjustable or Fixed 3.3V Output (16-Pin Version)
■ Programmable Fixed Frequency Operation: 100kHz to
500kHz
■ External Clock Synchronization
■ Soft-Start (16-Pin Version and LTC3830-1)
■ Low Shutdown Current: <10µA
■ Overtemperature Protection
■ Available in S8, S16 and SSOP-16 Packages
U
APPLICATIO S
■ CPU Power Supplies
■ Multiple Logic Supply Generator
■ Distributed Power Applications
■ High Efficiency Power Conversion
DESCRIPTIO
The LTC®3830/LTC3830-1 are high power, high effi-
ciency switching regulator controllers optimized for
3.3V-5V to 1.xV-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 LTC3830/LTC3830-1 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 FET, providing an adjustable current limit
without a current sense resistor.
The LTC3830/LTC3830-1 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 200kHz
free-running clock frequency can be externally adjusted or
synchronized with an external signal from 100kHz to 500kHz.
In shutdown mode, the LTC3830 supply current drops to
<10µA. The LTC3830-1 differs from the LTC3830 S8 ver-
sion by replacing shutdown with a soft-start function.
For a similar, pin compatible DC/DC converter with an
output voltage as low as 0.6V, please refer to the LTC3832.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
4.7µF
0.1µF
0.01µF
15k
12.7k 1%
LTC3830-1
SS PVCC2
G1
COMP
GND PVCC1
FB
G2
5.36k 1%
VIN
3V TO 6V
5.1Ω
+ 220µF
10V
MBR0520T1
M1
Si7806DN
0.1µF
L
3.2µH
M2
Si7806DN
B320A +
3.3nF
L: SUMIDA CDEP105-3R2MC-88
COUT: PANASONIC EEFUEOD271R
1.8V
9A
COUT
270µF
2V
3830 F01
Figure 1. High Efficiency 3V-6V to 1.8V Power Converter
Efficiency and Power Loss vs Load Current
4.0
100
3.5
90
3.0
80
2.5
70
2.0
60
1.5
50
1.0
40
0.5
VIN = 3.3V 30
VOUT = 1.8V
0
20
0 1 2 3 4 5 6 7 8 9 10
LOAD CURRENT (A)
3830 TA02
3830fa
1
