Datasheet LTC3830, LTC3830-1 (Analog Devices)

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