LTC3819 2-Phase, High Efficiency, Step-Down Controller for Sun Server CPUs

The LTC®3819 is a 2-phase, VID programmable, synchronous step-down switching regulator controller that drives two N-channel external power MOSFET stages in a fixed frequency architecture. The 2-phase controller drives its two output stages out of phase at frequencies up to 300kHz to minimize the RMS ripple currents in both input and output capacitors. The 2-phase technique effectively multiplies the fundamental frequency by two, improving transient response while operating each channel at an optimum frequency for efficiency. Thermal design is also simplified.

An operating mode select pin (FCB) can be used to select among three modes including Burst Mode® operation for highest efficiency. An internal differential amplifier provides true remote sensing of the regulated supply’s positive and negative output terminals as required in high current applications.

The RUN/SS pin provides soft-start and optional timed, short-circuit shutdown. Current foldback limits MOSFET dissipation during short-circuit conditions when the overcurrent latchoff is disabled. OPTI-LOOP compensation allows the transient response to be optimized for a wide range of output capacitors and ESR values

产品特点 Features

Output Stages Operate Antiphase Reducing Input and Output Capacitance Requirements and Power Supply Induced Noise
Dual Input Supply Capability for Load Sharing
5-Bit SUN CPU VID Code:
VOUT = 1.025V to 1.4125V
±1% Output Voltage Accuracy
True Remote Sensing Differential Amplifier
Power Good Output Voltage Monitor
Supports Active Voltage Positioning
Current Mode Control Ensures Current Sharing
OPTI-LOOP® Compensation Minimizes COUT
Three Operational Modes: PWM, Burst and Cycle Skip
Programmable Fixed Frequency: 150kHz to 300kHz
Wide VIN Range: 4V to 36V Operation
Adjustable Soft-Start Current Ramping
Internal Current Foldback and Short-Circuit Shutdown
Overvoltage Soft Latch Eliminates Nuisance Trips
Available in 36-Lead Narrow (0.209) SSOP Package

应用

Sun™ Server CPU Supply

典型应用图

参数

LTC3819 订购信息和价格参考Package Variations and Pricing

器件型号	封装	引脚	温度	价格 (以 1 ~ 99 片为批量)	价格 (以 1000 片为批量) *
LTC3819EG	SSOP	36	E	$5.15	$4.35
LTC3819EG#PBF	SSOP	36	E	$5.15	$4.35
LTC3819EG#TR	SSOP	36	E		$4.45
LTC3819EG#TRPBF	SSOP	36	E		$4.45

LTC3819 数据手册及相关资料下载

数据手册(英文) : LTC3819 - 2-Phase, High Efficiency, Step-Down Controller for Sun Server CPUs.PDF
可靠性数据 : R384 Reliability Data .PDF