MAX5974D集成电路（IC）的PMIC-稳压器-DCDC开关式控制器规格书PDF中文资料

MAX5974D属于集成电路（IC）的PMIC-稳压器-DCDC开关式控制器。由亚德诺半导体技术有限公司制造生产的MAX5974DDC-DC 开关控制器PMIC（电源管理集成电路）DC 到 DC 开关式控制器是用于高效率电路的稳压 IC，其配置为生成高于（突升或步升）或低于（突降或步降）输入电源的输出电源电压。其他拓扑结构可能包括：降压-升压、反激、正激、Cuk、SEPIC、全桥、半桥和推挽式。这些器件不同于需要最小电压并“烧尽”多余电压的线性稳压器。

FEATURES

► IEEE 802.3bt Powered Device (PD) Controller

► 400kHz I2C Interface

► Continuous Voltage, Current, and Power Telemetry

► Dedicated 14-Bit Delta-Sigma Current and Voltage ADCs

► Automatic Maintain Power Signature (MPS)

► Supports Up to 90W PDs with Extended Power

► 5-Event Classification Sensing with PSE Allocated Power Readback

► Seamless Switchover between Dual PD or PD/AUX Inputs

► Superior Surge Robustness (100V Absolute Maximum)

► Wide Junction Temperature Range (-40⁰C to 125⁰C)

► External Hot Swap N-Channel MOSFET for Lowest Power Dissipation

and Highest System Efficiency

► 50mΩ Current Sense Resistor

► Auxiliary Input Sense with Standby Modes

► 20-Pin 5mm x 5mm QFN Package

APPLICATIONS

► IEEE 802.3bt PDs with Power Telemetry

► Wireless Access Points/Pico Cells

► Internet Protocol (IP) Security Cameras

► Power over Ethernet (PoE) Lighting

DESCRIPTION

The LTC9105 is an IEEE 802.3af/at/bt (PoE 2) Power over

Ethernet (PoE) powered device (PD) controller with input current,

voltage, and power telemetry. The LTC9105 includes an I2C interface

to read telemetry, power sourcing equipment (PSE) allocated

power, and auxiliary input status, and to write power input priority.

The LTC9105 also features a configurable downstream power-up

disable with under-power indication when the PSE allocated power

is less than the PD requested power.

The LTC9105 utilizes an external, low RDS(ON), N-Channel, Hot

Swap MOSFET, and a 50mΩ current sense resistor, and supports

the LT4321 ideal bridge to extend the end-to-end power delivery efficiency.

Also included are a power good output, external signature

resistor, resistor programmable classification and pin-configurable

PD requested Class. The presence of an auxiliary power supply

is sensed at the AUX pin and reported through the I2C interface.

Automatic maintain power signature (MPS) circuitry keeps the PD

interface powered when downstream current draw falls below an

internal MPS threshold.

Two dedicated Delta-Sigma ADCs continuously measure PD controller

input voltage and current with a typical conversion time

of 100ms and with 14-bit resolution. Simultaneous conversion of

current and voltage measurements enables high-accuracy power

calculations.