Linear LTC2978八路PMBus接口电源监视方案

Linear 公司的LTC2978是八路PMBus兼容的电源监视器,管理器,顺序器和余量控制器,能监视8个输出通路和一个输入通路.它的PMBus功能包括告警和OV/UV阈值对故障响应.LTC2978具有可配置的EEPROM,可编程的看门狗定时器,有8个UV/OV电压管理器,8路顺序器,支持多路故障管理和片上数字温度传感器,可用在计算机和网络服务器.本文介绍了LTC2978主要特性,方框图以及典型应用电路,包括PMBus接口的八路电源控制框图, 用于供电和通信的LTC软件狗连接图, DC/DC转换器应用电路和给3.3V芯片供电的应用电路图.

The LTC2978 is an octal, PMBus compliant power supply monitor, supervisor, sequencer and margin controller. PMBus functions include warning and fault OV/UV threshold pairs for eight output channels and one input channel. Programmable fault response allows the power supplies to be disabled with optional retry after a fault has been detected. PMBus reads allow eight output voltages and one input voltage to be monitored. In addition, odd numbered channels can substitute sense resistor voltage measurements for output voltage measurements. PMBus commands support power supply sequencing and precisionpoint-of-load voltage servo to one of three programmed values: margin high, margin low and nominal. A programmable watchdog timer monitors microprocessor activity for a stalled condition and resets the micro if necessary.

The 1-wire synchronization bus supports power supply sequencing across multiple LTC2978 devices. User programmable parameters can be stored in EEPROM. Voltage supervisor, voltage monitor and temperature faults can also be logged to EEPROM.

LTC2978主要特性:

PMBus Compliant Interface and Command Set

Configuration EEPROM

Fault Logging to Internal EEPROM

Differential Input, 15-Bit ADC with Less Than 0.25% of Total Unadjusted Error

Monitors Eight Output Channels and One Input Voltage

8-Channel Sequencer

Programmable Watchdog Timer

Eight UV/OV Voltage Supervisors

Eight 10-Bit Voltage-Buffered IDACs with Soft Connect

Linear, Voltage Servo Adjusts Supply Voltages by Ramping Voltage-Buffered IDAC Outputs Up/Down

Supports Multichannel Fault Management

On-Chip Digital Temperature Sensor

Available in 64-Pin 9mmx9mm QFN Package

LTC2978应用:

Computers

Network Servers



图1. LTC2978方框图


图2. PMBus接口的八路电源控制框图


图2.用于供电和通信的LTC软件狗连接图

图3.LTC2978 VSENSE线路抗混淆滤波器

图4.带外接反馈电阻的DC/DC转换器应用电路


图5.带调整引脚的DC/DC转换器应用电路

图6.给3.3V芯片供电的LTC2978应用电路