Xilinx ML605 manual 12V Supply Monitor

Models: ML605

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Chapter 1: ML605 Evaluation Board

ML605 Board Power Monitor

In addition to monitoring the FPGA core supply power consumption, two auxiliary analog input channels (of the 16 that are available) are used to implement a power monitor for the entire ML605 board. The board power is monitored at the 12V power input connector.

Figure 1-31shows how the power monitor is implemented and connected to the System Monitor auxiliary input channels 12 and 13. A simple resistor divider is used to monitor the 12V supply voltage and to provide a reference voltage to an instrumentation amplifier (InAmp). The voltage on the auxiliary channel 12 is equal to supply voltage divided by 24 (~ 0.5V).

The InAmp is used to amplify (by a factor of 50) the voltage dropped across a 2 milliohm current sense shunt. The voltage at the output of the InAmp is proportional to the current. The voltage on auxiliary channel 13 = Current (amps) x 0.002 x 50. (e.g., 5A = 0.5V).

12V Supply Monitor

2mΩ ±1%

R1

R2

 

K1 K2

 

100nF

 

IN+

IN-

 

 

 

 

 

 

 

11.5kΩ ±0.5%

~0.5V

V+

INA213

OUT ~470Ω

 

 

 

 

 

SC70-6

1kΩ

 

 

 

 

 

 

 

 

REF

Package

 

 

499Ω ±0.5%

 

 

 

50V/V

 

10nF

 

 

 

 

 

10nF

 

 

 

 

 

 

 

 

 

 

GND

 

 

 

 

 

 

 

 

1kΩ

 

~470Ω

 

 

 

10nF

1kΩ

 

 

 

 

 

 

10nF

1kΩ

Figure 1-31:ML605 12V Power Monitor

VAUXP[13]

Current Channel

VAUXN[13]

VAUXP[12]

Voltage Channel

VAUXN[12]

UG534_38 _081209

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ML605 Hardware User Guide

 

 

UG534 (v1.2.1) January 21, 2010

Page 70
Image 70
Xilinx ML605 manual 12V Supply Monitor