UG534 Datasheet, PDF (73/96 Pages) –

Detailed Description
X-Ref Target - Figure 1-31
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 1-31 shows 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 mΩcurrent
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 ^{2m ±1%}
R1
R2
K1 K2
11.5k ±0.5%
499 ±0.5%
100nF
~0.5V
~470
IN+
IN-
V+ INA213
SC70-6
REF
Package
50V/V
~470
OUT
10nF
GND
10nF
Figure 1-31: ML605 12V Power Monitor
1k
10nF
1k
1k
10nF
1k
V_AUXP[13]
Current Channel
V_AUXN[13]
V_AUXP[12]
Voltage Channel
V_AUXN[12]
UG534_38 _081209
ML605 Hardware User Guide
www.xilinx.com
73
UG534 (v1.8) October 2, 2012