2 Hardware Speci
fi
cation
2.1 Power Consumption
The power consumption of the Level Shifter Board depends on its con
fi
guration. The
board will draw approximately 6 mA from the Adapter/Analyzer side when con
fi
gured to
power the target device, and approximately 4 mA when the target is supplying its own
power.
The current draw of the Level Shifter Board on the Target side is only applicable when
the target device is supplying power to the board. This current draw will be approximately
1 mA.
2.2 Speed
The Level Shifter Board is rated for I C communication at up to 800 kHz.
Maximum SPI and MDIO signaling rates are highly dependent on the speci
fi
c
con
fi
guration of the level shifting board and the timing speci
fi
cation of the target device.
The Level Shifter Board has been tested to operate at up to 18 MHz when shifting to
1.2 V, and up to 20 MHz when shifting to 3.3 V. When operating at higher speeds,
shorter cables are recommended to help maintain signal integrity.
Please note that individual results will vary.
2.3 I C Pull-up Resistors
The Adapter/Analyzer side will always require pull-up resistors for I C communication.
This is easily accomplished by using the built-in pull-up resistors of either an Aardvark I
C/SPI Host Adapter or Beagle I C/SPI/MDIO Protocol Analyzer. Additionally, any I C line
that is being used as a digital input line (GPIO) to the Adapter/Analyzer side, must also
include a pull-up on the adapter side.
It is recommended that pull-up resistors are always used on the Target side I C lines.
Users may
fi
nd that they can still communicate properly without these pull-ups; however,
Level Shifter Board User Manual v1.01
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