6
The I²C pins may be used as open-drain IO pins controlled by the DLL, if not used for I2C
functionality.
GPIO
– the USB-to-I2C hardware has one general purpose input and one general purpose
input.
IN
pin operates as an input with the following characteristics:
INPUT PORT CHARACTERISTICS
Vil low level input voltage
0.3*VDD = 0.99V
Vih high level input voltage
0.7*VDD = 2.31V
Note that the microcontroller is a 3.3V device but this input is 5V tolerant.
The
OUT
pin has the following characteristics:
OUTPUT PORT CHARACTERISTICS
V
oh
2.9V
(min @ 4 mA)
V
ol
0.4V
(max @ 3.2mA)
3.3V
Switched Output
– provides the user with the ability to power a low power target
system at 3.3V. The USB-to-I2C software has the ability to switch this output on and off. The
total current provided by the USB-to-I2C Hardware to the target system should not exceed
40mA. It is the user’s responsibility to ensure that excessive current is not drawn from this
supply pin.
5V
Switched Output
– provides the user with the ability to power a low power target
system at 5V. The USB-to-I2C software has the ability to switch this output on and off. The
total current provided by the USB-to-I2C Hardware to the target system should not exceed
40mA. It is the user’s responsibility to ensure that excessive current is not drawn from this
supply pin.
Jumper
RPU
allows the user to connect 3.3Kohm pull-up resistors, which are connected
between the I²C pins (SDA and SCL) and the VP pull-up voltage. The jumpers should be
removed when connecting the USB-to-I2C hardware to a target system, if pull-up resistors
are already available on the target system.
14-pin Ribbon Cable
The USB-to-I2C hardware is shipped with a 14-pin ribbon cable with a 2x7 pin connector.
The connector has a 0.1” (2.54mm) spacing. The pin configuration of the connector, when
viewed from above, is shown here.
