7
USB-TO-I2C HARDWARE TO TARGET CONNECTION
When connecting the USB-to-I2C Hardware to an I²C target system, a cable with a
minimum of three (3) wires will be required. The SDA, SCL, and GND on the USB-to-I2C
Hardware must be connected to their corresponding signals on the target.
The USB-to-I2C Hardware has 3.3 kOhm pull-up resistors connected to pin VP on the 14-
pin header. If the VP is not connected, you must remove the jumpers at RPU. If the
jumpers are left in the circuit, ensure that VP has a voltage source applied, and note that the
total I²C sink current of 3mA is not exceeded when the target pull-ups and USB-to-I2C pull-
ups are taken into consideration.
The SDA and SCL lines may be pulled up to a voltage range between 3.3V and 5.5V. It may
work at voltages down to 2.5V; however, the noise margins will be lower.
Minimum hardware connection between USB-to-I2C and User Hardware
(Jumpers at RPU removed)
14-pin
connector
VCC
VP
SSN
SCL
MISO
GND
MOSI
SDA
GND
IN
SCLK
OUT
3.3V
5V OUT
