Measurement Computing BTH-1208LS-OEM - Manual (Page 21)

BTH-1208LS-OEM User's Guide Specifications
21
Digital input/output
Table 11. Digital I/O specifications
Parameter Specification
Digital type 3.3 V open drain
Output value mapping 0 written: output drives to DGND
1 written: output is pulled up to 3.3 V via internal resistor
Number of I/O (Note 5) 8
Configuration Individually configurable
Input voltage range (Note 6) 0 V to 5.5 V
Pull up/pull-down configuration 47.5 k
Ω pull-up resistors (to 3.3 V), 2.2 kΩ series resistors
Input high voltage threshold 2.0 V min
Input high voltage limit 5.5 V absolute max
Input low voltage threshold 0.8 V max
Input low voltage limit –0.5 V absolute min
0 V recommended min
Output voltage range 0 V to 3.3 V (no external pull up resistor)
0 V to 5.5 V max (Note 6)
Output off state leakage current
(Note 7) 1.0 µA typ.
Sink current capability 50 mA max (continuous) per pin
Transistor on resistance 0.7
Ω max
Power on and reset state USB operation: All input
Bluetooth operation: The digital I/O can either be all input at power on / reset or may
be configured to have user-configurable patterns written to the DIO when the
Bluetooth host is connected or disconnected.
Note 5: Each transistor source pin is internally connected to DGND.
Note 6: The external pull-up is connected to the digital output bit through an external pull-up resistor. Adding
an external pull-up resistor connects it in parallel with the internal 47.5
kΩ pull-up resistor of that
particular digital input/output bit. Careful consideration should be made when considering the external
pull-up resistor value and the resultant pull-up voltage produced at the load.
Note 7: Does not include the additional leakage current contribution through the internal or any external pull-
up resistor.