CM0504 User Guide
15
4.4. INPUT4 and INPUT5, alternate functions
The•alternate•functions•for•inputs•INPUT4•-•INPUT5•is•as•digital•(active-high)•inputs•and•as•frequency•
(type•2)•or•resistive•(type•1)•inputs.
4.4.1.
INPUT4 and INPUT5, Resistive characteristics
The•following•table•provides•specifications•for•INPUT4•and•INPUT5:
Alternate functions input characteristics
Resistive configuration
Item
Min
Nom
Max
Unit
Input range
0.1
20
kΩ
Pull-up resistance
2.21
kΩ
Input resistance w.r.t. ground (pull-up/
pull-down inactive)
89
Ω
Filtering hardware cutoff frequency
39.3
Hz
Resolution (analog)
0.81
mV
4.4.2.
INPUT4 and INPUT5, Frequency or Digital active-high
characteristics
The•following•table•provides•specifications•for•INPUT4•and•INPUT5:
Alternate functions input characteristics
Frequency or Digital active-high configuration
Item
Min
Nom
Max
Unit
Input voltage range
0
32
V
Input frequency range
5
6500
Hz
Pull-up resistance
2.21
open
kΩ
Input resistance w.r.t. ground (pull-up/
pull-down inactive)
77.3
kΩ
Resolution
1
Hz
Positive threshold
5.18
V
Negative threshold
6.24
V
Filtering low pass cutoff frequency
8517
Hz
4.4.3.
Active-High Digital Input Connections
A•digital•input•is•typically•connected•to•a•switch•that•is•either•open•or•closed.
•
•
When•an•active-high•switch•is•open,•the•pull-down•resistor•ensures•that•no•voltage•exists•on•the•
input•signal,•which•will•be•interpreted•by•the•CM0504•as•inactive.
•
•
When•the•switch•is•closed,•the•input•is•connected•to•battery•voltage,•which•will•be•interpreted•by•the•
CM0504•as•active.
For•an•input•that•is•active-high
•
•
It•must•be•connected•to•battery•power•so•that•there•is•a•battery•connection•when•the•state•of•the•
input•changes.