Datasheet

DocID16364 Rev 3 15/27
VNL5160N3-E, VNL5160S5--E Application information
26
4.1 MCU I/O protection
ST suggests to insert a resistor (Rprot) in line to prevent the µC I/O pins from latching up
(a)
.
The value of these resistors is a compromise between the leakage current of µC and the
current required by the LSD I/Os (Input levels compatibility) with the latch-up limit of µC
I/Os:
0.7/I
latchup
≤ R
prot
≤ (V
OHµC
-V
IH
) / I
IHmax
Calculation example:
For the following conditions:
I
latchup
≥ 20mA
V
OHµC
≥ 4.5V
35Ω ≤ R
prot
≤100kΩ.
Recommended value is R
prot
=1kΩ
a. In case of negative transient on the drain pin.