beautypg.com

Matrix Orbital LCD0821 Legacy User Manual

Page 13

background image

LCD0821 rev 2

13

Note: The GPOs do not have any over current or over/under voltage protection so care must be taken when
using them. For instance if the external device is a relay it must be fully clamped (using a diode and
capacitor – see Figure 2-11) to absorb any generated back electro-motive force (EMF).

10 - 100 uF

1N400 1

Relay

coil

GPO

+

-

Figure 2-11 Clamping a Relay