WA_DEV_W218_PTS_002 Rev 005 Page 62 of 109

Product Technical Specification &

Customer Design Guidelines

Pulse-Width Modulators (PWMs)

The WISMO218 contains two Pulse-Width Modulators (PWMs). They can be used in conjunction with

an external transistor for driving a vibrator, or a backlight LED.

Features

Each PWM uses two 7-bit unsigned binary numbers: one for the output period and one for the pulse

width or the duty cycle.

The relative timing for the PWM output is shown in the figure below.

Figure 25. Relative Timing for the PWM Output
Table 21. PWM Electrical Characteristics
Param eter
Condi tion
Minim um
Typic al
Maxim um
Unit
VOH
High impedance load
2.7
2.85
-
V
Load with IoH = 4mA
-
2.4
-
V
VOL
-
-
-
0.1
V
IPEAK
-
-
-
4
mA
Frequ ency
-
25.6
-
1083.3
kHz
Duty cycle
-
0*
-
100*
%
Pin Description
Table 22. PWM Pin Descriptions
Signa l
Pin N umber
I/O
I/O Type
Descr iption
PWM0
36
O
2V8
PWM output
PWM1
35
O
2V8
PWM output
Application

Both the PWM0 and PWM1 signals can be used in conjunction with an external transistor for driving

a vibrator, or a backlight LED.