Sierra Wireless AIRPRIME WISMO218 - Manual (Page 58)

WA_DEV_W218_PTS_002 Rev 006 April 29, 2010 58
Product Technical Specification &
Customer Design Guidelines Interfaces
3.11. Pulse-Width Modulators (PWMs)
The AirPrime 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.
3.11.1. 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
Parameter Condition Minimum Typical Maximum Unit
V
OH
High impedance load 2.7 2.85 - V
Load with I
oH
= 4mA - 2.4 - V
V
OL
- - - 0.1 V
I
PEAK
- - - 4 mA
Frequency - 25.6 - 1083.3 kHz
Duty cycle - 0* - 100* %
3.11.2. Pin Description
Table 22: PWM Pin Descriptions
Signal Pin Number I/O I/O Type Description
PWM0 36 O 2V8 PWM output
PWM1 35 O 2V8 PWM output
3.11.3. Application
Both the PWM0 and PWM1 signals can be used in conjunction with an external transistor for driving a
vibrator, or a backlight LED.