W83697HG Nuvoton Technology Corporation of America, W83697HG Datasheet - Page 30

• Manufacturer Part Number: W83697HG
• Description: IC LPC SUPER I/O 128-PQFP
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of W83697HG

• Applications: PC's, PDA's
• Interface: LPC
• Voltage - Supply: 3.3V, 5V
• Package / Case: 128-XFQFN
• Mounting Type: Surface Mount
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

6.4.2
The W83697HF provides 2 sets for fan PWM speed control. The duty cycle of PWM can be
programmed by a 8-bit registers which are defined in the Bank0 CR5A and CR5B. The default duty
cycle is set to 100%, that is, the default 8-bit registers is set to FFh. The expression of duty can be
represented as follows.
The PWM clock frequency also can be program and defined in the Bank0.CR5C . The application
circuit is shown as follows.
Fan speed control
Duty cycle
−
PWM Clock Input
(%)
=
Programmed 8 - bit Register Value
G
D
S
R1
NMOS
Figure 9.5
- 27 -
+12V
R2
255
+
-
PNP Transistor
C
Publication Release Date: May 30, 2005
FAN
W83697HF/ HG
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Revision A1