W83627DHG Nuvoton Technology Corporation of America, W83627DHG Datasheet - Page 52

• Manufacturer Part Number: W83627DHG
• Description: IC I/O CONTROLLER 128-QFP
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of W83627DHG

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

W83627DHG
7.6.2
Fan Speed Control
The W83627DHG has four output pins for fan control, each of which offers PWM duty cycle and DC
voltage to control the fan speed. The output type (PWM or DC) of each pin is configured by Bank0
Index 04h, bits 1 ~ 0; Index 12h, bit 0; and Index 62h, bit 6.
For PWM, the duty cycle is programmed by eight-bit registers at Bank0 Index 01h, Index 03h, Index
11h and Index 61h. The duty cycle can be calculated using the following equation:
Programmed
- 8
bit
Register
Value
=
×
Dutycycle
(%)
100
%
255
The default duty cycle is FFh, or 100%. The PWM clock frequency is programmed at Bank0 Index 00h,
Index 02h, Index 10h and Index 60h.
For DC, the W83627DHG has a six bit digital-to-analog converter (DAC) that produces 0 to 3.3 Volts
DC. The analog output is programmed at Bank0 Index 01h, Index 03h, Index 11h and Index 61h. The
analog output can be calculated using the following equation:
Programmed
- 6
bit
Register
Value
= AVCC
×
`
OUTPUT Voltage (V)
64
The default value is 111111YY, or nearly 3.3 V, and Y is a reserved bit.
Publication Release Date: Aug, 22, 2007
-40-
Version 1.4