TC654 Microchip Technology, TC654 Datasheet - Page 21

• Manufacturer Part Number: TC654
• Description: (TC654 / TC655) PWM Fan Speed Controllers With Fan Fault Detection
• Manufacturer: Microchip Technology

6.5
The DUTY_CYCLE register is a 4-bit read/writable reg-
ister used to control the duty cycle of the V
The controllable duty cycle range via this register is
30% to 100%, with programming steps of 4.67%.This
method of duty cycle control is mainly used with the
SMBus interface. However, if the V
cycle control has been selected (or defaulted to), and
the V
setting of this register, which is 0010 (39.33%). The
duty cycle settings are shown in Register 6-5.
REGISTER 6-5:
D(3)
2002 Microchip Technology Inc.
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
IN
pin is open, the duty cycle will go to the default
DUTY-CYCLE Register
(DUTY_CYCLE)
D(2)
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
D(1)
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
DUTY-CYCLE REGISTER
(DUTY_CYCLE)
D(0)
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
30%
34.67%
39.33% (default for V
open and when SMBus
is not selected)
44%
48.67%
53.33%
58%
62.67%
67.33%
72%
76.67%
81.33%
86%
90.67%
95.33%
100%
IN
Duty-Cycle
method of duty
OUT
output.
IN
6.6
This register allows the user to identify the manufac-
turer of the part. The MFR_ID register is an 8-bit Read
only register. See Register 6-6 for the Microchip manu-
facturer ID.
REGISTER 6-6:
6.7
This register is used to indicate which version of the
device is being used, either the TC654 or the TC655.
This register is a simple 2-bit Read only register.
REGISTER 6-7:
D[7]
D[1]
0
0
0
D[6]
D[0] Version
Manufacturer’s Identification
Register (MFR_ID)
Version ID Register (VER_ID)
1
0
1
TC654
TC655
D[5]
0
TC654/TC655
D[4]
MANUFACTURER’S
IDENTIFICATION
REGISTER (MFR_ID)
VERSION ID REGISTER
(VER_ID)
1
D[3]
0
D[2]
DS21734A-page 21
1
D[1]
0
D[0]
0