6.5 DUTY-CYCLE Register
(DUTY_CYCLE)
The DUTY_CYCLE register is a 4-bit read/writable reg-
ister used to control the duty cycle of the VOUT output.
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 VIN method of duty
cycle control has been selected (or defaulted to), and
the VIN pin is open, the duty cycle will go to the default
setting of this register, which is 0010 (39.33%). The
duty cycle settings are shown in Register 6-5.
REGISTER 6-5: DUTY-CYCLE REGISTER
(DUTY_CYCLE)
D(3) D(2) D(1) D(0)
Duty-Cycle
0
0
0
0 30%
0
0
0
1 34.67%
0
0
1
0 39.33% (default for VIN
open and when SMBus
is not selected)
0
0
1
1 44%
0
1
0
0 48.67%
0
1
0
1 53.33%
0
1
1
0 58%
0
1
1
1 62.67%
1
0
0
0 67.33%
1
0
0
1 72%
1
0
1
0 76.67%
1
0
1
1 81.33%
1
1
0
0 86%
1
1
0
1 90.67%
1
1
1
0 95.33%
1
1
1
1 100%
TC654/TC655
6.6 Manufacturer’s Identification
Register (MFR_ID)
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:
MANUFACTURER’S
IDENTIFICATION
REGISTER (MFR_ID)
D[7] D[6] D[5] D[4] D[3] D[2] D[1] D[0]
01010100
6.7 Version ID Register (VER_ID)
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: VERSION ID REGISTER
(VER_ID)
D[1] D[0] Version
0 0 TC654
0 1 TC655
2002 Microchip Technology Inc.
DS21734A-page 21