S5N8943B Datasheet, PDF (15/22 Pages) Samsung semiconductor – G.Lite ADSL Analog Front End IC

S5N8943B
G.Lite ADSL Analog Front End IC
4.1.1.4 VCXO Control
The VCXO DAC is 10-bit voltage-mode DAC designed to be monotonic and intended to be
operated at a 4 kHz update rate. In order to update the DAC, the user must write to the VCXO register
through the serial port. The individual bit definitions are given below.
VCXO_CTL Register (A4A3A2A1A0=XX011)
DATA D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
NAME
RESET
VALUE
VC9 VC8 VC7 VC6 VC4 VC4 VC3 VC2 VC1 VC0
1000000000
VC[9:0]: VCXO DAC 10-bit word. The DAC nominal output voltages for extreme and mid-scale
codes are as follows.
VC[9:0] = 0000000000 = 0.5 V
VC[9:0] = 1000000000 = 1.5 V (mid-range)
VC[9:0] = 1111111111 = 2.5 V
A general expression for the DAC output voltage is
0.5 V + (CODE / 1024) X (2.0 V)
where CODE is the decimal integer value of the 10-bit word formed by VCXO[9:0].
CONFIDENTIAL
Preliminary Information (Rev.1.0)
15