DS4000 Dallas Semiconducotr, DS4000 Datasheet - Page 7

• Manufacturer Part Number: DS4000
• Description: Digitally Controlled TCXO
• Manufacturer: Dallas Semiconducotr

TEMPERATURE-COMPENSATED CRYSTAL OSCILLATOR
The DS4000 can either function as a standalone TCXO or as a digitally controlled TCXO. When used as a
standalone TCXO, the only requirements needed to function properly are power, ground, and an output. However,
the 2-wire interface must be used to tune (push and pull) the crystal.
The DS4000 is capable of supplying two different outputs, F
1) F
2) F
F
TCXO CONTROL REGISTER (60h)
DC, Duty Cycle Bit: If 50% duty cycle is desired, then this bit must be set to logic 1. The default condition at
power-up is logic 0.
F
F
F
2
T
1
2
Bit
Name
Default
Bit
Name
Default
: This bit must be programmed by the user to 0.
OE, F
OE, F
FREQUENCY SELECT REGISTER (FSR) (5Dh)
division of the base (F
division of F
1
2
is the base frequency of the crystal unit inside of the device. The output type is a CMOS square wave.
is a programmable frequency output. The frequency select register can program this output to an integer
1
2
Output Enable Bit: This bit allows the user to disable/enable the F
Output Enable Bit: This bit allows the user to disable/enable the F
1
.
D7
X
7
0
7
0
1
) frequency. The duty cycle (DC) bit determines if the output is an n + 1 or a 2(n + 1)
D6
X
6
0
6
0
F
2
F
= F
2
= F
1
D5
/ [2 x (FSR value + 1)]; with DC = 1
X
5
0
5
0
1
/ (FSR value + 1); with DC = 0
7 of 16
D4
X
4
0
4
0
1
and F
2
F
.
D3
2
3
0
3
0
OE
1
2
output.
output.
F
D2
1
2
0
2
OE
0
D1
F
1
0
1
0
T
DC
D0
0
0
0
0