ds4026 Maxim Integrated Products, Inc., ds4026 Datasheet - Page 8

• Manufacturer Part Number: ds4026
• Description: Ds4026 10mhz To 51.84mhz Tcxo
• Manufacturer: Maxim Integrated Products, Inc.

10MHz to 51.84MHz TCXO
Figure 2. Functional Diagram
The DS4026 is a TCXO capable of operating at 3.3V
±5%, and it allows digital tuning of the fundamental fre-
quency. The device is calibrated in the factory to
achieve an accuracy of ±1ppm over the industrial tem-
perature range, and its minimum pullability is ±8ppm
with a typical resolution of 1ppb (typ) per LSB.
The DS4026 contains the following blocks:
• Oscillator block with variable capacitor for compen-
• Output driver block
• Temperature sensor
8
sation
V
GND
SCL
SDA
OSC
_____________________________________________________________________
INTERFACE
GND
V
I
2
CC
C
Detailed Description
SENSOR
TEMP
V
CC
V
CC
CONTROLLER
GND
V
GND
A/D
CC
GNDOSC
• Controller to read the temperature, control lookup
• DAC output to adjust the capacitive load
• I
The oscillator block consists of an amplifier and variable
capacitor in a Pierce crystal oscillator with a crystal res-
onator of fundamental mode. The oscillator amplifier is a
single transistor amplifier and its transconductance is
temperature compensated. The variable capacitor is
adjusted by the DAC to provide temperature compensa-
tion. With the FTUNEH and FTUNEL registers, a minimum
pullability of ±8ppm (±5ppm for 10MHz) is achieved with
a typical resolution of 1ppb (typ) per LSB.
table, and adjust the DAC input
DAC
2
C interface to communicate with the chip
DS4026
EEPROM
ARRAY
BUFFER
CMOS
GNDD
V
GNDA
V
FOUT
REF
CCD