IC213 Datasheet, PDF (6/11 Pages) IC-Haus GmbH – PROGRAMMABLE OSCILLATOR MODULE

iC213
preliminary
PROGRAMMABLE OSCILLATOR MODULE
Example
A frequency of 100 MHz at the output of the oscillator
is to be programmed. Therefore the required values
for HS_DIV and N1 have to be chosen. The frequency
of the DCO f_DCO must be between 4.85 and 5.67 GHz.
For a low power consumption HS_DIV should be se-
lected as high as possible and N1 as low as possible.
Furthermore the DCO frequency f_DCO should also be
as low as possible.
Rev A1, Page 6/11
f_out
=
f_XTAL ∗ RFREQ
HS_DIV ∗ N1
=
f_DCO
HS_DIV ∗ N1
f_DCO = f_out ∗HS_DIV ∗N1 = 100 MHz ∗9∗6 = 5400 MHz
Thus f_DCO is within the valid range between 4.85 and
5.67 GHz. RFREQ multiplied by the referency fre-
quency f_XTAL has to yield 5400 MHz and hence:
5400 MHz
5400 MHz
RFREQ =
=
f_XTAL
114, 3363533 MHz
= 47, 229073204
For this examples the following values have been cho-
sen as:
HS_DIV = 9
N1
=6
f_out
Output frequency
f_XTAL
f_DCO
Reference frequency (= 114.3363533 MHz)
Output frequency of DCO
HS_DIV High-speed divider
N1
Output divider N1
RFREQ Multiplier
PROGRAMMING
There are two ways to set the frequency of the iC213
module. Three HEX switches with 4 bit each (= 12 bit)
allow the selection from a list of pre-defined frequen-
cies. Alternatively an I²C interface allows this module
to be programmed directly. Plus the trimmer P1 allows
a fine-tuning of the VCO frequency.
Selectable frequencies
Table 3 give the list of frequencies that can be selected
via the three HEX switches. The frequencies rise ex-
ponential. Thus an even distribution across the whole
frequency range from 39.3 kHz up to 1 GHz is granted.
The three HEX switches equal 4 bit each = 1 nibble and
are designated as {em high (high nibble), mid (middle
nibble) and low (low nibble). If for example
high 6
mid 3
low B
are chosen, this relates to 0x63B and hence a fre-
quency of 2 MHz.