IC213 Datasheet, PDF (4/11 Pages) IC-Haus GmbH – PROGRAMMABLE OSCILLATOR MODULE

iC213
preliminary
PROGRAMMABLE OSCILLATOR MODULE
LVDS AND TTL OUTPUTS
Rev A1, Page 4/11
The clock signal is supplied to J1 both as LVDS and
TTL signals. Additionally it is supplied to the RJ45 plug
also both as LVDS and TTL signals. The TTL signal
can be enabled/disabled by means of jumper JP1.
only be used up to this frequency. For higher frequen-
cies only the LVDS outputs should be used. The LVDS
outputs must be differentially terminated with 100 to
110 Ω.
The output of the core oscillator is LVDS level. To be
able to set lower frequencies than the lowest oscillator
frequency of 10 MHz two downstream LVDS frequency
dividers are used. These are cascaded in a way so that
the division factor can be set in three steps between 1,
64 and 256. Thus frequencies down to 39.0625 kHz
can be programmed.
These dividers are set automatically when choosing
from the predefines frequencies. Though they can also
be programmed manually via the I²C interface.
An additional fan-out buffer distributes the LVDS signal
to the four outputs (2 x TTL, 2 x LVDS) of the module.
The TTL signals are generated by two LDVS/TTL con-
verters. Since the operating frequency of these con-
verters is limited to 300 MHz, the TTL outputs should
Figure 1: Channel 2 (red) TTL output, Channel 3
(green) LVDS Output
ENABLE INPUT
Via the input EN_OSC the output of the module can
be enabled/disabled. This input is high active and fea-
tures an internal pull-up resistor. That means, connect-
ing this input to GND (low level) disables the outputs.
With an unconnected input EN_OSC the outputs are
enabled. Switch SW4 performs the same function.
TRIGGER
An SMA connector on the modules serves as a trig-
ger source e.g. for an oscilloscope. This connector
supplies the programmed clock signal. The internal
resistance of the trigger source is 50 Ω. Hence the
connected cable should have a characteristic wave
impedance of 50 Ω and be terminated also with a 50 Ω
resistor. The signal amplitude will then be about 200
und 600 mV.
Figure 2: Channel 1 (blue) trigger signal with
100 MHz