General Description
The 843034 is a general purpose, low phase noise
LVPECL synthesizer which can generate frequencies for a
wide variety of applications. The 843034 has a 4:1 input
Multiplexer from which the following inputs can be
selected: one differential input, one single-ended input, or
two crystal oscillators, thus making the device ideal for
frequency translation or frequency generation. Each
differential LVPECL output pair has an output divider
which can be independently set so that two different
frequencies can be generated. Additionally, each LVPECL
output pair has a dedicated power supply pin so the
outputs can run at 3.3V or 2.5V. The 843034 also supplies
a buffered copy of the test clock or crystal frequency on
the single-ended REF_OUT output pin which can be
enabled or disabled, (disabled by default). The output
frequency can be programmed using either a serial or
parallel programming interface.
The phase jitter of the 843034 is less than 1ps RMS, making it
suitable for use in Fiber Channel, SONET, and Ethernet applications.

Features
• Dual differential 3.3V LVPECL outputs which can be set
independently for either 3.3V or 2.5V
• 4:1 Input Mux:
One differential input
One single-ended input
Two crystal oscillator interfaces
• CLK, nCLK pair can accept the following differential input levels:
LVPECL, LVDS, LVHSTL, HCSL
• TEST_CLK accepts LVCMOS or LVTTL input levels
• Output frequency range: 35MHz to 625MHz
• Crystal input frequency range: 12MHz to 40MHz
• VCO range: 560MHz to 750MHz
• Parallel or serial interface for programming feedback divider and
output dividers
• RMS phase jitter at 333.3MHz, using a 22.222MHz crystal (12kHz
to 20MHz): 0.91ps (typical)
• Supply voltage modes:
LVPECL outputs
Core/ Output
3.3V/ 3.3V
3.3V/ 2.5V
REF_OUT output
Core/ Output
3.3V/ 3.3V
• 0°C to 70°C ambient operating temperature
• Industrial temperature available upon request with ePad option
• Lead-free (RoHS 6) packaging