Clock Buffer 1-3 – High-Performance Quad 1:3 Clock Fanout Buffer

• Split and buffer PCM/I2S signals – or any clock up to 200 MHz.
• EN-input to enable/disable clock outputs.
• Compact 85 mm x 30 mm 4-layer PCB.
• LMK1C110x clock buffers.
• Optional oscillator circuit to provide Master Clock.

Requires following supplies (indicated max current):

• 5V (20-100mA in normal use cases).
  • Current depends on clock frequency, number of outputs used, and output capacitance and termination.
• Supply provided via 2-pin Molex Micro-Fit (alternatively, wires can be soldered).

When do you need a Clock Buffer 1-3?

Typical use case is when connecting several DACs, ADCs or other digital audio boards to a DSP that has one set of clocks (Bit Clock BCLK, Word Clock WCLK, and possibly Master Clock MCLK) available. Splitting the clocks to all boards is not a good idea because clock signals cause strong reflections, lowering the reliability or stopping the converters from working altogether.

Proper way to connect the clocks to several boards is to use a clock fanout buffer with multiple outputs. If the host board such as a DSP has several independent clock outputs, external buffer is not needed.

Pay attention to clock directions. Typically DSPs and USB-modules are Masters (clocks are outputs), in which case the converters and boards connected to them must be Slaves. To connect two Masters or two Slaves, sample rate converter is required.

Optional oscillator

If the system does not have Master Clock (MCLK), Clock Buffer 1-3 can provide it with the optional oscillator circuit. OSC OUT can be connected directly to a Slave device or to one of the four clock inputs to split the OSC into three, to connect to multiple Slave devices.

Important information on order

• All SMD components are soldered down and the board is fully tested, connectors and headers are soldered if selected.
• Please ensure you have the skills to solder the remaining components and wires to connect the board in your system – and most of all understand what you are doing. Especially pay attention you have the correct power supplies and signal levels.
• Be careful with supply polarity and level, incorrect connections may damage the board and/or your power supply.
• If you need help prior to purchase, please contact us.

Order contents

See contents in the photo below:

• Fully tested board with all SMD components (except pinheaders) populated.
  • Optional oscillator also soldered if selected.
• 2-pin Molex power connector.
• 5pcs 1×2 male SMD-pinheader.

More information

For measurement results and version history, see the tab above.

Files

• Schematics
• Component placement (including board dimensions)