SY75712/14 LVCMOS Clock Buffers

Introduction

Microchip Technology’s SY75712/14 series consists of ultra-low-additive-jitter LVCMOS clock buffers for distributing a single clock input to multiple destinations. The SY75712 provides two outputs, while the SY75714 provides four, in a compact 2 mm × 2 mm, 8-pin TDFN package. A notable integration feature is the built-in 50 Ω series resistance on every output, intended to support direct connection to standard 50 Ω transmission lines without adding external series resistors.

What it does

The SY75712/14 accepts one LVCMOS input and reproduces it across either two or four LVCMOS outputs. The devices support output frequencies from DC to 250 MHz and operate from a 1.2 V to 1.8 V output supply range.

For timing-sensitive clock distribution, the series specifies 17 fs typical additive jitter at 156.25 MHz, measured over a 12 kHz to 20 MHz integration band. Typical propagation delay is 1.5 ns, while maximum output-to-output skew is specified at less than 50 ps. Output-enable control is also supported, allowing the clock outputs to be controlled as part of the surrounding system design.

Applications

• Distributing a single LVCMOS reference clock to two or four devices
• Clock fanout in compact digital systems operating up to 250 MHz
• Board-level clock routing over standard 50 Ω transmission lines
• Timing paths where low additive jitter and controlled output-to-output skew are important
• Space-constrained designs requiring a small TDFN-8 clock-buffer package

Design considerations

The SY75712 and SY75714 differ primarily in output count: select the two-output SY75712 or four-output SY75714 according to the required clock fanout.

Each LVCMOS output incorporates 50 Ω series resistance. This can simplify routing to standard 50 Ω transmission lines by removing the need for external series resistors, but the board interconnect should still be planned around the intended transmission-line environment.

System power design must accommodate the 1.2 V to 1.8 V output supply range. Designers should also account for the 1.5 ns typical propagation delay and less-than-50-ps maximum output-to-output skew when establishing timing budgets. The devices are specified for operation from -40 °C to +105 °C and use a 2 mm × 2 mm TDFN-8 package.

Availability and further information

The source/distributor and datasheet links on this page provide further information on the Microchip SY75712/14 clock-buffer series, including device variants and detailed electrical characteristics.