CY29948AXIT

Clock Buffers, Drivers Overview

The CY29948AXIT is a low-voltage clock distribution buffer supporting 2.5 V or 3.3 V operation with a maximum frequency of 200 MHz at 3.3 V (170 MHz at 2.5 V). It accepts LVPECL or LVCMOS/LVTTL inputs and provides 12 LVCMOS/LVTTL outputs, enabling an effective fanout of 1:24 for series-terminated transmission lines. The device features synchronous output enable and three-state control to eliminate glitches. Typical output-to-output skew is 150 ps, with propagation delays ranging from 4.0 ns to 10.9 ns depending on voltage and input source. It operates within -40°C to +85°C in a 32-pin TQFP package.

Clock Buffers, Drivers Feature Summary

• Supports 200 MHz clock frequencies with 12 LVCMOS/LVTTL outputs
• Accepts differential LVPECL or single-ended LVCMOS/LVTTL inputs via selectable pins
• Provides synchronous output enable (SYNC_OE) and three-state control (TS#)
• Features 150 ps typical output-to-output skew for precise timing alignment

Clock Buffers, Drivers Applications

• Nested clock trees in demanding synchronous systems
• Clock distribution for high-speed digital circuits requiring low skew
• Systems utilizing 50 Ω series or parallel terminated transmission lines

Clock Buffers, Drivers Procurement Notes

Verify the specific ordering suffix 'T' confirms Tape & Reel packaging rather than Tube. Confirm that the industrial temperature range (-40°C to +85°C) matches system requirements. Check current availability status as this component may be subject to end-of-life transitions or limited supply conditions common in legacy clock buffer families.

Clock Buffers, Drivers Selection Notes

Select this component when a 1:12 fanout with low skew is required for 2.5 V or 3.3 V logic levels. Ensure the input clock source matches either the PECL_CLK pins for differential signals or TCLK for single-ended LVCMOS/LVTTL signals. Verify that the 32-TQFP package dimensions fit the PCB layout constraints and that thermal resistance values are adequate for the application's power dissipation profile.

Clock Buffers, Drivers Part Context

The CY29948AXIT belongs to the CY29948 family of clock buffers manufactured by Infineon Technologies (formerly Cypress Semiconductor). It is pin-compatible with MPC948, MPC948L, and MPC9448 devices, facilitating potential design upgrades or replacements in existing architectures without board redesign.

Clock Buffers, Drivers Replacement Considerations

Publicly confirmed pin-compatible substitutes include MPC948, MPC948L, and MPC9448. Verify electrical specifications such as operating voltage and skew parameters against these alternatives before implementation.

Clock Buffers, Drivers FAQ

How is the input clock source selected?

Input selection is controlled by the TCLK_SEL pin. When TCLK_SEL is LOW, the PECL clock inputs (PECL_CLK/PECL_CLK#) are selected. When HIGH, the external reference/test clock input (TCLK) is selected.

What is the effective fanout capability of the CY29948AXIT?

While it has 12 physical outputs, each output can drive one or two traces when using series termination. This provides an effective fanout of 1:24 for driving 50 Ω series terminated transmission lines.

How does the synchronous output enable function work?

The SYNC_OE input enables or disables outputs synchronously with the falling edge of the input clock. Asserting SYNC_OE LOW disables outputs in a LOW state, while HIGH enables them, eliminating potential output glitching or runt pulses.