SY89874AUMG-TR

Overview

The SY89874AUMG-TR is a low-skew, low-jitter clock driver and fanout buffer manufactured by Microchip Technology. It integrates a programmable clock divider with ratios of 1, 2, 4, 8, or 16 and a 1:2 fanout buffer. The device accepts high-speed inputs (≥622 MHz) including LVTTL, LVCMOS, CML, PECL, LVDS, and HSTL via an internal termination network accessible through the VT pin. It provides two differential LVPECL outputs with a maximum toggle frequency of 2.5 GHz. Key electrical parameters include a maximum propagation delay of 760 ps, within-device skew of 15 ps, total jitter under 10 ps peak-to-peak, and cycle-to-cycle jitter under 1 ps RMS. It operates on a single 2.5V or 3.3V supply.

Feature Summary

• Integrated Programmable Clock Divider: Supports division ratios of 1, 2, 4, 8, and 16 for frequency synthesis.
• Flexible Input Interface: Accepts LVCMOS, LVTTL, CML, PECL, LVDS, and HSTL signals using unique internal termination and VT pin configuration.
• Low-Jitter Performance: Guarantees <10 psPP total jitter and <1 psRMS cycle-to-cycle jitter over temperature and voltage.
• LVPECL Outputs: Provides two differential LVPECL outputs with 100k ESD protection capability.

Applications

• SONET/SDH Line Cards
• Transponders
• High-End Multiprocessor Sensors

Procurement Notes

Verify the ordering suffix 'TR' indicates Tape and Reel packaging containing 1,000 units per reel. Confirm the 'M' suffix corresponds to the 16-Lead 3 mm x 3 mm QFN package. Ensure the 'G' suffix matches the –40°C to +85°C operating temperature range with NiPdAu lead-free finish. Cross-reference the full part number SY89874AUMG-TR against official Microchip documentation to confirm current manufacturing status and revision level DS20006200A.

Selection Notes

Select this component when a system requires dividing a high-frequency reference clock (up to 3.2 GHz input for divide-by-2 mode) down to lower auxiliary frequencies while maintaining low jitter. Choose the SY89874A over the SY89874U if the input signal offset is within the standard range; use SY89874U for wider input ranges required for DC-coupled low-offset differential signals. Ensure the application supports the 2.5V or 3.3V supply voltage options and utilizes LVPECL output standards.

Part Context

The SY89874AU belongs to the SY89874 series of clock dividers and fanout buffers. The 'A' denotes the specific device variant with 2.5 GHz max frequency. The 'U' indicates support for both 2.5V and 3.3V supplies. The 'M' specifies the 16-lead QFN package. The 'G' indicates the industrial temperature range (-40°C to +85°C). This part is a successor to Micrel designs acquired by Microchip, as indicated by the datasheet revision history.

Replacement Considerations

For DC-coupled low-offset differential signals requiring a wider input range, consider the SY89874U variant. For applications needing different divider ratios or output types, review other members of the SY89874 family such as the SY89874L or SY89874V. Verify pin compatibility and electrical specifications before substituting any alternative part numbers.

FAQ

How is the clock division ratio selected?

The division ratio is selected via three parallel programming pins (S0, S1, S2). Logic levels applied to these pins determine whether the output is the reference clock (divide by 1), divided by 2, 4, 8, or 16, as defined in the truth table.

What is the function of the VT pin?

The VT pin provides access to the internal termination network of the differential input buffer. It allows the user to configure the input interface for various logic standards (CML, LVDS, PECL, etc.) by connecting it to ground, VCC, or leaving it floating depending on the input type.

How does the /RESET pin operate?

The /RESET pin asynchronously resets the divider when active low. In pass-through mode (divide by 1), it also acts as a synchronous enable/disable function, turning the outputs off on the next falling edge of the input clock.