Micrel, Inc.

SM840004-11

July 2010

5

M9999-070110-A

Crystal Characteristics

Parameter

Min

Typ

Max

Units

Mode of Oscillation

Fundamental Parallel Resonant

Frequency

25

MHz

Equivalent Series Resistance (ESR)

50

Ω

Shunt Capacitor

7

pF

Drive Level

1

mW

Functional Description

The SM840004-11 provides a high performance and

high accuracy solution for a precision clock source at

either 62.5MHz or 125MHz derived from a low cost

25MHz Xtal. Four synchronous low skew 12mA capable

LVCMOS outputs are provided with tri state controlled

via an external pin (OE).

The design of the SM840004-11 consumes very low

power in the PLL due to a patented technology in the

VCO and the associated dividers. The VCO range is

~3.2GHz to 3.5GHz providing high resolution and easy

integer divide ratios. Output divider ratios are fixed at

either ÷26 or ÷52 via the F_SEL pin, and the feedback

divider is fixed at ÷130.

Duty Cycle is inherently

improved and provides tight control and stability on this

critical

specification.

This

provides

improved

specifications for Duty Cycle, Jitter, Phase Noise, Power

Consumption, and noise sensitivity. Additionally, the

SM840004-11 will operate at either 3.3V or 2.5V

supplies.