SY100S838L

The SY100S838L is a low skew (÷1, ÷2/3) or (÷2, ÷4/ 6) clock generation chip designed explicitly for low skew clock generation applications. The internal dividers are  synchronous to each other, therefore, the common output edges are all precisely aligned. The SY100S838L can be driven by either a differential or single-ended ECL or, if positive power supplies are used, PECL input signal. In addition, by using the VBB output, a sinusoidal source can be ACcoupled into the device. If a single-ended input is to be used, the VBB output should be connected to the CLK nput and bypassed to ground via a 0.01F capacitor. The VBB output is designed to act as the switching reference for the input of the SY100S838L under singleended input conditions. As a result, this pin can only source/sink up to 0.5mA of current.

The Function Select (FSEL) input is used to determine what clock generation chip function is. When FSEL input is LOW, SY100S838L functions as a divide by 2 and by 4/6 clock generation chip. However, if FSEL input is HIGH, it functions as a divide by 1 and by 2/3 clock chip.

The common enable (EN) is synchronous so that the internal dividers will only be enabled/disabled when the internal clock is already in the LOW state. This avoids any chance of generating a runt clock pulse on the internal clock when the SY100S838L is enabled/disabled as can happen with an asynchronous control. An internal runt pulse could lead to losing synchronization between the internal divider stages. The internal enable flip-flop is clocked on the falling edge of the input clock, therefore, all associated specification limits are referenced to the negative edge of the clock input.

Upon start-up, the internal flip-flops will attain a random state; the master reset (MR) input allows for the synchronization of the internal dividers, as well as for multiple SY100S838L in a system.