CY5057

The CY5057 is a flash-programmable, high-accuracy, PLL-based die designed for the crystal oscillator market. It also contains spread spectrum circuitry that can be enabled or disabled with an external pin. The die is integrated with a low-cost 25.1-MHz fundamental tuned crystal in a four- or six-pin through-hole or surface mount package. The oscillator devices can be stocked as blank parts and custom frequencies can be programmed in-package at the last stage before shipping. This enables fast-turn manufacturing of custom and standard crystal oscillators without the need for dedicated, expensive crystals.

The CY5057 contains an on-chip oscillator and unique oscillator tuning circuit for fine-tuning the output frequency. The crystal Cload can be selectively adjusted by programming a set of flash memory bits. This feature can be used to compensate for crystal variations or to obtain a more accurate synthesized frequency.

The CY5057 uses a simple two-pin programming interface excluding the VSS and VDD pins. Clock outputs can be generated from 5 MHz to 170 MHz at 3.3V ± 10% operating voltage. The entire Flash configuration can be reprogrammed multiple times, allowing programmed inventory to be altered or reused.

The CY5057 PLL die has been designed for very high resolution. It has a 10-bit feedback counter multiplier and a seven-bit reference counter divider. This enables the synthesis of highly accurate and stable output clock frequencies with zero or low PPM error. The output of the PLL or the oscillator can be further modified by a seven-bit linear post divider with a total of 126 divider options (2 to 127).

The CY5057 also contains flexible power management controls. These parts include both power-down mode (PD# = 0) and output enable mode (OE = 1). The power-down and output enable modes have an additional setting to determine timing (asynchronous or synchronous) with respect to the output signal.

Controlled rise and fall times, unique output driver circuits, and innovative circuit layout techniques enable the CY5057 to have low jitter and accurate outputs making it suitable for most PC, networking and consumer applications.

The CY5057 also has an additional spread spectrum feature that can be disabled or enabled with an external pin. Please refer to Spread Spectrum section for details.