DESCRIPTION

The DS1077 is a dual-output, programmable, fixed-frequency oscillator requiring no external components for operation. The DS1077 can be used as a processor-controlled frequency synthesizer or as a standalone oscillator. The two synchronous output operating frequencies are user-adjustable in submultiples of the master frequency through the use of two on-chip programmable prescalers and a divider. The specific output frequencies chosen are stored in NV (EEPROM) memory. The DS1077 defaults to these values upon power-up.

The DS1077 features a 2-wire serial interface that allows in-circuit on-the-fly programming of the programmable prescalers (P0 & P1) and divider (N) with the desired values being stored in NV (EEPROM) memory. Design changes can be accommodated in-circuit on-the-fly by simply programming different values into the device (or reprogramming previously programmed devices). Alternatively, for fixed frequency applications, previously programmed devices can be used and no connection to the serial interface is required. Pre-programmed devices can be ordered in customer requested frequencies.

The DS1077 is available in 8-pin SO or µSOP packages, allowing the generation of a clock signal easily, economically, and using minimal board area. Chip-scale packaging is also available on request.

FEATURES

■ Processor-controlled or standalone solid state oscillator

■ Frequency changes on-the-fly

■ Dual low-jitter, synchronous fixed frequency outputs

■ 2-wire serial interface

■ Frequency outputs 8.1kHz to 133MHz

■ ±0.5 variation over temp (+25°C to +70°C)

■ ±0.5 initial tolerance

■ Nonvolatile (NV) frequency settings

■ Single 5V supply

■ No external components

■ Power-down mode

■ Synchronous output gating