DS1077U-66+

Overview

The DS1077U-66+ is a dual-output, programmable fixed-frequency oscillator in an 8-pin µSOP package. It features a factory-trimmed internal master oscillator operating at 66.666MHz, with outputs ranging from 8.1kHz to 133MHz. The device includes two synchronous outputs (OUT0 and OUT1) generated via programmable prescalers and a divider. Frequency settings are stored in nonvolatile EEPROM memory, allowing for standalone operation or processor-controlled adjustment via a 2-wire serial interface. It operates on a single 5V supply with ±0.5% initial tolerance and low jitter characteristics.

Feature Summary

• Dual synchronous outputs (OUT0, OUT1) derived from a 66.666MHz master clock
• Nonvolatile EEPROM storage for frequency settings and control registers
• 2-wire serial interface for on-the-fly programming of prescalers and dividers
• Single 5V supply operation with power-down mode reducing current to 5µA

Applications

• Processor-controlled frequency synthesizers
• Standalone clock generation for digital systems
• Reference clock distribution in embedded applications
• Systems requiring adjustable frequency without external components

Procurement Notes

Verify the ordering suffix 'U' confirms the 8-pin 118mil µSOP package variant. Confirm the '-66' designation corresponds to the 66.666MHz master frequency option. Ensure the '+' suffix indicates lead-free compliance if required by specific manufacturing standards. Cross-reference the manufacturer's latest datasheet for any updates to pin assignments or electrical characteristics.

Selection Notes

Select this model when a 66.666MHz base frequency is required. Choose the 'U' package for space-constrained surface-mount designs. Consider the 'Z' package (SOIC) if wider pitch is preferred for assembly. Verify that the required output frequencies fall within the 8.1kHz to 133MHz range achievable through the internal prescaler and divider configurations.

Part Context

The DS1077 series belongs to the EconOscillator family, designed as solid-state oscillators requiring no external components. The DS1077U-66+ specifically utilizes the µSOP package format. This component integrates the oscillator, prescalers, and divider into a single chip, simplifying board design compared to discrete crystal and logic solutions.

Replacement Considerations

Direct replacements include other DS1077 variants with different packages (DS1077Z-66+) or master frequencies (e.g., DS1077U-100+, DS1077U-133+). Substitution requires verifying that the new master frequency allows derivation of the required output frequencies using the available prescaler and divider ratios.

FAQ

How is the output frequency determined?

Output frequencies are determined by the internal master clock divided by programmable prescalers (P0, P1) and a divider (N). Values are set via the 2-wire serial interface and stored in nonvolatile memory.

What is the function of the CTRL0 and CTRL1 pins?

CTRL0 and CTRL1 are multifunctional inputs configurable as Output Enable or Power-Down controls via register settings. They can also serve as MUX select inputs for OUT0 depending on configuration bits.

Can the device operate without a microcontroller?

Yes, the DS1077 can function as a standalone oscillator. Pre-programmed devices retain their frequency settings in EEPROM upon power-up without requiring serial interface connections.