DS1085Z-25+

Overview

The DS1085Z-25+ is a dual-output frequency synthesizer from Analog Devices/Maxim Integrated, housed in an 8-pin SO package with a 25kHz step size. It operates on a single 5V supply (4.75V to 5.25V) and generates frequencies from 8.1kHz to 133MHz without external timing components. Key electrical parameters include a master oscillator range of 66MHz to 133MHz, 0.75% absolute accuracy, and active supply current of 50mA. The device features nonvolatile EEPROM storage for frequency settings and supports both standard (100kHz) and fast (400kHz) 2-wire serial interface modes.

Feature Summary

• Dual synchronous outputs: OUT0 (reference, 8.2MHz–133MHz) and OUT1 (main, 8.1kHz–133MHz)
• Nonvolatile memory stores DAC, OFFSET, DIV, and MUX register settings for power-up defaults
• 2-wire serial interface allows dynamic reprogramming of frequency and prescaler/divider values
• Programmable prescalers (divide-by-1, 2, 4, or 8) and divider (divide-by-2 to 1025)

Applications

• Processor-controlled peripheral clock generation
• Standalone oscillator applications requiring fixed factory-programmed frequencies
• Systems requiring dynamic frequency modification via serial bus

Procurement Notes

Verify the specific ordering suffix matches the required step size (e.g., Z-25 for 25kHz resolution). Confirm that the application environment stays within the specified operating temperature range of 0°C to +70°C. Ensure the power supply voltage remains between 4.75V and 5.25V for optimal performance. Check if the 150mil SO package dimensions fit the target PCB layout constraints.

Selection Notes

Select the DS1085Z-25+ when a 25kHz frequency resolution is required. Compare against DS1085Z-10 (10kHz step) or DS1085Z-50 (50kHz step) based on precision needs. Consider the internal master oscillator range (66MHz–133MHz) and available OFFSET settings to ensure the desired output frequency range is achievable. Verify compatibility with the host system's 2-wire serial protocol speed (standard vs. fast mode).

Part Context

The DS1085 series belongs to the EconOscillator family, designed to replace discrete crystal and oscillator circuits. The 'Z' indicates a lead-free/RoHS-compliant variant, while the suffix '-25' specifies the 25kHz programming step size. This component integrates the master oscillator, prescalers, dividers, and control logic into a single IC, simplifying design by eliminating external timing components.

Replacement Considerations

Direct functional substitutes within the same family include DS1085Z-10+ (10kHz step) and DS1085Z-50+ (50kHz step), provided the step size difference is acceptable. No other cross-family replacements are confirmed in the provided documentation.