LTC6904CMS8#TRPBF

Programmable Timers And Oscillators Overview

The Analog Devices LTC6904CMS8#TRPBF is a low-power, self-contained digital frequency source providing a precision square wave output from 1.039 kHz to 68 MHz. It operates on a single supply voltage ranging from 2.7 V to 5.5 V and requires no external components other than a power supply bypass capacitor. The device features an industry-standard I2C compatible serial interface for digital control. Key electrical specifications include a typical initial frequency accuracy of 0.5%, a maximum operating frequency of 68 MHz, and a typical supply current of 1.7 mA at frequencies below 1 MHz with a 2.7 V supply.

Programmable Timers And Oscillators Feature Summary

• I2C Compatible Serial Interface: Utilizes standard I2C protocols for programming frequency settings via the SDI and SCK pins.
• High Precision Frequency Control: Offers 0.5% typical initial frequency accuracy and less than 1.1% total frequency error across all settings.
• Low Power Consumption: Draws a typical supply current of 1.7 mA at f < 1 MHz (VS = 2.7V) and includes an asynchronous Output Enable pin for power management.
• Wide Operating Temperature Range: The CMS8 variant is specified for operation from 0°C to 70°C, with functional guarantees from -40°C to 85°C.

Programmable Timers And Oscillators Applications

• Precision Digitally Controlled Oscillator
• Replacement for Direct Digital Frequency Synthesis (DDS)
• Switched Capacitor Filter Clock Source
• Power Management System Timing

Programmable Timers And Oscillators Procurement Notes

Verify that the specific ordering suffix #TRPBF corresponds to the Tape and Reel packaging format as indicated in the manufacturer's order information table. Confirm that the component grade matches the required operational temperature range, as the CMS8 designation specifies a commercial range of 0°C to 70°C with extended functional capabilities down to -40°C.

Programmable Timers And Oscillators Selection Notes

Select the LTC6904 over the LTC6903 when an I2C interface is preferred over the SPI-compatible interface. Ensure the application environment remains within the 0°C to 70°C guaranteed specification range for the CMS8 package; otherwise, consider the IMS8 or HMS8 variants for wider industrial or high-temperature ranges. Verify that the load capacitance on the CLK outputs does not exceed 5 pF to maintain specified accuracy without requiring additional buffering.

Programmable Timers And Oscillators Part Context

This component belongs to the LTC6903/LTC6904 family of low-power programmable oscillators manufactured by Analog Devices (formerly Linear Technology). The LTC6904 specifically distinguishes itself through its I2C interface, whereas the LTC6903 uses an SPI-compatible interface. Both share identical internal feedback loops and frequency setting equations but differ in their serial communication protocols.

Programmable Timers And Oscillators Replacement Considerations

The LTC6903CMS8#TRPBF serves as a direct functional substitute if the system design accommodates the SPI-compatible interface instead of I2C. For applications requiring higher maximum frequencies up to 30 MHz with lower power consumption, the LTC1799 may be considered, though it lacks the wide-range programmability of the LTC6904.

Programmable Timers And Oscillators FAQ

["What is the default output frequency upon power-up?","The device defaults to an output frequency of 1.039 kHz with both CLK outputs active immediately after power is applied."]

["How is the slave address determined for the I2C interface?","The first six bits of the 7-bit address are factory-programmed to 001011. The least significant bit is determined by the logic level on the ADR pin (Pin 4); pulling ADR low sets the address to 0010111, while pulling it high sets it to 0010110."]

["What is the impact of capacitive loading on output accuracy?","The device is designed to drive up to 5 pF on each output without degradation. Exceeding this load, such as using a standard 10x oscilloscope probe (10-15 pF), may degrade accuracy and typically requires a high-speed buffer for signals above 1 MHz."]