MC100EL1648MEL

Programmable Timers And Oscillators Overview

The MC100EL1648 is a 5 V ECL Voltage Controlled Oscillator Amplifier designed for high-speed applications. It operates at frequencies up to 1100 MHz with a typical power consumption of 19 mA at 5.0 Vdc. The device supports PECL mode (VCC = 4.2 V to 5.5 V, VEE = 0 V) and NECL mode (VCC = 0 V, VEE = -4.2 V to -5.5 V). It requires an external parallel tank circuit consisting of an inductor and capacitor, with provisions for varactor diode integration for voltage variable tuning. The output features on-chip termination facilitating direct AC coupling.

Programmable Timers And Oscillators Feature Summary

• Integrated Automatic Gain Control (AGC) limits current through the emitter-coupled pair to maintain optimum frequency response and spectral purity.
• Output buffer utilizes an on-chip pull-down resistor, eliminating the need for external pull-down resistors and enabling direct AC coupling to transmission lines.
• Capable of generating sine or square wave outputs by adjusting the AGC pin potential relative to power supply rails.

Programmable Timers And Oscillators Applications

• Local oscillator circuits
• Electronic test equipment
• Digital high-speed telecommunications

Programmable Timers And Oscillators Procurement Notes

Verify the specific package suffix against the datasheet ordering information. The 'DG' suffix indicates SOIC-8 NB Pb-Free packaging, while 'DTR2G' denotes TSSOP-8 Pb-Free packaging. Confirm that the required operating temperature range (-40°C to +85°C) aligns with system constraints. Ensure external bypassing capacitors are placed close to package pins to minimize lead inductance.

Programmable Timers And Oscillators Selection Notes

Select this component when a fixed frequency clock or voltage-tunable oscillator is required within the ECL logic family. The device is suitable for designs needing low power consumption and high spectral purity. Designers must account for external tank circuit components, as the internal circuitry relies on these passive elements to determine the oscillation frequency and quality factor.

Programmable Timers And Oscillators Part Context

The MC100EL1648 is based on the VCO circuit topology of the MC1648 but utilizes advanced bipolar process technology to extend the operational frequency range. It belongs to the MC100EL series of ECL devices. Unlike traditional open emitter structures, its output configuration includes integrated termination, simplifying interface design for high-speed digital systems requiring ECL compatibility.

Programmable Timers And Oscillators Replacement Considerations

Public confirmed substitute part numbers: None identified in source material.

Programmable Timers And Oscillators FAQ

Can the MC100EL1648 be used as a crystal oscillator?

No, the datasheet explicitly states that the MC100EL1648 is not usable as a crystal oscillator.

How is the output waveform shaped into a square wave?

To obtain a square wave output at frequencies above 100 MHz, tie a series resistor (minimum 1.0 kΩ) from the AGC pin to the most positive power potential (+5.0 V for PECL or ground for NECL).

What is the function of the BIAS pin?

The BIAS pin provides the OSC Input Reference Voltage. It guarantees the DC potential at the bias point for incorporating a varactor tuning diode.