LTC6420CUDC-20#PBF

Overview

The LTC6420CUDC-20#PBF is a dual high-speed differential amplifier and ADC driver from Analog Devices. It features a fixed gain of 10V/V (20dB) with a -3dB bandwidth of 1.8GHz. The device operates on a supply voltage range of 2.85V to 3.5V, drawing 80mA per amplifier. It provides rail-to-rail output swing, adjustable output common mode voltage between 1.1V and 1.6V, and low noise characteristics including a 6.2dB noise figure. Packaged in a 20-lead QFN.

Feature Summary

• Dual matched amplifiers with channel-to-channel gain matching of ±0.1dB and phase matching of ±0.1° at 100MHz.
• Fixed internal gain of 20dB (10V/V) with independent output common mode voltage control via external pin.
• Rail-to-rail output capability allowing direct driving of ADCs without transformers or AC-coupling capacitors.
• Low power consumption with shutdown mode functionality controlled by logic inputs.

Applications

• Differential ADC Driver
• Single Ended to Differential Conversion
• IF Sampling (Diversity) Receivers
• Broadband I/Q Amplifiers
• Satellite Communications

Procurement Notes

Verify the specific suffix 'C' indicates an operating temperature range of 0°C to 70°C, distinct from the 'I' grade which covers -40°C to 85°C. Confirm package type is 20-lead QFN. Check for lead-free finish compliance as indicated by '#PBF'. Ensure sourcing channels provide valid traceability documentation for this specific Analog Devices part number.

Selection Notes

Select this component when a fixed 20dB gain is required for signals up to 300MHz. It is suitable for applications needing precise gain and phase matching between two channels. Consider the 0°C to 70°C commercial temperature range if industrial specs are not needed. Evaluate power budget against the 80mA per amplifier requirement.

Part Context

This device belongs to the LTC6420-20 family of dual matched differential amplifiers. It shares architectural similarities with single-channel variants like the LTC6400-20 but integrates two channels in one compact package. The family targets broadband signal processing and ADC interfacing with minimal external support circuitry.

Replacement Considerations

LTC6420IUDC-20#PBF offers identical electrical performance but with an extended -40°C to 85°C operating temperature range.

FAQ

How is the output common mode voltage adjusted?

The output common mode voltage is set independently for each channel using the VOCMA and VOCMB pins, allowing adjustment within a range of 1.1V to 1.6V.

What is the input impedance of the LTC6420-20?

The differential input impedance is specified as 200Ω.