LTC6400CUD-8#PBF

Overview

The LTC6400CUD-8#PBF is a high-speed differential amplifier designed for processing signals from DC to 300MHz. It features a fixed gain of 2.5V/V (8dB) and a 2.2GHz –3dB bandwidth. The device operates on a single supply voltage ranging from 2.85V to 3.5V with a typical supply current of 85mA. It includes an adjustable output common mode voltage control pin, allowing direct interfacing with ADCs without external transformers or AC-coupling capacitors. The component is housed in a compact 16-lead 3mm × 3mm QFN package.

Feature Summary

• Low noise and low distortion performance optimized for driving 12-, 14-, and 16-bit ADCs
• Differential inputs and outputs with internal feedback network
• Adjustable output common mode voltage independent of input signals
• Integrated filtered outputs for simplified external filtering implementation

Applications

• Differential ADC Driver
• Single Ended to Differential Conversion
• IF Sampling Receivers
• SAW Filter Interfacing

Procurement Notes

Verify the specific suffix 'C' indicates the commercial temperature grade (0°C to 70°C), distinct from the industrial grade 'I'. Confirm the '#PBF' designation corresponds to lead-free packaging and tube shipping format. Ensure the datasheet revision matches the required specifications for your design. Cross-reference the manufacturer's official documentation for any updates regarding availability or lifecycle status.

Selection Notes

Select this part when a fixed 8dB gain and wide bandwidth are required for signal chain applications. Consider the 400Ω differential input impedance for source matching requirements. Evaluate the power consumption against alternatives if lower current draw is critical, as the LTC6401 family offers similar noise performance with reduced power at the cost of linearity at higher frequencies.

Part Context

This component belongs to the LTC6400 series of fully differential amplifiers. It shares pin compatibility with the LTC6401 family but offers higher output drive capability and different linearity characteristics. The series is targeted at broadband applications requiring precise gain and low noise, serving as a bridge between analog front-end stages and high-resolution data converters.

Replacement Considerations

LTC6400IUD-8#PBF: Industrial temperature grade (-40°C to 85°C).

FAQ

What is the function of the VOCM pin?

The VOCM pin sets the output common mode voltage, which can be adjusted between 1V and 1.6V. This allows the amplifier to directly drive ADCs without requiring external biasing components like transformers.

How does the LTC6400-8 handle input coupling?

The device supports both DC-coupled and AC-coupled operation at the inputs. When AC-coupled, the input common mode voltage is automatically biased approximately 450mV above the VOCM setting.