ADA4945-1ACPZ-RL

Overview

The ADA4945-1ACPZ-RL is a high-speed, fully differential ADC driver manufactured by Analog Devices Inc. It operates on a power supply range of 3 V to 10 V and features two selectable power modes: full power mode with 4 mA quiescent current and 145 MHz bandwidth, and low power mode with 1.4 mA quiescent current and 80 MHz bandwidth. The device provides rail-to-rail output swing, wide input common-mode voltage range from −VS to +VS − 1.3 V, and adjustable output clamps for ADC input protection. It exhibits low harmonic distortion, fast settling times, and an input voltage noise of 2.0 nV/√Hz at 100 kHz in full power mode.

Feature Summary

• Dual selectable power modes allow scaling between high performance (145 MHz) and low power consumption (1.4 mA).
• Internal common-mode feedback loop ensures exceptional output balance and suppression of even-order harmonic distortion.
• Adjustable output clamps provide protection against overvoltage conditions at the ADC input terminals.
• Fabricated using silicon germanium complementary bipolar process to achieve low distortion and low input voltage noise.

Applications

• Low power Sigma-Delta, PulSAR, and SAR ADC drivers
• Single-ended to differential converters
• Differential buffers
• Medical imaging systems
• Process control applications

Procurement Notes

Verify the specific ordering suffix RL indicates reel packaging when sourcing this component. Confirm that the device meets RoHS compliance requirements for your assembly process. Ensure the operating temperature range of -40°C to +125°C aligns with your system's environmental specifications. Check for moisture sensitivity levels if the component has been stored for extended periods before reflow soldering.

Selection Notes

Select the ADA4945-1ACPZ-RL when driving high-resolution successive approximation register or Sigma-Delta analog-to-digital converters requiring low noise and low distortion. Choose the full power mode for applications demanding maximum bandwidth and dynamic performance. Opt for the low power mode when battery life or thermal constraints necessitate reduced quiescent current. Ensure the external feedback network resistors are matched to maintain optimal common-mode rejection ratio.

Part Context

This component belongs to the ADA4945-1 series of fully differential amplifiers designed specifically as analog-to-digital converter drivers. It utilizes Analog Devices' proprietary silicon germanium process technology. The device is housed in a 16-lead LFCSP package measuring 3 mm by 3 mm. It is specified for industrial temperature ranges and offers adjustable common-mode voltage control to interface with various ADC input standards.

Replacement Considerations

No public confirmed substitute part numbers are available in the provided documentation.

FAQ

How does the ADA4945-1 switch between power modes?

The device switches between full power and low power modes by connecting the MODE pin to either the positive supply (+VS) for full power operation or the negative supply (-VS) for low power operation.

What is the function of the DISABLE pin?

The DISABLE pin allows the user to turn off the amplifier to reduce power consumption. When disabled, the quiescent current drops significantly, and the outputs enter a high-impedance state.

Can the ADA4945-1 drive capacitive loads directly?

Yes, the device can drive capacitive loads, but application notes recommend specific circuit configurations or isolation resistors to maintain stability when driving large capacitances.