ADA4945-1ACPZ-R7

ADA4945-1 is a low-noise, low-distortion fully differential amplifier optimized for high-resolution ADC driving. ACPZ stands for 16-lead 3mm×3mm LFCSP compact surface-mount package with exposed thermal pad. R7 refers to standard 7-inch tape-and-reel packaging designed for high-volume automated SMT mass production.

This silicon germanium bipolar fully differential amplifier features two switchable power consumption modes to balance bandwidth and power efficiency. The supply voltage range spans 3 V to 10 V, supporting single-supply operation to simplify system power architecture.

In full-power mode, quiescent current is 4 mA with a unity-gain bandwidth of 145 MHz; low-power mode draws only 1.4 mA and delivers 80 MHz bandwidth for battery-powered portable devices. It achieves ultra-low DC offset voltage and maximum offset drift of ±0.1 μV/°C across full temperature range, with maximum input offset voltage limited to ±115 μV from -40°C to +125°C.

Excellent harmonic distortion performance is maintained: HD2 = -133 dBc, HD3 = -140 dBc at 1 kHz input signal. Settling time reaches 50 ns for 16-bit accuracy and 100 ns for 18-bit precision, perfectly matching high-speed SAR and Σ-Δ analog-to-digital converters. Input voltage noise is 2.0 nV/√Hz at 100 kHz, minimizing signal noise floor for precision acquisition systems.

The device offers rail-to-rail output swing, wide input common-mode range from negative supply rail to VS-1.3 V, and adjustable output voltage clamps to implement overvoltage protection for connected ADC inputs. An on-chip VOCM pin sets differential output common-mode voltage flexibly to adapt to various ADC input requirements, while internal common-mode feedback suppresses even-order harmonic distortion effectively. A dedicated disable pin puts the amplifier into shutdown state for power saving during idle periods.

Housed in miniature 16-pin LFCSP package measuring 3 mm × 3 mm × 0.75 mm with central exposed thermal pad. The exposed pad shall be connected to negative supply rail for enhanced heat dissipation and stable electrical grounding. Moisture Sensitivity Level is MSL3; all reflow soldering procedures must be completed within 168 hours once the original vacuum packaging is opened. Continuous tape reel feeding is configured to fit automatic component placement equipment for large-scale assembly.

Industrial operating temperature range covers -40 °C to +125 °C, enabling stable continuous operation in industrial process control equipment, medical imaging devices, portable precision test instruments and high-speed data acquisition modules under severe temperature fluctuations. Manufactured with lead-free materials, the component complies with RoHS global environmental directives. Its fully differential architecture eliminates extra discrete components for single-ended to differential signal conversion, simplifying analog front-end PCB layout and reducing overall system BOM cost.

Driving circuit for high-resolution SAR and sigma-delta ADCs

Single-ended to differential signal conversion modules

Precision differential signal buffer stages

Portable battery-powered measurement instrumentation

Medical diagnostic imaging analog front-end circuits

Industrial process control signal acquisition systems