ADA4637-1BRZ

Overview

The ADA4637-1BRZ is a decompensated JFET operational amplifier manufactured by Analog Devices Inc. It features a gain bandwidth product of 79.9 MHz and a slew rate of 170 V/µs. The device operates on dual supplies ranging from ±5 V to ±15 V with a maximum supply voltage of 30 V. Key electrical specifications include a maximum input offset voltage of 200 µV (B Grade) and a typical drift of 1 µV/°C. Input bias current is limited to 5 pA maximum, while voltage noise density is 6.1 nV/√Hz at 1 kHz. The component supports an extended industrial temperature range from −40°C to +125°C.

Feature Summary

• Decompensated architecture ensuring stability at noise gains of 5 or greater
• JFET input stage providing extremely low input bias current and leakage
• High-speed performance combining wide bandwidth with precision DC characteristics
• Offset adjust pins available in SOIC package for external calibration

Applications

• High impedance sensors
• Photodiode amplifiers
• Precision instrumentation
• Phase-locked loop filters
• Professional audio equipment

Procurement Notes

Verify the B grade designation ensures the specified maximum offset voltage limits are met. Confirm the SOIC package variant matches the required pin configuration, noting that LFCSP variants lack offset adjust pins. Ensure circuit designs maintain a minimum noise gain of 5 to prevent instability associated with the decompensated topology.

Selection Notes

Select this component when high speed and precision must be combined in a single stage. The decompensated design offers superior bandwidth compared to unity-gain stable counterparts but requires careful gain setting. Consider PCB layout techniques such as guarding to preserve the low bias current performance against leakage paths.

Part Context

This part belongs to the ADA4627-1/ADA4637-1 family of wide bandwidth precision amplifiers. The ADA4637-1 serves as the decompensated version of the ADA4627-1, offering higher speed at the cost of reduced stability at lower gains. Both devices share similar noise and offset characteristics optimized for harsh environments.

Replacement Considerations

Publicly confirmed substitute part numbers are not provided in the source documentation.