LM4040AIM3-4.1/NOPB

The Texas Instruments LM4040AIM3-4.1/NOPB is a precision micropower shunt voltage reference that provides a stable 4.096V output with +/-0.1% initial accuracy. Designed for space-critical applications, it is available in the compact SOT-23-3 surface-mount package. The device uses laser-trimmed resistors and Zener-zap technology during wafer sort to achieve its high accuracy. Bandgap reference temperature drift curvature correction and low dynamic impedance (0.3 ohm typical) ensure stable output voltage over a wide range of operating temperatures and currents. The LM4040 requires no external stabilizing capacitor while maintaining stability with any capacitive load, simplifying PCB design.

The LM4040 operates as a two-terminal shunt (parallel) voltage reference: 1) Bandgap Core: The internal bandgap reference circuit generates a temperature-compensated voltage using curvature correction techniques. The 4.096V output is derived from the bandgap voltage through laser-trimmed resistive dividers, ensuring +/-0.1% initial accuracy. 2) Shunt Regulation: The device is connected in parallel with the load. A series resistor limits the total current, and the LM4040 shunts excess current to maintain a constant 4.096V across its terminals. Operating current can range from 73uA to 15mA. 3) Stability: The low dynamic impedance of 0.3 ohm at 120Hz ensures the reference voltage remains stable despite variations in load current and supply voltage, without requiring an external bypass capacitor.

• Precision voltage reference for 12-bit and higher ADC/DAC systems
• Portable and battery-powered data acquisition equipment
• Industrial process control and instrumentation
• Power supply voltage monitoring and threshold detection circuits
• Energy management and smart metering applications