LM4040B25IDCKRG4

PMIC - Voltage Reference - LM4040B25IDCKRG4 Application Field and Working Principle

The LM4040B25IDCKRG4 is a voltage reference manufactured by Texas Instruments. This device has been designed to provide precision, low-noise output voltage reference over a temperature range of -55°C to +125°C and an input voltage range of 0.2V up to 7V. It is packaged in the industry-standard SOT-23-3 package, making it easy to design in and draws a very low quiescent current. The device also features an Enable (EN) pin that has low leakage current and a low threshold level. This means that the device is capable of being disabled in order to conserve power.

Features

• Precision output voltage references
• 0.2V to 7V input voltage range
• Stability over temperature range of -55°C to +125°C
• Low quiescent current of 1.6μA max
• Enable (EN) pin with low leakage current and low threshold level
• Industry-standard SOT-23-3 package

Applications

• Battery-powered applications
• Data loggers
• High-resolution analog-to-digital converters (ADCs)
• Measuring and monitoring circuits
• Precision power supplies

Working Principle

The LM4040B25IDCKRG4 operates on the principle of input buffering and error amplification. The input buffering is achieved through the two P-channel MOSFETs configured as a source follower. The MOSFETs are driven by an operational transconductance amplifier (OTA). The OTA is an adjustable gain block and can be used to provide up to 63.2 dB of closed-loop gain. The buffered input is then used by the error amplifier consisting of an OTA, a resistor divider, a bypass capacitor and an N-channel pass FET. The output voltage from the error amplifier is then connected to the gate of the pass FET. The output voltage is clamped by the pass FET and the desired output voltage is maintained. The output voltage is adjusted by adjusting the resistor divider ratio.

The LM4040B25IDCKRG4 also features an Enable (EN) pin. This is an optional pin and can be connected to a logic level low to disable the device for power savings. An open-drain logic low output can be used to indicate the device is enabled. This enables the device to be turned off when not in use, saving power and extending battery life.

Conclusion

The LM4040B25IDCKRG4 is a precision, low-noise output voltage reference that has been designed to provide adjustable output voltage over a temperature range of -55°C to +125°C. It is packaged in the industry-standard SOT-23-3 package, is easy to design in, and draws a very low quiescent current. The device is ideal for battery-powered applications, data loggers, high-resolution ADCs, measuring and monitoring circuits, and precision power supplies. It features an Enable (EN) pin that has low leakage current and a low threshold level, allowing the device to be disabled in order to conserve power.