LT3029 Linear Regulator

Analog Devices' LT3029 is a dual, micropower, low noise, low dropout linear regulator. The device operates either with a common input supply or independent input supplies for each channel over an input voltage range of 1.8 V to 20 V. Each output supplies up to 500 mA of output current with a typical dropout voltage of 300 mV. Quiescent current is well controlled in dropout. With an external 10 nF bypass capacitor, output noise is only 20 μV_RMS over a 10 Hz to 100 kHz bandwidth. Designed for use in battery-powered systems, the low 55 μA quiescent current per channel makes it an ideal choice. In shutdown, the quiescent current drops to less than 1 μA. Shutdown control is independent for each channel, allowing for flexible power management.

The LT3029 optimizes stability and transient response with low ESR ceramic output capacitors, requiring a minimum of only 3.3 μF. The regulator does not require the addition of ESR, as is common with other regulators.

Internal circuitry provides reverse-battery protection, reverse-current protection, and current limiting with foldback and thermal shutdown. The device is available as an adjustable output voltage device with a 1.215 V reference voltage.

Demonstration circuit DC1408A is a dual input, 500 mA/500 mA linear regulator featuring the LT3029. The device operates either with a common input supply or independent input supplies for each channel over an input range of 1.8 V to 20 V; the demo board has a minimum input voltage of 2.3 V. Each output supplies up to 500 mA of output current with a typical dropout voltage of 300 mV. The output voltage is jumper-selectable for each channel and can be set to 1.5 V, 1.8 V, 2.5 V, 3.3 V, 5 V, or a user-defined value.