Features

• Low Noise: 20µV_RMS (10Hz to 100kHz)
• Low Quiescent Current: 30µA/Output
• Independent Inputs
• Wide Input Voltage Range: 1.8V to 20V
• Output Current: 100mA/500mA
• Very Low Shutdown Current: <0.1µA
• Low Dropout Voltage: 300mV/320mV at 100mA/500mA
• Adjustable Outputs from 1.22V to 20V
• Stable with as Low as 1µF/3.3µF Output Capacitor
• Stable with Aluminum, Tantalum or Ceramic Capacitors
• Reverse-Battery Protected
• No Protection Diodes Needed
• Overcurrent and Overtemperature Protected
• Tracking/Sequencing Capability
• Thermally Enhanced 16-Lead TSSOP and 16-Lead (5mm × 3mm) DFN Packages

Typical Application

Description

The LT3028 is a dual, micropower, low noise, low dropout regulator with independent inputs. With an external 0.01µF bypass capacitor, output noise is a low 20µV_RMS over a 10Hz to 100kHz bandwidth. Designed for use in battery-powered systems, the low 30µA quiescent current per output makes it an ideal choice. In shutdown, quiescent current drops to less than 0.1µA. Shutdown control is independent for each output, allowing for flexibility in power management. The device is capable of operating over an input voltage range of 1.8V to 20V. Output 1 can supply 500mA of output current with a dropout voltage of 320mV. The device can supply 100mA of output current from Output 2 with a dropout voltage of 300mV. Quiescent current is well controlled in dropout.

The LT3028 regulator is stable with output capacitors as low as 1µF for the 100mA output and 3.3µF for the 500mA output. Small ceramic capacitors can be used without the series resistance required by other regulators.

Internal protection circuitry includes reverse-battery protection, current limiting and thermal limiting protection. The device is available as an adjustable device with a 1.22V reference voltage. The LT3028 regulator is available in the thermally enhanced 16-lead TSSOP and 16-lead, low profile (5mm × 3mm × 0.75mm) DFN packages.

Protected by U.S. Patents including 6118263, 6144250.