5A, Low Noise, Programmable Output, 85mV Dropout Linear Regulator

The LT3070-1 is a low voltage, Ultrafast™ transient response linear regulator. The device supplies up to 5A of output current with a typical dropout voltage of 85mV. A 0.01μF reference bypass capacitor decreases output voltage noise to 25μVRMS. The LT3070-1 EN pin controls the reference soft-start behavior in comparison to the LT3070 which controls the reference soft-start via the BIAS pin supply voltage. The LT3070-1’s high bandwidth permits the use of low ESR ceramic capacitors, saving bulk capacitance and cost. The LT3070-1’s features make it ideal for high performance FPGAs, microprocessors or sensitive communication supply applications.

Output voltage is digitally selectable in 50mV increments over a 0.8V to 1.8V range. A margining function allows the user to adjust system output voltage in increments of ±1%, ±3% or ±5%. The IC incorporates a unique tracking function to control a buck regulator powering the LT3070-1’s input. This tracking function drives the buck regulator to maintain the LT3070-1’s input voltage to VOUT + 300mV, minimizing power dissipation.

Internal protection includes UVLO, reverse-current protection, precision current limiting with power foldback and thermal shutdown. The LT3070-1 regulator is available in a thermally enhanced 28-lead, 4mm × 5mm QFN package.

APPLICATIONS

* FPGA and DSP Supplies

* ASIC and Microprocessor Supplies

* Servers and Storage Devices

* Post Buck Regulation and Supply Isolation

* Output Current: 5A

* Dropout Voltage: 85mV Typical

* Enable Function Soft-Starts the Reference

* Digitally Programmable VOUT : 0.8V to 1.8V

* Digital Output Margining: ±1%, ±3% or ±5%

* Low Output Noise: 25μVRMS (10Hz to 100kHz)

* Parallel Multiple Devices for 10A or More

* Precision Current Limit: ±20%

* ±1% Accuracy Over Line, Load and Temperature