Demo board DC2783A features the LT3040, a 200mA high performance, robust voltage reference/DAC buffer. LT3040 has ultralow output noise, ultrahigh power supply rejection ratio (PSRR) and low dropout voltage for powering noise sensitive, high accuracy systems.
DC2783A has two inputs: V+ and VIN. V+ supplies power to the buffer, operating over a range from 2V to 20V. VIN is the regulation set-point for the output with a range from 0V to 15V. Current limit is programmable by connecting a resistor, R3, from ILIM to GND. The ILIM can also serve as a current monitor pin with a range from 0V to 300mV.
LT3040 has fast start capability. Connecting FS pin across an input low pass filter resistor, R2, fast starts the LT3040. Fast start circuitry is typically triggered active if VFS − VIN ≥ 100mV and stays active until VFS – VIN ≤ 7mV. If fast start functionality is not needed, connect FS to VIN by setting R2 to 0Ω and applying the input voltage at FS.
LT3040 has a fault flag to indicate faults at the output. Built-in protection includes reverse battery protection, reverse current protection, internal current limit with foldback and thermal limit with hysteresis.
The LT3040 datasheet gives a complete description of the part, operation and applications information. The datasheet must be read in conjunction with this Demo Manual for demonstration circuit DC2783A. The LT3040 is assembled in a 12-lead MSOP and a 10-lead (3mm x 3mm) plastic DFN package with an exposed pad on the bottom-side of the IC. Proper board layout is essential for maximum thermal performance.