LT3093

Demo circuit DC2952A features the LT3093, an ultralow noise, ultrahigh power supply rejection ratio (PSRR) negative low dropout (LDO) regulator. DC2952A operates over an input range of –3.8V to –20V, and can deliver up to 200mA output current. It features ultralow noise (0.8µVRMS from 10Hz to 100kHz) and very high PSRR (73dB at 1MHz).

The EN/UVLO of LT3093 is bidirectional and can be switched with either a positive or a negative voltage. LT3093 also offers programmable current limit functionality by connecting a resistor from ILIM to GND. The VIOC tracking function controls an up-stream switching converter to maintain a constant voltage across the regulator and hence minimize power dissipation. The power good feedback (PGFB) pin is used to set a programmable power good threshold, and activates the fast start-up circuitry. To use the power good function, connect an external voltage source at VEXT. If power good and fast start-up functionality are not needed, tie PGFB to IN.

Built-in protection includes internal current limit with foldback and thermal limit with hysteresis. 

The LT3093 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 DC2952A. The LT3093 is assembled in 12-lead MSOP and 3mm x 3mm DFN packages with an exposed pad on the bottom-side of the IC. Proper board layout is essential for maximum thermal performance.

• Companion module for Active Learning labs and workshops on ADCs, mixed-mode signal chain, and DSP related topics
• IIO-based software stack for broad, cross-platform compatibility with industry-standard tools, MATLAB, Python, and other languages
• Configurable 2nd-order analog filter for exploring the interaction between analog and digital filters
• Onboard clock divider provides sample rates from 5 MSPS to 40 MSPS
• Single USB connection provides all power and connectivity

The Analog Devices Active Learning Module - Mixed-Mode Signal Chain (ADALM-MMSC) is an educational board that facilitates hands-on exploration of fundamental signal chain concepts. The core of the circuit is the AD4080, 40 MSPS oversampling SAR analog-to-digital converter (ADC) with configurable digital filter and internal data capture memory (single-port FIFO). The board includes a highly configurable 2nd order analog filter with adjustable cutoff frequencies, input attenuation, and filter gain. An onboard selectable clock source provides sample rates from 5 MSPS to 40 MSPS. A MAX32666FTHR microcontroller runs an IIO server over a serial backend, allowing the use of standard tools such as Scopy, IIO Oscilloscope, Pyadi-iio, and ADI's MATLAB precision toolbox. The Libiio library provides language bindings for C, C#, MATLAB, Python, and other languages.

Concepts demonstrated include:

• Digital filtering
• Analog vs. digital anti alias filtering
• Properties of different digital filters
• Noise analysis
• Reference noise

APPLICATIONS

• Mixed Signal and Digital Signal Processing experiments, workshops, and lab exercises
• Precision data acquisition

• +/-5V Output Range
• 20-Bit Signal Generation Control
• On board precision 5V Reference
• All Power Rails Generated Using a Single 3.3V Source