Features and Benefits
- Ultralow Wideband Noise: 1.2µVRMS (10Hz to 100kHz)
- Ultralow 1/f Noise: 0.6µVP-P (0.1Hz to 10Hz)
- Ultralow Spot Noise: 4nV/√Hz at 1kHz and Above
- Ultrahigh PSRR: 73dB at 1MHz
- Ultralow Input Offset: 125µV
- Output Source Current: 200mA
- Wide Input Voltage Range: 1.8V to 20V
- Rail to Rail Output Voltage Range: 0V to 15V
- Single Capacitor Improves Noise and PSRR
- Fast Start-Up for VIN Pin
- FAULT Flag
- High Bandwidth: 1MHz
- Low Dropout Voltage: 350mV
- Programmable Current Limit
- Precision Enable/UVLO
- Parallelable for Lower Noise and Higher Current
- Internal Current Limit with Foldback
- Minimum Output Capacitor: 4.7µF Ceramic
- Reverse Supply and Reverse Current Protection
- Thermal Limit with Hysteresis
- 10-Lead 3mm × 3mm DFN and 12-Lead MSOP
The LT3040 is a high performance, robust Voltage Output Reference/DAC buffer that employs a unique architecture that seeks to maintain the precision and accuracy of the Reference or DAC while sourcing up to 200mA. It features ADI’s ultralow noise and ultrahigh PSRR architecture for powering noise sensitive, high accuracy systems. Designed as an advanced voltage buffer for Voltage Output References/DACs, the LT3040 features extremely low 1/f noise, very low wideband noise, excellent PSRR over a wide frequency range and low dropout performance – a typical 350mV dropout at 200mA of source current.
Operating quiescent current is nominally 2.5mA and drops to <1μA in shutdown. The LT3040’s wide output voltage range (0V to 15V) while maintaining unity-gain operation provides virtually constant output noise, PSRR, bandwidth and load regulation independent of the VIN voltage. Additionally, the buffer features programmable current limit, fast start capability and a FAULT flag to indicate faults on the output.
The LT3040 is stable with a minimum 4.7μF ceramic output capacitor. Built-in protection includes reverse supply voltage protection, reverse current protection, internal current limit with fold-back and thermal limit with hysteresis. The LT3040 is available in thermally enhanced 12-Lead MSOP and 10-Lead 3mm × 3mm DFN packages.
- High Speed/High Precision Data Converters
- High Precision Voltage References
- Very Low Noise Instrumentation
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (1)
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.
Tools & Simulations
LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.
Models for the following parts are available in LTspice:
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.