Summary of LT3042 – 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator
The LT3042 is a high-performance low dropout linear regulator designed for noise-sensitive RF applications. It features ultralow RMS noise, ultrahigh PSRR, and supports output currents up to 200mA with a wide input voltage range of 1.8V to 20V. Key capabilities include parallel operation for reduced noise and increased current, programmable current limits, fast start-up, and comprehensive protection against reverse battery and current conditions. It operates stably with a minimum 4.7μF ceramic capacitor and offers precision enable/UVLO control.
Parts used in the LT3042 Project:
- LT3042 Linear Regulator
- Ceramic Output Capacitor (Minimum 4.7μF)
- Single Resistor for Voltage Programming
- SET Pin for Current Reference
- 10-Lead MSOP Package
- 3mm × 3mm DFN Package
Features
- Ultralow RMS Noise: 0.8μVRMS (10Hz to 100kHz)
- Ultralow Spot Noise: 2nV/√Hz at 10kHz
- Ultrahigh PSRR: 79dB at 1MHz
- Output Current: 200mA
- Wide Input Voltage Range: 1.8V to 20V
- Single Capacitor Improves Noise and PSRR
- 100μA SET Pin Current: ±1% Initial Accuracy
- Single Resistor Programs Output Voltage
- High Bandwidth: 1MHz
- Programmable Current Limit
- Low Dropout Voltage: 350mV
- Output Voltage Range: 0V to 15V
- Programmable Power Good
- Fast Start-Up Capability
- Precision Enable/UVLO
- Parallelable for Lower Noise and Higher Current
- Internal Current Limit with Foldback
- Minimum Output Capacitor: 4.7μF Ceramic
- Reverse Battery and Reverse Current Protection
- 10-Lead MSOP and 3mm × 3mm DFN Packages
Description
The LT®3042 is a high performance low dropout linear regulator featuring LTC’s ultralow noise and ultrahigh PSRR architecture for powering noise sensitive RF applications. Designed as a precision current reference followed by a high performance voltage buffer, the LT3042 can be easily paralleled to further reduce noise, increase output current and spread heat on the PCB.
The device supplies 200mA at a typical 350mV dropout voltage. Operating quiescent current is nominally 2mA and drops to <<1μA in shutdown. The LT3042’s wide output voltage range (0V to 15V) while maintaining unitygain operation provides virtually constant output noise, PSRR, bandwidth and load regulation, independent of the programmed output voltage. Additionally, the regulator features programmable current limit, fast start-up capability and programmable power good to indicate output voltage regulation.
The LT3042 is stable with a minimum 4.7μF ceramic output capacitor. Built-in protection includes reverse battery protection, reverse current protection, internal current limit with foldback and thermal limit with hysteresis. The LT3042 is available in thermally enhanced 10-Lead MSOP and 3mm × 3mm DFN packages.
For More Details: LT3042 – 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator
- What is the maximum output current of the LT3042?
The device supplies 200mA at a typical 350mV dropout voltage. - How can I reduce noise further in this project?
The regulator can be easily paralleled to further reduce noise and increase output current. - Does the LT3042 require multiple capacitors for stability?
No, it is stable with a minimum 4.7μF ceramic output capacitor. - What is the input voltage range supported by this regulator?
The wide input voltage range is from 1.8V to 20V. - Can I program the current limit on the LT3042?
Yes, the device features a programmable current limit with internal foldback. - Does the LT3042 offer protection against reverse connections?
Yes, it includes built-in reverse battery and reverse current protection. - What packages are available for the LT3042?
The LT3042 is available in thermally enhanced 10-Lead MSOP and 3mm × 3mm DFN packages. - How does the quiescent current behave during shutdown?
Operating quiescent current drops to less than 1μA in shutdown.
