Through a proprietary design, this product provides very low spot noise of only 2nV/√Hz at 10kHz and offers 0.8μVRMS integrated output noise over a wide bandwidth of 10Hz to 100kHz. Its low-frequency and high-frequency PSRR performance is excellent.

Low-frequency PSRR exceeds 90dB up to 10kHz, and high-frequency PSRR performance exceeds 75dB up to 3MHz, silencing noisy or high-ripple input power supplies. The LT3042 utilizes LTC’s proprietary LDO architecture, a precision current source reference followed by a high-performance individual gain buffer, to deliver virtually constant bandwidth, noise, PSRR, and output voltage-independent load regulation performance. In addition, this architecture makes it possible to arrange multiple LT3042s in parallel, further reducing noise, increasing output current, and dissipating heat from the PCB.

The LT3042 provides up to 200mA output current with a 350mV dropout voltage at full load over a wide input voltage range of 1.8V to 20V. The output voltage range is 0V to 15V, and the output voltage tolerance is highly accurate at ±2% load line, load, and temperature. The device's wide input and output voltage ranges, high bandwidth, high PSRR, and ultra-low noise performance make it ideal for powering noise-sensitive applications such as PLLs/VCOs/mixers/LNAs, low-noise instrumentation, high-speed/high-precision data converters, medical applications including imaging and diagnostics, precision power supplies, and post-regulators for switching power supplies.

The LT3042 operates on a small, low-cost 4.7μF ceramic output capacitor and optimizes stability and transient response. A single resistor programs an external precision current limit (±10% at temperature). A single SET pin capacitor reduces output noise and provides a reference soft-start function, preventing output voltage overshoot upon turn-on. Additionally, the device's built-in protection circuitry includes reverse battery protection, reverse current protection, an internal current limit with foldback, and a thermal performance limit with hysteresis. Other features include fast startup performance (useful when a large value SET pin capacitor is used) and a power good flag with a programmable threshold to indicate output voltage regulation.

The LT3042 is available in thermally enhanced 10-pin 3mm x 3mm DFN and 10-pin MSOP packages, both of which offer a compact footprint. The Class E and Class I versions are available for operating junction temperatures of –40°C to 125°C. The high-temperature Class H is specified for –40°C to 150°C, and the high-reliability Class MP is available for –55°C to 150°C. The devices are currently available, with pricing starting at $2.25 for the Class E in 1,000-unit quantities. For more information, please refer to www.linear.com/product/LT3042.

Photo Caption: 20VIN, 200mA 0.8μVRMS Ultra-low Noise & Very High PSRR LDO

Product Features: LT3042

• Ultra-low RMS noise: 0.8μVRMS (10Hz ~ 100kHz)

• Ultra-low spot noise: 2nV/√Hz at 10kHz

• Very High PSRR: >90dB to 10kHz and >75dB to 3MHz

• Output current: 200mA

• Wide input voltage range: 1.8V ~ 20V

• Single capacitor improving noise & PSRR performance

• 100μA SET pin current: ±1% initial accuracy

•Single resistor that programs output voltage

• High bandwidth: 1 MHz

• Programmable current limit

• Low dropout voltage: 350mV

• Output voltage range: 0V ~ 15V

• Power good flag with programmable threshold

• High-speed startup performance

• Precision Enable/UVLO

• Parallel arrangement possible for low noise & high current

• Internal restriction feature with foldback

•Minimum output capacitor: 4.7μF ceramic

• Reverse Battery & Reverse Current Protection Function

• 10-pin MSOP & 3mm x 3mm DFN Package

USA List pricing information is for general budget planning purposes only, and international prices may vary depending on local customs duties, taxes, fees, exchange rates, etc.