Linear Technology introduces ultra-low noise, ultra-high Power Ripple suppression (PSRR) low voltage differential voltage linear regulators

     Linear Technology Corporation introduces the LT3042, the leading ultra-low noise, ultra-high Power Ripple suppression (PSRR) low voltage differential voltage linear regulator. The device's unique design has an ultra-low point noise of only 2nV/√Hz (at 10kHz) and an integrated output noise of 0.8µVRMS (within a broadband width of 10Hz to 100kHz). Low frequency and high frequency PSRR performance is exceptional. A low frequency PSRR of more than 90dB (up to 10kHz) and a high frequency PSRR of more than 75dB (up to 3MHz) can "quiet" a noisy or high ripple input power supply.

     The LT3042 utilizes LTC's proprietary LDO architecture, which lays a high-performance unit-gain buffer behind a high-precision current source reference to produce nearly constant bandwidth, noise, PSRR, and load regulation performance, independent of output voltage. In addition, the architecture allows multiple LT3042s to be used in parallel to further reduce noise, increase output current, and spread heat on the printed circuit board (PCB).

     The LT3042 delivers up to 200mA of output current and a 350mV differential voltage over a wide input voltage range of 1.8V to 20V at full load. The output voltage ranges from 0V to 15V, and the output voltage tolerance is highly accurate, ±2% over the entire voltage, load and temperature range. The device's wide input and output voltage range, high bandwidth, high PSRR, and low noise performance make it ideal for power applications that are sensitive to noise, such as: PLL/VCO/mixer/LNA, very low noise meters, high speed/high precision data converters, medical applications (e.g. Imaging and diagnostics), high-precision power supplies, and rear regulators used as switching power supplies.

     The LT3042 operates with a small and low-cost 4.7µF ceramic output capacitor, thus optimizing stability and transient response. A single resistor is responsible for setting the external precise current limit (±10% over the entire temperature range). A single SET pin capacitor is used to reduce output noise and provide a reference soft start that prevents output voltage overshoot when switched on. In addition, the internal protection circuit of the device also includes reverse battery protection, reverse current protection, internal current limit with retrace and thermal limit with hysteresis. Other features include quick start capability (suitable for use with large SET pin capacitors) and a power supply good marker with programmable thresholds (to indicate output voltage regulation).

     The LT3042 is available in heat-enhanced 10-lead 3mm x 3mm DFN and 10-lead MSOP packages, both of which are compact in terms of board area. Class E and Class I versions are available in stock and have an operating junction temperature range of -40 °C to 125°C. The high temperature H-class version has a rated operating temperature range of -40 °C to 150°C, while the high reliability MP class version is specified to operate in a temperature range of -55 °C to 150°C.