Dual channel, low noise bias generator in 3mm x 5mm QFN package

    Linear Technology Corporation introduces the dual-channel IC LT3095, a device that provides two very low noise, low ripple biased power supplies from a single input. Each channel incorporates a single-chip boost DC/DC converter, which is poststabilized by an integrated ultra-low noise and high PSRR (power rejection ratio) linear regulator. The LT3095 provides continuous output current up to 50mA at output voltages up to 20V, Total ripple and noise < 100µVP-P. The device operates in the input voltage range of 3V to 20V,  making it compatible with a wide range of power supplies

     The LT3095's fixed-frequency, peak-current mode boost DC/DC converter includes an integrated 950mA power switch, Schottky diodes, and internal frequency compensation. Switching frequencies from 450kHz to 2MHz can be programmed with a single resistor or synchronized to an external clock, thus allowing the use of delicate external components. Combined with a compact 3mm x 5mm QFN package, the LT3095 provides a simple, compact, and efficient solution for instrument amplifiers, RF and data conversion systems, and other low-noise bias applications.

    The LT3095's linear voltage regulator uses Linear Technology's proprietary current source reference architecture, which provides many advantages, such as the ability to set the output voltage with a single resistor, with bandwidth, noise, PSRR, and load regulation performance largely unaffected by output voltage. The integrated output noise (in the 10Hz to 100kHz bandwidth) is only 4µVRMS, and the PSRR exceeds 70dB over the entire switching frequency range, resulting in a total noise and ripple of <100µVP-P.

     The linear regulator adjusts the output voltage of the boost converter to be 2V higher than the linear regulator output voltage, thereby optimizing power consumption, transient response, and PSRR performance. To improve system reliability, the LT3095 provides short circuit and thermal protection, as well as individual and precise enable/UVLO thresholds for each channel. In micro-power operation, both EN pins are pulled down.

     The LT3095's symmetrical pin configuration simplifies PCB design. The device is available in an enhanced heat resistant 3mm x 5mm QFN-24 package, and both the industrial Class E and I versions operate in the temperature range of -40 °C to 125°C, and the military MP class versions operate in the temperature range of -55 °C to 125°C.