LTC3265 Low-Noise, High-Voltage Dual Polarity Output Power Supply

 Analog Devices' LTC3265 is a low-noise dual polarity output power supply, which includes a boost charge pump, an inverting charge pump, and two low-noise positive and negative LDO post regulators. The boost charge pump powers the positive LDO post regulator while the inverting charge pump powers the negative LDO regulator. Each LDO can provide up to 50 mA of output current. The LDO output voltages can be adjusted using external resistor dividers.

The charge pumps employ low quiescent current Burst Mode® operation or low-noise constant frequency mode. During Burst Mode operation, the boost charge pump regulates its output (V_OUT+) to 0.94 • 2 • V_{IN_P} while the inverting charge pump regulates its output (V_OUT-) to –0.94 • V_{IN_N}. In Burst Mode operation the LTC3265 draws only 135 μA of quiescent current with both LDOs on. In constant frequency mode, the boost and inverting charge pumps produce outputs equal to 2 • V_{IN_P} and -V_{IN_N} respectively and operate at a fixed 500 kHz or to a programmed value between 50 kHz to 500 kHz using an external resistor. The LTC3265 is available in low-profile 3 mm × 5 mm × 0.75 mm 18-lead DFN and thermally enhanced 20-lead TSSOP packages.

Features
Boost charge pump generates 2 • VIN_P (VIN_P range: 4.5 V to 16 V) Inverting charge pump generates -VIN_N (VIN_N range: 4.5 V to 32 V) Low-noise positive LDO post regulator up to 50 mA Low-noise negative LDO post regulator up to 50 mA 135 μA quiescent current in Burst Mode operation with both LDO regulators on		50 kHz to 500 kHz programmable oscillator frequency Stable with ceramic capacitors Short-circuit and thermal protection Low-profile 3 mm × 5 mm 18-lead DFN and thermally enhanced 20-lead TSSOP packages
Applications
Low-noise bipolar and inverting supplies		Industrial and instrumentation low-noise bias generators