1.5-A negative LDO offers fast transient response and low output noise
Output voltage noise is 60 µVrms over a 10 Hz to 100 kHz bandwidth. The LT3015 features operating current of 1.1 mA and <1 µA in shutdown, and quiescent current is well controlled in dropout. The LT3015 is the negative complement to one of Linear’s positive LDOs, the 1.5 A LT1963A, and is ideal for negative logic supplies, low noise instrumentation, industrial supplies and for post-regulating switching supplies.
The LT3015’s reference-amplifier topology provides precision DC characteristics, as well as good loop stability with a wide range of output capacitors, including small, low cost ceramic output capacitors. It is stable with only a 10 µF output capacitor. The external capacitors can be used without the necessary addition of series resistance (ESR) as is common with many other regulators. The LT3015 exhibits bidirectional shutdown capability that allows the device to operate with either positive or negative logic levels. Moreover, due to the LT3015’s high shutdown threshold accuracy, the SHDN pin can be used to set a programmable undervoltage lockout (UVLO) threshold for the regulator input supply. Internal protection circuitry for the IC includes reverse-output protection, precision current limiting with foldback to keep the power transistor in its safe operating area, and thermal limiting with hysteresis.
The LT3015 is available in a low profile (0.75 mm) 3 mm x 3 mm 8-lead DFN with backside thermal pad, a 12-lead MSOP package with backside thermal pad, a through-hole power TO-220 package, and a surface mount power DD-Pak package. E- and I-grade operating junction temperature is -40 to +125°C, and the MP grade is specified from -55 to +125°C. 1000-piece pricing for the E, I and MP grades in DFN, MSOP, TO-220 / DD-Pak starts at $2.67 each, and devices are available from stock.
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