●The LM27762 delivers very low-noise positive and negative outputs that are adjustable between ±1.5 V and ±5 V. Input-voltage range is from 2.7 V to 5.5 V, and output current goes up to ±250 mA. With an operating current of only 390 µA and 0.5-µA typical shutdown current, the LM27762 provides ideal performance for power amplifier and DAC bias and other high-current, low-noise negative voltage needs. The device provides a small solution size with few external components.
●Negative voltage is generated by a regulated inverting charge pump followed by a low-noise negative LDO. The inverting charge pump of the LM27762 device operates at 2-MHz (typical) switching frequency to reduce output resistance and voltage ripple. Positive voltage is generated from the input by a low-noise positive LDO.
●Positive and negative outputs of LM27762 have dedicated enable inputs. These outputs support independent timing for the positive and negative rails for specific system power-sequence needs. Enable inputs can be also shorted together and connected to the input voltage. The LM27762 has an optional Power Good feature.
●For all available packages, see the orderable addendum at the end of the data sheet.
● Generates Low-Noise Adjustable Positive Supply Voltage Between 1.5 V and 5 V and Negative Supply Voltage Between –1.5 V and –5 V
● Input Voltage Range 2.7 V to 5.5 V
● ±250-mA Output Current
● Inverting Charge Pump Followed by Negative LDO
● 2-MHz Low-Noise Fixed-Frequency Operation
● 2.5-Ω Inverter Output Impedance, VIN = 5 V
● Negative LDO Dropout Voltage 30 mV at 100 mA, VOUT = –5 V
● Positive LDO with 45-mV Dropout Voltage at 100 mA, VOUT = 5 V
● 390-µA Quiescent Current (Typical)
● Shutdown Quiescent Current to 0.5 µA (Typical)
● Current Limit and Thermal Protection
● Power Good Pin (Active Low)
● Create a Custom Design Using the LM27762 With the WEBENCH Power Designer