LM27762DSSR

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.

Applications

• Hi-Fi Audio Headphone Amplifiers
• Operational Amplifier Power Biasing
• Powering Data Converters
• Wireless Communication Systems
• Interface Power Supplies
• Handheld Instrumentation

Key features

• 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