FAN2558S18X

The FAN2558/9 low voltage CMOS LDOs feature fixed or adjustable output voltage, 180mA load current, delayed power good output (open drain) and 1% output accuracy with excellent line and load regulation. An external bypass capacitor provides ultra-low noise operation. The FAN2558/9 low voltage LDOs incorporate both thermal shutdown and short circuit protection. Output is stable with a 1μF, low ESR capacitor. The FAN2558/9 family is available in 5-Lead SOT-23, 6-Lead SOT-23 and 2x2mm MLP-6 packages. FAN2558: Fixed Output LDO with Power Good output FAN2558ADJ: Adjustable Output LDO with Power Good output FAN2559: Fixed Output LDO with Power Good output, Low Noise Available standard output voltages are 1.0, 1.2V, 1.3V, 1.5V, 1.8V, 2.5V, 3.3V, 3.5V, 3.6V, and 3.8V. Custom output voltage options are also available. Utilizing BiCMOS technology, the FAN2525/FAN2559 product family is optimized for use in compact battery powered systems. These LDOs offer a unique combination of high ripple rejection, low noise, low power consumption, high tolerance for a variety of output capacitors, and less than 1μA “OFF” current. In the circuit, a differential current sense amplifier controls a series-pass P-Channel MOSFET to achieve high ripple rejection. A separate error amplifier compares the load voltage at the output with an onboard trimmed low voltage bandgap reference for output regulation. Thermal shutdown and current limit circuits protect the device under extreme conditions. When the device temperature reaches 150°C, the output is disabled. When the device cools down by 10°C, it is re-enabled. The user can shut down the device using the Enable control pin at any time. The current limit circuit is trimmed, which leads to consistent power on /enable delays, and provides safe short circuit current densities even in narrow traces of the PCB. A carefully optimized control loop accommodates a wide range of ESR values in the output bypass capacitor, allowing the user to optimize space, cost, and performance requirements. An Enable pin shuts down the regulator output to conserve power, reducing supply current to less than 1μA. The fixed-voltage FAN2559 has a noise bypass pin. Power Good is available as a diagnostic function to indicate that the output voltage has reduced within 5% of the nominal value. The six pin adjustable-voltage version utilizes pin 5 to connect to an external voltage divider which feeds back to the regulator error amplifier, thus setting the output voltage to the desired value.

Applications

• Processor Power-up sequencing
• PDAs, Cell Phones
• Portable Electronic Equipment
• PCMCIA Vcc and Vpp regulation/switching

Key features

• Fixed 1.0V, 1.2V, 1.3V, 1.5V, 1.8V, 2.5V, 3.3V, 3.5V, 3.6V, 3.8V and Adjustable Output
• Power Good Indicator with Open Drain Output
• 180mA Output Current
• 100μA Ground Current Cbypass for Low Noise Operation
• Fast Enable for CDMA Applications
• High Ripple Rejection
• Current Limit
• Thermal Shutdown
• Excellent Line and Load Regulation
• Requires Only 1μF Output Capacitor
• Stable with 0 to 300mΩ ESR
• TTL-level Compatible Enable Input
• Active Output Discharge