feature

5V fixed output voltage 30mA maximum output current built-in charge pump, there are three modes of operation: 1×, 1.5×, 2×. Minimum External Components Flying Capacitor Only 0.22μF Low Noise, Constant Frequency Operation (1.2 MHz) High Efficiency at Heavy Load, Low Frequency Light Operation Load Low Quiescent Current Efficiency Up to 92% 2.9V to 5.5V Input Voltage Range Limits Inrush Current Soft Start Input Undervoltage Lockout Protection (UVLO) Short Circuit Protection (SCP) Thermal Shutdown Protection (TSD) 8-Bump 1.21 x 1.21mm, 0.4mm Pitch WLCSP

application

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illustrate

5665 -ic/" title="FAN5665 Product Parameters, Documentation and Sourcing Information" target="_blank">FAN5665 is a 5V switched capacitor boost input voltage 2.9V DC/DC converter to 5.5V. Switch reconfiguration and part The switch utilizes technology for the entire input voltage range. The FAN5665 includes built-in under-voltage lockout, short circuit and thermal protection circuits. The FAN5665 has 8 bumps with 0.4mm spacing in the WLCSP package.

Introduction to function description

The FAN5665 is a 5V switched capacitor regulator with low output ripple and high efficiency. The maximum output current is 30mA. Linear regulation loop The linear regulation loop (including the power transistor, output feedback and error amplifier is used to regulate the output voltage and reduce peaks when the current mode changes. When the soft start is energized, the device has a 0.5ms soft start control magnetizing inrush current to slowly increase the output. Operation mode FAN5665 has 1× mode, 1.5× mode and 2× mode. The input voltage is compared with reference to determine the mode. The light/heavy load monitor in 1.5×/2× mode, there is current sense output current. If When a light load condition is detected, the device switches to a lower switching frequency of 50 kHz. This frequency is a good compromise to achieve high light load efficiency with audible noise generation. If the load is heavy (typically over 5 mA), Device switches at 1.2 MHz to reduce output voltage ripple. Protects when die temperature exceeds 150 °C. Shuts down when temperature drops by about 10 °C. Short circuit protection helps avoid damage to device when output is shorted to ground. Whenever Output voltage is pulled below 150mV, short circuit triggers protection and limits input current. If voltage >150mV, protection is thermal protection and shuts down if die temperature exceeds 150°C. Application info High switching frequency of 1.2 MHz allows use of small capacitors, but capacitors The material affects input and output ripple, so low ESR capacitors are desirable.

Another parameter esr that is affected is efficiency. For proper operation, two ceramic barrel capacitors, as well as one ceramic input capacitor and one ceramic output capacitor are recommended. Input Capacitor Selection Often, ripple on the input power rail also affects. output ripple. The lower the esr of the input capacitor, the lower the input and output ripple. This may require adjustment of the input capacitors, including the value and their physical location on the PCB, depending on the characteristics of the voltage justifying the source of the input power. Generally, a 1 to 2µF ceramic capacitor close to the fan 5665 is enough. X5R and X7R capacitors provide adequate performance between -40°C and +85°C. The table below represents typical recommended input capacitors. Output Capacitor Selection In general, multilayer ceramic capacitors are recommended for low ESR. The switching frequency-dependent value of the output batch of a capacitive converter also determines the total output voltage ripple. Higher output capacitor values reduce voltage drop during load transients. In general, output capacitors can be larger than barrel capacitors, depending on the desired output ripple tolerance. X5R and X7R rated capacitors provide adequate performance over the -40°C to +85°C temperature range. The table below contains typical recommended output capacitors. Selection of Barrel Capacitors A barrel capacitor is usually the smallest capacitor in a charge pump circuit, but its esr can play an important role in determining output voltage tolerance. Only ceramic capacitors are recommended for this location. The flying capacitor is determined by the switching frequency. At 1.2 MHz, a 0.22 µF flight capacitor is suitable for most applications, but can be added to improve output tolerance. Rely on the materials of multilayer ceramic capacitors over a wide temperature range. Relatively stable capacitor temperature characteristics are recommended for at least X5R and X7R. Z5U or Y5V type capacitors are not recommended. The table below shows typical recommended barrel capacitors.

LED Driver The Fan 5665 can be configured as an LED driver by connecting a resistor in series with the LED to generate constant current as shown below. The value of the series resistor is led by the pass. The maximum current delivery time of the FAN5665 is 30 mA. The number of parallel branches and the current through the LED should be based on the maximum output current. PCB layout due to high switching frequency and corresponding transient currents. All external capacitors should be very close to the pins of the IC. A clean board layout with good ground planes ensures proper device operation. The printed circuit board recommends a two-layer board as shown. Note that the bottom layer is a dedicated ground plane.