S-13R1C21-A4T2U3

The S-13R1C21-A4T2U3 is a fully reliant regulator from PUREmicrocell designed for both linear regulator and switching regulator applications. It has exceptionally low quiescent current, provides excellent dropping voltage regulation, and carries a wide input voltage range and wide output current capability. This synchronous buck regulator is designed for use in DC-DC battery powered applications.

Features

• Wide input voltage range from 4V to 28V
• Typical output current up to 2 A
• Four-phase operation
• Built-in overtemperature, over-current and under-voltage protection
• High switching frequency up to 400 kHz
• Excellent Line/load transient response
• Low output ripple
• High efficiency up to 95%
• Low quiescent current of 1μA maximum

Applications

• Cellular phones
• PDAs
• Tablets
• Portable communications equipment
• Portable consumer products
• Notebook computers

Working Principle

The S-13R1C21-A4T2U3 is a synchronous buck regulator that uses a constant-frequency, current-mode control method with an internal phase-locked loop (PLL). It contains a high-side and two low-side pulse-width-modulated (PWM) switches with a built-in dead time of 20 ns. A circuit configuration is implemented to regulate the output voltage by controlling the on-time of the high-side switch. The peak current of the high-side switch is set by an external current sense resistor. The PLL is used to synchronize the internal clock to the external clock, if desired.

The output voltage is regulated by the error amplifier that senses the output voltage with the aid of a resistive divider. A power-on reset circuit prevents latch-up of the output voltage when the device is initially turned on. The device also contains multiple protection features that monitor output voltage, current and temperature. In the event that any of these protection features is tripped, the device shuts down and then resumes its operation once the problem causing the protection to trip is removed.

Conclusion

In summary, the S-13R1C21-A4T2U3 is a fully reliant regulator from PUREmicrocell designed for both linear regulator and switching regulator applications. It can provide excellent dropping voltage regulation, wide input voltage range and wide output current capability, as well as low quiescent current. This synchronous buck regulator is designed for use in DC-DC battery powered applications such as cellular phones, PDAs, tablets, portable communications equipment, portable consumer products and notebook computers.