Uninterruptable-supply

Description: This circuit provides a continuous supply of regulated +5 V, with automatic switch-over between line power and battery backup. When the line-powered input voltage is +5 V, it supplies 4 A to the MAX630 and trickle charges the battery. If the line-powered input falls below the battery voltage, the 3.6 V battery supplies power to the MAX630, which boosts the battery voltage up to +5 V, thus maintaining a continuous supply to the uninterruptible +5 V bus. Since the +5 V output is always supplied through the MAX630, there are no power spikes or glitches during power transfer. The MAX630's low-battery detector monitors the line-powered +5 V, and the LBD output can be used to shut down unnecessary sections of the system during power failures. Alternatively, the low-battery detector could monitor the NiCad battery voltage and provide a warning of power loss when the battery is nearly discharged. Unlike battery backup systems that use 9-V batteries, this circuit does not need +12 or +15 V to recharge the battery. Consequently, it can be used to provide +5 V backup on modules or circuit cards which only have 5 V available.

This circuit functions as a reliable power management system that ensures a steady supply of +5 V to connected devices, utilizing the MAX630 voltage regulator for optimal performance. The automatic switch-over feature between line power and battery backup is crucial for applications requiring uninterrupted power, such as in telecommunications or critical computing environments.

The circuit begins with a line-powered input that delivers +5 V, capable of supplying up to 4 A to the MAX630. This regulator is responsible for providing a stable output voltage, even under varying load conditions. In addition, while the line power is active, the system simultaneously trickle charges a 3.6 V NiCad battery, ensuring that the battery remains ready for use in case of power failure.

When the input voltage drops below the battery voltage, the circuit seamlessly transitions to battery operation. The MAX630 boosts the battery's 3.6 V output to the required +5 V, thus maintaining the supply to the load without interruption. This design minimizes the risk of power spikes or glitches during the switch-over, which is critical for sensitive electronic devices.

The inclusion of a low-battery detector (LBD) within the MAX630 adds an additional layer of functionality. This detector continuously monitors the input voltage and can signal the system to shut down non-essential components during power failure scenarios, effectively conserving battery life. Furthermore, it can also monitor the battery voltage, alerting users when the battery is nearing depletion, which is essential for maintaining operational readiness.

One significant advantage of this circuit is its independence from higher voltage sources for battery recharging. Unlike traditional battery backup systems that require +12 V or +15 V for charging, this design is optimized for environments where only +5 V is available. This feature makes it particularly suitable for modules or circuit cards designed around a +5 V supply, simplifying integration into existing systems.

Overall, the circuit is a robust solution for providing uninterrupted power, ensuring reliability and efficiency in critical applications where power continuity is paramount.This circuit provides a continuous supply of regulated + 5 V, with automatic switch-over between line power and battery backup. When the line-powered input voltage is a + 5 V, it provides 4A V to the MAX630 and trickle charges the battery, If the line-powered input falls below the battery voltage, the 3.6 V battery supplies power to the MAX630, which boosts the battery voltage up to +5 V, thus maintaining a continuous supply to the uninterruptable +5 V bus.

Since the +5 V output is always supplied through the MAX630, there are no power spikes or glitches during power transfer. The MAX630"s low-battery detector monitors the line-powered + 5 V, and -the LBD output can be used to shut down unnecessary sections of the system during power failures. Alternatively, the low-battery detector could monitor the NiCad battery voltage and provide warning of power loss when the battery is nearly discharged.

Unlike battery backup systems that use 9-V batteries, this circuit does not need +12 or +15 V to recharge the battery, Consequently, it can be used to provide + 5 V backup on modules or circuit cards which only have 5 V available.