3A Ultra Low Dropout Regulator for Server Power Management ET5C108

As server processors and high-performance electronic components continue to operate at lower voltages, power management becomes increasingly demanding. Designers need to deliver high current while minimizing voltage loss, maintaining stable output voltage, and managing thermal performance.

The ET5C108 from ETEK is a high-performance CMOS ultra low dropout regulator designed for high-current power applications. It supports up to 3A output current, a wide 0.8V to 5.5V input voltage range, and adjustable 0.8V to 3.6V output voltage. With a typical dropout voltage of only 95mV at 3A, ET5C108 provides an efficient solution for server and other low-voltage power systems.

Why Ultra Low Dropout Matters in High-Current Power Systems

For a conventional LDO, the voltage difference between input and output must be sufficiently large to maintain regulation. When the dropout voltage is high, more voltage is converted into heat, resulting in greater power dissipation.

An ultra low dropout regulator reduces the required voltage headroom between VIN and VOUT. This is particularly valuable in server power architectures, where a high-current rail may have only a limited voltage margin.

ET5C108 achieves a typical dropout voltage of 95mV at 3A, allowing it to maintain regulation even when the input voltage is close to the required output voltage. This low-dropout characteristic can help reduce unnecessary voltage loss and improve thermal performance in compact power designs.

ET5C108 Delivers 3A Output with Flexible Voltage Configuration

The core advantage of ET5C108 is its combination of high output current and low dropout performance. The device can deliver up to 3A load current, making it suitable for power rails supplying processors, FPGAs, DSPs, memory, and other demanding electronic components.

The main input voltage range is 0.8V to 5.5V, while the BIAS supply supports 2.2V to 5.5V. The output voltage can be externally programmed from 0.8V to 3.6V through the FB pin and an external resistor divider.

This flexible configuration allows the ultra low dropout regulator to support different voltage rails without requiring a fixed output version for every application.

Other important features include:

– Up to 3A output current

– 95mV typical dropout voltage at 3A

– 0.8V to 5.5V input voltage

– 2.2V to 5.5V BIAS voltage

– 0.8V to 3.6V adjustable output

– Power Good (PG) output

– Excellent input and load transient response

– Soft-start function

– Current-limit protection

– Thermal shutdown protection

– Surge current suppression

– DFN10 package, 3mm × 3mm

How the ET5C108 Pin Configuration Supports Power Design

The ET5C108 DFN10 package integrates the key control and power pins required for a high-current LDO design. IN is connected to the main input supply, while OUT provides the regulated output voltage.

The FB pin works with an external resistor divider to determine the output voltage. BIAS provides the bias supply, while EN controls the device’s enable and shutdown operation.

The SS pin can be connected to an external capacitor to control the soft-start process, helping manage the output voltage rise during startup. The PG pin provides a power-status indication that can be monitored by a system controller.

The provided pin-definition diagram shows the DFN10 and QFN20 package configurations, including the thermal pad, giving engineers a clear reference for PCB layout and component integration.

Typical Application: Adjustable High-Current LDO Regulation

In the typical application circuit, VIN is connected to the input supply through a 1μF input capacitor, while the BIAS pin uses a separate bias supply and bypass capacitor. The EN pin determines whether the regulator is enabled or disabled.

At the output side, R1 and R2 form the feedback network connected to FB, allowing engineers to configure the required VOUT. A 10μF output capacitor supports stable regulation, while the SS capacitor controls the startup ramp.

The PG output can also be connected to a system monitoring circuit to indicate whether the output voltage has reached the expected operating condition.

This configuration demonstrates how the ultra low dropout regulator can be integrated into a compact adjustable power rail with relatively few external components.

Protection Functions for Reliable Server Power

High-current server power rails require not only low dropout performance but also reliable protection. ET5C108 integrates multiple protection functions, including current limiting, thermal shutdown.

Its soft-start function also helps control the output voltage rise during startup, reducing the impact of inrush current on the power system. Combined with its strong input and load transient response, these features help the ultra low dropout regulator maintain stable operation under changing load conditions.

The compact DFN10 package further helps designers integrate the device into space-constrained server boards and other high-density electronic systems.

Where Can the ET5C108 Ultra Low Dropout Regulator Be Used?

With 3A output capability, adjustable voltage, low dropout performance, and integrated protection, ET5C108 is suitable for:

– Server power management

– FPGA and DSP power rails

– Processor and memory power supplies

– Telecom equipment

– Industrial electronics

– High-current post-regulation

– Compact power management systems

For engineers developing low-voltage, high-current power rails, ET5C108 provides a practical ultra low dropout regulator solution that balances efficiency, flexibility, and reliability.

Explore ET5C108 for Your Next Power Design

Looking for an ultra low dropout regulator capable of delivering 3A for a server or high-performance electronic system?

Explore the ET5C108 product page to review the complete electrical specifications, pin configuration, typical application circuit, and technical documentation.

👉Contact ETEK today to discuss your power management requirements, request technical support or samples, and find the right ultra low dropout regulator for your next design.