GLF71325 Load Switch IC: Datasheet, Pinout & Applications

The GLF71325 from GLF Integrated Power is a 4A, ultra-low-power load switch IC designed for efficient power distribution in compact electronic systems. Featuring a 1.1V to 5.5V input voltage range, 18mΩ typical on-resistance at 3.3V and just 1nA typical quiescent current, the GLF71325 is suitable for battery-powered devices, SSD power management and low-power subsystems.

This guide covers the GLF71325 datasheet specifications, pinout, operating principles, PCB design considerations and application scenarios to help engineers and purchasing teams evaluate the device.

1. GLF71325 Overview

The GLF71325 is part of the GLF Integrated Power IQSmart family of integrated load switches. It combines low conduction resistance, ultra-low current consumption and controlled output voltage rise time in a compact 6-bump wafer-level chip-scale package (WLCSP).

Unlike a basic discrete MOSFET switching arrangement, the GLF71325 integrates control circuitry, an enable input with an internal pull-down resistor and an output discharge function.

Its controlled turn-on behavior helps reduce inrush current associated with charging downstream capacitors, minimizing supply voltage disturbance during power sequencing.

Key Features

• Ultra-low power consumption: 1nA typical quiescent current at 3.3V input.

• Low conduction loss: 18mΩ typical on-resistance at 3.3V.

• Controlled switching: 2.2ms typical output voltage rise time under specified test conditions.

• Maximum continuous switch current rating of 4A.

• Integrated output discharge and active-high enable control.

• Compact 0.97 × 1.47 × 0.55mm WLCSP package.

2. GLF71325 Datasheet Specifications

The following specifications are based on the manufacturer's GLF71325 Product Specification, Revision 0.3, August 2023. Typical values depend on the stated operating and test conditions.

Important: The 4A rating does not mean the device can continuously carry 4A under every PCB layout, ambient temperature or input-voltage condition. Designers should evaluate on-resistance, power dissipation and thermal performance under actual operating conditions.

3. GLF71325 Pinout and Pin Functions

The GLF71325 is supplied in a 6-bump WLCSP measuring approximately 0.97 × 1.47 × 0.55mm.

The package provides two input connections, two output connections, one ground connection and one enable input.

Pinout note: The pin assignments above follow the manufacturer datasheet. Refer to the official top-view and bottom-view package drawings before creating the PCB footprint. The two views are mirrored and must not be interchanged.

How Does the Enable Pin Work?

The GLF71325 uses an active-high enable input:

• EN High: The main switch is enabled and VOUT rises with the controlled slew rate.

• EN Low: The main switch turns off and the internal output discharge circuit helps discharge the output capacitor.

An internal pull-down resistor helps establish a defined disabled state when the external enable signal is not actively driven.

4. How Does the GLF71325 Load Switch Work?

The GLF71325 controls the connection between an upstream supply rail and a downstream load.

When the enable signal is asserted, the internal switching device turns on gradually. This controlled transition reduces the sudden charging current that would otherwise flow into downstream capacitors.

Low On-Resistance and Conduction Loss

The typical on-resistance is 18mΩ at a 3.3V input under the specified datasheet test conditions.

For an illustrative 2A current at the stated typical resistance:

Voltage drop = I × RON = 2A × 0.018Ω = 36mV

Conduction loss = I² × RON = 2² × 0.018 = 0.072W

These are theoretical calculations using a typical resistance value, not guaranteed worst-case results. Actual losses change with input voltage, temperature and device operating conditions.

Ultra-Low Quiescent and Shutdown Current

At VIN = 3.3V, the GLF71325 specifies a typical quiescent current of 1nA and shutdown current of 16nA.

Low current consumption is particularly relevant for designs that spend extended periods in standby or operate from a limited energy source.

However, total system standby consumption also depends on external circuitry, downstream leakage and operating temperature. The typical 25°C current figures should not be used as guaranteed current limits across the full temperature range.

Controlled Slew Rate

The integrated slew-rate control provides a typical VOUT rise time of 2.2ms under the manufacturer's specified measurement conditions.

By slowing the output voltage transition, the device can reduce peak charging current into capacitive loads and help avoid excessive voltage droop on a shared input supply.

The GLF71325 is a load switch, not a voltage regulator. When enabled, the output voltage generally follows the input supply minus the voltage drop across the switch.

5. GLF71325 PCB Design and Application Circuit Considerations

Proper PCB layout is essential for achieving stable switching operation, low voltage drop and acceptable thermal performance.

Input Capacitor Placement

Place a suitable input capacitor close to the VIN connection and ground return. Local input capacitance helps reduce voltage disturbance caused by transient current during switching.

Output Capacitor Placement

An output capacitor can help reduce voltage undershoot during turn-off, especially when PCB trace inductance or an inductive load is present.

Place the output capacitor close to the VOUT and GND connections where practical. Select capacitance based on the load, output discharge behavior and the manufacturer's application guidance.

PCB Routing and Thermal Design

• Keep VIN and VOUT power paths short.

• Use appropriately wide copper traces to minimize resistive loss.

• Minimize parasitic inductance in the switching current path.

• Verify WLCSP footprint dimensions, bump pitch and assembly requirements.

• Evaluate temperature rise at the maximum intended load current.

For designs operating near the 4A current limit, thermal evaluation and real-board testing are especially important.

6. GLF71325 Applications

6.1 SSD and Data Storage Power Management

The GLF71325 can be considered for controlled power switching in SSD and data-storage subsystems that operate within its voltage and current limits.

Its low standby consumption and controlled turn-on behavior can be useful in power-managed storage architectures where downstream rails are enabled and disabled according to system operating states.

6.2 Mobile and Battery-Powered Devices

For mobile electronics, low quiescent current and low on-resistance help reduce unnecessary power consumption while enabling controlled power delivery to individual subsystems.

6.3 Wearable and IoT Electronics

Compact, battery-powered systems may benefit from the GLF71325's small WLCSP footprint and low standby consumption.

Typical design considerations include available PCB area, operating voltage, startup behavior and sleep-mode leakage.

6.4 Low-Power Subsystem Switching

The GLF71325 may be used to control peripheral or subsystem supply rails, allowing a host controller to disconnect power when a subsystem is not required.

Such applications should verify enable logic compatibility, load capacitance and power sequencing requirements.

7. GLF71325 Selection and Replacement Considerations

When choosing the GLF71325 for a new design or evaluating a substitute for an existing load switch, engineers should check the following parameters.

Devices with similar input-voltage and current ratings are not necessarily drop-in replacements. Package configuration, timing, protection features and output discharge behavior may differ.

8. GLF71325 Datasheet Download

For complete electrical characteristics, pin configuration, timing diagrams, recommended footprint and packaging information, refer to the official GLF Integrated Power documentation.

Official GLF71325 Datasheet:
   GLF71325 Product Specification Rev. 0.3 (PDF)

Manufacturer Product Page:
   GLF Integrated Power – GLF71325

The manufacturer datasheet should be treated as the primary technical reference. Verify the latest document revision before finalizing a production design.

9. GLF71325 Pricing, Availability and RFQ

If you are sourcing the GLF71325 load switch IC for prototyping, production or BOM procurement, DataStorageIC can assist with a quotation request and availability inquiry.

When requesting a quotation, please provide:

• Manufacturer Part Number: GLF71325

• Required quantity

• Target price, if available

• Requested delivery date

• Destination country or region

• Any required packaging or documentation

Pricing, lead time and available quantities are subject to confirmation at the time of inquiry.

Request GLF71325 Pricing and Availability: Visit DataStorageIC and submit your part-number requirements through the website inquiry form.

10. Related Products and Further Reading

For engineers exploring other GLF Integrated Power devices, additional product information is available through the DataStorageIC load switch product category.

• GLF Integrated Power Load Switch ICs – Browse GLF71325 and related load switch products.

• DataStorageIC Electronic Components – Explore electronic components and BOM sourcing options.

Conclusion

The GLF71325 offers a combination of 4A current capability, ultra-low quiescent current, low on-resistance and controlled output switching in a small WLCSP package.

For engineers designing compact and energy-efficient electronics, its integrated enable and output discharge functions can simplify power-path control. Proper evaluation of load current, thermal conditions, PCB layout and power sequencing remains essential.

For GLF71325 sourcing, pricing or availability information, contact DataStorageIC with your target quantity and delivery requirements.