RSM3223 - Compact 3A CoolModule for Space-Constrained Designs

RSM3223 1A Buck CoolModule™ with Integrated Inductor

The RSM3223 is a compact, high-efficiency 1A buck CoolModule™ with an integrated inductor, designed for space-constrained point-of-load (PoL) power applications. Operating from a 2.4V to 5V input supply, this integrated DC-DC power module combines power conversion and magnetic integration in a miniature 2.5mm × 2.5mm × 1.2mm, 14-pin LGA package.

The RSM3223 offers an adjustable-output configuration using a 0.6V feedback reference, along with four fixed-output voltage options: 1.2V, 1.8V, 2.5V, and 3.3V. Fixed-output variants eliminate the need for an external feedback resistor divider, simplifying circuit implementation and reducing external component requirements.

High-Performance 1A Buck Power Conversion

The RSM3223 delivers up to 1A of output current with 1% output voltage accuracy and a 2MHz switching frequency. Its Constant-On-Time (COT) control architecture provides fast transient response, helping maintain stable output voltage regulation during rapid load changes.

The combination of high switching frequency and integrated magnetic components supports compact power supply designs with fewer external components. This makes the RSM3223 particularly suitable for distributed point-of-load power architectures where board space and component placement are important design considerations.

For electronic systems requiring a dedicated low-current power rail, the RSM3223 provides regulated DC-DC conversion in a small, integrated package.

Flexible PFM/PWM Control for Improved Light-Load Efficiency

The RSM3223 supports automatic Pulse Frequency Modulation (PFM)/Pulse Width Modulation (PWM) and forced PWM operating modes, allowing designers to select the switching behavior appropriate for their application.

Under light-load conditions, automatic PFM/PWM operation reduces switching activity to minimize switching losses and improve power conversion efficiency. As output current increases, the converter transitions to PWM operation to support changing load requirements.

Forced PWM mode maintains 2MHz switching operation, providing predictable switching-frequency behavior for applications where power supply noise and frequency management are important.

These operating modes make the RSM3223 suitable for electronic systems with varying power demands, including portable and battery-powered devices.

Adjustable and Fixed-Output Voltage Options

The RSM3223 supports five output-voltage configurations to accommodate different low-voltage power requirements.

Adjustable-Output Configuration

The adjustable-output version uses a 0.6V feedback reference and an external resistor divider to establish the desired output voltage. This provides flexibility for applications requiring a voltage outside the available fixed-output options.

Fixed-Output Configurations

Four fixed-output versions are available:

• 1.2V: Low-voltage digital logic and embedded electronics
• 1.8V: Digital interfaces and peripheral circuitry
• 2.5V: Sensors, interface circuits, and auxiliary power rails
• 3.3V: Microcontrollers, communication interfaces, and general-purpose logic

The fixed-output configurations eliminate the external feedback resistor divider, simplifying component selection and PCB layout. Designers can select the required output voltage while maintaining a common CoolModule™ package footprint.

Integrated Inductor and Ultra-Compact LGA Packaging

The RSM3223 integrates the power inductor within a miniature 2.5mm × 2.5mm × 1.2mm LGA package. With a package footprint of just 6.25mm², the device is well suited for high-density PCB layouts where space is limited.

Unlike conventional discrete buck converters that require an external inductor, the integrated CoolModule™ architecture reduces component count and simplifies power supply implementation.

The low-profile 1.2mm package height also makes the RSM3223 attractive for thin electronic assemblies, including wearable devices, smartphones, optical modules, and compact camera systems.

By integrating the inductor and power conversion circuitry, the RSM3223 helps designers minimize power supply complexity while maintaining a compact solution footprint.

Integrated Monitoring and Protection

The RSM3223 incorporates power-good monitoring, output discharge, overcurrent protection, and short-circuit protection to support reliable power supply operation.

An open-drain power-good output provides a status indication for system monitoring and power sequencing. The integrated output discharge function helps manage output voltage during shutdown, while overcurrent and short-circuit protection provide safeguards against abnormal load conditions.

These integrated functions help reduce the need for additional external circuitry and simplify system-level power management.

Applications for Compact 1A Point-of-Load Power

The RSM3223 is designed for applications requiring efficient, low-voltage power conversion in space-constrained electronic systems. Typical applications include optical transceiver modules, smartphones and mobile devices, wearable electronics, camera modules, industrial IoT (IIoT) systems, smart sensors, and Narrowband IoT (NB-IoT) devices.

Its combination of 1A output capability, integrated inductor, flexible operating modes, and multiple output-voltage configurations makes the RSM3223 CoolModule™ a compact solution for modern low-power electronic systems.

Explore our growing family of CoolModule™ integrated power solutions.