ADI LTM8063: 40-V 2-A uModule Step-Down Converter
Overview
The LTM8063 from Analog Devices is a complete step-down DC-DC power supply housed in a small surface-mount BGA package. Inside the module are the switching controller, the power MOSFETs, the inductor and the support components, so the designer adds only input and output capacitors and a couple of setting resistors. With a 3.2 V to 40 V input range and a 2 A continuous output rating, it is aimed at engineers who want the simplicity of a power module in a wide-input industrial or automotive rail without designing a discrete converter. This article covers its verified specifications, thermal behavior, and design notes.
Part Overview
The uModule (power module) approach moves the magnetics and the power stage inside the package. The LTM8063 integrates the controller, the power switches, the shielded inductor and the compensation network in a 6.25 mm by 4 mm by 2.22 mm overmolded BGA. This means the difficult layout choices, such as inductor selection and switching-loop area, are resolved inside the module; the PCB outside the package only carries the input and output capacitance and the feedback and enable connections. An adjustable output down to 0.8 V allows the module to power modern low-voltage MCUs, FPGAs and analog rails from a wide bus.Key Features
Complete DC-DC in one package: controller, FETs, inductor and support components.
40 V input rating for industrial and automotive buses.
2 A continuous output (2.5 A peak capability).
Adjustable output from an internal reference near 0.8 V.
Silent Switcher architecture integrated into the module for low EMI.
Small 28-ball BGA suitable for automated surface-mount assembly.
Minimal external components, which shortens design time.
Key Specifications
Input voltage range: 3.2 V to 40 V (per datasheet)
Output current: 2 A continuous, 2.5 A peak (per datasheet)
Output voltage range: adjustable from about 0.8 V up to about 15 V (per datasheet)
Topology: integrated synchronous buck uModule (power module)
Internal contents: controller, power switches, shielded inductor, support components
EMI: Silent Switcher architecture for low radiated and conducted emissions
Package: 28-ball BGA, about 6.25 mm x 4 mm x 2.22 mm
Operation temperature: -40 C to 125 C (per datasheet)
(Values per the official LTM8063 datasheet; verify thermal derating for your Vin.)Applications and Design Notes
The LTM8063 fits applications where board space and design time are scarcer than the module cost: industrial control buses, automotive auxiliary rails, distributed point-of-load supplies, and any 24 V or 12 V system that must generate a low-voltage rail quickly without a full converter design cycle. The integrated inductor also removes the largest external component from the bill of materials and from the board placement.
Design guidance:Place the input and output capacitors as close as possible to the module pins to keep the switching loop tight even though the hot loop is mostly inside the package.
Use a low-ESR ceramic input capacitor rated for the input ripple current, and size the output capacitance for the load-transient requirement.
Set the output voltage with a feedback resistor divider to the 0.8 V internal reference.
Provide the recommended ground plane and thermal vias under the BGA; the package dissipates heat through the underside, and the vias set the achievable output current at high ambient temperature.
Respect the minimum input-to-output headroom and dropout; at low input voltage the available output current drops.
Design Considerations and Common Mistakes
The module simplifies layout but does not eliminate thermal design. The 2 A rating assumes a defined copper and via layout; on a thin, poorly grounded board the part derates earlier than expected.
Do not skimp on the input capacitor. Even with the hot loop inside the package, the external input capacitor must handle the ripple current and keep the input rail stable.
Because the inductor is inside the package, you cannot change it to tune the loop. Follow the recommended external capacitor values rather than experimenting with non-standard values.
The output maximum is limited (around 15 V per datasheet) even though the input goes to 40 V. Confirm your target output sits inside the valid range.
Mounting and reflow follow standard surface-mount processes, but the BGA ball pitch requires standard SMT assembly capability.
Conclusion
The LTM8063 trades the cost and flexibility of a discrete converter for a very short design cycle: a 40 V, 2 A step-down that fits in a small BGA with the inductor and power stage already designed in. For teams that need a reliable wide-input rail without allocating converter-layout effort, it is a low-risk choice. The remaining design work is ordinary power-module care: good input capacitance, an honest thermal layout, and an output divider set to the required rail.
FAQ
Q: What is inside the LTM8063 package?
A: The switching controller, the power MOSFETs, a shielded inductor, and the support and compensation components, so the external design needs only capacitors and setting resistors.
Q: What input voltages can it accept?
A: 3.2 V to 40 V, which covers 12 V and 24 V industrial and automotive buses.
Q: How much output current can it supply?
A: 2 A continuous, with a 2.5 A peak capability, subject to thermal derating at high input voltage and ambient temperature.
Q: Does it need an external inductor?
A: No. The inductor is integrated inside the package, which is the main reason the external design is so simple.
Q: Why use a uModule instead of a discrete buck?
A: To save design time and board area. The trade-off is higher per-unit cost and less freedom to tune the power stage for a specific niche efficiency target.
For exact specifications and design guidance, refer to the official Analog Devices datasheet for LTM8063:
https://www.analog.com/media/en/technical-documentation/data-sheets/ltm8063.pdf
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