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Summary: This article reviews the LTM4622IY#PBF (Analog Devices) µModule buck regulator. Core specifications: 3.6–20V input, programmable 0.6–5.5V output, and 2.5A continuous per channel for both channels (see the official datasheet for details). Design recommendations and thermal derating are based on the official datasheet and PCB layout practices.
Official Datasheet (PDF): Download the LTM4622 Datasheet (Analog Devices)
LTM4622IY#PBF
Part Number: LTM4622IY#PBF
Manufacturer: Analog Devices Inc.
Description: DC DC CNVRTR 0.6–5.5V
Data Sheet: Download PDF
Category: DC DC Converters
Unit Price: View Product
In Stock: 5000
Lead Time: To be Confirmed
Introduction
The LTM4622IY#PBF is a dual-channel µModule buck regulator from Analog Devices. It puts the controller, MOSFETs, inductor, and some passive parts inside one small package. This saves time in design and saves board space. The part can work from 3.6 V to 20 V input. The output can be set from 0.6 V to 5.5 V with only one resistor. Each channel can give about 2.5 A continuous current. You can connect the two channels in parallel to get more current. This makes the module good for use in point-of-load power for FPGAs, ASICs, DSPs, or other high-speed chips.
Key Specifications
| Parameter | Value | Note |
|---|---|---|
| Input Voltage (VIN) | 3.6 V – 20 V | Wide range for many systems |
| Output Voltage (VOUT) | 0.6 V – 5.5 V | Set by one resistor |
| Output Current | 2.5 A per channel | Can parallel for more |
| Channels | 2 | Independent or parallel use |
| Switching Frequency | ~1 MHz default | Adjustable |
| Package Size | 6.25 × 6.25 mm | µModule package |
| Protections | OCP, OVP, Thermal, PGOOD | Built-in safety |
Performance and Efficiency
The default switching frequency near 1 MHz means smaller inductors and capacitors. Efficiency depends on input, output, and load. For example, with 12 V in and 3.3 V out at 2 A load, efficiency can be around 88–90%. With lower output voltages, efficiency may drop a bit because of higher duty cycle. The datasheet shows many graphs for different conditions. You can use these to check the best operating point for your design.
Detailed Data and Observations
(The following data is based on the official datasheet/product page. Thermal derating should be performed on the actual PCB in conjunction with layout and heat dissipation calculations.)- Input/Output: Officially stated VIN range is 3.6–20V, and VOUT is programmable from 0.6–5.5V. Suitable for generating low-voltage core rails (e.g., 1.0V, 1.2V, 1.5V, etc.) from 12V and 5V rails.
- Current Capability: Continuous 2.5A per channel (short-term peak capability is higher, but this depends on thermal performance and package heat dissipation). Suitable for driving SoC/FPGA power rails or distributing multiple low-current modules.
- Switching Frequency and Transient: Default 1MHz. Internal current-mode control provides fast transient response. Efficiency can reach between 80s and ~90% under typical operating conditions (depending on VIN/VOUT and load). If lower ripple is required or multi-phase outputs are connected in parallel, higher total current and lower output ripple can be achieved through synchronization and paralleling.
- Thermal characteristics: The device specifies thermal parameters such as θJC and θJA (e.g., θJCtop ≈ 17°C/W, θJCbottom ≈ 11°C/W, with a typical board-level θJA ≈ 22°C/W). At high currents, derating and copper placement should be performed according to the heatsinking/packaging recommendations in the datasheet.
Comparison with Similar Modules
| Feature | LTM4622IY#PBF | Similar Dual Buck Module |
|---|---|---|
| Channels | 2 × 2.5 A | 2 × 3 A |
| Max VIN | 20 V | 17 V |
| Size | 6.25 × 6.25 mm | Larger |
| Thermal Performance | Needs good PCB | Slightly better due to size |
| Cost | Higher | Lower |
Application Experience and Design Recommendations
Layout: Place the ceramic bypass capacitors for VIN and VOUT as close to the corresponding device pins as possible. Ensure the ground plane is continuous and has short copper traces. Refer to the datasheet for recommended PCB layout. Long inductors and return paths increase EMI and ripple.FREQ/Synchronization: The default setting is 1MHz. To synchronize with the system clock or reduce inductor ripple, connect an external resistor or clock to the FREQ or SYNC pins. Paralleling multiple modules can improve overall ripple and distribute heat (the datasheet provides examples of multi-phase parallel connection).
Heat Dissipation: Although the package is small, its thermal performance is limited. For high current and long-term operation, evaluate the PCB copper thickness and thermal vias. If necessary, use heat dissipation layers or parallel multiple modules in different areas to distribute heat flow.
| Item | LTM4622IY#PBF | LTM4623IY#PBF (Comparison) |
|---|---|---|
| Output Current | Dual 2.5 A (can parallel for 5 A) | Single channel / single die 3 A (some variants support 3 A and have different input thresholds) |
| Input Range | 3.6–20 V | Typical 4–20 V (some LTM4623 variants differ at low VIN, see datasheet) |
| Default Frequency | 1 MHz (adjustable) | 1 MHz (adjustable, supports phase-lock/parallel features) |
| Package / Size | 6.25 × 6.25 mm ultra-thin µModule | Similar package (6.25 × 6.25 mm series) |
| Selection Advice | Preferred when dual channel, small size, ~2.5 A per channel is needed | Consider LTM4623 if single channel 3 A is enough and input requirements / tracking features suit it better |
LTM4622IY#PBF Advantages/Disadvantages
Advantages:
Highly integrated (controller + FET + inductor + some bypass components), reducing design time and board space. The 1MHz default switching frequency is suitable for small inductors and compact layouts, and offers fast transient response.Disadvantages:
The package has significant thermal limitations at high currents, requiring careful PCB heatsinking and derating.Compared to discrete solutions, the cost may be higher, but the savings in engineering time and layout often outweigh this (depending on the BOM and production volume).
Ending
If your design requires reliable, fast transient response point-of-load power supply on a very small PCB area, and the current per rail is at the ~2.5A level, the LTM4622 provides an "out-of-the-box" highly integrated, high-performance solution; however, in high continuous current scenarios, thermal derating and board-level heat dissipation design must be performed according to the datasheet.
FAQ
What type of device is LTM4622IY#PBF?
LTM4622IY#PBF is a highly integrated µModule buck regulator launched by Analog Devices (formerly Linear Technology). The package contains a controller, power MOSFET, inductor and necessary bypass components. It is mainly used for point-of-load (PoL) power supply.
What are its main electrical specifications (input/output/current)?
The usual input voltage range is about 3.6V to 20V. The output voltage can be set from about 0.6V to 5.5V. Each channel can provide a steady output of about 2.5A. If you combine two channels, you can increase the total current. Specific values should be based on the official data sheet.
What typical application scenarios is the LTM4622 suitable for?
It is good for point-of-load (PoL) applications with limited space. It needs a fast response time. This includes the main voltage for SoC/FPGA. It also covers power supply for low-current modules. Additionally, it involves local voltage regulation in communication devices and embedded systems.
References
Analog Devices — LTM4622 Datasheet (PDF): https://www.analog.com/media/en/technical-documentation/data-sheets/ltm4622.pdf
Analog Devices — LTM4622 product page: https://www.analog.com/en/products/ltm4622.html
Mouser — LTM4622 listing: https://www.mouser.com/ProductDetail/Analog-Devices/LTM4622IYPBF
Digi-Key — LTM4622 overview: https://www.digikey.com/en/product-highlight/l/linear-tech/ltm4622-step-down-umodule-regulator
