LTM4644IY-1#PBF Quad-Channel µModule Explained

The demand for multi-rail power delivery in modern embedded systems continues to rise. ADI's LTM4644IY-1#PBF integrates four step-down channels, each delivering 4A, with an input range of 4V to 14V and an output range of 0.6V to 5.5V. It embeds inductors and compensation networks inside a compact 15mm × 9mm × 5.01mm package. Peak current-mode control ensures fast transient response and cycle-by-cycle current limiting. Output voltage accuracy is ±1.5%, with remote differential sensing to maintain precise regulation at the load. Only external capacitors are needed. The 1MHz switching frequency is synchronizable. Comprehensive protection features make it robust, with a junction temperature range of -40°C to +125°C.

Key specifications are shown in the table below:

Parameter	Specification
Input Voltage	4V to 14V
Output Voltage	0.6V to 5.5V
Current per Channel	4A (5A peak)
Voltage Accuracy	±1.5%
Switching Frequency	1MHz (synchronizable)
Package	15mm × 9mm × 5.01mm BGA
Junction Temperature	-40°C to +125°C
Protections	OCP/OTP/UVLO

Ideal for FPGA/SoC multi-rail power supplies, the four independent channels can be paralleled for 8A or 12A outputs, meeting core and I/O voltage requirements. It is an excellent choice for space-constrained applications such as industrial control, communications equipment, and medical instruments. With 4A per channel, parallel configurations deliver 8A, 12A, or 16A, offering flexible high-current solutions. Typical use cases include powering Xilinx Kintex/Virtex FPGAs, where multiple channels simultaneously supply core voltages, I/O, and auxiliary rails, simplifying the power tree and enhancing system reliability.

Q&A
Q: What does the suffix IY-1#PBF mean?
A: I: Industrial temperature grade (-40°C to +125°C), Y: BGA package, -1: Internal compensation, #PBF: Lead-free.

Q: How to set the output voltage and sequencing?
A: Set the output voltage via an FB resistor divider: VOUT = 0.6 × (1 + RTOP/RBOTTOM). A capacitor on the TRACK/SS pin programs soft-start. Apply an external ramp signal to achieve sequential power-up across multiple channels.

Q: How to reduce EMI?
A: The 1MHz frequency can be synchronized to an external clock. Burst Mode operation reduces light-load noise. Symmetrical pinout and shielded inductors minimize radiated emissions.

Q: Thermal design considerations?
A: The package features low thermal resistance. Use PCB copper planes for heat dissipation. In most operating conditions, no heatsink is required. Ensure the junction temperature does not exceed 125°C.

With high integration, multiple channels, and ease of use, the LTM4644IY-1#PBF stands out as an ideal choice for multi-rail power designs, enabling engineers to quickly realize high-performance solutions. Its industrial temperature grade and complete protection features guarantee long-term reliability.

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