Compact Power Regulator Targets FPGAs, GPUs and ASICs

Analog Devices has announced the Power by Linear LTM4646, a dual 10 A or single 20 A output, step-down µModule point-of-load regulator from 5V or 12V input supply rails. The LTM4646 includes the inductors, MOSFETs, a DC/DC controller and supporting components and is housed in a 11.25 mm x 15 mm x 5.01 mm BGA package. Compared to the prior 2 x single 10 A output module solutions, the LTM4646 reduces the solution size of more than 25%.
With its dual regulator design, small package size, and precise voltage regulation, the LTM4646 meets the PCB area constraints of densely populated system boards to power low voltage and high current devices such as FPGAs, ASICs, microprocessors and GPUs. Applications include PCIe boards, communication infrastructure, cloud computing-based systems, as well as medical, industrial, and test and measurement equipment.

Total output voltage DC accuracy is guaranteed at ±1.5% over line, load and temperature (–40°C to 125°C). Moreover, the onboard remote sense amplifiers on both outputs compensate for voltage drop caused by trace impedance of the PC board due to large load currents. The LTM4646 has selectable internal or external feedback loop compensation, enabling users to optimize loop stability and transient performance while minimizing the number of output capacitors. The peak efficiency at 12 VIN to 1.0 VOUT is 86%. With 200LFM air flow, the LTM4646 delivers a full 20A  continuously up to 85°C ambient. The current mode architecture allows multiphase parallel operation to increase output current with very good current sharing.

Standalone, the LTM4646 operates from 4.5 V to 20 V input range. When 5 V external bias is available, the device can operate from 2.375 V. The output voltages are adjustable from 0.6 V to 5.5 V, enabling the device to generate not only low voltage for digital devices but also 2.5 V, 3.3 V and  5V, which are commonly needed in system bus voltages. The switching frequency can be programmed from 250 kHz to 1.3 MHz with one resistor, and can also be synchronized to an external clock ranging from 300 kHz to 1 MHz for noise-sensitive applications. Additionally, it features overvoltage and overcurrent protection. The LTM4646 operates from –40°C to 125°C.

Summary of Features: LTM4646

  •     Dual 10A or Single 20A Output
  •     Wide Input Voltage Range: 4.5V to 20V
  •     2.375VMIN with CPWR Bias
  •     Output Voltage Range: 0.6V to 5.5V
  •     ±1.5% Maximum Total DC Output Error
  •     Multiphase Current Sharing
  •     Differential Remote Sense Amplifier, Each Channel
  •     Internal or External Compensation
  •     11.25mm x 15mm x 5.01mm BGA Package
  •     BGA Ball Finishes Available: SAC305 (RoHS), SnPb (63/37)


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