The LMH0324 is designed to provide flexibility in supply rails. There are two ways to power the LMH0324:

• Single 2.5 V Supply Mode: This mode offers ease of use and pin compatibility with the LMH1219 (11.88 Gbps Ultra-HD Adaptive Cable Equalizer with Integrated Reclocker). The internal circuitry receives power from the on-chip 1.8 V regulator. In this mode, 2.5 V is applied to VIN, VDDIO, and RSV_L. This mode supports SPI or SMBus serial interface. See Figure 24 for more details.
• Single 1.8 V Supply Mode: This mode provides the lowest power consumption. In this mode, 1.8 V is connected to VIN, VDD_LDO and VDDIO. RSV_L is tied to VSS. In this mode, SPI is supported, but SMBus serial interface is not. In Single 1.8 V Supply Mode, the LMH0324 is not drop-in compatible with the LMH1219. See Figure 25 for more details.

Figure 24. Single 2.5 V Supply Mode - Compatible with LMH1219

Figure 25. Single 1.8 V Supply Mode - Not Compatible with LMH1219

For power supply de-coupling, 0.1-μF surface-mount ceramic capacitors are recommended to be placed close to each supply pin to VSS. Larger bulk capacitors (for example, 10 µF and 1 µF) are recommended to be placed close to each LMH0324 device. Good supply bypassing requires low inductance capacitors. This can be achieved through an array of multiple small body size surface-mount bypass capacitors in order to keep low supply impedance. Better results can be achieved through the use of a buried capacitor formed by a VDD and VSS plane separated by 2-4 mil dielectric in a printed circuit board.