A Voltage Regulator to Keep Pluggable Optics Plugging Away

To limit electromagnetic interference (EMI) without limiting efficiency, the device leverages Analog Devices’ Silent Switcher technology to enable fast switching transients with very low radiated emissions. The fast switching transitions lead to low switching losses of the power supply. As a result, it can operate a high switching frequency of up to 3 MHz without experiencing excessive losses.

To further reduce output-voltage ripple, a variant of the LT7176 can be used: The LT7176-1 is almost identical, featuring a pair of phase-shifted channels with the same maximum output current of 24 A. However, two inductors are required for this solution. The advantage is that these inductors only need to handle half the total power; therefore, engineers can specify devices with a lower overall height. The vertical space savings can be helpful for applications that are limited in height.

In addition to accurate voltage regulation, high reliability of voltage conversion is important. Using a digital connection of the LT7176, the state of the input and output voltage, input current, device temperature, and other fault states and operating conditions can be queried.

It’s also possible to execute various settings of the device through the existing PMBus connection. This includes setting the output voltage, a current limit, switching on and off, soft start and soft stop, and many other parameters such as control-loop compensation.

Figure 3 shows the graphical user interface LTpowerPlay, which allows the circuit to be evaluated and configured with different settings.