Specifications

Chapter 5 – Power Supplies for PL Smart Transceivers
162 PL 3120/PL 3150/PL 3170 Power Line Smart Transceiver Data Boo
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In summary, an energy storage linear supply differs from a traditional linear supply in the following ways:
• Allows the use of a smaller transformer
• Requires more output capacitance for energy storage
• Requires that the device be programmed to enable power management, as described in Chapter 8.
• Under typical conditions, exhibits transmit duty cycles which are not limited. Over the full range of line
voltage and component tolerance, the power management circuitry of the PL Smart Transceiver may act to
regulate transmit duty cycle of the device (to ≥10% in the above example).
Traditional Linear Power Supplies
This option is usually suitable if the physical size of the power supply is not constrained by the application, since
linear supplies tend to be physically larger than switching power supplies. Linear power supplies do not load the
power line in the range of the PL Smart Transceiver communication frequencies, nor do they generate significant
noise. For these reasons, a linear power supply can be used without concern that communication performance will be
adversely affected by the supply.
Pre-Verified Switching Power Supplies
Switch mode power supplies provide a number of desirable features such as multi-country support and optional
circuit isolation. While generally smaller than linear power supplies, switching power supplies can be a significant
source of noise and power line signal attenuation unless they are specifically designed to avoid these effects. To
minimize development effort, three types of switching power supplies have been pre-verified to preserve the high
performance communication capabilities of the PL Smart Transceiver. These three types are listed below and
described in detail in the sections that follow.
• Pre-Verified Energy Storage Switching Supply
• Pre-Verified Switching Supply
• 5W and 10W Echelon Power Supply Plus Couplers
Pre-Verified Energy Storage Switching Supply
Bias Power LLC has developed a small (2.6 x 2.3cm), switching power supply module that has been tested for
compatibility with the PL 3120 and PL 3170 Smart Transceivers. This power supply option is a good choice when
the benefits of a switching supply (small size, universal input, safety isolation, and good efficiency) are needed but
simplicity of design is also a priority.
The Bias Power LLC BPS 1-14-00 power supply module provides approximately 1 watt of output power at 14VDC.
It must be operated as an energy storage supply by the addition of an energy storage output capacitor. Figure 5.6
illustrates the required application schematic for use of the BPS 1-14-00 module with the PL 3120 or PL 3170 Smart
Transceivers. Note that a simple RC circuit has also been added to the input of the Bias Power module in order to
avoid any degradation of power line communication signals due to excessive noise or loading. Note also that because
this is an energy storage design the power management feature of the PL Smart Transceiver must be enabled as
described in Chapter 8.