Power Supplies and Alternative Low Power Mode

Computers are continuing to change and introducing new power states. One of these new power states is generically called an Alternative Low Power Mode (ALPM). Some examples of Alternative Low Power Modes are Microsoft* Windows 10 Modern Standby or Google* Chrome* Lucid Sleep. These low power states have created requirements for power supplies. Below is a summary of these requirements as they are mentioned throughout the document. All ALPM features are required in this Single Rail Desktop Power Supply Design Guide.

• Section 4.2.4: Other Lower Power System Requirements
• To help meet multiple world-wide Energy Regulations the +5VSB standby rail must meet the following efficiency as shown in Table 4-5 which is measured with the main outputs off (PS_​ON# high state). These World-Wide Energy Regulations and standards include: Blue Angel* system requirements, RAL-UZ 78, US Presidential executive order 13221, ENERGY STAR*, ErP Lot 6 requirements (2010 and 2013 levels), and 2014 ErP Lot 3 requirements. Additionally, if any Computers use an Alternative Low Power Mode (ALPM) then the +5VSB standby efficiency has similar requirements as shown below.
• Table 4-5 shows that ALPM requirements are at the 230 mA and 625 mA load levels.
• Section 4.3:
• Table 4-9 “Required” timing values of T1 and T3 support ALPM. Multi rail power supply design guide has the Required T1 and T3 timing values as recommended for ALPM.
• Section 4.2.2– PS_​ON#
• Section 10.2:
• The number of times a PSU toggles on and off is expected to increase.
• Section 4.3.2:
• PSU response quickly to toggling of PS_​ON# signal