Cap-Drop Offline Power Supply for Standard-Compliant Feature-Rich E-Meters Reference Design


Design files


The PMP9311 is a low power capacitor-drop type of offline converter that takes a 50Hz AC input of 85V to 230V and puts out a regulated DC 3.3V at up to 85mA. It is used for electronic electricity meters where apparent power consumption is regulated and galvanic isolation is not required. The high output current capability for the same input apparent power limit supports a feature-rich electricity meter design. The increased output power is achieved by allowing the clamped zener voltage to be as high as 42V, and the employment of a wide input range buck switching regulator.

  • 85V-230V 50Hz AC input, 3.3V DC output
  • 15mA output at 85V input, and 85mA output at 230V input
  • 1.83VA input apparent power @ 120VAC in and 29mA out
  • 6.78VA input apparent power @ 230VAC in and 85mA out
  • Up to 50% overall power efficiency
?? View video with transcript Video

A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.

TIDU238.PDF (744 K)

Test results for the reference design, including efficiency graphs, test prerequisites and more

TIDC294.ZIP (336 K)

Detailed schematic diagram for design layout and components

TIDR419.PDF (82 K)

Detailed schematic diagram for design layout and components

TIDR421.PDF (59 K)

Detailed schematic diagram for design layout and components

TIDR420.PDF (34 K)

Complete listing of design components, reference designators, and manufacturers/part numbers


Includes TI products in the design and potential alternatives.

AC/DC & DC/DC converters (integrated FET)

LM2842SIMPLE SWITCHER® 4.5V to 42V, 0.6A Step-Down DC/DC Switching Regulator in Thin SOT-23

Data sheet: PDF | HTML

Technical documentation

No results found. Please clear your search and try again.
View all 1
Type Title Date
Test report PMP9311 Test Results Feb. 27, 2014

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​