Natural Input Current Limit Reference Design for Super-Cap Charge Circuits PMP15044 (ACTIVE)

Description & Features

Technical Documents

Support & Training

Order Now

See the Important Notice and Disclaimer covering reference designs and other TI resources.

Key Document


The TI design PMP15044 uses the natural-input current-limit characteristic of the flyback topology. During start-up, even though the initial output voltage of the super CAP is zero, the primary winding current is always limited by the peak-switch current limit of the TPS61087 device. Considering the duty cycle during soft-start, the input current will be lower than the peak-switch current-limit value of the TPS61087 device by nature. So no extra components are needed.

The primary winding and secondary winding share the same ground, so the flyback inductor does not need reinforced insulation; basic insulation is enough. Therefore, this is a compact and low-cost solution for the super-CAP charge-up circuit application.

  • 2.5-6V input voltage range
  • Can effectively limit the input current below 3A
  • Isolates the input side and the output side when shut down
  • Low cost and small solution size

See the Important Notice and Disclaimer covering reference designs and other TI resources.


Schematic/Block Diagram

Quickly understand overall system functionality.

Download Schematic

Test Data

Get results faster with test and simulation data that's been verified.

Download Test Data

Design Files

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

Download Design Files

(Output Voltage 1)
Vin (Min) (V)2.5
Vin (Max) (V)6
Vout (Nom) (V)13.5
Iout (Max) (A).4
Output Power (W)5.4
Input TypeDC
TopologyFlyback- Non Sync

TI Devices (1)

Order samples, get tools and find more information on the TI products in this reference design.

Part Number Name Product Family Sample & Buy Design Kits & Evaluation Modules
TPS61087  18.5V, 3.2A, 650kHz / 1.2MHz Step-Up DC-DC Converter with Forced PWM Mode  Step-up (boost)  Sample & Buy View Design Kits & Evaluation Modules

CAD/CAE symbols

Part # Package | Pins CAD File (.bxl) STEP Model (.stp)
TPS61087 Download Download
Download Download

Texas Instruments and Accelerated Designs, Inc. have collaborated together to provide TI customers with schematic symbols and PCB layout footprints for TI products.

Step 1: Download and install the free download.

Step 2: Download the Symbol and Footprint from the CAD.bxl file table.

Technical Documents

See the Important Notice and Disclaimer covering reference designs and other TI resources.

User guides (1)
Title Type Size (KB) Date
PDF 273 13 Apr 2018
Design files (6)
Title Type Size (KB) Date
ZIP 1156 11 Apr 2018
ZIP 503 11 Apr 2018
PDF 490 11 Apr 2018
PDF 97 11 Apr 2018
PDF 94 11 Apr 2018
PDF 92 11 Apr 2018

Support & training

Search our extensive online knowledge base where millions of technical questions and answers are available 24/7.

Search answers from TI experts

Content is provided 'AS IS' by the respective 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 visit our Support page.

Technical articles