The TPS7A78 improves the overall efficiency and standby-power in power-supplies in an easy-to-use, non-magnetic approach to AC/DC conversion. The TPS7A78 uses a capacitor-drop architecture to lower the AC source voltage before actively clamping the rectified voltage. The device then regulates this rectified voltage down to the application-specific operating voltage. The unique architecture of the device allows the standby power to be reduced to just a few 10s of milliwatts. The TPS7A78 switched-capacitor stage reduces power losses by stepping down the rectified input voltage by a factor of four and increasing the output-to-input current by the same ratio, as given by PIN ≅ POUT and VIN ≅ VOUT × 4. Compared to a traditional capacitor-drop (cap-drop) stage, this step down reduces input current, thus minimizing the value of the capacitance needed.
Electricity-metering applications, where the power supply must be reliable and magnetic tamper-proof, benefits from using the TPS7A78 because this device does not require external magnetics. This feature makes complying with IEC 61000-4-8 easier while minimizing magnetic shielding cost.
Additionally, the TPS7A78 also comes with a user-programmable, power-fail detection threshold that can provide an early alert to power failures and enable shutdown before complete power loss. The power-good indicator (PG) is also provided for sequencing or resetting a microcontroller.
The TPS7A78 is available in a 14-pin HTSSOP (PWP) package.
| Type | Title | Date | ||
|---|---|---|---|---|
| * | Data sheet | TPS7A78 120-mA, Smart AC/DC Linear Voltage Regulator datasheet (Rev. A) | PDF | HTML | 17 Sep 2019 |
| Application note | How to Make a Simple Nonmagnetic AC/DC Power Supply | 21 Feb 2020 | ||
| White paper | How to detect and harden a meter against tampering by neutral disconnection | 12 Feb 2020 | ||
| Technical article | Understanding the difference between capacitors, capacitance and capacitive drop power supplies | 10 Sep 2019 | ||
| EVM User's guide | TPS7A78EVM-011 evaluation module user's guide | 12 Mar 2019 | ||
| Technical article | Searching for the newest innovations in power? Find them at APEC | 09 Feb 2019 |
For additional terms or required resources, click any title below to view the detail page where available.
The TPS7A78EVM-011 evaluation module (EVM) is designed for a typical configuration to evaluate the operation and performance of the TPS7A78, which is a 120-mA smart AC/DC low-dropout (LDO) linear voltage regulator.
The TPS7A78EVM-011 circuit board is configured to be a reference design for (...)
| Package | Pins | Download |
|---|---|---|
| HTSSOP (PWP) | 14 | View options |
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