120-mA smart cap-drop low-dropout (LDO) linear voltage regulator
Product details
Parameters
Package | Pins | Size
Features
- Non-isolated power solution for ≥ 18 VAC RMS:
- Up to 75% efficiency
- Standby power consumption: 15 mW (typical)
- Line-voltage, cap-drop capacitor as small as 1/4th the size of linear solutions
- Available in fixed output voltages:
- 1.3 V to 5 V (50-mV steps)
- Power-fail detection
- Power-good indication
- 1% typical accuracy
- Package:
- 5-mm × 6.5-mm HTSSOP-14 (PWP)
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Description
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.
Technical documentation
Type | Title | Date | |
---|---|---|---|
* | Datasheet | TPS7A78 120-mA, Smart AC/DC Linear Voltage Regulator datasheet (Rev. A) | Sep. 17, 2019 |
Application note | How to Make a Simple Nonmagnetic AC/DC Power Supply | Feb. 21, 2020 | |
White paper | How to detect and harden a meter against tampering by neutral disconnection | Feb. 12, 2020 | |
Technical article | Understanding the difference between capacitors, capacitance and capacitive drop power supplies | Sep. 10, 2019 | |
User guide | TPS7A78EVM-011 evaluation module user's guide | Mar. 12, 2019 | |
Technical article | Searching for the newest innovations in power? Find them at APEC | Feb. 09, 2019 | |
Technical article | LDO basics: capacitor vs. capacitance | Aug. 01, 2018 | |
Technical article | LDO Basics: Preventing reverse current | Jul. 25, 2018 |
Design & development
For additional terms or required resources, click any title below to view the detail page where available.Hardware development
Description
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 engineering (...)
Features
- Nonisolated power solution for 90 VAC to 360 VAC
- Supports output voltages from 1.25 V to 5 V
- Less than 10-mW standby power consumption
- Cap-drop capacitor can be 1/4th the size of traditional solutions
- Power good
Software development
Design tools & simulation
Reference designs
Design files
-
download TIDA-010036 BOM.pdf (168KB) -
download TIDA-010036 Assembly Drawing.pdf (394KB) -
download TIDA-010036 PCB.pdf (1817KB) -
download TIDA-010036 CAD Files.zip (14699KB) -
download TIDA-010036 Gerber.zip (1888KB)
- Off-line switcher using inductor
- AC line regulator (...)
Design files
-
download TIDA-010060 BOM.pdf (40KB) -
download TIDA-010060 Assembly Drawing.pdf (196KB) -
download TIDA-010060 PCB.pdf (1007KB) -
download TIDA-010060 CAD Files.zip (815KB) -
download TIDA-010060 Gerber.zip (747KB)
CAD/CAE symbols
Package | Pins | Download |
---|---|---|
HTSSOP (PWP) | 14 | View options |
Ordering & quality
- RoHS
- REACH
- Device marking
- Lead finish/Ball material
- MSL rating/Peak reflow
- MTBF/FIT estimates
- Material content
- Qualification summary
- Ongoing reliability monitoring
Recommended products may have parameters, evaluation modules or reference designs related to this TI product.
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