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TPS7A78

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120-mA, smart, capacitance-drop, low-dropout (LDO) linear voltage regulator

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Data sheet

TPS7A78

ACTIVE
Data sheet Order now

Product details

Output options Fixed Output Iout (max) (A) 0.12 Vin (max) (V) 23 Vin (min) (V) 17 Vout (max) (V) 5 Vout (min) (V) 1.25 Fixed output options (V) 3.3, 3.6, 5 Iq (typ) (mA) 0.28 Thermal resistance θJA (°C/W) 48.0 Rating Catalog Load capacitance (min) (µF) 1 Regulated outputs (#) 1 Features AC/DC regulation, Power good, Power-fail detect Accuracy (%) 2 Operating temperature range (°C) -40 to 125
Output options Fixed Output Iout (max) (A) 0.12 Vin (max) (V) 23 Vin (min) (V) 17 Vout (max) (V) 5 Vout (min) (V) 1.25 Fixed output options (V) 3.3, 3.6, 5 Iq (typ) (mA) 0.28 Thermal resistance θJA (°C/W) 48.0 Rating Catalog Load capacitance (min) (µF) 1 Regulated outputs (#) 1 Features AC/DC regulation, Power good, Power-fail detect Accuracy (%) 2 Operating temperature range (°C) -40 to 125
HTSSOP (PWP) 14 32 mm² 5 x 6.4
  • 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)
  • 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)

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.


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.


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Technical documentation

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Type Title Date
* Data sheet TPS7A78 120-mA, Smart AC/DC Linear Voltage Regulator datasheet (Rev. A) PDF | HTML 17 Sep 2019
EVM User's guide TPS7A78EVM-041 Evaluation Module User's Guide PDF | HTML 16 Aug 2023
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 p PDF | HTML 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 PDF | HTML 09 Feb 2019

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

TPS7A78EVM-011 — TPS7A78 evaluation module for 120-mA, smart, capacitance-drop, LDO linear voltage regulator

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 (...)

User guide: PDF
Not available on TI.com
Evaluation board

TPS7A78EVM-041 — TPS7A78 evaluation module for 120-mA smart AC/DC low-dropout linear voltage regulator

The TPS7A78 evaluation module (EVM) evaluates the operation and performance of the TPS7A78 AC/DC linear regulator. This EVM configuration contains a single low standby power, variable output voltage, linear regulator for a wide range of applications. The regulator is capable of delivering up to 120 (...)

User guide: PDF | HTML
Not available on TI.com
Support software

SBVC046 — TPS7A78 Calculator Form

Supported products & hardware

Supported products & hardware

Products
Linear & low-dropout (LDO) regulators
TPS7A78 — 120-mA, smart, capacitance-drop, low-dropout (LDO) linear voltage regulator
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Simulation model

TPS7A78 SIMPLIS 3.3 V Model

SBVM957.ZIP (110 KB) - SIMPLIS Model
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Simulation model

TPS7A78 SIMPLIS 3.6 V Model

SBVM958.ZIP (6 KB) - SIMPLIS Model
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Simulation model

TPS7A78 SIMPLIS Model (Rev. A)

SBVM947A.ZIP (107 KB) - SIMPLIS Model
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Reference designs

TIDA-010036 — One-phase shunt electricity meter reference design using standalone ADCs

This reference design implements Class 0.5 single-phase energy measurement using standalone multi-channel analog-to-digital converters (ADC) to sample a shunt current sensor. With the combination of the shunt sensor and a compact magnetically immune power supply, the design provides protection (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-010060 — Off-line (non-isolated) AC/DC power supply architectures reference design for grid applications

This reference design showcases three non-isolated AC/DC power supply topologies for line-powered applications such as residential circuit interrupters, circuit breakers, home automation equipment and appliances for < 100 mA. The three topologies are:
  • Off-line switcher using inductor
  • AC line (...)
Design guide: PDF
Schematic: PDF
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HTSSOP (PWP) 14 Ultra Librarian
TI's Standard Terms and Conditions for Evaluation Items apply.

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