TPS7A78 120-mA smart AC/DC low-dropout (LDO) linear voltage regulator |


120-mA smart AC/DC low-dropout (LDO) linear voltage regulator


Sample availability

Preproduction samples are available (PTPS7A7833PWPT). Order now


The TPS7A78 improves the overall efficiency and standby power in power supplies for an easy-to-use non-magnetic approach to AC/DC conversion. The TPS7A78 uses an external capacitor to create a current source and actively clamps the rectified voltage. The device then regulates the voltage down to the application-specific operating voltage. The unique architecture of the device allows the standby power to be reduced from several 100s of milliwatts to just a few 10s of milliwatts. The TPS7A78 takes advantage of an innovative switched capacitor stage to reduce the clamped voltage down by approximately 1/4th of the value, which in turn multiplies the current by 4. Thus, the current source capacitor can be much smaller in size, which minimizes standby power, reduces solution size, and can lead to a lower system cost.

The TPS7A78 is optimized for e-metering applications where the power supply must be reliable and magnetic tamper-proof. The TPS7A78 requires no external magnetics, which makes complying with IEC 61000-4-8 easier while minimizing costly magnetic shielding in e-metering applications.

Additionally, the TPS7A78 also comes with a user-programmable power-fail detection threshold that can provide an early alert to power failures so the system can save data before completely losing power. A power-good indication can also be used for sequencing or to provide a reset to a micro-controller.

The TPS7A78 is available in a 14-pin TSSOP (PWP) package.


  • Non-isolated power solution for 70 VAC to 270 VAC, 45 Hz to 65 Hz (bench tested):
    • Up to approximately 75% efficiency
  • Supports output voltages from 1.25 V to 5 V
  • Standby power consumption: 15 mW (cap-drop = 150 nF)
  • Line voltage drop capacitor can be 1/4th the size of linear solutions
  • Power-fail detection
  • Power-good indication
  • 3% precision voltage regulation over line, load, temperature
  • Package:
    • 5-mm × 6.5-mm TSSOP-14 (PWP)

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Part number Order Output options Iout (Max) (A) Vin (Max) (V) Vin (Min) (V) Vout (Max) (V) Vout (Min) (V) Fixed output options (V) Package Group Features Regulated outputs (#) Operating temperature range (C) Thermal resistance θJA (°C/W) Approx. price (US$) Rating Output capacitor type Accuracy (%) Iq (Typ) (mA) Package size: mm2:W x L (PKG)
TPS7A78 Order now Fixed Output     0.12     23     17     1.25     5     1.25
HTSSOP | 14     Power-Fail Detect
Power Good
AC/DC Regulation    
1     -40 to 125     48     1.15 | 1ku     Catalog     Ceramic     2     0.280     14HTSSOP: 32 mm2: 6.4 x 5 (HTSSOP | 14)