UCC283 Low-Dropout, 3-A, Linear Regulators | TI.com

UCC283 (ACTIVE) Low-Dropout, 3-A, Linear Regulators


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The UCC283–3/–5/–ADJ family of positive linear series pass voltage regulators are tailored for low-drop-out applications where low quiescent power is important. Fabricated with a BiCMOS technology ideally suited for low input-to-output differential applications, the UCC283–5 passes 3 A while requiring only 0.45 V of typical input voltage headroom (ensured 0.6-V dropout).

These regulators include reverse voltage sensing that prevents current in the reverse direction. Quiescent current is always less than 650 µA. These devices have been internally compensated in such a way that the need for a minimum output capacitor has been eliminated.

UCC283–3 and UCC283–5 versions are in 3-lead packages and have preset outputs at 3.3 V and 5.0 V respectively. The output voltage is regulated to 1.5% at room temperature. The UCC283–ADJ version, in a 5-lead package, regulates the output voltage programmed by an external resistor ratio.

Short-circuit current is internally limited. The device responds to a sustained overcurrent condition by turning off after a tON time delay. The device then stays off for a period, tOFF, that is 32 times the tON delay. The device then begins pulsing on and off at the tON/(tON +tOFF) duty cycle of 3%. This drastically reduces the power dissipation during short-circuit and means heat sinks need only accommodate normal operation. On the 3-leaded versions of the device tON is fixed at 750 µs, on the adjustable 5-leaded versions an external capacitor sets the on time. The off time is always 32 × tON. The external timing control pin, CT, on the 5-leaded versions also serves as a shutdown input when pulled low.

Internal power dissipation is further controlled with thermal overload protection circuitry. Thermal shutdown occurs if the junction temperature exceeds 165°C. The chip remains off until the temperature has dropped 20°C.

The UCC283 series is specified for operation over the industrial range of –40°C to 85°C, and the UCC383 series is specified from 0°C to 70°C. These devices are available in 3- and 5-pin TO–220 and TO–263 power packages.


  • Precision Positive Linear Series Pass Voltage Regulation
  • 0.45 V Dropout at 3 A
  • 50 mV Dropout at 10 mA
  • Quiescent Current Under 650 µA Irrespective of Load
  • Adjustable (5-Lead) Output Voltage Version
  • Fixed (3-Lead) Versions for 3.3-V and 5-V Outputs
  • Logic Shutdown Capability
  • Short-Circuit Power Limit of (3% × VIN × ISHORT)
  • Low VOUT to VIN Reverse Leakage
  • Thermal Shutdown

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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 PSRR @ 100 KHz (dB) Accuracy (%) Dropout voltage (Vdo) (Typ) (mV) Iq (Typ) (mA) Package size: mm2:W x L (PKG)
UCC283 Order now Adjustable Output
Fixed Output    
3     9     2.8     8.5     1.2     3.3
DDPAK/TO-263 | 3
DDPAK/TO-263 | 5
TO-220 | 5    
Reverse Current Protection     1     -40 to 85     70     3.16 | 1ku     Catalog     18     2.5     400     0.4     3DDPAK/TO-263: 155 mm2: 15.24 x 10.16 (DDPAK/TO-263 | 3)
5DDPAK/TO-263: 155 mm2: 15.24 x 10.16 (DDPAK/TO-263 | 5)
5TO-220: 86 mm2: 8.51 x 10.16 (TO-220 | 5)