UCC284

ACTIVE

500-mA, negative, adjustable low-dropout voltage regulator from -40°C to +85°C

Product details

Output options Adjustable Output, Fixed Output Iout (max) (A) 0.5 Vin (max) (V) -3.2 Vin (min) (V) -15 Vout (max) (V) -1.2 Vout (min) (V) -15 Fixed output options (V) -12, -5 Noise (µVrms) 200 Iq (typ) (mA) 0.2 Thermal resistance θJA (°C/W) 70 Rating Catalog Load capacitance (min) (µF) 4.7 Regulated outputs (#) 1 Accuracy (%) 2.5 Dropout voltage (Vdo) (typ) (mV) 250 Operating temperature range (°C) -40 to 85
Output options Adjustable Output, Fixed Output Iout (max) (A) 0.5 Vin (max) (V) -3.2 Vin (min) (V) -15 Vout (max) (V) -1.2 Vout (min) (V) -15 Fixed output options (V) -12, -5 Noise (µVrms) 200 Iq (typ) (mA) 0.2 Thermal resistance θJA (°C/W) 70 Rating Catalog Load capacitance (min) (µF) 4.7 Regulated outputs (#) 1 Accuracy (%) 2.5 Dropout voltage (Vdo) (typ) (mV) 250 Operating temperature range (°C) -40 to 85
SOIC (D) 8 29.4 mm² 4.9 x 6
  • Precision Negative Series Pass Voltage Regulation
  • 0.2 V Dropout at 0.5 A
  • Wide Input Voltage Range –3.2 V to –15 V
  • Low Quiescent Current Irrespective of Load
  • Simple Logic Shutdown Interfacing
  • –5 V, –12 V, and Adjustable Output
  • 2.5% Duty Cycle Short Circuit Protection

  • Precision Negative Series Pass Voltage Regulation
  • 0.2 V Dropout at 0.5 A
  • Wide Input Voltage Range –3.2 V to –15 V
  • Low Quiescent Current Irrespective of Load
  • Simple Logic Shutdown Interfacing
  • –5 V, –12 V, and Adjustable Output
  • 2.5% Duty Cycle Short Circuit Protection

The UCC384-x family of negative linear-series pass regulators is tailored for low-dropout applications where low-quiescent power is important. Fabricated with a BCDMOS technology ideally suited for low input-to-output differential applications, the UCC384-x passes 0.5 A while requiring only 0.2 V of input-voltage headroom. Dropout voltage decreases linearly with output current, so that dropout at 50 mA is less than 20 mV.

Quiescent current consumption for the device under normal (non-dropout) conditions is typically 200 uA. An integrated charge pump is internally enabled only when the device is operating near dropout with low VIN. This ensured that the device meets the dropout specifications even for maximum load current and a VIN of –3.2 V with only a modest increase in quiescent current. Quiescent current is always less than 350 uA, with the charge pump enabled. The quiescent current of the UCC384 does not increase with load current.

Short-circuit current is internally limited. The device responds to a sustained overcurrent condition by turning off after a tON delay. The device then stays off for a period, tOFF, that is 40 times the tON delay. The device then begins pulsing on and off at the tON/tOFF duty cycle of 2.5%. This drastically reduces the power dissipation during short circuit such that heat sinking, if at all required, must only accommodate normal operation. An external capacitor sets the on time. The off time is always 40 times tON.

The UCCx84-x can be shutdown to 45 uA (maximum) by pulling the SD/CT pin more positive than –0.7 V. To allow for simpler interfacing, the SD/CT pin may be pulled up to 6 V above the ground pin without turning on clamping diodes.

Internal power dissipation is further controlled with thermal-overload protection circuitry. Thermal shutdown occurs if the junction temperature exceeds 140°C. The chip remains off until the temperature has dropped 20°C (TJ = 120°C).

The UCC384-x family of negative linear-series pass regulators is tailored for low-dropout applications where low-quiescent power is important. Fabricated with a BCDMOS technology ideally suited for low input-to-output differential applications, the UCC384-x passes 0.5 A while requiring only 0.2 V of input-voltage headroom. Dropout voltage decreases linearly with output current, so that dropout at 50 mA is less than 20 mV.

Quiescent current consumption for the device under normal (non-dropout) conditions is typically 200 uA. An integrated charge pump is internally enabled only when the device is operating near dropout with low VIN. This ensured that the device meets the dropout specifications even for maximum load current and a VIN of –3.2 V with only a modest increase in quiescent current. Quiescent current is always less than 350 uA, with the charge pump enabled. The quiescent current of the UCC384 does not increase with load current.

Short-circuit current is internally limited. The device responds to a sustained overcurrent condition by turning off after a tON delay. The device then stays off for a period, tOFF, that is 40 times the tON delay. The device then begins pulsing on and off at the tON/tOFF duty cycle of 2.5%. This drastically reduces the power dissipation during short circuit such that heat sinking, if at all required, must only accommodate normal operation. An external capacitor sets the on time. The off time is always 40 times tON.

The UCCx84-x can be shutdown to 45 uA (maximum) by pulling the SD/CT pin more positive than –0.7 V. To allow for simpler interfacing, the SD/CT pin may be pulled up to 6 V above the ground pin without turning on clamping diodes.

Internal power dissipation is further controlled with thermal-overload protection circuitry. Thermal shutdown occurs if the junction temperature exceeds 140°C. The chip remains off until the temperature has dropped 20°C (TJ = 120°C).

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Type Title Date
* Data sheet Low-Dropout 0.5-A Negative Linear Regulator datasheet (Rev. D) 05 Feb 2002
Application note LDO Noise Demystified (Rev. B) PDF | HTML 18 Aug 2020
Application note LDO PSRR Measurement Simplified (Rev. A) PDF | HTML 09 Aug 2017
EVM User's guide TSW3070EVM: Amplifier Interface to Current Sink DAC - (Rev. A) 23 May 2016
User guide Voltage-Controlled Amplifier Evaluation Kit 25 Aug 2008

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Reference designs

TIDA-00075 — Wide-Bandwidth and High-Voltage Arbitrary Waveform Generator Front End

This design shows how to use an active interface with the current sink output of the DAC5682Z - typical applications for this include front ends for arbitrary waveform generators. The EVM includes the DAC5682Z for digital-to-analog conversion, an OPA695 to demonstrate an active interface (...)
Design guide: PDF
Schematic: PDF
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