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Dual Synchronous, Step-Down Controller With 5-V and 3.3-V LDOs, internal 3.2ms soft start


Package | PIN: RUK | 20
Temp: I (-40 to 85)
Carrier: Cut Tape
Qty Price
1-9 $3.42
10-24 $3.08
25-99 $2.86
100-249 $2.51
250-499 $2.35
500-749 $2.00
750-999 $1.69
1000+ $1.61


  • Input Voltage Range: 5 V to 24 V
  • Output Voltages: 5 V and 3.3 V
    (Adjustable Range ±10%)
  • Built-in, 100-mA, 5-V and 3.3-V
  • Clock Output for Charge-Pump
  • ±1% Reference Accuracy
  • Adaptive On-Time D-CAP Mode Control
    Architecture with 400 kHz (CH1) and
    475 kHz (CH2) Frequency
  • Auto-skip and ULQ modes for long
    battery life in system stand-by mode
  • Internal 0.8-ms Voltage Servo Soft-Start
  • Low-Side RDS(on) Current Sensing Scheme
  • Built-In Output Discharge Function
  • Separate Enable Input for Switchers
  • Dedicated OC Setting Terminals
  • Power Good Indicator
  • OVP, UVP and OCP Protection
  • Non-Latch UVLO and OTP Protection
  • 20-Pin, 3 mm × 3 mm, QFN (RUK)

Texas Instruments  TPS51285ARUKT

The TPS51285A and TPS51285B are cost-effective, dual synchronous buck controllers with 5-V and 3.3-V LDOs, targeted for notebook system-power supply solutions. The device achieves low power consumption by the use of auto-skip and ULQ™ modes, which is beneficial for long battery life in system stand-by mode. The 256-kHz VCLK output is provided to drive an external charge pump, generating gate drive voltage for the load switches with minimum power consumption in the main converter. The device employs adaptive on-time D-CAP™ mode control which enables fast load transient response without external compensation network. The TPS51285A/B operates with supply input voltage ranging from 5V to 24V and supports output voltages of 5 V and 3.3 V. The TPS51285A and TPS51285B are available in a 20-pin 3 x 3 (mm) QFN package and is specified from –40°C to 85°C.