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2.2MHz wide VIN non-synchronous boost/SEPIC/flyback controller


Package | PIN: WSON (DSS) | 12
Temp: S (-40 to 150)
Carrier: Cut Tape
Qty Price
1-9 $2.12
10-24 $1.91
25-99 $1.77
100-249 $1.55
250-499 $1.46
500-749 $1.24
750-999 $1.05
1000+ $1.00


  • AEC-Q100 Qualified for Automotive Applications
    • Temperature Grade 1: –40°C to+125°C TA
  • Wide Input Operating Range for Car and Portable Battery Applications
    • 3.5-V to 45-V Operating Range
    • 2.97-V to 16-V When BIAS = VCC
    • MinimumBoost Supply Voltage 1.5 V When BIAS ≥ 3.5 V
    • InputTransient Protection up to 50 V
  • Minimized Battery Drain
    • LowShutdown Current ( IQ ≤ 2.6 µA )
    • Low Operating Current ( IQ ≤ 480 µA)
  • Small Solution Size and Low Cost
    • Maximum Switching Frequency of 2.2MHz
    • 12-Pin WSONPackage (3 mm × 2 mm) With Wettable Flanks
    • IntegratedError Amplifier Allows Primary-Side Regulation Without Optocoupler (Flyback)
    • Minimized Undershoot During Cranking (Start-stop Application)
  • Higher Efficiency With Low-Power Dissipation
    • 100-mV ±7% Low Current Limit Threshold
    • Strong 1.5-A Peak Standard MOSFET Driver
    • Supports External VCC Supply
  • Avoid AM Band Interference and Crosstalk
    • Optional Clock Synchronization
    • Dynamically ProgrammableSwitching Frequency from 100 kHz to 2.2 MHz
  • Integrated Protection Features
    • Constant Peak Current Limiting Over InputVoltage
    • Optional Hiccup Mode Short-Circuit Protection (seethe Device Comparison Table)
    • Programmable LineUVLO
    • OVP Protection
    • ThermalShutdown
  • Accurate ±1% Accuracy Feedback Reference
  • Programmable Extra Slope Compensation
  • Adjustable Soft Start
  • PGOOD Indicator
  • Create a Custom Design Using the LM5155x With the WEBENCH® Power Designer

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Texas Instruments  XLM51551QDSSTQ1

The LM5155x-Q1 ( LM5155-Q1 and LM51551-Q1 ) device is a wide input range, non-synchronous boostcontroller that uses peak current mode control. The device can be used in boost, SEPIC, and flybacktopologies.

The LM5155x-Q1 device can start up from a 1-cell battery with a minimum of2.97 V if the BIAS pin is connected to the VCC pin. It can operate with the input supply voltage aslow as 1.5 V if the BIAS pin is greater than 3.5 V.

The internal VCC regulator also supports BIAS pin operation up to 45 V (50-V absolutemaximum) for automotive load dump. The switching frequencyis dynamically programmable with an external resistor from 100 kHz to 2.2 MHz. Switching at 2.2 MHzminimizes AM band interference and allows for a small solution size and fast transientresponse.

The device features a 1.5-A standard MOSFET driver and a low 100-mV current limitthreshold. The device also supports the use of an external VCC supply to improve efficiency. Lowoperating current and pulse-skipping operation improve efficiency at light loads.

The device has built-in protection features such as cycle-by-cycle current limit,overvoltage protection, line UVLO, and thermal shutdown. Hiccup mode overload protection isavailable in the LM51551-Q1 device option. Additional features include low shutdownIQ, programmable soft start, programmable slope compensation, precisionreference, power-good indicator, and external clock synchronization.