電流 - 輸出/通道 ±5%
狀態 Prod
Vdd(V) 5-100
腳位數 SOP-8
文件 AC_EB, MR16_EB, DC_EB
驅動類型 Boost Step-up
效率(%) 90
功率晶體管 External
IC代碼 3948 = 3948
產品系列 31 = Commercial/Industrial Analog
產品類別 LT = Lighting LED Driver
腳位/封裝 GR = SOP
焊料類型 L = Lead-free (RoHS Compliant)
Temperature Grade S4 = Industrial temp. (-40°C to 125°C)
包裝選項 TR = Tape & Reel
外包裝 Tape on Reel

IS31LT3948-GRLS4-TR 特徵

  • Wide input voltage range: 5V~100V
  • Constant current output limited only by external component selection (Note)
  • No loop compensation required
  • Internal over-voltage protection
  • Internal over-temperature protection
  • Operating temperature range -40C to +85C (IS31LT3948-GRLS2-TR)
  • Operating temperature range -40C to +125C (IS31LT3948-GRLS4-TR)
  • SOP-8 package Note: The maximum output current is determined by VOUT/VIN ratio as well as the external components. If output current and VOUT/VIN ratio is high, high current components of inductor and NMOS are needed.
  • TV monitor backlighting
  • Notebook
  • Automotive
  • Street lamp


The IS31LT3948 is a PFM step-up DC-DC converter designed for driving the white LED arrays for large size LCD panel backlighting applications. It can deliver stable constant output current from a few milliamps up to 2A, programmed via an external resistor. The IS31LT3948 utilizes a control scheme in which the output is automatically adjusted to the optimum output voltage for the system, maximizing the efficiency. Furthermore, the control scheme is inherently stable removing the need to provide additional loop compensation. The device features external PWM dimming, which allows the flexible control of the back-lighting luminance. The IS31LT3948 has a wide input voltage range from 5V to 100V (Note). An integrated OVP circuit protects the chip and the system even under no-load conditions. The chip is assembled in SOP-8 package. It operates from 5V to 100V over two temperature ranges of -40°C to +85°C and -40°C to +125°C. Note: The IS31LT3948 has an internal 5V shunt regulator connected to the VCC pin. A dropping resistor must be connected between the VCC pin and VIN to limit current flow. VIN voltages above 100V are allowed but care must be taken to ensure that the output voltage remains greater than VIN, and that the NMOS voltage rating is sufficiently large.