通道數 1
電壓 - 電源 4.5~40
電流 - 輸出/通道 (mA) 3A
Sink Source Buck
調光 PWM
腳位/封裝 SOP-8-EP
狀態 S=Q2/17
產品系列 32 = 汽車模擬和混合信號
產品類別 LT = 照明LED驅動器
IC代碼 3953
焊接 L = 無鉛
温規 A3 = 車規 (-40C to +125°C)
外包裝 卷轴包
相關IC编號

IS32LT3953-GRLA3-TR 特徵

  • Wide input voltage supply from 4.5V to 40V
  • True average output current control
  • 3A maximum output over operating temperature range
  • Cycle-by-cycle current limit
  • Dimming via direct logic input or power supply Integrated high-side MOSFET switch voltage Internal control loop compensation
  • Under-voltage lockout (UVLO) and thermal shutdown protection
  • 2μA low power shutdown
  • Spread spectrum to optimize EMI
  • Robust fault protection:
  • - Pin-to-GND short - Component open/short faults - Adjacent pin-to-pin short - LED open/short
  • Automotive and avionic lighting
  • Dimmable interior lights
  • Daytime running lights
  • Turn/stop lights
  • Front and rear fog lights

概觀

The IS32LT3953 is a DC-to-DC switching converter, which integrate an N-channel MOSFET to operate in a buck configuration. The device supply a wide input voltage between 4.5V and 40V and provides a constant current of up to 3A for driving a single LED or multiple series connected LEDs. The external resistor, RSET, is used to adjust LED output current, which allowing the output voltage to be automatically adjusted for a variety of LED configurations. The IS32LT3953 operates in a fixed frequency mode during switching. There is an external resistor connected between the VCC and TON pins used to configure the on-time (switching frequency). The switching frequency is dithered for spread spectrum feature to spread the electromagnetic emitting energy into a wider frequency band. It is helpful to optimize the EMI performance. A logic input PWM signal to the enable (EN) pin is applied to adjust the LED current. The brightness of LED is proportional to the duty cycle of the PWM signal. True average output current operation is achieved with fast transient response by using cycle-by-cycle, controlled on-time method. IS32LT3953 is available in an SOP-8-EP package with an exposed pad for enhanced thermal dissipation. It operates from 4.5V to 40V over the temperature range of -40°C to +125°C.