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Richtek

The RT8555 is a high efficiency driver for white LEDs. It is suitable for single/two cell battery input to drive LED light bars which contains six strings in parallel and up to 10 WLEDs per string. The internal current sinks support a maximum of ±2% current mismatching for excellent brightness uniformity in each string of LEDs. To provide enough headroom for current sink operation, the Boost controller monitors the minimum voltage of the feedback pins and regulates an optimized output voltage for power efficiency.

The RT8555 has a wide input voltage operating range from 2.7V to 24V and contains I2C interface for controlling the dimming mode, operating frequency and the LED current. The internal 100mΩ, 36V power switch with current-mode control provides over-current protection. The switching frequency of the RT8555 is adjustable from 300kHz to 2MHz, which allows flexibility between efficiency and component size.

The RT8555 is available in the WL-CSP-20B 1.65 x 2.05 (BSC), with pitch 0.4mm package.

應用

  • Tablet and Notebook Backlight
主要規格
RT8555
Status Active
Vin (min) (V) 2.7
Vin (max) (V) 24
SW Freq (typ) (kHz) 900
Number of LEDs (max) (pcs) 11
Iout (max)/channel (mA) 35
Iq (typ) (mA) 2.7
Dimming Control I2C;PWM
Topology Boost + Current Source
Features Adjustable Frequency;Adjustable Soft-Start;Current Mode Control;Cycle-by-Cycle Current Limit;Enable Input;OCP;OVP
Package Type WL-CSP1.65x2.05-20(BSC)
關鍵特性
  • Wide Operating Input Voltage : 2.7V to 24V
  • High Output Voltage : Up to 36V
  • Programmable Channel Current : 10mA to 35mA
  • Channel Current Regulation with Accuracy ±3% and Matching ±2%
  • Dimming Controls
    ► Direct PWM Dimming up to 20kHz and Minimum On-Time to 400ns
    ► PWM to Analog Dimming up to 20kHz with 8-bit Resolution
  • I2C Programs LED Current, Switching Frequency, Dimming Mode
  • Embedded Memory by OTP
  • Switching Frequency : 300kHz to 2MHz
  • Protections
    ► LED Strings Open Detection
    ► Current Limit
    ► Programmable Over Voltage Protection
    ► Over-Temperature Protection
  • 20-Ball WL-CSP, with pitch 0.4mm Package
  • RoHS Compliant and Halogen Free
Datasheet
TitleLast UpdateDownload
36V High Efficiency Boost Converter with I2C Controlled 6-CH LED Driver2015/03/20
Technical Documents
TitleItem TypeLast UpdateDownload
立錡全系列產品選擇指南 [Jan., 2024] Selection Guide2024/01/19
Evaluation Boards
TitleLast UpdateDownload
RT8555WSC Evaluation Board2015/09/21
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT8555WSCWL-CSP1.65x2.05-20(BSC)3000 Request Buy from Distributor
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