|Package | PIN:||RGR | 20|
|Temp:||I (-40 to 85)|
- 2.5-V to 24-V Input Voltage Range
- 39-V Maximum Output Voltage
- Integrated 1.8-A, 40-V MOSFET
- 450-kHz to 1.2-MHz Programmable Switching Frequency
- Adaptive Boost Output to WLED Voltages
- 100-Hz to 25-kHz Wide Input PWM Dimming Frequency Range
- 1% Minimum Dimming Duty Cycle
- Small External Components
- Integrated Loop Compensation
- Six Current Sinks of 30 mA Maximum
- 1% (Typical) Current Matching
- Input PWM Glitch Filter
- PWM Brightness Interface Control
- Three Optional Dimming Methods, including Direct PWM Dimming, Analog Dimming, and Analog and PWM Mixed Dimming
- Built-in WLED Open Protection
- Thermal Shutdown
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Texas Instruments TPS61177ARGRR
The TPS61177A device provides a highly integrated white LED (WLED) driver solution fornotebook LCD backlight. This device has a built-in high-efficiency boost regulator with integrated1.8-A, 40-V power MOSFET. The six current sink regulators provide high precision current regulationand matching. In total, the device can support up to 72 WLEDs. In addition, the boost outputautomatically adjusts its voltage to the WLED forward voltage to optimize efficiency.
The TPS61177A supports the analog dimming, analog and PWM dimming, and direct PWM dimmingmethod. During analog dimming mode, each CS current linearly varies depending on the duty cycleinformation on the PWMB pin. During analog and PWM mixed dimming mode, the input PWM duty cycleinformation is translated to an analog signal to control the WLED current linearly over 25% to 100%brightness area. The device also allows adding PWM dimming when the analog current is down to 25%.Below 25%, the analog signal translates to PWM duty cycle information to control the on or off ofWLED current and averages the WLED current down to 1%. The frequency of adding PWM dimming is sameto input PWM frequency on the PWMB pin. While the TPS61177A also supports a direct PWM dimmingmethod, in direct PWM dimming mode the WLED current is turned on or off, synchronized with theinput PWM signal.