替代:
EMD2055-PWM Step-Up DC/DC Converter for Panel Backlight 
DataSheet
General Description
The EMD2055 is a highly efficient, step-up DC/DC converter for driving white LEDs. The device can drive up to 11 serially connected white LEDs from a single Li-Ion battery, or to drive multiple serial and parallel combinations with a DC power supply from 2.5V to 5.5V. The EMD2055 uses current mode and pulse-width modulated (PWM) operation. Its high switching operation frequency of 1.0MHz allows the system to use small inductor, input and output capacitors. An internal compensation circuit can reduce the external component count.
To safeguard the system, the EMD2055 includes various protection circuits such as under-voltage lockout, current limit, over voltage and thermal shutdown. EMD2055 are available in the tiny packages of SOT-23-6L and TDFN-8L (2x2mm).
Applications
Mobile Phone
Digital Still Cameras
Portable applications
MP3 Players
GPS Receivers
Features
Up to 11 WLEDs supports
Low Quiescent Current: 120 μA
Over Voltage Protection: 36.5V
Inherently Matched LED Current
Shutdown Current < 1μA
Reference Voltage 0.24V
PWM Dimming Control (100Hz~100kHz)
Internal Soft Start and Compensation
1.5A Internal power MOSFET Switch
Low Profile SOT-23-6 and TDFN-8L Packages
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General Description
The EMD2053 designed with high efficiency step up DC/DC converter for driving white LEDs. The device can drive up 11 white LEDs from a single Li-Ion battery or a DC power 2.5V to 5.5V. The EMD2053 uses current mode and pulse-width modulated (PWM) operation. It switches at 1.2MHz and allows using small inductor and both of input/output capacitors. An internal compensation can reduce external component.
The EMD2053 include under-voltage lockout, current limit, over voltage and thermal shutdown protection.
The EMD2053 is available in SOT-26 package.
Features
WLEDs supports (20mA for each channel):
Up to 11S2P at VIN=3.7V
Up to 11S4P at VIN=5.0V
(Note: S Series; P Parallel)
Low Quiescent Current: 55 μA
Over Voltage Protection: 37V
Inherently Matched LED Current
Shutdown Current < 1μA
Reference Voltage 0.245V
Efficiency : 85% (Typ) at VIN=5.0V
PWM Dimming Control
Internal Soft Start and Compensation
1.4A Internal power MOSFET Switch
Low Profile SOT-26 Package
Applications
Mobile Phone
Digital Still Cameras
Portable applications
MP3 Players
GPS Receivers