Datasheet LT3492 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | Triple Output LED Driver with 3000:1 PWM Dimming |
| Seiten / Seite | 22 / 1 — FEATURES. DESCRIPTION. True Color PWM™ Dimming Delivers Up to 3000:1. … |
| Dateiformat / Größe | PDF / 338 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. True Color PWM™ Dimming Delivers Up to 3000:1. Dimming Ratio
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LT3492 Triple Output LED Driver with 3000:1 PWM Dimming
FEATURES DESCRIPTION
n
True Color PWM™ Dimming Delivers Up to 3000:1
The LT®3492 is a triple output DC/DC converter designed
Dimming Ratio
to operate as a constant-current source and is ideal for n
Built-In Gate Driver for PMOS LED Disconnect
driving LEDs. The LT3492 works in buck, boost or buck- n
Three Independent Driver Channels with 600mA,
boost mode. The LT3492 uses a fi xed frequency, current
60V Internal Switches
mode architecture resulting in stable operation over a n
Operates in Buck, Boost, Buck-Boost Modes
wide range of supply and output voltages. A frequency n CTRL Pin Accurately Sets LED Current Sense adjust pin allows the user to program switching frequency Threshold Over a Range of 10mV to 100mV between 330kHz and 2.1MHz to optimize effi ciency and n Adjustable Frequency: 330kHz to 2.1MHz external component size. n Open LED Protection The external PWM input provides 3000:1 LED dimming n Wide Input Voltage Range: on each channel. Each of the three channels has a built-in Operation from 3V to 30V gate driver to drive an external LED-disconnect P-channel Transient Protection to 40V MOSFET, allowing high dimming range. The output current n Surface Mount Components range of each channel of the LT3492 is programmed with n 28-Lead (4mm × 5mm) QFN and TSSOP Packages an external sense resistor.
APPLICATIONS
The CTRL pin is used to adjust the LED current either for analog dimming or overtemperature protection. n RGB Lighting L n , LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Billboards and Large Displays Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation. n Automotive and Avionic Lighting All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203, and others pending. n Constant-Current Sources
TYPICAL APPLICATION High Dimming Ratio Triple Output Buck-Mode LED Power Supply
PVIN 58V ISP1 ISP2 1μF ISP3 s3 330mΩ 330mΩ 330mΩ ISN1 ISN2 ISN3
3000:1 PWM Dimming at 100Hz
TG1 TG2 TG3 PWM 5V/DIV 10 LEDs 0.3A 0.3A 0.3A ILED 0.47μF 0.47μF 0.47μF 0.2A/DIV IL 0.5A/DIV 33μH 33μH 33μH 1μs/DIV 3492 TA01b SW1 SW2 SW3 TG1-3 ISP1-3 VC1-3 ISN1-3 VREF VIN V CTRL1-3 IN 3V TO 24V PWM1-3 1μF 150k 10k LT3492 SHDN FADJ 49.9k 680pF 1.3MHz GND OVP1-3 3492 TA01a 3492fa 1
FEATURES DESCRIPTION
n
True Color PWM™ Dimming Delivers Up to 3000:1
The LT®3492 is a triple output DC/DC converter designed
Dimming Ratio
to operate as a constant-current source and is ideal for n
Built-In Gate Driver for PMOS LED Disconnect
driving LEDs. The LT3492 works in buck, boost or buck- n
Three Independent Driver Channels with 600mA,
boost mode. The LT3492 uses a fi xed frequency, current
60V Internal Switches
mode architecture resulting in stable operation over a n
Operates in Buck, Boost, Buck-Boost Modes
wide range of supply and output voltages. A frequency n CTRL Pin Accurately Sets LED Current Sense adjust pin allows the user to program switching frequency Threshold Over a Range of 10mV to 100mV between 330kHz and 2.1MHz to optimize effi ciency and n Adjustable Frequency: 330kHz to 2.1MHz external component size. n Open LED Protection The external PWM input provides 3000:1 LED dimming n Wide Input Voltage Range: on each channel. Each of the three channels has a built-in Operation from 3V to 30V gate driver to drive an external LED-disconnect P-channel Transient Protection to 40V MOSFET, allowing high dimming range. The output current n Surface Mount Components range of each channel of the LT3492 is programmed with n 28-Lead (4mm × 5mm) QFN and TSSOP Packages an external sense resistor.
APPLICATIONS
The CTRL pin is used to adjust the LED current either for analog dimming or overtemperature protection. n RGB Lighting L n , LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Billboards and Large Displays Technology Corporation. True Color PWM is a trademark of Linear Technology Corporation. n Automotive and Avionic Lighting All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 7199560, 7321203, and others pending. n Constant-Current Sources
TYPICAL APPLICATION High Dimming Ratio Triple Output Buck-Mode LED Power Supply
PVIN 58V ISP1 ISP2 1μF ISP3 s3 330mΩ 330mΩ 330mΩ ISN1 ISN2 ISN3
3000:1 PWM Dimming at 100Hz
TG1 TG2 TG3 PWM 5V/DIV 10 LEDs 0.3A 0.3A 0.3A ILED 0.47μF 0.47μF 0.47μF 0.2A/DIV IL 0.5A/DIV 33μH 33μH 33μH 1μs/DIV 3492 TA01b SW1 SW2 SW3 TG1-3 ISP1-3 VC1-3 ISN1-3 VREF VIN V CTRL1-3 IN 3V TO 24V PWM1-3 1μF 150k 10k LT3492 SHDN FADJ 49.9k 680pF 1.3MHz GND OVP1-3 3492 TA01a 3492fa 1