LM3500TLX-21 ,Synchronous Step-up DC/DC Converter for White LED ApplicationsFeaturesn Synchronous rectification, high efficiency and noThe LM3500 is a fixed-frequency step-up ..
LM3501TL-16 ,Synchronous Step-up DC/DC Converter for White LED ApplicationsApplicationsTypical Application Circuit20065301FIGURE 1. Typical 3 LED Application 2005 National Se ..
LM3501TL-16 ,Synchronous Step-up DC/DC Converter for White LED Applicationsapplications for n Uses small surface mount componentscellular phone back-lighting requiring low cu ..
LM3501TL-16 ,Synchronous Step-up DC/DC Converter for White LED Applicationsapplications, arequiredsingle external resistor is used to set the maximum LEDn Requires only a sma ..
LM3501TLX-16 ,Synchronous Step-up DC/DC Converter for White LED ApplicationsPin Description/FunctionsPin Name FunctionA1 AGND Analog ground.B1 V Analog and Power supply input. ..
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LMS8117ADTX-3.3 ,1A Low-Dropout Linear RegulatorLMS8117A 1A Low-Dropout Linear RegulatorJuly 2001LMS8117A1A Low-Dropout Linear Regulator
LMS8117ADTX-3.3 ,1A Low-Dropout Linear RegulatorLMS8117A 1A Low-Dropout Linear RegulatorJuly 2001LMS8117A1A Low-Dropout Linear Regulator
LMS8117ADTX-ADJ ,1A Low-Dropout Linear RegulatorApplicationsIts circuit includes a zener trimmed bandgap reference ton Post Regulator for Switching ..
LM3500TL-21-LM3500TLX-16-LM3500TLX-21
Synchronous Step-up DC/DC Converter for White LED Applications
LM3500
Synchronous Step-up DC/DC Converter for White LED
Applications
General DescriptionThe LM3500isa fixed-frequency step-up DC/DC converter
thatis idealfor driving white LEDsfor display backlighting
and other lighting functions. With fully intergrated synchro-
nous switching (no external schottky diode required) anda
low feedback voltage (500mV), power efficiencyof the
LM3500 circuit has been optimizedfor lighting applications wireless phones and other portable products (single cell
Li-Ionor 3-cell NiMH battery supplies). The LM3500 oper-
ates witha fixed 1MHz switching frequency. When used with
ceramic input and output capacitors,the LM3500 providesa
small, low-noise, low-cost solution.
Two LM3500 optionsare available with different output volt-
age capabilities. The LM3500-21 hasa maximum output
voltageof 21V andis typically suitedfor driving4or5 white
LEDsin series. The LM3500-16 hasa maximum output
voltageof 16V andis typically suitedfor driving3or4 white
LEDsin series (maximum numberof series LEDs dependent LED forward voltage).Ifthe primary white LED network
shouldbe disconnected, the LM3500 uses internal protec-
tion circuitryon the outputto preventa destructive over-
voltage event. single external resistoris usedto set the maximum LED
currentin LED-drive applications. The LED current can eas-
ilybe adjusted usinga pulse width modulated (PWM) signal the shutdown pin.In shutdown, the LM3500 completely
disconnectsthe input from output, creating total isolation and
preventing any leakage currents from trickling intothe LEDs.
Features Synchronous rectification, high efficiency andno
external schottky diode required Uses small surface mount components Can drive2-5 white LEDsin series
(may function with more low-VF LEDs) 2.7Vto7V input range Internal output over-voltage protection (OVP) circuitry,
withno external zener diode required
LM3500-16: 15.5V OVP; LM3500-21: 20.5V OVP. True shutdown isolation Input undervoltage lockout Requires only small ceramic capacitorsat the input and
output Thermal Shutdown 0.1µA shutdown current Small 8-bump thin micro SMD package
Applications LCD Bias Supplies White LED Backlighting Handheld Devices Digital Cameras Portable Applications
Typical Application CircuitFebruary 2005
Synchronous
Step-up
DC/DC
Converter
for
White
LED
Applications
