ZXLD1321DCATC Diodes Zetex, ZXLD1321DCATC Datasheet

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ZXLD1321 Boost mode DC-DC converter for LED driving with 1A output and current control Description The ZXLD1321 is an inductive converter, with an internal switch, designed for driving single or multiple LEDs in series total of 1A ...

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Pin connections (top-view) Package 14-Pin DFN with exposed pad 4mm x 3mm 0.50mm pitch 1.5W @T =70°C A Block diagram Issue 1 - January 2008 © Zetex Semiconductors plc 2008 Package view DFN14 package (bottom view). 45° chamfer denotes Pin ...

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Absolute maximum ratings (Voltages relative to GND unless otherwise stated) Operating temperature (top) Storage temperature (Tst) Junction temperature (Tj) Package power dissipation (Ptot) DFN-14 with exposed pad: 4mmx3mm, 0.5mm Pitch DC-DC converter Supply voltage (VIN) ADJ CFB ISENSE TADJ BIAS ...

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Pin description Name Pin # Description ADJ 1 Adjust input • Leave floating, or connect to VREF to set 100% output current. • Drive with dc voltage. (50mV<VADJ< VREF) to adjust output • Drive with low frequency (200Hz) PWM control ...

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Electrical characteristics ( DC-DC converter supply parameters Symbol Parameter V Supply voltage IN V (Start) Supply voltage for start- Under-voltage detection threshold UV- Normal operation to start-up mode V Under-voltage detection threshold UV+ Start-up mode to normal operation ...

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DC-DC converter output parameters Symbol Parameter Toff(100) Discharge pulse width Toff(10) Discharge pulse width f Maximum operating LXmax frequency f Switching frequency in start mode Switching NPN transistor Symbol Parameter I Average continuous switch SW (c) current I ...

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High-side current monitor Symbol Parameter V Supply voltage M_VIN V Sense voltage MON I Input current M_LOAD TCO Temperature coefficient (MON) BW Bandwidth Gm Transconductance Iout/ VMON Acc Accuracy Reference current monitor Symbol Parameter VADJ Adjust Voltage TCO Temperature Coefficient ...

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... This refers to the accuracy of output current regulation under normal operation when the feedback loop incorporating the current monitor is active. The tolerances of external components are not included in this figure. Ordering information Device Reel size (mm) ZXLD1321DCATC 33.02 Issue 1 - January 2008 © Zetex Semiconductors plc 2008 Conditions VIN>3V (g) 3.0V< ...

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Device description The ZXLD1321 is a inductive boost DC-DC converter, with an internal switch, designed for driving single or multiple LEDs in series total of 1A output current. Depending upon supply voltage (V ), LED forward voltage ...

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Low voltage operation (start-up mode) For supply voltages below 2V, the normal control loop will have insufficient headroom to operate reliably. This condition is detected by the 'under-voltage comparator', which compares a fraction of the internal supply voltage (Vcc) against ...

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Application notes Setting peak coil current The peak current in the coil is set by the resistor (R according SWpeak Rsense The minimum peak current will depend on operating mode, coil inductance and supply voltage range. ...

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PWM control A wider dimming range can be achieved by applying a PWM control signal to the ADJ pin to turn the device on and off, giving an average output current proportional to the duty cycle of the control signal. ...

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Thermal compensation of LED current High-luminance LEDs often need to be supplied with a temperature compensated current in order to maintain stable and reliable operation at high temperatures. This is usually achieved by reducing the LED current proportionally from its ...

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Typical operating conditions Inductive converters can operate in either CONTINUOUS mode, where current always flows in the inductor, but rises during the ON period and falls during the OFF period, or DISCONTINUOUS mode, where the current falls to zero during ...

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The LED current is sensed by R3 and the controller varies this until the drop in R3 equals 20 Hence making R3 = 100m ADJ 500mV V results in 100mV across R3 which equals 1 Amp. Making ...

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Operation in bootstrap mode Operation of bootstrap LED driver This is used when the input voltage is less than 2 volts. Note that the chip VIN now goes to the cathode of the Schottky diode D1. The control loop can ...

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The LED current is sensed by R3 and the controller varies this until the drop in R3 equals 20% of VADJ. Hence making R3 = 100m 500mV VADJ results in 100mV across R3 which equals 1 Amp. Making VADJ = ...

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Additional notes which apply to all operational modes Note with all these circuits that the ON time is set by the time it takes the coil to reach the peak current. This peak value is reduced by the control loop ...

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Package outline - DFN14 (4x3x0.75) 60.3938 E PIN 1 DOT BY MARKING DIM Inches Min Max A 0.0276 0.0315 A1 0.00 0.002 A3 0.008 REF. b 0.0079 0.0118 D 0.1555 0.1594 Note: Controlling dimensions are in millimeters. Approximate dimensions are ...

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Definitions Product change Zetex Semiconductors reserves the right to alter, without notice, specifications, design, price or conditions of supply of any product or service. Customers are solely responsible for obtaining the latest relevant information before placing orders. Applications disclaimer The ...