ZXLD1371QESTTC Diodes Inc. / Zetex, ZXLD1371QESTTC Datasheet

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HIGH A Descriptio on The ZXLD137 LED D driver contr external MOS FETs to drive high current topology contr roller enabling it to efficiently through series s connected LE EDs. The multi to operate in b ...

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Pin Descriptions Pin Type Pin Name (Note 2) Adjust input (for dc output current control) Connect to REF to set 100% output current. ADJ 1 I Drive with dc voltage (125mV<V of set value. The ADJ pin has an internal ...

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Functional Block Diagram Absolute Maximum Ratings Symbol V Input supply voltage IN V Auxiliary supply voltage AUX V Current monitor input relative to GND ISM V Current monitor sense voltage (V SENSE V Gate driver output voltage GATE I Gate ...

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Package Thermal Data Thermal Resistance Junction-to-Ambient, θ (Note 4) JA Junction-to-Case, θ JC Recommended Operating Conditions Symbol Parameter Input supply voltage range V IN Auxiliary supply voltage range (Note 6) V AUX Differential input voltage V SENSE External dc control ...

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Electrical Characteristics (Test conditions: V Symbol Parameter Supply and reference parameters Under-Voltage detection threshold V UV- Normal operation to switch disabled Under-Voltage detection threshold V UV+ Switch disabled to normal operation I Quiescent current into V Q- Quiescent ...

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Electrical Characteristics (cont.) Symbol Parameter Output Parameters V FLAG pin low level output voltage FLAGL I FLAG pin open-drain leakage current FLAGOFF STATUS Flag no-load output voltage V STATUS (Note 10) R Output impedance of STATUS output STATUS Driver output ...

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Typical Characteristics 3 2.5 2 1 1.252 1.2515 1.251 1.2505 1.25 1.2495 1.249 1.2485 1.248 -40 -25 100% 90% 80% 70% 60% 50% 40% 30% 20% 10 ZXLD1371 Document number: DS35436 Rev. ...

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Typical Characteristics – Linear/DC Dimming 750 600 450 300 150 0 0 700 600 500 400 300 200 100 0 0 0.25 350 300 Switching Frequency 250 200 150 100 ZXLD1371 Document number: DS35436 Rev ...

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Typical C Characteris stics – PWM 1500 T = 25° 1250 33µ 100Hz PWM 1000 750 500 250 LED 100% 80% 60% 40% 20 ...

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Typical Characteristics – Buck Mode – R 3.2 3.1 3.0 2.9 2.8 2.7 2 700 T = 25° 15µ 75m 600 C = 100µ 500 1 LED 400 300 200 ...

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Typical Characteristics – Buck Mode – R 700 T = 25° 33µ 150m 600 C = 100µF IN 400 300 200 1 LED 100 1000 900 800 700 600 500 400 300 ...

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Typical Characteristics – Boost 0.45 0.40 0.35 0.30 0.25 0.20 0. 800 700 600 500 400 300 200 100 0 5 100 ZXLD1371 Document number: DS35436 Rev Mode – ...

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Typical Characteristics – Boost 0.45 0.43 0.41 0.39 0.37 0.35 0.33 0.31 0.29 0.27 0. 500 450 400 350 300 250 8 LEDs 200 150 100 100 LEDs 50 ...

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Typical Characteristics – Boost 0.45 0.43 0. 33µH 0.39 0.37 0.35 0. 100µH 0.31 0.29 0.27 0. 500 450 400 350 300 250 200 150 100 100 L = 100µH ...

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Typical Characteristics – Boost 0.60 0.50 0.40 0.30 0.20 0. 800 700 600 500 400 300 I LED 200 100 100 ZXLD1371 Document number: ...

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Typical Characteristics – Buck-Boost 0.450 0.425 5 LEDs 0.400 0.375 0.350 0.325 7 LEDs 8 LEDs 0.300 9 LEDs 0.275 0.250 5 900 800 700 600 500 400 300 200 100 ...

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Typical Characteristics – Buck-Boost 0.45 0.43 0.41 5 LEDs 0.39 0.37 0.35 0.33 0.31 0.29 0.27 0. 600 500 400 300 200 100 LEDs Bootstrap ...

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Typical Characteristics – Buck-Boost 0.450 0.425 0.400 0.375 0.350 0.325 0.300 0.275 0.250 5 6 600 500 400 300 200 100 100µ 68µ ...

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Typical Characteristics – Buck-Boost 0.60 0.55 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0. 1000 900 800 700 600 500 400 300 200 100 ...

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Applications Information The ZXLD1371 is a high accuracy hysteretic inductive buck/boost/buck-boost controller designed to be used with an external NMOS switch for current-driving single or multiple series-connected LEDs. The device can be configured to operate in buck, boost, or buck-boost ...

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Applications Information (cont.) b) Boost and Buck-Boost modes – the most simple boost/buck-boost circuit is shown in Figure 3 Control in Boost and Buck-boost mode is achieved by sensing the coil current in the series resistor Rs, connected between the ...

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Applications Information (cont.) 0.225 1-D = GI_ADJ LED This shows that the LED current depends on the ADJ pin voltage, the reference voltage and 3 resistor values (RS, RGI1 and RGI2 independent ...

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Applications Information (cont.) APPLICATION CIRCUIT DESIGN External component selection is driven by the characteristics of the load and the input supply, since this will determine the kind of topology being used for the system. inductor/frequency setting and the MOSFET selection. ...

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Applications Information (cont.) The additional terms are relatively small, so the exact equations will only make a significant difference at lower operating voltages at the input and output, i.e. low input voltage or a small number of LEDs connected in ...

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Applications Information (cont.) Buck topology In Buck mode connected to ADJ as in Figure 5. The LED current depends only upon ADJ above, ⎛ ⎞ ⎛ ⎞ 218 V ⎜ ⎜ ⎟ ...

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Applications Information (cont.) This will give small enough I error for most practical purposes. Satisfactory operation will be obtained if V LED about 80mV. This means GI_ADJ should be greater than (1-D There is also a maximum limit on V ...

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Applications Information (cont.) Inductor Selection and frequency Control The selection of the inductor coil, L1, requires knowledge of the switching frequency and current ripple, and also depends on the duty cycle to some extent. In the hysteretic converter, the frequency ...

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Applications Information (cont.) The ZXLD1371 sets the ripple current, ΔI from Equation 8 . The device adjusts the ripple current within this range in order to regulate the switching frequency. We therefore need to use a ΔI value of 20% ...

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Applications Information (cont.) During the on-time, the MOSFET switch current is equal to the coil current. The rms MOSFET current the mean coil current. Therefore the approximate RMS current in the MOSFET during t COIL Buck ...

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Applications Information (cont.) Example 2) Using the ZXMN6A09K (V = 60V, I DS(MAX 29nC 10V G GS ZXLD1371 I = 300mA PEAK 300 mA ...

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Applications Information (cont.) Diodes Selection For maximum efficiency and performance, the rectifier (D1) should be a fast low capacitance Schottky diode* with low reverse leakage at the maximum operating voltage and temperature. The Schottky diode also provides better efficiency than ...

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Applications Information (cont.) Input Capacitor The input capacitor can be calculated knowing the input voltage ripple ΔV Buck − LED C IN Δ − Boost ...

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Applications Information (cont.) PWM Output Current Control & Dimming The ZXLD1371 has a dedicated PWM dimming input that allows a wide dimming frequency range from 100Hz to 1kHz with up to 1000:1 resolution; however higher dimming frequencies can be used ...

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Applications Information (cont.) LED current can be adjusted digitally, by applying a low frequency PWM logic signal to the PWM pin to turn the controller on and off. This will produce an average output current proportional to the duty cycle ...

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Applications Information (cont.) The thermistor resistance temperature of T degrees Kelvin is given Where R is the thermistor resistance at the ...

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Applications Information (cont.) FLAG/STATUS Outputs The FLAG/STATUS outputs provide a warning of extreme operating or fault conditions. FLAG is an open-drain logic output, which is normally off, but switches low to indicate that a warning, or fault condition exists. STATUS ...

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Applications Information (cont.) In the event of more than one fault/warning condition occurring, the higher severity condition will take precedence. E.g. ‘Excessive coil current’ and ‘Out of regulation’ occurring together will produce an output of 0.9V on the STATUS pin. ...

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Applications Information (cont.) Boosting V Supply Voltage in Boost and Buck-Boost Mode AUX This means that depending on the characteristics of the external MOSFET, the gate voltage may not be enough to fully enhance the power MOSFET. A boot-strap boosting ...

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Applications Information (cont.) Over-Voltage Protection The ZXLD1371 is inherently protected against open-circuit load when used in Buck configuration. However care has to be taken with open-circuit load conditions in Buck-Boost or Boost configurations. This is because in these configurations there ...

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Applications Information (cont.) PCB Layout Considerations PCB layout is a fundamental to device performance in all configurations. ZXLD1371 PCB layout. Inductor, Switch and Freewheeling diode Here are some considerations useful for the PCB layout using ZXLD1371 in Buck, Boost and ...

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... Ordering Information Device (Note 19) Packaging ZXLD1371EST16TC TSSOP-16EP ZXLD1371QESTTC TSSOP-16EP Note: 19. For Automotive grade with AEC-Q100 qualification the ZXLD1371QESTTC should be ordered. Where YY is last two digits of year and WW is two digit week number Package Outline Dimensions Pin 1 Indent Suggested Pad Layout ...

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DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY ...