LT1932 Linear Technology, LT1932 Datasheet
LT1932
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LT1932 Summary of contents
Page 1
... A single external resistor sets LED current between 5mA and 40mA, which can then be easily adjusted using either a DC voltage or a pulse width modulated (PWM) signal. When the LT1932 is placed in shutdown, the LEDs are disconnected from the output, ensuring a quiescent current of under 1 A for the entire circuit. The device’ ...
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... Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LT1932E is guaranteed to meet specifications from Specifications over the – operating temperature range are assured by design, characterization and correlation with statistical process controls ...
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... INPUT VOLTAGE (V) 1932 G05 Switching Waveforms V SW 10V/DIV I L1 200mA/DIV V OUT 20mV/DIV AC COUPLED I LED 10mA/DIV 0.5 s/DIV IN 4 WHITE LEDs I = 15mA LED CIRCUIT ON FIRST PAGE OF THIS DATA SHEET 10 1932 G08 LT1932 = 10V IN = 1.2V IN 125 75 100 1932 G03 8 10 1932 G06 1093 G09 3 ...
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... LED current (that flows into the LED pin). This pin is also used to provide LED dimming. SHDN (Pin 5): Shutdown Pin. Tie this pin higher than 0.85V to turn on the LT1932; tie below 0.25V to turn it off. V (Pin 6): Input Supply Pin. Bypass this pin with a IN capacitor to ground as close to the device as possible ...
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... U U APPLICATIO S I FOR ATIO Inductor Selection Several inductors that work well with the LT1932 are listed in Table 1. Many different sizes and shapes are available. Consult each manufacturer for more detailed information and for their entire selection of related parts. As core losses at 1.2MHz are much lower for ferrite cores that for the cheaper powdered-iron ones, ferrite core inductors should be used to obtain the best efficiency ...
Page 6
... Ceramic capacitors also make a good choice for the input decoupling capacitor, which should be placed as close as possible to the LT1932 4.7 F input capacitor is sufficient for most applications. Table 2 shows a list of several ceramic capacitor manufacturers. Consult the manufacturers for detailed information on their entire selection of ceramic parts ...
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... When a PWM control signal is used to drive the SHDN pin the LT1932 (see Figure 6), the LEDs are turned off and 15mA on at the PWM frequency. The current through them alternates between full current and zero current, so the average current changes with duty cycle ...
Page 8
... R 225 ADJ Regulating LED Current when V The LT1932 contains special circuitry that enables it to regulate the LED current even when the input voltage is higher than the output voltage. When V the internal NPN LED switch (transistor Q2 in Figure 1) is saturated to provide a lower power loss. When V greater than V saturation to keep the LED current in regulation ...
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... C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN GMK325BJ225 (408) 573-4150 D1: ZETEX ZHCS400 (631) 543-7100 L1: MURATA LQH3C100M24 (814) 237-1431 W U Figure 7. Recommended Component Placement C2 2.2 F 100 100 30mA 1932 TA14a LT1932 SHDN 3 4 GND R SET DIMMING ...
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... DIMMING CONTROL R SET 1.50k C1, C2: TAIYO YUDEN JMK212BJ475 D1: ZETEX ZHCS400 L1: MURATA LQH3C4R7M24 Single Cell Driver for Two White LEDs LT1932 5 C1 SHDN LED 4 GND SET 4 2 2.5V PWM 24.9k DIMMING CONTROL R SET 1.50k C1: TAIYO YUDEN JMK212BJ475 C2: TAIYO YUDEN LMK212BJ225 ...
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... L1: MURATA LQH3C4R7M24 2.2 F 15mA (408) 573-4150 1932 TA15a (408) 573-4150 (631) 543-7100 (814) 237-1431 2.2 F 15mA (408) 573-4150 1932 TA06a (408) 573-4150 (631) 543-7100 (814) 237-1431 LT1932 Efficiency 1. LED CURRENT (mA) ...
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... C1: TAIYO YUDEN JMK212BJ475 C2: TAIYO YUDEN EMK212BJ105 D1: ZETEX ZHCS400 L1: MURATA LQH3C4R7M24 2-Cell Driver for Five White LEDs LT1932 PWM 5 SHDN LED DIMMING CONTROL R GND SET SET 1.50k C1: TAIYO YUDEN JMK212BJ475 (408) 573-4150 C2: TAIYO YUDEN TMK316BJ105 ...
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... C2 2.2 F 15mA 2 (408) 573-4150 1932 TA08a (408) 573-4150 (631) 543-7100 (714) 373-7334 LED 2.2 F 15mA 2 (408) 573-4150 1932 TA09a (408) 573-4150 (631) 543-7100 (714) 373-7334 LT1932 Efficiency 4. 2. LED CURRENT (mA) 1932 TA08b Efficiency ...
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... C1: TAIYO YUDEN JMK212BJ475 C2: TAIYO YUDEN EMK212BJ105 D1: ZETEX ZHCS400 L1: PANASONIC ELJEA6R8 Li-Ion Driver for Five White LEDs L1 4 2. LT1932 PWM 5 SHDN LED DIMMING CONTROL R GND SET SET 1.50k C1: TAIYO YUDEN JMK212BJ475 C2: TAIYO YUDEN TMK316BJ105 D1: ZETEX ZHCS400 ...
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... MAX) .00 – 0.15 .01 – .10 A1 (.00 – .006) (.0004 – .004) .90 – 1.30 .80 – .90 A2 (.035 – .051) (.031 – .035) .35 – .55 .30 – .50 REF L (.014 – .021) (.012 – .019 REF) LT1932 Efficiency 4. ...
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... R SET 750 C1: TAIYO YUDEN JMK212BJ475 C2: TAIYO YUDEN TMK325BJ475 D1: ZETEX ZHCS400 L1: MURATA LQH3C100M24 Li-Ion Driver for Six White LEDs L1 4 2. LT1932 5 C1 SHDN LED 4 GND SET 4 3.3V DC 80.6k DIMMING CONTROL R SET 1.50k C1: TAIYO YUDEN JMK212BJ475 C2: TAIYO YUDEN TMK316BJ105 ...