LM3407MY National Semiconductor, LM3407MY Datasheet
LM3407MY
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LM3407MY Summary of contents
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... An ex- posed pad eMSOP-8 package provides excellent heat dissi- pation and thermal performance. Input UVLO and output open-circuit protection ensure a robust LED driver solution. Typical Application © 2008 National Semiconductor Corporation Features ■ Input operating range 4.5V to 30V ■ ...
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... Connection Diagram Ordering Information Order Number LM3407MY LM3407MYX Pin Descriptions Pin(s) Name Description 1 ISNS LED Current Sense pin Connect resistor R 2 DIM PWM Dimming Input pin Applying logic level PWM signal to this pin controls the average brightness of the 3 EN Device Enable pin ...
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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VIN to GND VIN to GND (Transient GND LX to GND (Transient) -3V (2 ns), 42V (500 ms) ISNS, FS, DIM GND ESD Rating Human Body Model (Note 2) ...
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Typical Performance Characteristics application 12V 25°C, and Output Current vs Input Voltage (T = -40°C) A Output Current vs Input Voltage (T = 125°C) A Efficiency vs Input Voltage (T = 25°C) ...
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Switch On Time vs Input Voltage 30046607 VCC Voltage vs Input Voltage 30046609 Switching Frequency 30046611 Operating Input Current vs Input Voltage Output Current vs R Continuous Mode Operation (V = 12V 33µ ...
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Continuous Mode Operation (V = 12V 33µ Continuous Mode Operation (V = 24V 33µ DIM Pin Disable Transient (V = 12V 33µ www.national.com = 500kHz) SW 30046613 = ...
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Simplified Functional Block Diagram Functional Description OVERVIEW The LM3407 is a constant current output floating buck switch- ing converter with wide input voltage range and low feedback current sense reference voltage. These characteristics make the LM3407 an efficient solution to ...
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FIGURE 1. Operating Waveforms of a Floating Buck Converter PULSE LEVEL MODULATION (PLM) The LM3407 incorporates the innovative Pulse Level Modu- lation technique. With an external 1% thick film resistor con- nected to the ISNS pin, the converter output voltage ...
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The switching frequency and duty ratio of the converter equal: By comparing the area of V and V ISNS RP an error signal is generated. Such a comparison is function- ally equivalent to comparing the middle level of I during ...
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FIGURE 4. Implementation of the PWM Switching Signal FIGURE 5. Waveforms of V INTERNAL VCC REGULATOR The LM3407 has an internal 4.5V linear regulator. This regu- lated voltage is used for powering the internal circuitry only and any external loading ...
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UVLO threshold, 3.6V typical, the in- ternal circuits are then enabled and normal operation begins. Application Information SWITCHING FREQUENCY SELECTION The selection of switching frequency is based on the consid- eration of the conversion efficiency, size ...
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FIGURE 6. Relationship between I Table 1 provides the suggested inductance of the inductor for 500 kHz and 1 MHz switching frequency operation with C = 4.7µF and OUT L(ripple) OUT TABLE 1. Suggested Inductance ...
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PRINTED CIRCUIT BOARD DESIGN Since the copper traces of PCBs carry resistance and para- sitic inductance, the longer the copper trace, the higher the resistance and inductance. These factors introduce voltage and current spikes to the switching nodes and may ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 8-Lead Plastic eMSOP Package NS Package Number MUY08A 14 ...
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Notes 15 www.national.com ...
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