LM3409HVMYX National Semiconductor, LM3409HVMYX Datasheet
LM3409HVMYX
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LM3409HVMYX Summary of contents
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... Pro- grammable UVLO, low-power shutdown, and thermal shut- down complete the feature set. Typical Application © 2009 National Semiconductor Corporation LM3409 LM3409HV Features ■ 2Ω, 1A Peak MosFET Gate Drive ■ ...
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... Connection Diagram Ordering Information Order Number NSC Package Drawing LM3409MY MUC10A LM3409MYX MUC10A LM3409HVMY MUC10A LM3409HVMYX MUC10A Pin Descriptions Pin(s) Name Description 1 UVLO Input under-voltage lockout 2 IADJ Analog LED current adjust 3 EN Logic level enable / PWM dimming 4 COFF Off-time programming 5 GND ...
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... Absolute Maximum Ratings LM3409/09HV (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VIN, EN, UVLO to GND VIN to VCC, PGATE VIN to PGATE VIN to CSP, CSN COFF to GND COFF current IADJ Current Junction Temperature ...
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Symbol Parameter V Rising UVLO threshold UVLO-R I UVLO hysteresis current UVLO-HYS ENABLE I EN pin current pin threshold EN- pin hysteresis EN-HYS t EN pin rising delay EN pin falling delay EN-F ...
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Typical Performance Characteristics T = +25° 24V, and characteristics are identical for LM3409 and LM3409HV unless otherwise specified vs. Junction Temperature CST V vs. Junction Temperature ADJ V vs. Junction Temperature OFT V vs. Junction ...
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LM3409 Efficiency vs. Input Voltage V = 17V (5 LEDs LED LM3409 LED Current vs. Input Voltage = 17V (5 LEDs) (Note Normalized Switching Frequency vs. Input Voltage www.national.com LM3409HV Efficiency vs. Input Voltage = ...
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Internal EN Pin PWM Dimming V = 17V (5 LEDs 24V O IN 20kHz 50% EN pin PWM dimming = 48V (Note 42V (12 LEDs 20kHz 50% EN pin PWM dimming (rising ...
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Block Diagram Theory of Operation The LM3409/09HV are P-channel MosFET (PFET) con- trollers for step-down (buck) current regulators which are ideal for driving LED loads. They have wide input voltage range allowing for regulation of a variety of LED loads. ...
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FIGURE 1. Ideal CCM Buck Converter Inductor Current i CONTROLLED OFF-TIME (COFT) ARCHITECTURE The COFT architecture is used by the LM3409/09HV to con- trol combination of peak current detection and a LED one-shot off-timer that ...
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There are three different methods to set the current sense threshold (V ) using the multi-function IADJ pin: CST 1. IADJ pin left open: 5µA internal current source biases the Zener diode and clamps the IADJ pin voltage (V 1.24V ...
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AVERAGE LED CURRENT For a buck converter, the average LED current is simply the average inductor current. FIGURE 5. Sense Voltage v Using the COFT architecture, the peak transistor current ( sensed as shown in Figure 5, which ...
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FIGURE 7. LED Current i PWM DIMMING USING THE EN PIN The enable pin (EN TTL compatible input for PWM dim- ming of the LED. A logic low (below 0.5V will disable the internal driver and ...
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Design Considerations OPERATION NEAR DROPOUT Because the power MosFET is a PFET, the LM3409/09HV can be operated into dropout which occurs when the input voltage is approximately equal to output voltage. Once the input voltage drops below the nominal output ...
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INPUT CAPACITORS Input capacitors are selected using requirements for mini- mum capacitance and RMS ripple current. The PFET current during t is approximately I , therefore the input capacitors ON LED discharge the difference between I LED current (I ) ...
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FIGURE 10. Ideal LED Current i EXTERNAL PARALLEL FET PWM DIMMING Any buck topology LED driver is a good candidate for parallel FET dimming because high slew rates are achievable, due to the fact that no output capacitance is required. ...
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Design Guide TYPICAL APPLICATION SPECIFICATIONS Nominal input voltage Maximum input voltage: V IN-MAX Nominal output voltage (# of LEDs x forward voltage): V LED string dynamic resistance Switching frequency (at nominal V IN Average LED current: ...
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OUTPUT CAPACITANCE A minimum output capacitance (C ) may be necessary to O-MIN reduce Δi below Δi . With the specified Δi LED-PP L-PP the known dynamic resistance ( the LED string, solve for D the required ...
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Design Example #1 EN PIN PWM DIMMING APPLICATION FOR 10 LEDS SPECIFICATIONS f = 525kHz 48V 75V IN IN-MAX V = 35V LED Δi = Δ LED-PP L-PP Δv ...
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AVERAGE LED CURRENT Determine I : L-MAX Assume V = 1.24V and solve for R ADJ SNS The closest 1% tolerance resistor is 0.1 Ω therefore the I is: The chosen component from step 3 is: 4. OUTPUT CAPACITANCE ...
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INPUT UVLO Solve for R : UV2 The closest 1% tolerance resistor is 49.9 kΩ therefore V is: Solve for R : UV1 Design #1 Bill of Materials Qty Part ID 1 LM3409HV IN1 IN2 ...
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Design Example #2 ANALOG DIMMING APPLICATION FOR 4 LEDS SPECIFICATIONS f = 500kHz 24V 42V IN IN-MAX V = 14V LED Δi = 450mA; Δi = 50mA L-PP LED-PP Δv = ...
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AVERAGE LED CURRENT Determine I : L-MAX Assume V = 1.24V and solve for R ADJ The closest 1% tolerance resistor is 0.2 Ω therefore I The chosen component from step 3 is: 4. OUTPUT CAPACITANCE = 2 Ω ...
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INPUT UVLO Solve for R : UV2 The closest 1% tolerance resistor is 49.9 kΩ therefore V is: Solve for R : UV1 Design #2 Bill of Materials Qty Part ID 1 LM3409 2 C IN1 ...
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Applications Information DESIGN #3: EXTERNAL PARALLEL FET PWM DIMMING APPLICATION FOR 10 LEDS Design #3 Bill of Materials Qty Part ID 1 LM3409HV IN1 IN2 OFF ...
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DESIGN #4: SINGLE POTENTIOMETER ANALOG DIMMING APPLICATION FOR 6 LEDS Design #4 Bill of Materials Qty Part ID 1 LM3409 IN1 IN2 OFF ...
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DESIGN #5: 75°C THERMAL FOLDBACK APPLICATION FOR 16 LEDS Design #5 Bill of Materials Qty Part ID 1 LM3409HV IN1 IN2 OFF ...
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DESIGN #6: HIGH CURRENT APPLICATION FOR 4 LEDS Design #6 Bill of Materials Qty Part ID 1 LM3409 2 C IN1 OFF ...
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Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 10-Lead Exposed Pad Plastic eMSOP Package NS Package Number MUC10A 28 ...
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Notes 29 www.national.com ...
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