LM3407EVAL National Semiconductor, LM3407EVAL Datasheet
LM3407EVAL
Specifications of LM3407EVAL
Related parts for LM3407EVAL
LM3407EVAL Summary of contents
Page 1
... 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 © 2009 National Semiconductor Corporation Features ■ Input operating range 4.5V to 30V ■ ...
Page 2
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 ...
Page 3
... 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) ...
Page 4
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) ...
Page 5
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 ...
Page 6
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 = ...
Page 7
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 ...
Page 8
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 ...
Page 9
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 ...
Page 10
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 ...
Page 11
EN pin is internally pulled high by a 5µA current source. Con- necting the EN pin to ground will force the device to enter low power shutdown mode. To resume normal operation, leave the EN pin open or drive with ...
Page 12
For applications with no output capacitor in place, the mag- nitude of the inductor ripple current should not be more than 20% of the average inductor current, which is equivalent to FIGURE 6. Relationship between I Table 1 provides the ...
Page 13
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 ...
Page 14
Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 8-Lead Plastic eMSOP Package NS Package Number MUY08A 14 ...
Page 15
Notes 15 www.national.com ...
Page 16
... For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock and Timing www.national.com/timing Data Converters www.national.com/adc Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators www.national.com/switchers LDOs www.national.com/ldo LED Lighting www ...