LM3414电路设计

LM3414,LM3414HV

LM3414/LM3414HV 1A 60W* Common Anode Capable Constant Current Buck LED Driver Requires No External Current Sensing Resistor

Literature Number: SNVS678D

LM3414/LM3414HV

November 2, 2011

1A 60W* Common Anode Capable Constant Current Buck LED Driver Requires No External Current Sensing Resistor

General Description

The LM3414 and LM3414HV are 1A 60W* common anode capable constant current buck LED drivers.

They are excep-tionally suitable to drive single string of 3W HBLED with up to 96% efficiency. They accept input voltages from 4.5VDC to 65VDC and deliver up to 1A average LED current with ±3% accuracy. The integrated low-side N-channel power MOSFET and current sensing element realize simple and low compo-nent count circuitry as no bootstrapping capacitor and exter-nal current sensing resistor are required. An external small-signal resistor to ground provides very fine LED current adjustment, analog dimming as well as thermal fold-back functions.

Constant switching frequency operation eases EMI. No ex-ternal loop compensation network is needed. The proprietary Pulse-Level-Modulation (PLM) control method benefits in high conversion efficiency and true average LED current reg-ulation. Fast response time realizes fine LED current pulse fulfilling the 240 Hz 256-step dimming resolution requirement for general lighting.

The LM3414 and LM3414HV are available in ePSOP-8 and 3mm x 3mm LLP-8 packages.

*Thermal de-rating applies according to actual operation con-ditions Features

■Support LED power up to 60W*: 18x 3W HBLEDs

■Requires NO external current sensing resistor

■±3% LED current accuracy

■Up to 96% efficiency

■High contrast ratio (Minimum dimming current pulse width

<10 µS)

■Integrated low-side N-channel MOSFET

■Adjustable Constant LED current from 350mA to 1000mA ■Support analog dimming and thermal fold-back

■Wide input voltage range:

4.5V to 42V (LM3414)

4.5V to 65V (LM3414HV)

■Constant Switching Frequency adjustable from 250 kHz to 1000 kHz

■Thermal shutdown protection

■Power enhanced ePSOP-8 or 3mm x 3mm LLP-8 package Appications

■High Power LED Driver

■Architectural Lighting, Office Troffer

■Automotive Lighting

■MR-16 LED Lamp

Simplified Application Schematic

30124801

Connection Diagram

30124803

Ordering Information

Order Number Package Type NSC Package Drawing

Supplied As

LM3414MR ePSOP-8

MRA08A

95 Units in Anti-Static Rails LM3414MRX 2,500 Units on Tape and Reel LM3414HVMR 95 Units in Anti-Static Rails LM3414HVMRX 2500 Units on Tape and Reel LM3414SD LLP-8

SDA08AG

1,000 Units on Tape and Reel LM3414SDX 4,500 Units on Tape and Reel LM3414HVSD 1,000 Units on Tape and Reel LM3414HVSDX

4,500 Units on Tape and Reel

L M 3414/L M 3414H V

LM3414/LM3414HV Pin Descriptions

Pin(s)Name Description Application Information

1VCC Internal Regulator Output Pin This pin should be bypassed to ground by a ceramic capacitor

with a minimum value of 1µF.

2PGND Power Ground Pin Ground for power circuitry. Reference point for all stated

voltages. Must be externally connected to EP and GND.

from this pin to ground to adjust the 3IADJ Average Output Current Adjustment Pin Connect resistor R

IADJ

average output current.

4GND Analog Ground Pin Analog ground connection for internal circuitry, must be

connected to PGND external to the package.

from this pin to ground to set the 5FS Switching Frequency Setting Pin Connect resistor R

switching frequency.

6DIM PWM Dimming Control Pin Apply logic level PWM signal to this pin controls the intend

brightness of the LED string.

7LX Drain of N-MOSFET Switch Connect this pin to the output inductor and anode of the

schottky diode.

8VIN Input Voltage Pin The input voltage should be in the range of 4.5V to 42V

(LM3414) or 4.5V to 65V (LM3414HV).

EP EP Thermal Pad (Power Ground)Used to dissipate heat from the package during operation.

Must be electrically connected to PGND external to the

package.

Absolute Maximum Ratings (LM3414) (Note 1)

If Military/Aerospace specified devices are required,please contact the Texas Instruments Sales Office/Distributors for availability and specifications.VIN to GND

-0.3V to 42V VIN to GND (Transient)45V (500 ms)LX to PGND

-0.3V to 42V

LX to PGND (Transient)-3V(2 ns) to 45V (500 ms)

FS, IADJ to GND -0.3V to 5V DIM to GND -0.3V to 6V

ESD Rating

Human Body Model (Note 2)

2kV

Storage Temp. Range -65°C to 125°C

Soldering Information

Lead Temp. (Soldering 10s)

260°C Infrared/Convection Reflow (20sec)

235°C

Operating Ratings (LM3414)

V IN

4.5V to 42V Junction Temperature Range −40°C to +125°C

Thermal Resistance θJA (ePSOP-8 Package)45°C/W Thermal Resistance θJA (LLP-8 Package)

54°C/W

L M 3414/L M 3414H V

Absolute Maximum Ratings

(LM3414HV) (Note 1)

If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and specifications.

VIN to GND-0.3V to 65V VIN to GND (Transient)67V (500 ms) LX to PGND-0.3V to 65V LX to PGND (Transient)-3V(2 ns) to 67V (500 ms) FS, IADJ to GND-0.3V to 5V DIM to GND-0.3V to 6V ESD Rating

Human Body Mode (Note 2)2kV

Storage Temp. Range-65°C to 125°C

Soldering Information

Lead Temp. (Soldering 10s)260°C

Infrared/Convection Reflow (20sec)235°C

Operating Ratings (LM3414HV)

4.5V to 65V

Junction Temperature Range−40°C to +125°C

Thermal Resistance θ

(ePSOP-8 Package)45°C/W

Thermal Resistance θ

(LLP-8 Package)54°C/W