Datasheet LT3478, LT3478-1 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | 4.5A Monolithic LED Drivers with True Color PWM Dimming |
| Pages / Page | 24 / 4 — ELECTRICAL CHARACTERISTICS. Note 1:. Note 4:. Note 2:. Note 5:. Note 3:. … |
| File Format / Size | PDF / 295 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. Note 1:. Note 4:. Note 2:. Note 5:. Note 3:. Note 6:. TYPICAL PERFOR A CE CHARACTERISTICS
Model Line for this Datasheet
Text Version of Document
LT3478/LT3478-1
ELECTRICAL CHARACTERISTICS Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature will exceed 125°C when over-temperature protection is active. may cause permanent damage to the device. Exposure to any Absolute Continuous operation above the specifi ed maximum operating junction Maximum Rating condition for extended periods may affect device temperature may impair device reliability. reliability and lifetime.
Note 4:
For maximum operating ambient temperature, see the “Thermal
Note 2:
The LT3478EFE/LT3478EFE-1 are guaranteed to meet performance Calculations” section in the Applications Information section. specifi cations from 0°C to 125°C junction temperature. Specifi cations over
Note 5:
The maximum operational voltage for VIN is limited by thermal and the –40°C to 125°C operating junction temperature range are assured by effi ciency considerations. Power switch base current is delivered from VIN design, characterization and correlation with statistical process controls. and should therefore be driven from the lowest available power supply in The LT3478IFE/LT3478IFE-1 are guaranteed over the full –40°C to 125°C the system. See “Thermal Calculations” in the Applications Information operating junction temperature range. section.
Note 3:
This IC includes over-temperature protection that is intended
Note 6:
For LT3478, parameter scales • (RSENSE/0.1Ω). to protect the device during momentary overload conditions. Junction
W U TYPICAL PERFOR A CE CHARACTERISTICS LED Current vs PWM Duty Cycle Wide PWM Dimming Range LED Current vs CTRL1 LED Current vs Temperature (3000:1)
1400 1400 1000 TA = 25°C (FOR LT3478 SCALE BY 0.1Ω/RSENSE) TA = 25°C CTRL2 = VREF VIN = VS = 12V (FOR LT3478 SCALE BY 0.1Ω/RSENSE) 6 LEDS AT 500mA ILED = 1050mA, CTRL1 = CTRL2 = VREF PWM FREQ = 100Hz 1050 1050 100 CTRL1 = 0.5V CTRL2 = VREF LT3478-1 LT3478-1 FOSC = 1.6MHz L = 2.2µH 700 700 10 LED CURRENT (mA) LED CURRENT (mA) LED CURRENT (mA) 350 350 1 ILED = 100mA, CTRL1 = 100mV, VREF CTRL2 = VREF 0 0 0 0 0.35 0.70 1.05 1.40 –50 –25 0 25 50 75 100 125 0.01 0.1 1 10 100 CTRL1 (V) JUNCTION TEMPERATURE (°C) PWM DUTY CYCLE (%) 3478 G03 3478 G01 3478 G02
CTRL1 Pin Current vs Switch VCE (SAT) vs Switch Switch and Inductor Peak Current Temperature Current Limits vs Temperature
50 240 7.0 TA = 25°C CTRL1 = 0.1V 40 210 6.5 SWITCH 30 180 6.0 (SAT) (mV) INDUCTOR CE CTRL1 = 0.35V 20 120 CTRL2 = V 5.5 REF CTRL1 AND CTRL2 PINS CURRENT LIMIT (A) INTERCHANGEABLE SWITCH V 10 CTRL1 = 0.7V 60 5.0 CTRL1 PIN CURRENT X (–1) (nA) CTRL1 = 0.9V 0 0 4.5 –50 –25 0 25 50 75 100 125 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 –50 –25 0 25 50 75 100 125 JUNCTION TEMPERATURE (°C) SWITCH CURRENT (A) JUNCTION TEMPERATURE (°C) 3478 G04 3478 G05 3478 G06 34781f 4
ELECTRICAL CHARACTERISTICS Note 1:
Stresses beyond those listed under Absolute Maximum Ratings temperature will exceed 125°C when over-temperature protection is active. may cause permanent damage to the device. Exposure to any Absolute Continuous operation above the specifi ed maximum operating junction Maximum Rating condition for extended periods may affect device temperature may impair device reliability. reliability and lifetime.
Note 4:
For maximum operating ambient temperature, see the “Thermal
Note 2:
The LT3478EFE/LT3478EFE-1 are guaranteed to meet performance Calculations” section in the Applications Information section. specifi cations from 0°C to 125°C junction temperature. Specifi cations over
Note 5:
The maximum operational voltage for VIN is limited by thermal and the –40°C to 125°C operating junction temperature range are assured by effi ciency considerations. Power switch base current is delivered from VIN design, characterization and correlation with statistical process controls. and should therefore be driven from the lowest available power supply in The LT3478IFE/LT3478IFE-1 are guaranteed over the full –40°C to 125°C the system. See “Thermal Calculations” in the Applications Information operating junction temperature range. section.
Note 3:
This IC includes over-temperature protection that is intended
Note 6:
For LT3478, parameter scales • (RSENSE/0.1Ω). to protect the device during momentary overload conditions. Junction
W U TYPICAL PERFOR A CE CHARACTERISTICS LED Current vs PWM Duty Cycle Wide PWM Dimming Range LED Current vs CTRL1 LED Current vs Temperature (3000:1)
1400 1400 1000 TA = 25°C (FOR LT3478 SCALE BY 0.1Ω/RSENSE) TA = 25°C CTRL2 = VREF VIN = VS = 12V (FOR LT3478 SCALE BY 0.1Ω/RSENSE) 6 LEDS AT 500mA ILED = 1050mA, CTRL1 = CTRL2 = VREF PWM FREQ = 100Hz 1050 1050 100 CTRL1 = 0.5V CTRL2 = VREF LT3478-1 LT3478-1 FOSC = 1.6MHz L = 2.2µH 700 700 10 LED CURRENT (mA) LED CURRENT (mA) LED CURRENT (mA) 350 350 1 ILED = 100mA, CTRL1 = 100mV, VREF CTRL2 = VREF 0 0 0 0 0.35 0.70 1.05 1.40 –50 –25 0 25 50 75 100 125 0.01 0.1 1 10 100 CTRL1 (V) JUNCTION TEMPERATURE (°C) PWM DUTY CYCLE (%) 3478 G03 3478 G01 3478 G02
CTRL1 Pin Current vs Switch VCE (SAT) vs Switch Switch and Inductor Peak Current Temperature Current Limits vs Temperature
50 240 7.0 TA = 25°C CTRL1 = 0.1V 40 210 6.5 SWITCH 30 180 6.0 (SAT) (mV) INDUCTOR CE CTRL1 = 0.35V 20 120 CTRL2 = V 5.5 REF CTRL1 AND CTRL2 PINS CURRENT LIMIT (A) INTERCHANGEABLE SWITCH V 10 CTRL1 = 0.7V 60 5.0 CTRL1 PIN CURRENT X (–1) (nA) CTRL1 = 0.9V 0 0 4.5 –50 –25 0 25 50 75 100 125 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 –50 –25 0 25 50 75 100 125 JUNCTION TEMPERATURE (°C) SWITCH CURRENT (A) JUNCTION TEMPERATURE (°C) 3478 G04 3478 G05 3478 G06 34781f 4
