Datasheet LT3475, LT3475-1 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Dual Step-Down 1.5A LED Driver |
| Pages / Page | 20 / 3 — The. ELECTRICAL CHARACTERISTICS. denotes the specifi cations which apply … |
| File Format / Size | PDF / 249 Kb |
| Document Language | English |
The. ELECTRICAL CHARACTERISTICS. denotes the specifi cations which apply over the full operating
Model Line for this Datasheet
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LT3475/LT3475-1
The ELECTRICAL CHARACTERISTICS
●
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 12V, VBOOST = 16V, VOUT = 4V unless otherwise noted (Note 3) PARAMETER CONDITIONS MIN TYP MAX UNITS
LED Pin Current VADJ Tied to VREF • 2/3 0.97 1.00 1.03 A ● 0.94 1.04 A VADJ Tied to VREF • 7/30 0.336 0.350 0.364 A LT3475E/LT3475E-1 0°C to 85°C 0.325 0.375 A ● 0.31 0.385 A REF Voltage ● 1.22 1.25 1.27 V Reference Voltage Line Regulation 4V < VIN < 40V 0.05 %/V Reference Voltage Load Regulation 0 < IREF < 500μA 0.0002 %/μA VADJ Pin Bias Current (Note 4) ● 40 400 nA Switching Frequency RT = 24.3k ● 530 600 640 kHz Maximum Duty Cycle RT = 24.3k ● 90 95 % RT = 4.32k 80 % RT = 100k 98 % Switching Phase RT = 24.3k 150 180 210 Deg Foldback Frequency RT = 24.3k, VOUT = 0V 80 kHz SHDN Threshold (to Switch) 2.5 2.6 2.74 V SHDN Pin Current (Note 5) VSHDN = 2.6V 7 9 11 μA PWM Threshold 0.3 0.8 1.2 V VC Switching Threshold 0.8 V VC Source Current VC = 1V 50 μA VC Sink Current VC = 1V 50 μA LED to VC Transresistance 500 V/A LED to VC Current Gain 1 mA/μA VC to Switch Current Gain 2.6 A/V VC Clamp Voltage 1.8 V VC Pin Current in PWM Mode VC = 1V, VPWM = 0.3V ● 10 400 nA OUT Pin Clamp Voltage (LT3475) 13.5 14 14.5 V OUT Pin Current in PWM Mode VOUT = 4V, VPWM = 0.3V ● 25 50 μA Switch Current Limit (Note 6) 2.3 2.7 3.2 A Switch VCESAT ISW =1.5A 350 500 mV BOOST Pin Current ISW =1.5A 25 40 mA Switch Leakage Current 0.1 10 μA Minimum Boost Voltage Above SW 1.8 2.5 V
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
The LT3475E and LT3475E-1 are guaranteed to meet performance may cause permanent damage to the device. Exposure to any Absolute specifi cations from 0°C to 85°C. Specifi cations over the –40°C to 85°C Maximum Rating condition for extended periods may affect device operating temperature range are assured by design, characterization and reliability and lifetime. correlation with statistical process controls. The LT3475I and LT3475I-1
Note 2:
This IC includes overtemperature protection that is intended are guaranteed to meet performance specifi cations over the –40°C to to protect the device during momentary overload conditions. Junction 125°C operating temperature range. temperature will exceed 125°C when overtemperature protection is active.
Note 4:
Current fl ows out of pin. Continuous operation above the specifi ed maximum operating junction
Note 5:
Current fl ows into pin. temperature may impair device reliability.
Note 6:
Current limit is guaranteed by design and/or correlation to static test. Slope compensation reduces current limit at higher duty cycles. 3475fb 3
The ELECTRICAL CHARACTERISTICS
●
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 12V, VBOOST = 16V, VOUT = 4V unless otherwise noted (Note 3) PARAMETER CONDITIONS MIN TYP MAX UNITS
LED Pin Current VADJ Tied to VREF • 2/3 0.97 1.00 1.03 A ● 0.94 1.04 A VADJ Tied to VREF • 7/30 0.336 0.350 0.364 A LT3475E/LT3475E-1 0°C to 85°C 0.325 0.375 A ● 0.31 0.385 A REF Voltage ● 1.22 1.25 1.27 V Reference Voltage Line Regulation 4V < VIN < 40V 0.05 %/V Reference Voltage Load Regulation 0 < IREF < 500μA 0.0002 %/μA VADJ Pin Bias Current (Note 4) ● 40 400 nA Switching Frequency RT = 24.3k ● 530 600 640 kHz Maximum Duty Cycle RT = 24.3k ● 90 95 % RT = 4.32k 80 % RT = 100k 98 % Switching Phase RT = 24.3k 150 180 210 Deg Foldback Frequency RT = 24.3k, VOUT = 0V 80 kHz SHDN Threshold (to Switch) 2.5 2.6 2.74 V SHDN Pin Current (Note 5) VSHDN = 2.6V 7 9 11 μA PWM Threshold 0.3 0.8 1.2 V VC Switching Threshold 0.8 V VC Source Current VC = 1V 50 μA VC Sink Current VC = 1V 50 μA LED to VC Transresistance 500 V/A LED to VC Current Gain 1 mA/μA VC to Switch Current Gain 2.6 A/V VC Clamp Voltage 1.8 V VC Pin Current in PWM Mode VC = 1V, VPWM = 0.3V ● 10 400 nA OUT Pin Clamp Voltage (LT3475) 13.5 14 14.5 V OUT Pin Current in PWM Mode VOUT = 4V, VPWM = 0.3V ● 25 50 μA Switch Current Limit (Note 6) 2.3 2.7 3.2 A Switch VCESAT ISW =1.5A 350 500 mV BOOST Pin Current ISW =1.5A 25 40 mA Switch Leakage Current 0.1 10 μA Minimum Boost Voltage Above SW 1.8 2.5 V
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
The LT3475E and LT3475E-1 are guaranteed to meet performance may cause permanent damage to the device. Exposure to any Absolute specifi cations from 0°C to 85°C. Specifi cations over the –40°C to 85°C Maximum Rating condition for extended periods may affect device operating temperature range are assured by design, characterization and reliability and lifetime. correlation with statistical process controls. The LT3475I and LT3475I-1
Note 2:
This IC includes overtemperature protection that is intended are guaranteed to meet performance specifi cations over the –40°C to to protect the device during momentary overload conditions. Junction 125°C operating temperature range. temperature will exceed 125°C when overtemperature protection is active.
Note 4:
Current fl ows out of pin. Continuous operation above the specifi ed maximum operating junction
Note 5:
Current fl ows into pin. temperature may impair device reliability.
Note 6:
Current limit is guaranteed by design and/or correlation to static test. Slope compensation reduces current limit at higher duty cycles. 3475fb 3
