Datasheet LT1767, LT1767-1.8, LT1767-2.5, LT1767-3.3, LT1767-5 (Analog Devices) - 3

LT1767/LT1767-1.8/ LT1767-2.5/LT1767-3.3/LT1767-5
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 15V, VC = 0.8V, Boost = VIN + 5V, SHDN, SYNC and switch open unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
Maximum Switch Current Limit TA = 0°C to 125°C 1.5 2 3 A TA = < 0°C 1.3 3 A Oscillator Frequency 3.3V < VIN < 25V 1.1 1.25 1.4 MHz l 1.1 1.5 MHz Switch On Voltage Drop ISW = –1.5A, 0°C ≤ TA ≤ 125°C and –1.3A, TA < 0°C 330 400 mV l 500 mV VIN Undervoltage Lockout (Note 3) l 2.47 2.6 2.73 V VIN Supply Current VFB = VNOM + 17% l 1 1.3 mA Shutdown Supply Current VSHDN = 0V, VIN = 25V, VSW = 0V 6 20 µA l 45 µA Feedback Voltage 3V < VIN < 25V, 0.4V < VC < 0.9V LT1767 (Adj) 1.182 1.2 1.218 V (Note 3) l 1.176 1.224 V LT1767-1.8 l 1.764 1.8 1.836 V LT1767-2.5 l 2.45 2.5 2.55 V LT1767-3.3 l 3.234 3.3 3.366 V LT1767-5 l 4.9 5 5.1 V FB Input Current LT1767 (Adj) l –0.25 –0.5 µA FB Input Resistance LT1767-1.8 l 10.5 15 21 kΩ LT1767-2.5 l 14.7 21 30 kΩ LT1767-3.3 l 19 27.5 39 kΩ LT1767-5 l 29 42 60 kΩ Error Amp Voltage Gain 0.4V < VC < 0.9V 150 350 Error Amp Transconductance ∆IVC = ±10µA l 500 850 1300 µMho VC Pin Source Current VFB = VNOM – 17% l 80 120 160 µA VC Pin Sink Current VFB = VNOM + 17% l 70 110 180 µA VC Pin to Switch Current Transconductance 2.5 A/V VC Pin Minimum Switching Threshold Duty Cycle = 0% 0.35 V VC Pin 1.5A ISW Threshold 0.9 V Maximum Switch Duty Cycle VC = 1.2V, ISW = 400mA 85 90 % l 80 % Minimum Boost Voltage Above Switch ISW = –1.5A, 0°C ≤ TA ≤ 125°C and –1.3A, TA < 0°C l 1.8 2.7 V Boost Current ISW = –0.5A (Note 4) l 10 15 mA ISW = –1.5A, 0°C ≤ TA ≤ 125°C and –1.3A, TA < 0°C (Note 4) l 30 45 mA SHDN Threshold Voltage l 1.27 1.33 1.40 V SHDN Input Current (Shutting Down) SHDN = 60mV Above Threshold l –7 –10 –13 µA SHDN Threshold Current Hysteresis SHDN = 100mV Below Threshold l 4 7 10 µA SYNC Threshold Voltage 1.5 2.2 V SYNC Input Frequency 1.5 2 MHz SYNC Pin Resistance ISYNC = 1mA 20 kΩ 1767fb For more information www.linear.com/LT1767 3 Document Outline Description Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Application