Datasheet LT1765, LT1765-1.8, LT1765-2.5, LT1765-3.3, LT1765-5 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Monolithic 3A, 1.25MHz Step-Down Switching Regulator |
| Pages / Page | 20 / 3 — ELECTRICAL CHARACTERISTICS. The |
| File Format / Size | PDF / 216 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The
Model Line for this Datasheet
Text Version of Document
LT1765/LT1765-1.8/LT1765-2.5/ LT1765-3.3/LT1765-5
ELECTRICAL CHARACTERISTICS The
l
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations 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 3 4 6 A Oscillator Frequency 3.3V < VIN < 25V l 1.1 1.25 1.6 MHz Switch On Voltage Drop I = 3A l 270 430 mV VIN Undervoltage Lockout (Note 3) l 2.47 2.6 2.73 V VIN Supply Current l 1 1.3 mA Shutdown Supply Current VSHDN = 0V, VIN = 25V, VSW = 0V 15 35 μA l 55 μA Feedback Voltage 3V < VIN < 25V, 0.4V < VC < 0.9V LT1765 (Adj) 1.182 1.2 1.218 V (Note 3) l 1.176 1.224 V LT1765-1.8 l 1.764 1.8 1.836 V LT1765-2.5 l 2.45 2.5 2.55 V LT1765-3.3 l 3.234 3.3 3.366 V LT1765-5 l 4.9 5 5.1 V FB Input Current LT1765 (Adj) l –0.25 –0.5 μA FB Input Resistance LT1765-1.8 l 10.5 15 21 kΩ LT1765-2.5 l 14.7 21 30 kΩ LT1765-3.3 l 19 27.5 39 kΩ LT1765-5 l 29 42 60 kΩ FB Error Amp Voltage Gain 0.4V < VC < 0.9V 150 350 FB Error Amp Transconductance ΔIVC = ±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 5 A/V VC Pin Minimum Switching Threshold Duty Cycle = 0% 0.4 V VC Pin 3A ISW Threshold 0.9 V Maximum Switch Duty Cycle VC = 1.2V, ISW = 800mA, VIN = 6V 85 90 % l 80 % Minimum Boost Voltage Above Switch ISW = 3A l 1.8 2.7 V Boost Current ISW = 1A (Note 4) l 20 30 mA ISW = 3A (Note 4) l 70 140 mA SHDN Threshold Voltage l 1.27 1.33 1.40 V SHDN Threshold Current Hysteresis l 4 7 10 μA SHDN Input Current (Shutting Down) SHDN = 60mV Above Threshold l –7 –10 –13 μA SYNC Threshold Voltage 1.5 2.2 V SYNC Input Frequency 1.6 2 MHz SYNC Pin Resistance ISYNC = 1mA 20 kΩ
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
Minimum input voltage is defi ned as the voltage where the internal may cause permanent damage to the device. Exposure to any Absolute regulator enters lockout. Actual minimum input voltage to maintain a Maximum Rating condition for extended periods may affect device regulated output will depend on output voltage and load current. See reliability and lifetime. Applications Information.
Note 2:
The LT1765E is guaranteed to meet performance specifi cations
Note 4:
Current fl ows into the BOOST pin only during the on period of the from 0°C to 125°C. Specifi cations over the –40°C to 125°C operating switch cycle. junction temperature range are assured by design, characterization and correlation with statistical process controls. 1765fd 3
ELECTRICAL CHARACTERISTICS The
l
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations 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 3 4 6 A Oscillator Frequency 3.3V < VIN < 25V l 1.1 1.25 1.6 MHz Switch On Voltage Drop I = 3A l 270 430 mV VIN Undervoltage Lockout (Note 3) l 2.47 2.6 2.73 V VIN Supply Current l 1 1.3 mA Shutdown Supply Current VSHDN = 0V, VIN = 25V, VSW = 0V 15 35 μA l 55 μA Feedback Voltage 3V < VIN < 25V, 0.4V < VC < 0.9V LT1765 (Adj) 1.182 1.2 1.218 V (Note 3) l 1.176 1.224 V LT1765-1.8 l 1.764 1.8 1.836 V LT1765-2.5 l 2.45 2.5 2.55 V LT1765-3.3 l 3.234 3.3 3.366 V LT1765-5 l 4.9 5 5.1 V FB Input Current LT1765 (Adj) l –0.25 –0.5 μA FB Input Resistance LT1765-1.8 l 10.5 15 21 kΩ LT1765-2.5 l 14.7 21 30 kΩ LT1765-3.3 l 19 27.5 39 kΩ LT1765-5 l 29 42 60 kΩ FB Error Amp Voltage Gain 0.4V < VC < 0.9V 150 350 FB Error Amp Transconductance ΔIVC = ±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 5 A/V VC Pin Minimum Switching Threshold Duty Cycle = 0% 0.4 V VC Pin 3A ISW Threshold 0.9 V Maximum Switch Duty Cycle VC = 1.2V, ISW = 800mA, VIN = 6V 85 90 % l 80 % Minimum Boost Voltage Above Switch ISW = 3A l 1.8 2.7 V Boost Current ISW = 1A (Note 4) l 20 30 mA ISW = 3A (Note 4) l 70 140 mA SHDN Threshold Voltage l 1.27 1.33 1.40 V SHDN Threshold Current Hysteresis l 4 7 10 μA SHDN Input Current (Shutting Down) SHDN = 60mV Above Threshold l –7 –10 –13 μA SYNC Threshold Voltage 1.5 2.2 V SYNC Input Frequency 1.6 2 MHz SYNC Pin Resistance ISYNC = 1mA 20 kΩ
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 3:
Minimum input voltage is defi ned as the voltage where the internal may cause permanent damage to the device. Exposure to any Absolute regulator enters lockout. Actual minimum input voltage to maintain a Maximum Rating condition for extended periods may affect device regulated output will depend on output voltage and load current. See reliability and lifetime. Applications Information.
Note 2:
The LT1765E is guaranteed to meet performance specifi cations
Note 4:
Current fl ows into the BOOST pin only during the on period of the from 0°C to 125°C. Specifi cations over the –40°C to 125°C operating switch cycle. junction temperature range are assured by design, characterization and correlation with statistical process controls. 1765fd 3
