Datasheet LT8645S, LT8646S (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | 65V, 8A Synchronous Step-Down Silent Switcher 2 with 2.5μA Quiescent Current |
| Pages / Page | 30 / 3 — The. denotes the specifications which apply over the full operating |
| File Format / Size | PDF / 457 Kb |
| Document Language | English |
The. denotes the specifications which apply over the full operating
Text Version of Document
LT8645S/LT8646S ELECTRICAL CHARACTERISTICS
The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage l 3.0 3.4 V VIN Quiescent Current in Shutdown VEN/UV = 0V 0.9 3 µA l 0.9 10 µA LT8645S VIN Quiescent Current in Sleep VEN/UV = 2V, VFB > 0.97V, VSYNC = 0V 1.7 4 µA (Internal Compensation) l 1.7 10 µA LT8646S VIN Quiescent Current in Sleep VEN/UV = 2V, VFB > 0.97V, VSYNC = 0V, VBIAS = 0V 230 290 µA (External Compensation) l 230 340 µA VEN/UV = 2V, VFB > 0.97V, VSYNC = 0V, VBIAS = 5V 16 25 µA LT8646S BIAS Quiescent Current in Sleep VEN/UV = 2V, VFB > 0.97V, VSYNC = 0V, VBIAS = 5V 200 260 µA LT8645S VIN Quiescent Current when Active VEN/UV = 2V, VFB > 0.97V, VSYNC = 2V, RT = 60.4k, VBIAS = 0V 0.4 0.6 mA LT8646S VIN Quiescent Current when Active VEN/UV = 2V, VFB > 0.97V, VSYNC = 2V, RT = 60.4k, VBIAS = 0V 0.6 0.8 mA LT8645S VIN Current in Regulation VOUT = 0.97V, VIN = 6V, ILOAD = 100µA, VSYNC = 0V l 17 60 µA VOUT = 0.97V, VIN = 6V, ILOAD = 1mA, VSYNC = 0V l 200 400 µA Feedback Reference Voltage VIN = 6V 0.964 0.970 0.976 V VIN = 6V l 0.958 0.970 0.982 V Feedback Voltage Line Regulation VIN = 4.0V to 42V l 0.004 0.025 %/V Feedback Pin Input Current VFB = 1V –20 20 nA LT8646S Error Amp Transconductance VC = 1.25V 1.7 mS LT8646S Error Amp Gain 350 V/V LT8646S VC Source Current VFB = 0.77V, VC = 1.25V 350 µA LT8646S VC Sink Current VFB = 1.17V, VC = 1.25V 350 µA LT8646S VC Pin to Switch Current Gain 8 A/V LT8646S VC Clamp Voltage 2.6 V BIAS Pin Current Consumption VBIAS = 3.3V, fSW = 2MHz 22 mA Minimum On-Time ILOAD = 2A, SYNC = 0V l 40 65 ns ILOAD = 2A, SYNC = 2V l 35 60 ns Minimum Off-Time 80 110 ns Oscillator Frequency RT = 221k l 180 210 240 kHz RT = 60.4k l 665 700 735 kHz RT = 18.2k l 1.8 1.95 2.1 MHz Top Power NMOS On-Resistance ISW = 1A 36 mΩ Top Power NMOS Current Limit l 10.5 14 17.5 A Bottom Power NMOS On-Resistance VINTVCC = 3.4V, ISW = 1A 25 mΩ Bottom Power NMOS Current Limit VINTVCC = 3.4V 8.5 11 13.5 A SW Leakage Current VIN = 42V, VSW = 0V, 42V –1.5 1.5 µA EN/UV Pin Threshold EN/UV Rising l 0.95 1.01 1.07 V EN/UV Pin Hysteresis 45 mV EN/UV Pin Current VEN/UV = 2V –20 20 nA PG Upper Threshold Offset from VFB VFB Falling l 5 7.5 10 % PG Lower Threshold Offset from VFB VFB Rising l –10.5 –8 –5.5 % 8645Sfa For more information www.linear.com/LT8645S 3
The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage l 3.0 3.4 V VIN Quiescent Current in Shutdown VEN/UV = 0V 0.9 3 µA l 0.9 10 µA LT8645S VIN Quiescent Current in Sleep VEN/UV = 2V, VFB > 0.97V, VSYNC = 0V 1.7 4 µA (Internal Compensation) l 1.7 10 µA LT8646S VIN Quiescent Current in Sleep VEN/UV = 2V, VFB > 0.97V, VSYNC = 0V, VBIAS = 0V 230 290 µA (External Compensation) l 230 340 µA VEN/UV = 2V, VFB > 0.97V, VSYNC = 0V, VBIAS = 5V 16 25 µA LT8646S BIAS Quiescent Current in Sleep VEN/UV = 2V, VFB > 0.97V, VSYNC = 0V, VBIAS = 5V 200 260 µA LT8645S VIN Quiescent Current when Active VEN/UV = 2V, VFB > 0.97V, VSYNC = 2V, RT = 60.4k, VBIAS = 0V 0.4 0.6 mA LT8646S VIN Quiescent Current when Active VEN/UV = 2V, VFB > 0.97V, VSYNC = 2V, RT = 60.4k, VBIAS = 0V 0.6 0.8 mA LT8645S VIN Current in Regulation VOUT = 0.97V, VIN = 6V, ILOAD = 100µA, VSYNC = 0V l 17 60 µA VOUT = 0.97V, VIN = 6V, ILOAD = 1mA, VSYNC = 0V l 200 400 µA Feedback Reference Voltage VIN = 6V 0.964 0.970 0.976 V VIN = 6V l 0.958 0.970 0.982 V Feedback Voltage Line Regulation VIN = 4.0V to 42V l 0.004 0.025 %/V Feedback Pin Input Current VFB = 1V –20 20 nA LT8646S Error Amp Transconductance VC = 1.25V 1.7 mS LT8646S Error Amp Gain 350 V/V LT8646S VC Source Current VFB = 0.77V, VC = 1.25V 350 µA LT8646S VC Sink Current VFB = 1.17V, VC = 1.25V 350 µA LT8646S VC Pin to Switch Current Gain 8 A/V LT8646S VC Clamp Voltage 2.6 V BIAS Pin Current Consumption VBIAS = 3.3V, fSW = 2MHz 22 mA Minimum On-Time ILOAD = 2A, SYNC = 0V l 40 65 ns ILOAD = 2A, SYNC = 2V l 35 60 ns Minimum Off-Time 80 110 ns Oscillator Frequency RT = 221k l 180 210 240 kHz RT = 60.4k l 665 700 735 kHz RT = 18.2k l 1.8 1.95 2.1 MHz Top Power NMOS On-Resistance ISW = 1A 36 mΩ Top Power NMOS Current Limit l 10.5 14 17.5 A Bottom Power NMOS On-Resistance VINTVCC = 3.4V, ISW = 1A 25 mΩ Bottom Power NMOS Current Limit VINTVCC = 3.4V 8.5 11 13.5 A SW Leakage Current VIN = 42V, VSW = 0V, 42V –1.5 1.5 µA EN/UV Pin Threshold EN/UV Rising l 0.95 1.01 1.07 V EN/UV Pin Hysteresis 45 mV EN/UV Pin Current VEN/UV = 2V –20 20 nA PG Upper Threshold Offset from VFB VFB Falling l 5 7.5 10 % PG Lower Threshold Offset from VFB VFB Rising l –10.5 –8 –5.5 % 8645Sfa For more information www.linear.com/LT8645S 3
