Datasheet LTC3785 (Analog Devices) - 3
| Hersteller | Analog Devices |
| Beschreibung | 10V, High Efficiency, Synchronous, No RSENSE Buck-Boost Controller |
| Seiten / Seite | 20 / 3 — The. denotes the specifications which apply over the full operating … |
| Dateiformat / Größe | PDF / 287 Kb |
| Dokumentensprache | Englisch |
The. denotes the specifications which apply over the full operating junction
Modelllinie für dieses Datenblatt
Textversion des Dokuments
LTC3785 elecTrical characTerisTics
The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C. VIN = ISVOUT = VDRV = VBST1 = VBST2 = 3.6V, RT = 49.9k, RILSET = 59k. PARAMETER CONDITIONS MIN TYP MAX UNITS
Error Amp Source Current –500 µA Error Amp Sink Current 900 µA Error Amp AVOL 90 dB Overvoltage Threshold VSENSE Pin % Above FB LTC3785E l 6 10 14 % LTC3785I l 6 10 15 % Undervoltage Threshold VSENSE Pin % Below FB LTC3785E l –3.5 –6.5 –9.5 % LTC3785I l –3.5 –6.5 –10.5 % VSENSE Input Current VSENSE = Measured FB Voltage 1 500 nA
VCC Regulator
VCC Maximum Regulating Voltage VIN = 5V, IVCC = –20mA l 4.15 4.35 4.55 V VCC Regulation Voltage VIN = 3.6V, IVCC = –20mA l 3.3 3.5 3.6 V VCC Regulator Sink Current ISVOUT = VCC = 5V 800 µA
Run/Soft-Start
RUN/SS Threshold When IC is Enabled l 0.35 0.7 1.1 V When EA is at Maximum Boost Duty Cycle 1.9 V RUN/SS Input Current RUN/SS = 0V –1 µA RUN/SS Discharge Current During Current Limit 20 30 µA
Current Limit
Current Limit Sense Threshold ISVIN to ISSW1, RILSET = 121k l 20 60 100 mV ISVIN to ISSW1, RILSET = 59k l 55 105 155 mV Reverse Current Limit Sense Threshold ISSW2 to ISVOUT, CCM > 2V –50 –110 –170 mV ISSW2 to ISVOUT, CCM < 0.4V, LTC3785E l –15 –35 mV ISSW2 to ISVOUT, CCM < 0.4V, LTC3785I l –15 –40 mV Input Current ISVIN 80 150 µA ISVOUT 10 20 µA ISSW1, ISSW2 0.1 5 µA CCM Input Threshold (High) l 2.2 V CCM Input Threshold (Low) l 0.4 V CCM Input Current CCM = 3.6V 0.01 1 µA
Burst Mode Operation
Mode Threshold l 0.8 1.5 2.2 V Mode Input Current 0.01 1 µA tON Time 1.4 µs
Oscillator
Frequency Accuracy l 370 509 650 kHz
Switching Characteristics
Maximum Duty Cycle Boost (% Switch BG2 On) l 80 90 % Buck (% Switch TG1 On) 99 % TG1, TG2 Driver Impedance 2 Ω BG1, BG2 Driver Impedance 2 Ω TG1, TG2 Rise Time CLOAD = 3300pF (Note 3) 20 ns 3785fc Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts
The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C. VIN = ISVOUT = VDRV = VBST1 = VBST2 = 3.6V, RT = 49.9k, RILSET = 59k. PARAMETER CONDITIONS MIN TYP MAX UNITS
Error Amp Source Current –500 µA Error Amp Sink Current 900 µA Error Amp AVOL 90 dB Overvoltage Threshold VSENSE Pin % Above FB LTC3785E l 6 10 14 % LTC3785I l 6 10 15 % Undervoltage Threshold VSENSE Pin % Below FB LTC3785E l –3.5 –6.5 –9.5 % LTC3785I l –3.5 –6.5 –10.5 % VSENSE Input Current VSENSE = Measured FB Voltage 1 500 nA
VCC Regulator
VCC Maximum Regulating Voltage VIN = 5V, IVCC = –20mA l 4.15 4.35 4.55 V VCC Regulation Voltage VIN = 3.6V, IVCC = –20mA l 3.3 3.5 3.6 V VCC Regulator Sink Current ISVOUT = VCC = 5V 800 µA
Run/Soft-Start
RUN/SS Threshold When IC is Enabled l 0.35 0.7 1.1 V When EA is at Maximum Boost Duty Cycle 1.9 V RUN/SS Input Current RUN/SS = 0V –1 µA RUN/SS Discharge Current During Current Limit 20 30 µA
Current Limit
Current Limit Sense Threshold ISVIN to ISSW1, RILSET = 121k l 20 60 100 mV ISVIN to ISSW1, RILSET = 59k l 55 105 155 mV Reverse Current Limit Sense Threshold ISSW2 to ISVOUT, CCM > 2V –50 –110 –170 mV ISSW2 to ISVOUT, CCM < 0.4V, LTC3785E l –15 –35 mV ISSW2 to ISVOUT, CCM < 0.4V, LTC3785I l –15 –40 mV Input Current ISVIN 80 150 µA ISVOUT 10 20 µA ISSW1, ISSW2 0.1 5 µA CCM Input Threshold (High) l 2.2 V CCM Input Threshold (Low) l 0.4 V CCM Input Current CCM = 3.6V 0.01 1 µA
Burst Mode Operation
Mode Threshold l 0.8 1.5 2.2 V Mode Input Current 0.01 1 µA tON Time 1.4 µs
Oscillator
Frequency Accuracy l 370 509 650 kHz
Switching Characteristics
Maximum Duty Cycle Boost (% Switch BG2 On) l 80 90 % Buck (% Switch TG1 On) 99 % TG1, TG2 Driver Impedance 2 Ω BG1, BG2 Driver Impedance 2 Ω TG1, TG2 Rise Time CLOAD = 3300pF (Note 3) 20 ns 3785fc Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts