Datasheet LTC3805 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Adjustable Frequency Current Mode Flyback DC/DC Controller |
| Pages / Page | 20 / 3 — e lectrical characteristics The. denotes the specifications which apply … |
| File Format / Size | PDF / 268 Kb |
| Document Language | English |
e lectrical characteristics The. denotes the specifications which apply over the specified operating
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LTC3805
e lectrical characteristics The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C, VCC = 8V, unless otherwise noted (Note 2). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VTURNON VCC Turn-On Voltage l 7.75 8.4 9 V VTURNOFF VCC Turn-Off Voltage l 3.75 3.95 4.15 V VHYST VCC Hysteresis 4.5 V VCLAMP1mA VCC Shunt Regulator Voltage VCC Sinking 1mA, VRUN = 0 l 8.8 9.25 9.65 V VCLAMP25mA VCC Shunt Regulator Voltage VCC Sinking 25mA, VRUN = 0 l 8.9 9.5 9.9 V ICC Input DC Supply Current Normal Operation (fOSC = 200kHz) 360 µA (Note 4) VRUN < VRUNON or VCC < VTURNON – 100mV l 40 90 µA (Micropower Start-Up) VRUNON RUN Turn-On Voltage VCC Sinking 1mA l 1.122 1.207 1.292 V VRUNOFF RUN Turn-Off Voltage VCC Sinking 1mA l 1.092 1.170 1.248 V IRUN(HYST) RUN Hysteresis Current l 4 5 5.8 µA VFB Regulated Feedback Voltage 0°C ≤ TJ ≤ 85°C (E-Grade) (Note 5) 0.788 0.800 0.812 V –40°C ≤ TJ ≤ 85°C (E-Grade) (Note 5) l 0.780 0.800 0.812 V –40°C ≤ TJ ≤ 125°C (I-Grade) (Note 5) l 0.780 0.800 0.812 V –40°C ≤ TJ ≤ 150°C (H-Grade) (Note 5) l 0.770 0.800 0.820 V –55°C ≤ TJ ≤ 150°C (MP-Grade) l 0.770 0.800 0.820 V IFB VFB Input Current VITH = 1.3V (Note 5) 20 nA gm Error Amplifier Transconductance ITH Pin Load = ±5µA (Note 5) 333 µA/V ∆VO(LINE) Output Voltage Line Regulation VTURNOFF < VCC < VCLAMP1mA (Note 5) 0.05 mV/V ∆VO(LOAD) Output Voltage Load Regulation ITH Sinking 5µA (Note 5) 3 mV/µA ITH Sourcing 5µA (Note 5) 3 mV/µA fOSC Oscillator Frequency RFS = 350k 70 kHz RFS = 36k 700 kHz DCON(MIN) Minimum Switch-On Duty Cycle fOSC = 200kHz 6 9 % DCON(MAX) Maximum Switch-On Duty Cycle fOSC = 200kHz 70 80 95 % fSYNC As a Function of fOSC 70kHz < fOSC < 700kHz, 67 133 % 70kHz < fSYNC < 700kHz VSYNC Minimum SYNC Amplitude 2.9 V ISS Soft-Start Current –6 µA IFTO Fault Timeout Current 2 µA tSS(INT) Internal Soft-Start Time No External Capacitor on SSFLT 1.8 ms tFTO(INT) Internal Fault Timeout No External Capacitor on SSFLT 4.5 ms tRISE Gate Drive Rise Time CLOAD = 3000pF 30 ns tFALL Gate Drive Fall Time CLOAD = 3000pF 30 ns VI(MAX) Peak Current Sense Voltage RSL = 0 (Note 6) l 85 100 115 mV ISL(MAX) Peak Slope Compensation Output (Note 7) 10 µA Current VOCT Overcurrent Threshold ROC = 0 (Note 8) l 85 100 115 mV IOC Overcurrent Threshold Adjust Current 10 µA 3805fg 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration 0rder Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts
e lectrical characteristics The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C, VCC = 8V, unless otherwise noted (Note 2). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VTURNON VCC Turn-On Voltage l 7.75 8.4 9 V VTURNOFF VCC Turn-Off Voltage l 3.75 3.95 4.15 V VHYST VCC Hysteresis 4.5 V VCLAMP1mA VCC Shunt Regulator Voltage VCC Sinking 1mA, VRUN = 0 l 8.8 9.25 9.65 V VCLAMP25mA VCC Shunt Regulator Voltage VCC Sinking 25mA, VRUN = 0 l 8.9 9.5 9.9 V ICC Input DC Supply Current Normal Operation (fOSC = 200kHz) 360 µA (Note 4) VRUN < VRUNON or VCC < VTURNON – 100mV l 40 90 µA (Micropower Start-Up) VRUNON RUN Turn-On Voltage VCC Sinking 1mA l 1.122 1.207 1.292 V VRUNOFF RUN Turn-Off Voltage VCC Sinking 1mA l 1.092 1.170 1.248 V IRUN(HYST) RUN Hysteresis Current l 4 5 5.8 µA VFB Regulated Feedback Voltage 0°C ≤ TJ ≤ 85°C (E-Grade) (Note 5) 0.788 0.800 0.812 V –40°C ≤ TJ ≤ 85°C (E-Grade) (Note 5) l 0.780 0.800 0.812 V –40°C ≤ TJ ≤ 125°C (I-Grade) (Note 5) l 0.780 0.800 0.812 V –40°C ≤ TJ ≤ 150°C (H-Grade) (Note 5) l 0.770 0.800 0.820 V –55°C ≤ TJ ≤ 150°C (MP-Grade) l 0.770 0.800 0.820 V IFB VFB Input Current VITH = 1.3V (Note 5) 20 nA gm Error Amplifier Transconductance ITH Pin Load = ±5µA (Note 5) 333 µA/V ∆VO(LINE) Output Voltage Line Regulation VTURNOFF < VCC < VCLAMP1mA (Note 5) 0.05 mV/V ∆VO(LOAD) Output Voltage Load Regulation ITH Sinking 5µA (Note 5) 3 mV/µA ITH Sourcing 5µA (Note 5) 3 mV/µA fOSC Oscillator Frequency RFS = 350k 70 kHz RFS = 36k 700 kHz DCON(MIN) Minimum Switch-On Duty Cycle fOSC = 200kHz 6 9 % DCON(MAX) Maximum Switch-On Duty Cycle fOSC = 200kHz 70 80 95 % fSYNC As a Function of fOSC 70kHz < fOSC < 700kHz, 67 133 % 70kHz < fSYNC < 700kHz VSYNC Minimum SYNC Amplitude 2.9 V ISS Soft-Start Current –6 µA IFTO Fault Timeout Current 2 µA tSS(INT) Internal Soft-Start Time No External Capacitor on SSFLT 1.8 ms tFTO(INT) Internal Fault Timeout No External Capacitor on SSFLT 4.5 ms tRISE Gate Drive Rise Time CLOAD = 3000pF 30 ns tFALL Gate Drive Fall Time CLOAD = 3000pF 30 ns VI(MAX) Peak Current Sense Voltage RSL = 0 (Note 6) l 85 100 115 mV ISL(MAX) Peak Slope Compensation Output (Note 7) 10 µA Current VOCT Overcurrent Threshold ROC = 0 (Note 8) l 85 100 115 mV IOC Overcurrent Threshold Adjust Current 10 µA 3805fg 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration 0rder Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Package Description Revision History Typical Application Related Parts
