Datasheet LTC3707 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | High Efficiency, 2-Phase Synchronous Step-Down Switching Regulator |
| Pages / Page | 32 / 3 — ELECTRICAL CHARACTERISTICS. The. denotes the specifi cations which apply … |
| File Format / Size | PDF / 398 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifi cations which apply over the full operating
Model Line for this Datasheet
Text Version of Document
LTC3707
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, VRUN/SS1, 2 = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
gmGBW1, 2 Transconductance Amplifi er GBW ITH1, 2 = 1.2V; (Note 4) 3 MHz IQ Input DC Supply Current (Note 5) Normal Mode EXTVCC Tied to VOUT1 = 5V 350 μA Standby VRUN/SS1, 2 = 0V, VSTBYMD > 2V 125 μA Shutdown VRUN.SS1, 2 = 0V, VSTBYMD = Open 20 35 μA VFCB Forced Continuous Threshold l 0.76 0.800 0.84 V IFCB Forced Continuous Pin Current VFCB = 0.85V –0.30 –0.18 –0.1 μA VBINHIBIT Burst Inhibit (Constant Frequency) Measured at FCB pin 4.3 4.8 V Threshold UVLO Undervoltage Lockout VIN Ramping Down l 3.5 4 V VOVL Feedback Overvoltage Lockout Measured at VOSENSE1, 2 l 0.84 0.86 0.88 V ISENSE Sense Pins Total Source Current (Each Channel); VSENSE1–, 2– = VSENSE1+, 2+ = 0V –90 –60 μA VSTBYMD MS Master Shutdown Threshold VSTBYMD Ramping Down 0.4 0.6 V VSTBYMD KA Keep-Alive Power On-Threshold VSTBYMD Ramping Up, RUNSS1, 2 = 0V 1.5 2 V DFMAX Maximum Duty Factor In Dropout 98 99.4 % IRUN/SS1, 2 Soft-Start Charge Current VRUN/SS1, 2 = 1.9V 0.5 1.2 μA VRUN/SS1, 2 ON RUN/SS Pin ON Threshold VRUN/SS1, VRUN/SS2, Rising 1.0 1.5 2.0 V VRUN/SS1, 2 LT RUN/SS Pin Latchoff Arming VRUN/SS1, VRUN/SS2, Rising from 3V 4.1 4.75 V Threshold ISCL1, 2 RUN/SS Discharge Current Soft Short Condition VOSENSE1, 2 = 0.5V; 0.5 2 4 μA VRUN/SS1, 2 = 4.5V ISDLHO Shutdown Latch Disable Current VOSENSE1, 2 = 0.5V 1.6 5 μA VSENSE(MAX) Maximum Current Sense Threshold VOSENSE1, 2 = 0.7V, VOSENSE1–, 2– = 5V 65 75 85 mV l 62 75 88 mV TG Transition Time: (Note 6) TG1, 2 tr Rise Time CLOAD = 3300pF 60 110 ns TG1, 2 tf Fall Time CLOAD = 3300pF 60 110 ns BG Transition Time: (Note 6) BG1, 2 tr Rise Time CLOAD = 3300pF 50 110 ns BG1, 2 tf Fall Time CLOAD = 3300pF 50 100 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay Synchronous Switch-On Delay Time CLOAD = 3300pF Each Driver 80 ns BG/TG t2D Bottom Gate Off to Top Gate On Delay Top Switch-On Delay Time CLOAD = 3300pF Each Driver 80 ns tON(MIN) Minimum On-Time Tested with a Square Wave (Note 7) 180 ns
INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 30V, VEXTCC = 4V 4.8 5.0 5.2 V VLDO INT INTVCC Load Regulation ICC = 0 to 20mA, VEXTVCC = 4V 0.2 2.0 % VLDO EXT EXTVCC Voltage Drop ICC = 20mA, VEXTVCC = 5V 100 200 mV VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, EXTVCC Ramping Positive l 4.5 4.7 V VLDOHYS EXTVCC Hysteresis 0.2 V
Oscillator
fOSC Oscillator Frequency VFREQSET = Open (Note 8) 190 220 250 kHz fLOW Lowest Frequency VFREQSET = 0V 120 140 160 kHz 3707fb 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, VRUN/SS1, 2 = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
gmGBW1, 2 Transconductance Amplifi er GBW ITH1, 2 = 1.2V; (Note 4) 3 MHz IQ Input DC Supply Current (Note 5) Normal Mode EXTVCC Tied to VOUT1 = 5V 350 μA Standby VRUN/SS1, 2 = 0V, VSTBYMD > 2V 125 μA Shutdown VRUN.SS1, 2 = 0V, VSTBYMD = Open 20 35 μA VFCB Forced Continuous Threshold l 0.76 0.800 0.84 V IFCB Forced Continuous Pin Current VFCB = 0.85V –0.30 –0.18 –0.1 μA VBINHIBIT Burst Inhibit (Constant Frequency) Measured at FCB pin 4.3 4.8 V Threshold UVLO Undervoltage Lockout VIN Ramping Down l 3.5 4 V VOVL Feedback Overvoltage Lockout Measured at VOSENSE1, 2 l 0.84 0.86 0.88 V ISENSE Sense Pins Total Source Current (Each Channel); VSENSE1–, 2– = VSENSE1+, 2+ = 0V –90 –60 μA VSTBYMD MS Master Shutdown Threshold VSTBYMD Ramping Down 0.4 0.6 V VSTBYMD KA Keep-Alive Power On-Threshold VSTBYMD Ramping Up, RUNSS1, 2 = 0V 1.5 2 V DFMAX Maximum Duty Factor In Dropout 98 99.4 % IRUN/SS1, 2 Soft-Start Charge Current VRUN/SS1, 2 = 1.9V 0.5 1.2 μA VRUN/SS1, 2 ON RUN/SS Pin ON Threshold VRUN/SS1, VRUN/SS2, Rising 1.0 1.5 2.0 V VRUN/SS1, 2 LT RUN/SS Pin Latchoff Arming VRUN/SS1, VRUN/SS2, Rising from 3V 4.1 4.75 V Threshold ISCL1, 2 RUN/SS Discharge Current Soft Short Condition VOSENSE1, 2 = 0.5V; 0.5 2 4 μA VRUN/SS1, 2 = 4.5V ISDLHO Shutdown Latch Disable Current VOSENSE1, 2 = 0.5V 1.6 5 μA VSENSE(MAX) Maximum Current Sense Threshold VOSENSE1, 2 = 0.7V, VOSENSE1–, 2– = 5V 65 75 85 mV l 62 75 88 mV TG Transition Time: (Note 6) TG1, 2 tr Rise Time CLOAD = 3300pF 60 110 ns TG1, 2 tf Fall Time CLOAD = 3300pF 60 110 ns BG Transition Time: (Note 6) BG1, 2 tr Rise Time CLOAD = 3300pF 50 110 ns BG1, 2 tf Fall Time CLOAD = 3300pF 50 100 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay Synchronous Switch-On Delay Time CLOAD = 3300pF Each Driver 80 ns BG/TG t2D Bottom Gate Off to Top Gate On Delay Top Switch-On Delay Time CLOAD = 3300pF Each Driver 80 ns tON(MIN) Minimum On-Time Tested with a Square Wave (Note 7) 180 ns
INTVCC Linear Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 30V, VEXTCC = 4V 4.8 5.0 5.2 V VLDO INT INTVCC Load Regulation ICC = 0 to 20mA, VEXTVCC = 4V 0.2 2.0 % VLDO EXT EXTVCC Voltage Drop ICC = 20mA, VEXTVCC = 5V 100 200 mV VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, EXTVCC Ramping Positive l 4.5 4.7 V VLDOHYS EXTVCC Hysteresis 0.2 V
Oscillator
fOSC Oscillator Frequency VFREQSET = Open (Note 8) 190 220 250 kHz fLOW Lowest Frequency VFREQSET = 0V 120 140 160 kHz 3707fb 3
