Datasheet LTC1735 (Analog Devices) - 3
| Hersteller | Analog Devices |
| Beschreibung | High Efficiency Synchronous Step-Down Switching Regulator |
| Seiten / Seite | 32 / 3 — ELECTRICAL CHARACTERISTICS The. denotes specifications which apply over … |
| Dateiformat / Größe | PDF / 415 Kb |
| Dokumentensprache | Englisch |
ELECTRICAL CHARACTERISTICS The. denotes specifications which apply over the full operating
Modelllinie für dieses Datenblatt
- LTC1735CF#PBF LTC1735CF#PBF LTC1735CF#TRPBF LTC1735CF#TRPBF LTC1735CGN#PBF LTC1735CGN#PBF LTC1735CGN#TRPBF LTC1735CGN#TRPBF LTC1735CS#PBF LTC1735CS#PBF LTC1735CS#TRPBF LTC1735CS#TRPBF LTC1735EGN#PBF LTC1735EGN#PBF LTC1735EGN#TRPBF LTC1735EGN#TRPBF LTC1735IF#PBF LTC1735IF#PBF LTC1735IF#TRPBF LTC1735IF#TRPBF LTC1735IGN#PBF LTC1735IGN#PBF LTC1735IGN#TRPBF LTC1735IGN#TRPBF LTC1735IS#PBF LTC1735IS#PBF LTC1735IS#TRPBF LTC1735IS#TRPBF
Textversion des Dokuments
LTC1735
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 15V, VRUN/SS = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VOVL Feedback Overvoltage Lockout ● 0.84 0.86 0.88 V IQ Input DC Supply Current (Note 4) Normal Mode 450 µA Shutdown VRUN/SS = 0V 15 25 µA VRUN/SS Run Pin Start Threshold VRUN/SS, Ramping Positive 1.0 1.5 1.9 V VRUN/SS Run Pin Begin Latchoff Threshold VRUN/SS, Ramping Positive 4.1 4.5 V IRUN/SS Soft-Start Charge Current VRUN/SS = 0V – 0.7 – 1.2 µA ISCL RUN/SS Discharge Current Soft Short Condition, VOSENSE = 0.5V, 0.5 2 4 µA VRUN/SS = 4.5V UVLO Undervoltage Lockout Measured at VIN Pin (VIN Ramping Down) ● 3.5 3.9 V ∆VSENSE(MAX) Maximum Current Sense Threshold VOSENSE = 0.7V ● 60 75 85 mV I – + SENSE Sense Pins Total Source Current VSENSE = VSENSE = 0V 60 80 µA tON(MIN) Minimum On-Time Tested with a Square Wave (Note 6) 160 200 ns TG Transition Time: (Note 7) TG tr Rise Time CLOAD = 3300pF 50 90 ns TG tf Fall Time CLOAD = 3300pF 50 90 ns BG Transition Time: (Note 7) BG tr Rise Time CLOAD = 3300pF 50 90 ns BG tf Fall Time CLOAD = 3300pF 40 80 ns TG/BG t1D Top Gate Off to Synchronous CLOAD = 3300pF Each Driver 100 ns Gate On Delay Time TG/BG t2D Synchronous Gate Off to Top CLOAD = 3300pF Each Driver 70 ns Gate On Delay Time
Internal VCC Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 30V, VEXTVCC = 4V 5.0 5.2 5.4 V VLDO(INT) Internal VCC Load Regulation ICC = 0 to 20mA, VEXTVCC = 4V 0.2 1 % VLDO(EXT) EXTVCC Drop Voltage ICC = 20mA, VEXTVCC = 5V 130 200 mV VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, EXTVCC Ramping Positive ● 4.5 4.7 V VEXTVCC(HYS) EXTVCC Hysteresis 0.2 V
Oscillator
fOSC Oscillator Frequency COSC = 43pF (Note 5) 265 300 335 kHz fH/fOSC Maximum Sync Frequency Ratio 1.3 fFCB(SYNC) FCB Pin Threshold For Sync Ramping Negative 0.9 1.2 V
PGOOD Output (LTC1735F Only)
VPGL PGOOD Voltage Low IPGOOD = 2mA 110 200 mV IPGOOD PGOOD Leakage Current VPGOOD = 5V ±1 µA VPG PGOOD Trip Level VOSENSE with Respect to Set Output Voltage VOSENSE Ramping Negative – 6.0 – 7.5 – 9.5 % VOSENSE Ramping Positive 6.0 7.5 9.5 %
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 2:
TJ is calculated from the ambient temperature TA and power of a device may be impaired. dissipation PD according to the following formulas: LTC1735CS, LTC1735IS: TJ = TA + (PD • 110 °C/W) LTC1735CGN, LTC1735IGN, LTC1735EGN: TJ = TA + (PD • 130°C/W) LTC1735CF, LTC1735IF: TJ = TA + (PD • 110°C/W) 1735fc 3
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 15V, VRUN/SS = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VOVL Feedback Overvoltage Lockout ● 0.84 0.86 0.88 V IQ Input DC Supply Current (Note 4) Normal Mode 450 µA Shutdown VRUN/SS = 0V 15 25 µA VRUN/SS Run Pin Start Threshold VRUN/SS, Ramping Positive 1.0 1.5 1.9 V VRUN/SS Run Pin Begin Latchoff Threshold VRUN/SS, Ramping Positive 4.1 4.5 V IRUN/SS Soft-Start Charge Current VRUN/SS = 0V – 0.7 – 1.2 µA ISCL RUN/SS Discharge Current Soft Short Condition, VOSENSE = 0.5V, 0.5 2 4 µA VRUN/SS = 4.5V UVLO Undervoltage Lockout Measured at VIN Pin (VIN Ramping Down) ● 3.5 3.9 V ∆VSENSE(MAX) Maximum Current Sense Threshold VOSENSE = 0.7V ● 60 75 85 mV I – + SENSE Sense Pins Total Source Current VSENSE = VSENSE = 0V 60 80 µA tON(MIN) Minimum On-Time Tested with a Square Wave (Note 6) 160 200 ns TG Transition Time: (Note 7) TG tr Rise Time CLOAD = 3300pF 50 90 ns TG tf Fall Time CLOAD = 3300pF 50 90 ns BG Transition Time: (Note 7) BG tr Rise Time CLOAD = 3300pF 50 90 ns BG tf Fall Time CLOAD = 3300pF 40 80 ns TG/BG t1D Top Gate Off to Synchronous CLOAD = 3300pF Each Driver 100 ns Gate On Delay Time TG/BG t2D Synchronous Gate Off to Top CLOAD = 3300pF Each Driver 70 ns Gate On Delay Time
Internal VCC Regulator
VINTVCC Internal VCC Voltage 6V < VIN < 30V, VEXTVCC = 4V 5.0 5.2 5.4 V VLDO(INT) Internal VCC Load Regulation ICC = 0 to 20mA, VEXTVCC = 4V 0.2 1 % VLDO(EXT) EXTVCC Drop Voltage ICC = 20mA, VEXTVCC = 5V 130 200 mV VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, EXTVCC Ramping Positive ● 4.5 4.7 V VEXTVCC(HYS) EXTVCC Hysteresis 0.2 V
Oscillator
fOSC Oscillator Frequency COSC = 43pF (Note 5) 265 300 335 kHz fH/fOSC Maximum Sync Frequency Ratio 1.3 fFCB(SYNC) FCB Pin Threshold For Sync Ramping Negative 0.9 1.2 V
PGOOD Output (LTC1735F Only)
VPGL PGOOD Voltage Low IPGOOD = 2mA 110 200 mV IPGOOD PGOOD Leakage Current VPGOOD = 5V ±1 µA VPG PGOOD Trip Level VOSENSE with Respect to Set Output Voltage VOSENSE Ramping Negative – 6.0 – 7.5 – 9.5 % VOSENSE Ramping Positive 6.0 7.5 9.5 %
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 2:
TJ is calculated from the ambient temperature TA and power of a device may be impaired. dissipation PD according to the following formulas: LTC1735CS, LTC1735IS: TJ = TA + (PD • 110 °C/W) LTC1735CGN, LTC1735IGN, LTC1735EGN: TJ = TA + (PD • 130°C/W) LTC1735CF, LTC1735IF: TJ = TA + (PD • 110°C/W) 1735fc 3