Datasheet LTC3772 (Analog Devices) - 3
| Hersteller | Analog Devices |
| Beschreibung | Micropower No RSENSE Constant Frequency Step-Down DC/DC Controller |
| Seiten / Seite | 20 / 3 — ELECTRICAL CHARACTERISTICS The. indicates specifications which apply over … |
| Dateiformat / Größe | PDF / 259 Kb |
| Dokumentensprache | Englisch |
ELECTRICAL CHARACTERISTICS The. indicates specifications which apply over the full operating
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LTC3772
ELECTRICAL CHARACTERISTICS The
●
indicates specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 4.2V unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS
VFB Input Current (Note 5) –10 2 10 nA Overvoltage Protect Threshold Measured at VFB 0.850 0.880 0.910 V Overvoltage Protect Hysteresis 40 mV Oscillator Frequency Normal Operation VFB = 0.8V 500 550 650 kHz Output Short Circuit VFB = 0V 200 kHz Gate Drive Rise Time CLOAD = 3000pF 40 ns Gate Drive Fall Time CLOAD = 3000pF 40 ns Peak Current Sense Voltage IPRG = GND (Note 6) ● 90 105 120 mV IPRG = Floating ● 160 175 190 mV IPRG = VIN ● 228 245 262 mV Default Soft-Start Time 0.6 ms
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
Dynamic supply current is higher due to the gate charge being of a device may be impaired. delivered at the switching frequency.
Note 2:
The LTC3772ETS8/LTC3772EDDB are guaranteed to meet
Note 5:
The LTC3772 are tested in a feedback loop that servos VFB to the specifications from 0°C to 70°C. Specifications over the –40°C to 85°C output of the error amplifier while maintaining ITH/RUN at the midpoint of operating temperature range are assured by design, characterization and the current limit range. correlation with statistical process controls.
Note 6:
Peak current sense voltage is reduced dependent on duty cycle as
Note 3:
TJ is calculated from the ambient temperature TA and power given in Figure 1. dissipation PD according to the following formula: TJ = TA + (PD • θJA°C/W)
W U TYPICAL PERFOR A CE CHARACTERISTICS Quiescent Current (No Load) Quiescent Current (No Load) Quiescent Current (Shutdown) vs Input Voltage vs Temperature vs Input Voltage
60 55 25 55 50 20 A) A) A) µ 50 µ 45 µ 45 15 40 40 35 35 10 30 QUIESCENT CURRENT ( 30 QUIESCENT CURRENT ( QUIESCENT CURRENT ( 5 25 25 20 20 0 2 3 4 5 6 7 8 9 10 –60 –40 –20 0 20 40 60 80 100 2 3 4 5 6 7 8 9 10 INPUT VOLTAGE (V) TEMPERATURE (°C) INPUT VOLTAGE (V) 3772 G01 3772 G02 3772 G03 3772f 3
ELECTRICAL CHARACTERISTICS The
●
indicates specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 4.2V unless otherwise noted. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS
VFB Input Current (Note 5) –10 2 10 nA Overvoltage Protect Threshold Measured at VFB 0.850 0.880 0.910 V Overvoltage Protect Hysteresis 40 mV Oscillator Frequency Normal Operation VFB = 0.8V 500 550 650 kHz Output Short Circuit VFB = 0V 200 kHz Gate Drive Rise Time CLOAD = 3000pF 40 ns Gate Drive Fall Time CLOAD = 3000pF 40 ns Peak Current Sense Voltage IPRG = GND (Note 6) ● 90 105 120 mV IPRG = Floating ● 160 175 190 mV IPRG = VIN ● 228 245 262 mV Default Soft-Start Time 0.6 ms
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
Dynamic supply current is higher due to the gate charge being of a device may be impaired. delivered at the switching frequency.
Note 2:
The LTC3772ETS8/LTC3772EDDB are guaranteed to meet
Note 5:
The LTC3772 are tested in a feedback loop that servos VFB to the specifications from 0°C to 70°C. Specifications over the –40°C to 85°C output of the error amplifier while maintaining ITH/RUN at the midpoint of operating temperature range are assured by design, characterization and the current limit range. correlation with statistical process controls.
Note 6:
Peak current sense voltage is reduced dependent on duty cycle as
Note 3:
TJ is calculated from the ambient temperature TA and power given in Figure 1. dissipation PD according to the following formula: TJ = TA + (PD • θJA°C/W)
W U TYPICAL PERFOR A CE CHARACTERISTICS Quiescent Current (No Load) Quiescent Current (No Load) Quiescent Current (Shutdown) vs Input Voltage vs Temperature vs Input Voltage
60 55 25 55 50 20 A) A) A) µ 50 µ 45 µ 45 15 40 40 35 35 10 30 QUIESCENT CURRENT ( 30 QUIESCENT CURRENT ( QUIESCENT CURRENT ( 5 25 25 20 20 0 2 3 4 5 6 7 8 9 10 –60 –40 –20 0 20 40 60 80 100 2 3 4 5 6 7 8 9 10 INPUT VOLTAGE (V) TEMPERATURE (°C) INPUT VOLTAGE (V) 3772 G01 3772 G02 3772 G03 3772f 3