Datasheet LTC1622 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Low Input Voltage Current Mode Step-Down DC/DC Controller |
| Pages / Page | 16 / 3 — ELECTRICAL CHARACTERISTICS The. denotes specifications which apply over … |
| File Format / Size | PDF / 198 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS The. denotes specifications which apply over the full operating
Model Line for this Datasheet
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LTC1622
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 4.2V SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
PDRV tr Gate Drive Rise Time CLOAD = 3000pF 80 140 ns PDRV tf Gate Drive Fall Time CLOAD = 3000pF 100 140 ns ∆VSENSE(MAX) Maximum Current Sense Voltage ● 80 110 140 mV
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 3:
The LTC1622 is tested in a feedback loop that servos VFB to the of a device may be impaired. feedback point for the error amplifier (VITH = 0.8V).
Note 2:
TJ is calculated from the ambient temperature TA and power
Note 4:
Dynamic supply current is higher due to the gate charge being dissipation PD according to the following formula: delivered at the switching frequency. LTC1622CS8; TJ = TA + (PD • 150°C/W), LTC1622CMS8; TJ = TA + (PD • 250°C/W)
W U TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Current Maximum Current Sense Voltage vs Supply Voltage RUN/SS Current vs Supply Voltage vs Duty Cycle
45 3.50 110 VIN = 4.2V 40 100 3.00 µA) 35 µA) 90 30 UNSYNC 80 2.50 25 70 20 2.00 60 15 TRIP VOLTAGE (mV) SHUTDOWN CURRENT ( 10 50 SOFT-START CURRENT ( 1.50 5 40 0 1.00 30 2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) DUTY CYCLE (%) 1622 G01 1622 G02 1622 G03
Normalized Oscillator Frequency Reference Voltage Undervoltage Lockout Voltage vs Temperature vs Temperature vs Temperature
10.0 0.810 2.10 VIN = 4.2V VIN = 4.2V 7.5 0.805 2.05 5.0 0.800 2.00 2.5 0.795 1.95 0 0.790 1.90 –2.5 0.785 1.85 –5.0 REFERENCE VOLTAGE (V) NORMALIZED FREQUENCY (%) 0.780 1.80 –7.5 UNDERVOLTAGE LOCKOUT VOLTAGE (V) –10.0 0.775 1.75 –55 –35 –15 5 25 45 65 85 105 125 –55 –35 –15 5 25 45 65 85 105 125 –55 –35 –15 5 25 45 65 85 105 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 1622 G04 1622 G05 1622 G06 3
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VIN = 4.2V SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
PDRV tr Gate Drive Rise Time CLOAD = 3000pF 80 140 ns PDRV tf Gate Drive Fall Time CLOAD = 3000pF 100 140 ns ∆VSENSE(MAX) Maximum Current Sense Voltage ● 80 110 140 mV
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 3:
The LTC1622 is tested in a feedback loop that servos VFB to the of a device may be impaired. feedback point for the error amplifier (VITH = 0.8V).
Note 2:
TJ is calculated from the ambient temperature TA and power
Note 4:
Dynamic supply current is higher due to the gate charge being dissipation PD according to the following formula: delivered at the switching frequency. LTC1622CS8; TJ = TA + (PD • 150°C/W), LTC1622CMS8; TJ = TA + (PD • 250°C/W)
W U TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Current Maximum Current Sense Voltage vs Supply Voltage RUN/SS Current vs Supply Voltage vs Duty Cycle
45 3.50 110 VIN = 4.2V 40 100 3.00 µA) 35 µA) 90 30 UNSYNC 80 2.50 25 70 20 2.00 60 15 TRIP VOLTAGE (mV) SHUTDOWN CURRENT ( 10 50 SOFT-START CURRENT ( 1.50 5 40 0 1.00 30 2 3 4 5 6 7 8 9 10 2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 100 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) DUTY CYCLE (%) 1622 G01 1622 G02 1622 G03
Normalized Oscillator Frequency Reference Voltage Undervoltage Lockout Voltage vs Temperature vs Temperature vs Temperature
10.0 0.810 2.10 VIN = 4.2V VIN = 4.2V 7.5 0.805 2.05 5.0 0.800 2.00 2.5 0.795 1.95 0 0.790 1.90 –2.5 0.785 1.85 –5.0 REFERENCE VOLTAGE (V) NORMALIZED FREQUENCY (%) 0.780 1.80 –7.5 UNDERVOLTAGE LOCKOUT VOLTAGE (V) –10.0 0.775 1.75 –55 –35 –15 5 25 45 65 85 105 125 –55 –35 –15 5 25 45 65 85 105 125 –55 –35 –15 5 25 45 65 85 105 125 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) 1622 G04 1622 G05 1622 G06 3
