Datasheet LTC1878 (Analog Devices) - 3
| Hersteller | Analog Devices |
| Beschreibung | High Efficiency Monolithic Synchronous Step-Down Regulator |
| Seiten / Seite | 16 / 3 — ELECTRICAL CHARACTERISTICS The |
| Dateiformat / Größe | PDF / 239 Kb |
| Dokumentensprache | Englisch |
ELECTRICAL CHARACTERISTICS The
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LTC1878
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25
°
C. VIN = 3.6V unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
IPK Peak Inductor Current VIN = 3.3V, VFB = 0.7V, Duty Cycle < 35% 0.8 1.0 1.25 A ILSW SW Leakage VRUN = 0V, VSW = 0V or 6V, VIN = 6V ±0.01 ±1 µA VSYNC/MODE SYNC/MODE Threshold VSYNC/MODE Rising ● 0.3 1.0 1.5 V ISYNC/MODE SYNC/MODE Leakage Current ±0.01 ±1 µA VRUN RUN Threshold VRUN Rising ● 0.3 0.7 1.5 V IRUN RUN Input Current ±0.01 ±1 µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
The LTC1878 is tested in a feedback loop which servos VFB to the of a device may be impaired. balance point for the error amplifier (VITH = 1.2V).
Note 2:
The LTC1878E is guaranteed to meet performance specifications
Note 5:
Dynamic supply current is higher due to the gate charge being from 0°C to 70°C. Specifications over the – 40°C to 85°C operating delivered at the switching frequency. temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3:
TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formulas: LTC1878EMS8: TJ = TA + (PD)(150°C/W)
W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency vs Input Voltage Efficiency vs Output Current Efficiency vs Output Current
100 100 95 90 VIN = 3.6V 90 95 I L = 15µH LOAD = 100mA ILOAD = 10mA 80 VIN = 4.2V 85 L = 10µH 90 70 ILOAD = 300mA 80 85 I 60 LOAD = 1mA V 75 IN = 3.6V 80 50 I V 70 LOAD = 0.1mA IN = 4.2V 40 75 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 65 30 70 60 20 PULSE SKIPPING MODE Burst Mode OPERATION Burst Mode OPERATION Burst Mode OPERATION 65 V 55 V OUT = 2.5V 10 VOUT = 1.8V IN = 6V L = 10µH L = 10µH VOUT = 2.5V 60 0 50 2 3 4 5 6 7 8 0.1 1 10 100 1000 0.1 1 10 100 1000 INPUT VOLTAGE (V) OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 1878 G03 1878 G01 1878 G02 3
ELECTRICAL CHARACTERISTICS The
●
denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25
°
C. VIN = 3.6V unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
IPK Peak Inductor Current VIN = 3.3V, VFB = 0.7V, Duty Cycle < 35% 0.8 1.0 1.25 A ILSW SW Leakage VRUN = 0V, VSW = 0V or 6V, VIN = 6V ±0.01 ±1 µA VSYNC/MODE SYNC/MODE Threshold VSYNC/MODE Rising ● 0.3 1.0 1.5 V ISYNC/MODE SYNC/MODE Leakage Current ±0.01 ±1 µA VRUN RUN Threshold VRUN Rising ● 0.3 0.7 1.5 V IRUN RUN Input Current ±0.01 ±1 µA
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 4:
The LTC1878 is tested in a feedback loop which servos VFB to the of a device may be impaired. balance point for the error amplifier (VITH = 1.2V).
Note 2:
The LTC1878E is guaranteed to meet performance specifications
Note 5:
Dynamic supply current is higher due to the gate charge being from 0°C to 70°C. Specifications over the – 40°C to 85°C operating delivered at the switching frequency. temperature range are assured by design, characterization and correlation with statistical process controls.
Note 3:
TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formulas: LTC1878EMS8: TJ = TA + (PD)(150°C/W)
W U TYPICAL PERFOR A CE CHARACTERISTICS Efficiency vs Input Voltage Efficiency vs Output Current Efficiency vs Output Current
100 100 95 90 VIN = 3.6V 90 95 I L = 15µH LOAD = 100mA ILOAD = 10mA 80 VIN = 4.2V 85 L = 10µH 90 70 ILOAD = 300mA 80 85 I 60 LOAD = 1mA V 75 IN = 3.6V 80 50 I V 70 LOAD = 0.1mA IN = 4.2V 40 75 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 65 30 70 60 20 PULSE SKIPPING MODE Burst Mode OPERATION Burst Mode OPERATION Burst Mode OPERATION 65 V 55 V OUT = 2.5V 10 VOUT = 1.8V IN = 6V L = 10µH L = 10µH VOUT = 2.5V 60 0 50 2 3 4 5 6 7 8 0.1 1 10 100 1000 0.1 1 10 100 1000 INPUT VOLTAGE (V) OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 1878 G03 1878 G01 1878 G02 3