Datasheet LTC3728 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | Dual, 550kHz, 2-Phase Synchronous Step-Down Switching Regulator |
| Pages / Page | 36 / 4 — ELECTRICAL CHARACTERISTICS. The. denotes the specifi cations which apply … |
| File Format / Size | PDF / 1.7 Mb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifi cations which apply over the full operating
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LTC3728
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
VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, EXTVCC Ramping Positive l 4.5 4.7 V VLDOHYS EXTVCC Hysteresis 0.2 V
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VPLLFLTR = 1.2V 360 400 440 kHz fLOW Lowest Frequency VPLLFLTR = 0V 230 260 290 kHz fHIGH Highest Frequency VPLLFLTR ≥ 2.4V 480 550 590 kHz RPLLIN PLLIN Input Resistance 50 kΩ IPLLFLTR Phase Detector Output Current Sinking Capability fPLLIN < fOSC –15 μA Sourcing Capability fPLLIN > fOSC 15 μA
3.3V Linear Regulator
V3.3OUT 3.3V Regulator Output Voltage No Load l 3.25 3.35 3.45 V V3.3IL 3.3V Regulator Load Regulation I3.3 = 0 to 10mA 0.5 2 % V3.3VL 3.3V Regulator Line Regulation 6V < VIN < 30V 0.05 0.2 % I3.3LEAK Leakage Current of 3.3V Regulator in VRUN/SS1, 2 = 0V, VIN = 25V 10 50 μA Shutdown
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±1 μA VPG PGOOD Trip Level, Either Controller VOSENSE with Respect to Set Output Voltage VOSENSE Ramping Negative –6 –7.5 –9.5 % VOSENSE Ramping Positive 6 7.5 9.5 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 5:
Rise and fall times are measured using 10% and 90% levels. Delay may cause permanent damage to the device. Exposure to any Absolute times are measured using 50% levels. Maximum Rating condition for extended periods may affect device
Note 6:
The IC minimum on-time is tested under an ideal condition reliability and lifetime. without external power FETs. It can be different when the IC is working in
Note 2:
TJ is calculated from the ambient temperature TA and power an actual circuit. See Minimum On-Time Considerations in the Application dissipation PD according to the following formulas: Information section. LTC3728: TJ = TA + (PD • 95 °C/W)
Note 7:
The LTC3728E is guaranteed to meet performance specifi cations
Note 3:
The LTC3728 is tested in a feedback loop that servos V from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating ITH1, 2 to a specifi ed voltage and measures the resultant V temperature range are assured by design, characterization and correlation OSENSE1, 2.
Note 4:
Dynamic supply current is higher due to the gate charge being with statistical process controls. The LTC3728I is guaranteed to meet delivered at the switching frequency. See Applications Information. performance specifi cations over the full –40°C to 85°C operating temperature range. 3728fg 4
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
VEXTVCC EXTVCC Switchover Voltage ICC = 20mA, EXTVCC Ramping Positive l 4.5 4.7 V VLDOHYS EXTVCC Hysteresis 0.2 V
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VPLLFLTR = 1.2V 360 400 440 kHz fLOW Lowest Frequency VPLLFLTR = 0V 230 260 290 kHz fHIGH Highest Frequency VPLLFLTR ≥ 2.4V 480 550 590 kHz RPLLIN PLLIN Input Resistance 50 kΩ IPLLFLTR Phase Detector Output Current Sinking Capability fPLLIN < fOSC –15 μA Sourcing Capability fPLLIN > fOSC 15 μA
3.3V Linear Regulator
V3.3OUT 3.3V Regulator Output Voltage No Load l 3.25 3.35 3.45 V V3.3IL 3.3V Regulator Load Regulation I3.3 = 0 to 10mA 0.5 2 % V3.3VL 3.3V Regulator Line Regulation 6V < VIN < 30V 0.05 0.2 % I3.3LEAK Leakage Current of 3.3V Regulator in VRUN/SS1, 2 = 0V, VIN = 25V 10 50 μA Shutdown
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±1 μA VPG PGOOD Trip Level, Either Controller VOSENSE with Respect to Set Output Voltage VOSENSE Ramping Negative –6 –7.5 –9.5 % VOSENSE Ramping Positive 6 7.5 9.5 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 5:
Rise and fall times are measured using 10% and 90% levels. Delay may cause permanent damage to the device. Exposure to any Absolute times are measured using 50% levels. Maximum Rating condition for extended periods may affect device
Note 6:
The IC minimum on-time is tested under an ideal condition reliability and lifetime. without external power FETs. It can be different when the IC is working in
Note 2:
TJ is calculated from the ambient temperature TA and power an actual circuit. See Minimum On-Time Considerations in the Application dissipation PD according to the following formulas: Information section. LTC3728: TJ = TA + (PD • 95 °C/W)
Note 7:
The LTC3728E is guaranteed to meet performance specifi cations
Note 3:
The LTC3728 is tested in a feedback loop that servos V from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating ITH1, 2 to a specifi ed voltage and measures the resultant V temperature range are assured by design, characterization and correlation OSENSE1, 2.
Note 4:
Dynamic supply current is higher due to the gate charge being with statistical process controls. The LTC3728I is guaranteed to meet delivered at the switching frequency. See Applications Information. performance specifi cations over the full –40°C to 85°C operating temperature range. 3728fg 4
