Datasheet LTC3545, LTC3545-1 (Analog Devices) - 3
| Manufacturer | Analog Devices |
| Description | Triple 800mA Synchronous Step-Down Regulator - 2.25MHz |
| Pages / Page | 20 / 3 — ELECTRICAL CHARACTERISTICS. The. denotes the specifi cations which apply … |
| File Format / Size | PDF / 305 Kb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifi cations which apply over the full operating
Model Line for this Datasheet
Text Version of Document
LTC3545/LTC3545-1
ELECTRICAL CHARACTERISTICS The
●
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = PVIN = 3.6V unless otherwise noted. (Note 3) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VLOADREG Output Voltage Load Regulation (Notes 5, 6) 0.5 % IFBx Feedback Pin Leakage (Note 5) 80 nA IS Input DC Bias Current (All Regulators Enabled) ILOAD = 0A, 2.25MHz Pulse Skip (Active Mode) VFBx = 0.5V 680 750 μA Burst Mode Operation (All Regulators Sleeping) VFBx = 0.7V 58 70 μA Shutdown (RUNX = 0V) 0.1 2.0 μA fOSC Oscillator Frequency ● 1.8 2.25 2.7 MHz fSYNC Synchronization Frequency LTC3545 Only ● 1 3 MHz VRUN(HIGH) RUNx Input High Voltage ● 1 V VRUN(LOW) RUNx Input Low Voltage ● 0.3 V IRUNx RUN Leakage Current ±0.1 ±1 μA ILSWx SWx Leakage VRUNx = 0V, VSWx = 0V or 5.5V, VIN = 5.5V ±0.1 ±1 μA ISYNC SYNC Leakage VRUN = 0V, VSYNC = 0V or 5.5V, ±0.1 ±1 μA VIN = 5.5V TPGOODx Power Good Threshold–Deviation From VFB VFBx Ramping Up –7.5 % Steady State (0.6V) VFBx Ramping Down –10 % RPGOODx Power Good Pull-Down On-Resistance IPGD = 50mA ● 14 50 Ω MODE/SYNC Thresholds 0.93 V
Individual Regulator Characteristics (One Regulator Enabled)
tSS Soft-Start Period VFBx = 10% to 90% Fullscale 850 1100 μs IPK Peak Switch Current Limit 1 1.3 1.6 A IQ Input DC Bias Current ILOAD = 0A, 2.25MHz Pulse Skip (Active Mode) VFBx = 0.5V 310 μA Burst Mode Operation (Sleeping) VFBx = 0.7V 31 μA RPFET RDS(ON) of P-Channel FET (Note 7) ISWx = 100mA 0.35 Ω RNFET RDS(ON) of N-Channel FET (Note 7) ISWx = –100mA 0.35 Ω VUVLO Undervoltage Lockout (High VCC to Low) ● 1.8 2.25 V
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings will exceed 125°C when overtemperature is active. Continuous operation may cause permanent damage to the device. Exposure to any Absolute above the specifi ed maximum operating junction temperature may impair Maximum Rating condition for extended periods may affect device device reliability. reliability and lifetime.
Note 4:
This IC includes overtemperature protection that is intended
Note 2:
The LTC3545E/LTC3545E-1 are guaranteed to meet performance to protect the device during momentary overload conditions. Junction specifi cations from 0°C to 85°C. Specifi cations over the –40°C to temperature will exceed 125°C when overtemperature is active. 125°C operating junction temperature range are assured by design, Continuous operation above the specifi ed maximum operating junction characterization and correlation with statistical process controls. The temperature may impair device reliability. LTC3545I/LTC3545I-1 are guaranteed to meet performance specifi cations
Note 5:
The LTC3545/LTC3545-1 are tested in a proprietary test mode that over the full –40°C to 125°C operating junction temperature range. connects VFB to the output of the error amplifi er.
Note 3:
TJ is calculated from the ambient temperature TA and power
Note 6:
Load regulation is inferred by measuring the regulation loop gain. dissipation PD according to the following formula:
Note 7:
The QFN switch-on resistance is guaranteed by correlation to TJ = TA + (PD)(68°C/W) water level measurements. This IC includes overtemperature protection that is intended to protect
Note 8:
Guaranteed by long-term current density limitations. the device during momentary overload conditions. Junction temperature 35451fb 3
ELECTRICAL CHARACTERISTICS The
●
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = PVIN = 3.6V unless otherwise noted. (Note 3) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VLOADREG Output Voltage Load Regulation (Notes 5, 6) 0.5 % IFBx Feedback Pin Leakage (Note 5) 80 nA IS Input DC Bias Current (All Regulators Enabled) ILOAD = 0A, 2.25MHz Pulse Skip (Active Mode) VFBx = 0.5V 680 750 μA Burst Mode Operation (All Regulators Sleeping) VFBx = 0.7V 58 70 μA Shutdown (RUNX = 0V) 0.1 2.0 μA fOSC Oscillator Frequency ● 1.8 2.25 2.7 MHz fSYNC Synchronization Frequency LTC3545 Only ● 1 3 MHz VRUN(HIGH) RUNx Input High Voltage ● 1 V VRUN(LOW) RUNx Input Low Voltage ● 0.3 V IRUNx RUN Leakage Current ±0.1 ±1 μA ILSWx SWx Leakage VRUNx = 0V, VSWx = 0V or 5.5V, VIN = 5.5V ±0.1 ±1 μA ISYNC SYNC Leakage VRUN = 0V, VSYNC = 0V or 5.5V, ±0.1 ±1 μA VIN = 5.5V TPGOODx Power Good Threshold–Deviation From VFB VFBx Ramping Up –7.5 % Steady State (0.6V) VFBx Ramping Down –10 % RPGOODx Power Good Pull-Down On-Resistance IPGD = 50mA ● 14 50 Ω MODE/SYNC Thresholds 0.93 V
Individual Regulator Characteristics (One Regulator Enabled)
tSS Soft-Start Period VFBx = 10% to 90% Fullscale 850 1100 μs IPK Peak Switch Current Limit 1 1.3 1.6 A IQ Input DC Bias Current ILOAD = 0A, 2.25MHz Pulse Skip (Active Mode) VFBx = 0.5V 310 μA Burst Mode Operation (Sleeping) VFBx = 0.7V 31 μA RPFET RDS(ON) of P-Channel FET (Note 7) ISWx = 100mA 0.35 Ω RNFET RDS(ON) of N-Channel FET (Note 7) ISWx = –100mA 0.35 Ω VUVLO Undervoltage Lockout (High VCC to Low) ● 1.8 2.25 V
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings will exceed 125°C when overtemperature is active. Continuous operation may cause permanent damage to the device. Exposure to any Absolute above the specifi ed maximum operating junction temperature may impair Maximum Rating condition for extended periods may affect device device reliability. reliability and lifetime.
Note 4:
This IC includes overtemperature protection that is intended
Note 2:
The LTC3545E/LTC3545E-1 are guaranteed to meet performance to protect the device during momentary overload conditions. Junction specifi cations from 0°C to 85°C. Specifi cations over the –40°C to temperature will exceed 125°C when overtemperature is active. 125°C operating junction temperature range are assured by design, Continuous operation above the specifi ed maximum operating junction characterization and correlation with statistical process controls. The temperature may impair device reliability. LTC3545I/LTC3545I-1 are guaranteed to meet performance specifi cations
Note 5:
The LTC3545/LTC3545-1 are tested in a proprietary test mode that over the full –40°C to 125°C operating junction temperature range. connects VFB to the output of the error amplifi er.
Note 3:
TJ is calculated from the ambient temperature TA and power
Note 6:
Load regulation is inferred by measuring the regulation loop gain. dissipation PD according to the following formula:
Note 7:
The QFN switch-on resistance is guaranteed by correlation to TJ = TA + (PD)(68°C/W) water level measurements. This IC includes overtemperature protection that is intended to protect
Note 8:
Guaranteed by long-term current density limitations. the device during momentary overload conditions. Junction temperature 35451fb 3
