Datasheet LTC3894 (Analog Devices) - 4
| Manufacturer | Analog Devices |
| Description | 150V Low IQ Step-Down DC/DC Controller with 100% Duty Cycle Capability |
| Pages / Page | 36 / 4 — ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply … |
| Revision | A |
| File Format / Size | PDF / 2.9 Mb |
| Document Language | English |
ELECTRICAL CHARACTERISTICS. The. denotes the specifications which apply over the specified operating
Model Line for this Datasheet
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link to page 2 link to page 1 link to page 32 LTC3894
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, unless otherwise noted. (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
fLO Low Switching Frequency FREQ = 0V 320 350 380 kHz fHI High Switching Frequency FREQ = Open 470 530 590 kHz fSYNC Synchronization Frequency l 75 800 kHz VCLK(HI) Clock Input High Level into PLLIN/MODE l 2 V VCLK(LO) Clock Input Low Level into PLLIN/MODE l 0.5 V
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.2 0.35 V IPG PGOOD Leakage Current VPGOOD = 65V 1 µA VPGOV PGOOD Overvoltage Trip Threshold VFB Ramping Positive with Respect to Set 7 10 13 % Regulated Voltage Hysteresis 2.5 % VPGUV PGOOD Undervoltage Trip Threshold VPGUV Ramping Negative 700 720 740 mV Hysteresis 2.5 % tPGDL PGOOD Delay PGOOD High to Low 100 µs PGOOD Low to High 100 µs VFBOV VFB Overvoltage Lockout Threshold VFB Ramping Positive with Respect to Set 10 % Regulated Voltage Hysteresis 2.5 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings junction temperature may impair device reliability or permanently damage may cause permanent damage to the device. Exposure to any Absolute the device. Maximum Rating condition for extended periods may affect device
Note 4:
The minimum input supply operating range is dependent on the reliability and lifetime. UVLO thresholds as determined by the DRVUV/EXTG pin setting.
Note 2:
The LTC3894 is tested under pulsed load conditions such that
Note 5:
The DC supply current is measured when the LTC3894 is not TJ ≈ TA. The LTC3894E is guaranteed to meet performance specifications switching. Dynamic supply current is higher due to the gate charge being from 0°C to 85°C. Specifications over the –40°C to 125°C operating delivered at the switching frequency. junction temperature range are assured by design, characterization and
Note 6:
SENSE1– bias current is reflected to the input supply by the correlation with statistical process controls. The LTC3894I is guaranteed formula over the –40°C to 125°C operating junction temperature range and the I – • V LTC3894H is guaranteed over the –40°C to 150°C operating junction VIN = ISENSE1 OUT/(VIN • η), where η is the efficiency. temperature range. Note that the maximum ambient temperature
Note 7:
The total input supply current in Burst Mode is the total current consistent with these specifications is determined by specific operating drawn from input supply as measured in the Typical Application circuit on conditions in conjunction with board layout, the rated package thermal page 1 and Figure 14 on page 32 with no load current. The specification impedance and other environmental factors. High temperatures degrade is not tested in production. operating lifetimes; operating lifetime is derated for junction temperatures
Note 8:
The LTC3894 is tested in a feedback loop that servos the error greater than 125ºC. The junction temperature (T amplifier output voltage (on ITH pin) to a specified voltage and measures J, in °C) is calculated from the ambient temperature (T the resultant V A, in °C) and power dissipation (PD, in Watts) FB voltage. according to the formula:
Note 9:
Positive ICAP current flows into the CAP pin and discharges the T capacitor between the V J = TA + (PD • θJA) IN and CAP pins. where θ
Note 10:
The minimum on-time condition is specified for an inductor JA = 38°C/W for the TSSOP package.
Note 3:
This IC includes overtemperature protection that is intended to peak-to-peak ripple current > 40% of IMAX. protect the device during momentary overload conditions. The maximum
Note 11:
The absolute maximum rating for TRACK/SS pin is 2.8V when the rated junction temperature will be exceeded when this protection is active. pin is driven externally. When the pin is not driven, it may be pulled higher Continuous operation above the specified absolute maximum operating by the IC, typically to 4.7V. Rev. A 4 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, unless otherwise noted. (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
fLO Low Switching Frequency FREQ = 0V 320 350 380 kHz fHI High Switching Frequency FREQ = Open 470 530 590 kHz fSYNC Synchronization Frequency l 75 800 kHz VCLK(HI) Clock Input High Level into PLLIN/MODE l 2 V VCLK(LO) Clock Input Low Level into PLLIN/MODE l 0.5 V
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.2 0.35 V IPG PGOOD Leakage Current VPGOOD = 65V 1 µA VPGOV PGOOD Overvoltage Trip Threshold VFB Ramping Positive with Respect to Set 7 10 13 % Regulated Voltage Hysteresis 2.5 % VPGUV PGOOD Undervoltage Trip Threshold VPGUV Ramping Negative 700 720 740 mV Hysteresis 2.5 % tPGDL PGOOD Delay PGOOD High to Low 100 µs PGOOD Low to High 100 µs VFBOV VFB Overvoltage Lockout Threshold VFB Ramping Positive with Respect to Set 10 % Regulated Voltage Hysteresis 2.5 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings junction temperature may impair device reliability or permanently damage may cause permanent damage to the device. Exposure to any Absolute the device. Maximum Rating condition for extended periods may affect device
Note 4:
The minimum input supply operating range is dependent on the reliability and lifetime. UVLO thresholds as determined by the DRVUV/EXTG pin setting.
Note 2:
The LTC3894 is tested under pulsed load conditions such that
Note 5:
The DC supply current is measured when the LTC3894 is not TJ ≈ TA. The LTC3894E is guaranteed to meet performance specifications switching. Dynamic supply current is higher due to the gate charge being from 0°C to 85°C. Specifications over the –40°C to 125°C operating delivered at the switching frequency. junction temperature range are assured by design, characterization and
Note 6:
SENSE1– bias current is reflected to the input supply by the correlation with statistical process controls. The LTC3894I is guaranteed formula over the –40°C to 125°C operating junction temperature range and the I – • V LTC3894H is guaranteed over the –40°C to 150°C operating junction VIN = ISENSE1 OUT/(VIN • η), where η is the efficiency. temperature range. Note that the maximum ambient temperature
Note 7:
The total input supply current in Burst Mode is the total current consistent with these specifications is determined by specific operating drawn from input supply as measured in the Typical Application circuit on conditions in conjunction with board layout, the rated package thermal page 1 and Figure 14 on page 32 with no load current. The specification impedance and other environmental factors. High temperatures degrade is not tested in production. operating lifetimes; operating lifetime is derated for junction temperatures
Note 8:
The LTC3894 is tested in a feedback loop that servos the error greater than 125ºC. The junction temperature (T amplifier output voltage (on ITH pin) to a specified voltage and measures J, in °C) is calculated from the ambient temperature (T the resultant V A, in °C) and power dissipation (PD, in Watts) FB voltage. according to the formula:
Note 9:
Positive ICAP current flows into the CAP pin and discharges the T capacitor between the V J = TA + (PD • θJA) IN and CAP pins. where θ
Note 10:
The minimum on-time condition is specified for an inductor JA = 38°C/W for the TSSOP package.
Note 3:
This IC includes overtemperature protection that is intended to peak-to-peak ripple current > 40% of IMAX. protect the device during momentary overload conditions. The maximum
Note 11:
The absolute maximum rating for TRACK/SS pin is 2.8V when the rated junction temperature will be exceeded when this protection is active. pin is driven externally. When the pin is not driven, it may be pulled higher Continuous operation above the specified absolute maximum operating by the IC, typically to 4.7V. Rev. A 4 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
