Datasheet LTC7801 (Analog Devices) - 5

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ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2), VIN = 12V, VRUN = 5V, VEXTVCC = 0V, VDRVSET = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS INTVCC LDO Regulator
VINTVCC INTVCC Voltage ICC = 0mA to 2mA 4.7 5.0 5.2 V
Oscillator and Phase-Locked Loop
Programmable Frequency RFREQ = 25k, PLLIN = DC Voltage 105 kHz Programmable Frequency RFREQ = 65k, PLLIN = DC Voltage 375 440 505 kHz Programmable Frequency RFREQ =105k, PLLIN = DC Voltage 835 kHz Low Fixed Frequency VFREQ = 0V, PLLIN = DC Voltage 320 350 380 kHz High Fixed Frequency VFREQ = INTVCC, PLLIN = DC Voltage 485 535 585 kHz fSYNC Synchronizable Frequency PLLIN = External Clock l 75 850 kHz PLLIN Input High Level PLLIN = External Clock l 2.8 V PLLIN Input Low Level PLLIN = External Clock l 0.5 V
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.02 0.04 V IPGOOD PGOOD Leakage Current VPGOOD = 3.3V 10 µA PGOOD Trip Level VFB with Respect to Set Regulated Voltage VFB Ramping Negative –13 –10 –7 % Hysteresis 2.5 % VFB with Respect to Set Regulated Voltage VFB Ramping Positive 7 10 13 % Hysteresis 2.5 % Delay for Reporting a Fault 40 µs
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 Ratings for extended periods may affect device reliability
Note 4:
The LTC7801 is tested in a feedback loop that servos VITH to a and lifetime. specified voltage and measures the resultant VFB. The specification at 85°C
Note 2:
The LTC7801 is tested under pulsed load conditions such that TJ ≈ is not tested in production and is assured by design, characterization and TA. The LTC7801E is guaranteed to meet performance specifications from correlation to production testing at other temperatures (125°C for the 0°C to 85°C. Specifications over the –40°C to 125°C operating junction LTC7801E and LTC7801I, 150°C for the LTC7801H). For the LTC7801I temperature range are assured by design, characterization and correlation and LTC7801H, the specification at 0°C is not tested in production and is with statistical process controls. The LTC7801I is guaranteed over the assured by design, characterization and correlation to production testing –40°C to 125°C operating junction temperature range and the LTC7801H at –40°C. is guaranteed over the –40°C to 150°C operating junction temperature
Note 5:
Dynamic supply current is higher due to the gate charge range. Note that the maximum ambient temperature consistent with being delivered at the switching frequency. See the Applications these specifications is determined by specific operating conditions in Information section. conjunction with board layout, the rated package thermal impedance
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay and other environmental factors. High temperatures degrade operating times are measured using 50% levels. lifetimes; operating lifetime is derated for junction temperatures greater
Note 7:
The minimum on-time condition is specified for an inductor than 125ºC. The junction temperature (TJ, in °C) is calculated from the peak-to-peak ripple current >40% of I ambient temperature (T MAX (See Minimum On-Time A, in °C) and power dissipation (PD, in Watts) Considerations in the Applications Information section). according to the formula:
Note 8:
Do not apply a voltage or current source to these pins. They must TJ = TA + (PD • θJA) be connected to capacitive loads only, otherwise permanent damage where θJA = 33°C/W for the TSSOP package and θJA = 43°C/W for the may occur. QFN package.
Note 9:
Do not apply a voltage or current source to the NDRV pin, other
Note 3:
This IC includes overtemperature protection that is intended to than tying NDRV to DRVCC when not used. If used it must be connected protect the device during momentary overload conditions. The maximum to capacitive loads only (see DRVCC Regulators in the Applications rated junction temperature will be exceeded when this protection is active. Information section), otherwise permanent damage may occur. Continuous operation above the specified absolute maximum operating
Note 10:
The minimum input supply operating range is dependent on the DRVCC UVLO thresholds as determined by the DRVUV pin setting. Rev. A For more information www.analog.com 5 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts