Datasheet LTC1698 (Analog Devices) - 3

LTC1698
ELECTRICAL CHARACTERISTICS The
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indicates specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25
°
C. VDD = 8V, unless otherwise noted. (Note 4) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS VAUX
VAUX Auxiliary Supply Voltage CVAUX = 0.1µF, ILOAD = 0mA to 10mA, VDD = 7V to 12.6V ● 3.135 3.320 3.465 V
Current Limit Amplifier
IISNSGND ISNSGND Input Current VISNSGND = 0V ● 0.05 1 µA IISNS ISNS Input Current VISNS = 0V ● 0.05 1 µA VILIMTH Current Limit Threshold VICOMP = 2.5V, VISNSGND = 0V – 27.0 – 25 – 23.0 mV (VISNS – VISNSGND) ● – 27.5 – 25 – 22.5 mV IICOMP ICOMP Source Current VISNSGND = 0V, VISNS = – 0.3V, VICOMP = 2.5V (Note 8) – 280 – 200 – 120 µA ● – 370 – 200 – 80 µA ICOMP Sink Current VISNSGND = 0V, VISNS = 0.3V, VICOMP = 2.5V (Note 8) 120 200 280 µA ● 80 200 370 µA gmILIM Current Limit Amplifier VISNSGND = 0V, VICOMP = 2.5V, IICOMP = ±10µA ● 2.2 3.5 5 millimho Transconductance GICOMP Current Limit Amplifier VICOMP = 2.5V, No Load ● 48 60 dB Open-Loop DC Gain
PWRGD and OVP Comparators
VPWRGD Percent Below VFB VFB ↓, MARGIN = Open (Note 9) ● – 9 – 6 – 3 % IPWRGD Power Good Sink Current VFB = 2V ● 10 µA VFB = 0V ● 10 mA VOL Power Good Output Low Voltage IPWRGD = 3mA, VFB = 0V ● 0.4 V VOVPREF OVPIN Threshold VFB = VISNS = VISNSGND = 0V, OVPIN ↑ (Note 9) ● 1.18 1.233 1.28 V IOVPIN OVPIN Input Bias Current VOVPIN = 1.233V ● 0.1 1 µA tPWRGD Power Good Response Time VFB ↑ ● 1 2 5 ms Power Bad Response Time VFB ↓ ● 0.5 1 2.5 ms tOVP Overvoltage Response Time VOVPIN ↑, COPTODRV = 0.1µF ● 5 20 µs
SYNC and Drivers
VPT SYNC Input Positive Threshold ● 1 1.6 2.2 V VNT SYNC Input Negative Threshold ● – 2.2 –1.6 –1 V ISYNC SYNC Input Current VSYNC = ±10V ● 1 50 µA fSYNC SYNC Frequency Range CFG = CCG = 1000pF, VSYNC = ±5V ● 50 400 kHz td SYNC Input to Driver Output Delay CFG = CCG = 1000pF, fSYNC = 100kHz, VSYNC = ±5V ● 40 90 ns tSYNC Minimum SYNC Pulse Width fSYNC = 100kHz, VSYNC = ±10V (Note 6) ● 75 ns tr, tf Driver Rise and Fall Time CFG = CCG = 1000pF, fSYNC = 100kHz, VSYNC = ±5V, ● 10 40 ns 10% to 90% tDDIS Driver Disable Time-Out CFG = CCG = 1000pF, fSYNC = 100kHz, VSYNC = ±5V Measured from CG ↑ (Note 10) ● 10 15 20 µs
Note 1:
Absolute Maximum Ratings are those values beyond which the life
Note 5:
Supply current in active operation is dominated by the current of a device may be impaired. All voltages refer to GND. needed to charge and discharge the external FET gates. This will vary with
Note 2:
The LTC1698 incorporates a 5V linear regulator to power internal the LTC1698 operating frequency, supply voltage and the external FETs circuitry. Driving these pins above 5.3V may cause excessive current flow. used. Guaranteed by design and not subject to test.
Note 6:
This parameter is guaranteed by correlation and is not tested.
Note 3:
The LTC1698E is guaranteed to meet performance specifications
Note 7:
VFB is tested in an op amp feedback loop which servos VFB to the from 0°C to 70°C. Specifications over the – 40°C to 85°C operating internal bandgap voltage. temperature range are assured by design, characterization and correlation
Note 8:
The current comparator output current varies linearly with with statistical process controls. For guaranteed performance to temperature. specifications over the –40°C to 85°C range, the LTC1698I is available.
Note 9:
The PWRGD and OVP comparators incorporate 10mV of
Note 4:
All currents into device pins are positive; all currents out of the hysteresis. device pins are negative. All voltages are referenced to ground unless
Note 10:
The driver disable time-out is proportional to the SYNC period otherwise specified. For applications with VDD < 7V, refer to the Typical within the frequency synchronization range. Performance Characteristics. 1698f 3