Datasheet LTC7892 (Analog Devices) - 8

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Data Sheet LTC7892
(Specifications are at TJ = -40°C to +125°C for the minimum and maximum values, TA = 25°C for the typical values, VBIAS = 12V, RUN1 and RUN2 = 5V, VPRG1 = Float, EXTVCC = 0V, DRVSET = 0V, DRVUV = 0V, DTCA and DTCB = 0V, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS/COMMENTS MIN TYP MAX UNITS PGOODx Outputs
PGOODx Voltage Low PGOODx = 2mA, TA = 25°C 0.2 0.4 V PGOODx Leakage PGOODx = 5V, T Current A = 25°C -1 0 +1 µA TA = 25°C PGOODx Trip Level VFBx Rising 7 10 13 % (VFBx with respect to Hysteresis 1.6 % Set Regulated Voltage) VFBx Falling -13 -10 -7 % Hysteresis 1.6 % PGOODx Delay for 25 µs Reporting a Fault .1 The LTC7892 is tested in a feedback loop that servos ITHx voltage (VITHx) to a specified voltage and measures the resultant feedback voltage (VFBx). 2 SENSE1+ bias current is reflected in the bias supply by the formula I + VBIAS = ISENSE1 × VBIAS/(VOUT1 × η), where η is the efficiency. 3 Rise and fall times are measured using 10% and 90% levels. Delay times are measured using 50% levels unless otherwise noted. 4 TGxxx falling to BGxxx rising and BGxxx falling to TGxxx rising delay times are measured at the rising and falling thresholds on TGxxx and BGxxx of approximately 1V. See Figure 40 and Figure 41 for more details. 5 The minimum on-time condition specified for inductor peak-to-peak ripple current is >40% of the maximum load current (IMAX). See the Minimum On-Time Considerations for more details.
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Rev. 0 8 of 50 Document Outline Features Applications General Description Typical Application Revision History Specifications Absolute Maximum Ratings Pin Configurations and Function Descriptions Typical Performance Characteristics Functional Diagram Theory of Operation Main Control Loop Power and Bias Supplies (VBIAS, EXTVCC, DRVCC, INTVCC) High Side Bootstrap Capacitor Dead Time Control (DTCA and DTCB Pins) Start-Up and Shutdown (RUN and SS Pins) Light Load Operation: Burst Mode Operation, Pulse-Skipping Mode, or Forced Continuous Mode (MODE Pin) Frequency Selection, Spread Spectrum, and Phase-Locked Loop (FREQ and PLLIN/SPREAD Pins) Output Overvoltage Protection Power Good Applications Information Inductor Value Calculation Inductor Core Selection Current Sense Selection Low Value Resistor Current Sensing Inductor DCR Current Sensing Setting the Operating Frequency Selecting the Light-Load Operating Mode Dead Time Control (DTCA and DTCB Pins) DTCx Pin Tied to Ground (Adaptive Dead Time Control) DTCx Pin connected with a resistor to GND Power FET Selection CIN and COUT Selection Single Output 2-Phase Operation Setting the Output Voltage RUNx Pins and Undervoltage Lockout Soft Start (SSx Pins) INTVCC Regulators (OPTI-DRIVE) Topside FET Driver Supply (CB) Minimum On-Time Considerations Fault Conditions: Overtemperature Protection Phase-Locked Loop and Frequency Synchronization Efficiency Considerations Checking Transient Response Design Example PCB Board Layout Checklist PCB Layout Debugging Typical Applications Related Parts Outline Dimensions Ordering Guide