Datasheet LTC3371 (Analog Devices) - 4

LTC3371
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) VCC = VINA-H = 3.3V, unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VCC VCC Voltage Range l 2.7 5.5 V VCC(UVLO) Undervoltage Threshold on VCC VCC Voltage Falling l 2.325 2.45 2.575 V VCC Voltage Rising l 2.425 2.55 2.675 V IVCC(ALLOFF) VCC Input Supply Current All Switching Regulators in Shutdown 15 25 µA IVCC VCC Input Supply Current One Buck Active PLL/MODE = 0V, RT = 400k, 50 75 µA VFB_BUCK = 0.85V PLL/MODE = 2MHz 175 250 µA fOSC Internal Oscillator Frequency VRT = VCC, PLL/MODE = 0V 1.8 2 2.2 MHz VRT = VCC, PLL/MODE = 0V l 1.75 2 2.25 MHz RT = 400k, PLL/MODE = 0V l 1.8 2 2.2 MHz fPLL/MODE Synchronization Frequency tLOW, tHIGH > 60ns l 1 3 MHz VPLL/MODE PLL/MODE Level High For Synchronization l 1.2 V PLL/MODE Level Low For Synchronization l 0.4 V VRT RT Servo Voltage RT = 400k l 780 800 820 mV
Temp Monitor
VTEMP(ROOM) TEMP Voltage at 25°C 180 220 260 mV ΔVTEMP/°C VTEMP Slope 7 mV/°C OT Overtemperature Shutdown 170 °C OT Hyst Overtemperature Hysteresis 10 °C
1A Buck Regulators
VIN Buck Input Voltage Range l 2.25 5.5 V VOUT Buck Output Voltage Range l VFB VIN V VIN(UVLO) Undervoltage Threshold on VIN VIN Voltage Falling l 1.95 2.05 2.15 V VIN Voltage Rising l 2.05 2.15 2.25 V IVIN Burst Mode Operation Input Current VFB = 0.85V (Note 4) 18 30 µA Forced Continuous Mode Operation Input Current ISW(BUCK) = 0µA, FB = 0V 400 600 µA Shutdown Input Current 0 2.5 µA IFWD PMOS Current Limit (Note 5) 1.9 2.3 2.7 A VFB1 Feedback Regulation Voltage for Buck 1 l 792 800 808 mV VFB Feedback Regulation Voltage for Bucks 2-4 l 780 800 820 mV IFB Feedback Leakage Current VFB = 0.85V –50 50 nA DMAX Maximum Duty Cycle VFB = 0V l 100 % RPMOS PMOS On-Resistance ISW = 100mA 300 mΩ RNMOS NMOS On-Resistance ISW = –100mA 240 mΩ ILEAKP PMOS Leakage Current EN = 0 –2 2 µA ILEAKN NMOS Leakage Current EN = 0 –2 2 µA tSS Soft-Start Time 1 ms VPGOOD(FALL) Falling PGOOD Threshold for Buck 1 % of Regulated VFB 96.8 98 99.2 % Falling PGOOD Threshold for Bucks 2 to 4 % of Regulated VFB 93 95 97 % VPGOOD(HYS) PGOOD Hysteresis for Bucks 1 to 4 % of Regulated VFB 0.3 % 3371fb 4 For more information www.linear.com/LTC3371 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Buck Switching Regulators Buck Regulators with Combined Power Stages Power Failure Reporting Via RST Pins Temperature Monitoring and Overtemperature Protection Programming the Operating Frequency Windowed Watchdog Timer Choosing the CT Capacitor Applications Information Buck Switching Regulator Output Voltage and Feedback Network Buck Regulators Combined Buck Power Stages Input and Output Decoupling Capacitor Selection PCB Considerations Typical Applications Package Description Revision History Typical Application Related Parts