Datasheet LTC3374A (Analog Devices) - 3

LTC3374A
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 = VIN1-8 = 3.3V, unless otherwise specified. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VCC VCC Voltage Range l 2.7 5.5 V Undervoltage Lockout (UVLO) VCC Voltage Falling l 2.35 2.45 2.55 V Threshold on VCC VCC Voltage Rising l 2.45 2.55 2.65 V ICC VCC Input Supply Current All Switching Regulators in Shutdown 0 1 µA One or More Bucks Active SYNC = 0V, All Enabled Bucks Sleeping 45 75 µA One Buck Enabled, Not Sleeping, SYNC = 0V 155 230 µA All Bucks Enabled, Not Sleeping, SYNC = 2MHz 200 300 µA fOSC Internal Oscillator Frequency VRT = VCC, SYNC = 0V 1.9 2 2.1 MHz VRT = VCC, SYNC = 0V l 1.75 2 2.25 MHz RT = 400k, SYNC = 0V l 1.85 2 2.15 MHz Synchronization Frequency tLOW, tHIGH > 40ns l 1 3 MHz VSYNC SYNC Level High l 1.2 V SYNC Level Low l 0.4 V VRT RT Servo Voltage RT = 400k l 780 800 820 mV
1A Buck Regulators
VIN Buck Input Voltage Range l 2.25 5.5 V Undervoltage Lockout (UVLO) VIN Voltage Falling l 1.95 2.05 2.15 V Threshold on VIN VIN Voltage Rising l 2.05 2.15 2.25 V VOUT Buck Output Voltage Range l VFB VIN V IVIN Shutdown Input Current 0 2 µA Burst Mode® Operation Buck in Regulation, Sleeping 20.5 35 µA Burst Mode Operation Buck in Regulation, Not Sleeping, ISW = 0µA (Note 4) 400 550 µA Forced Continuous Mode Operation ISW = 0µA, VFB = 0V (Note 4) 400 550 µA ILIM PMOS Current Limit 1 Buck Converter (Note 5) 1.4 1.8 2.2 A 2 Buck Converters Combined (Note 5) 3.6 A 3 Buck Converters Combined (Note 5) 5.4 A 4 Buck Converters Combined (Note 5) 7.2 A VFB1 Feedback Regulation Voltage Buck 1 796 800 804 mV Buck 1 l 792 800 808 mV VFB2-8 Feedback Regulation Voltage Bucks 2 to 8 l 784 800 816 mV Feedback Pin Leakage Current –50 0 50 nA Maximum Duty Cycle VFB = 0V l 100 % RPMOS PMOS On-Resistance ISW = 100mA, VIN = 5.0V 205 mΩ ISW = 100mA, VIN = 3.3V 245 mΩ RNMOS NMOS On-Resistance ISW = 100mA, VIN = 5.0V 125 mΩ ISW = 100mA, VIN = 3.3V 135 mΩ PMOS Leakage Current EN = 0 –100 0 100 nA NMOS Leakage Current EN = 0 –100 0 100 nA Soft-Start Time (Note 6) l 0.25 1.3 3 ms Rising PGOOD Threshold Voltage Buck 1, as a Percentage of the Regulated VOUT l 97 98 99 % Bucks 2 to 8, as a Percentage of the Regulated VOUT l 94 95 96 % PGOOD Hysteresis As a Percentage of the Regulated VOUT 0.5 1 1.5 % Overvoltage Indication As a Percentage of the Regulated VOUT l 106 107.5 109 % Overvoltage Hysteresis As a Percentage of the Regulated VOUT 2 3 4 % 3374af For more information www.linear.com/LTC3374A 3 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information (http://www.linear.com/product/LTC3374A#orderinfo) Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Buck Switching Regulators Buck Regulators with Combined Power Stages Power Failure Reporting Via PGOOD_ALL Pin Temperature Monitoring and Overtemperature Protection Programming the Operating Frequency Applications Information Buck Switching Regulator Output Voltage and Feedback Network Input and Output Decoupling Capacitor Selection Combined Buck Regulators Buck Regulators PCB Considerations Package Description Typical Application Related Parts