Datasheet LTC3375 (Analog Devices) - 4

LTC3375
e lecTrical characTerisTics The
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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
VVCC VCC Voltage Range l 2.7 5.5 V VVCC_UVLO Undervoltage Threshold on VCC VCC Voltage Falling l 2.35 2.45 2.55 V VCC Voltage Rising l 2.45 2.55 2.65 V IVCC_ALLOFF VCC Input Supply Current All Switching Regulators in Shutdown, 11 25 µA PB = HIGH IVCC VCC Input Supply Current At Least 1 Buck Active, SYNC = 0V, RT = 400k, 50 85 µA VFB_BUCK = 0.85V At Least 1 Buck Active, SYNC = 2MHz 200 325 µA fOSC Internal Oscillator Frequency VRT = VCC, SYNC = 0V 1.8 2 2.2 MHz VRT = VCC, SYNC = 0V l 1.75 2 2.25 MHz RRT = 400k, SYNC = 0V l 1.8 2 2.2 MHz fSYNC Synchronization Frequency tLOW, tHIGH > 40ns 1 3 MHz VSYNC SYNC Level High l 1.2 V SYNC Level Low l 0.4 V VRT RT Servo Voltage RRT = 400k l 780 800 820 mV
Temperature Monitor
VTEMP(ROOM) TEMP Voltage at 25°C 150 mV ∆VTEMP/°C VTEMP Slope l 6.75 mV/°C OT Overtemperature Shutdown Temperature Rising 165 °C OT_HYST Overtemperature Hysteresis 10 °C DT_WARN Die Temperature Warning Threshold (Die DT[1], DT[0] = 00 Inactive Temperature that Causes IRQ = 0) DT[1], DT[0] = 01 140 °C DT[1], DT[0] = 10 125 °C DT[1], DT[0] = 11 110 °C
1A Buck Regulators
VBUCK Buck Input Voltage Range l 2.25 5.5 V VOUT 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_BUCK Burst Mode® Operation VFB_BUCK = 0.85V (Note 4) 18 50 µA Forced Continuous Mode Operation ISW_BUCK = 0µA, VFB_BUCK = 0V 400 550 µA Shutdown Input Current All Switching Regulators in Shutdown 0 1 µA Shutdown Input Current At Least One Other Buck Active 1 2 µA IFWD PMOS Current Limit (Note 5) 2.0 2.3 2.7 A VFB (Default) Feedback Regulation Voltage Forced Continuous Mode Default (1, 1, 0, 0) l 705 725 745 mV VFB (High) Feedback Regulation Voltage Forced Continuous Mode Full Scale (1, 1, 1, 1) l 780 800 820 mV VFB (Low) Feedback Regulation Voltage Forced Continuous Mode Zero Scale (0, 0, 0, 0) l 405 425 445 mV VLSB VFB Servo Voltage Step Size 25 mV IFB Feedback Leakage Current VFB_BUCK = 0.85V –50 50 nA DMAX Maximum Duty Cycle VFB_BUCK = 0V l 100 % RPMOS PMOS On-Resistance ISW_BUCK = 100mA 335 mΩ RNMOS NMOS On-Resistance ISW_BUCK = –100mA 315 mΩ ILEAKP PMOS Leakage Current EN_BUCK = 0 –2 2 µA ILEAKN NMOS Leakage Current EN_BUCK = 0 –2 2 µA RSWPD Output Pull-Down Resistance in Shutdown EN_BUCK = 0 (I2C Bit Set) 1 kΩ tSS Soft-Start Time Default (1, 1, 0, 0) Reference Voltage 1 ms 3375fd 4 For more information www.linear.com/3375 Document Outline Features Applications Description Typical Application Table of Contents Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Buck Switching Regulators Buck Regulators with Combined Power Stages Pushbutton Interface Power-Up and Power-Down Via Pushbutton Power-Up and Power-Down Via Enable Pin or I2C I2C Interface I2C Bus Speed I2C Start and Stop Conditions I2C Byte Format I2C Acknowledge I2C Slave Address I2C Sub-Addressed Writing I2C Bus Write Operation I2C Bus Read Operation Error Condition Reporting Via RST and IRQ Pins Temperature Monitoring and Overtemperature Protection RESET_ALL Functionality Programming the Operating Frequency VCC Shunt Regulator Watchdog Timer Applications Information Buck Switching Regulator Output Voltage and Feedback Network Buck Regulators Combined Buck Regulators VCC Shunt Regulator Input and Output Decoupling Capacitor Selection Choosing the CT Capacitor Programming the Global Register Programming the RST and IRQ Mask Registers Status Byte Read Back Typical Applications Package Description Typical Application Related Parts