3X3MLPQ-16

LX2750 SINGLE INPUT SUPPLY PWM CONTROLLER WITH LDO CONTROLLER PRODUCTION DATA SHEET Pb Free Product DESCRIPTION The LX2750 controller IC is a compact synchronous Buck controller IC with 16 lead MLPQ package designed for step-down DC to DC converter applications. Selectable feedforward voltage mode control or constant on time control provides fast dynamic response. Selectable diode emulation mode greatly improves the light load efficiency. The LX2750 controller is optimized to convert single supply 12V bus voltage to as low as 0.8V output voltage. An internal regulator converts bus voltage to 5V, which provides voltage supply to internal logic and driver circuit. The LX2750 employs programmable loss-less current limiting by sensing the Rdson of synchronous MOSFET followed by hiccup feature. Feedback under voltage also triggers hiccup. Internal UVLO keeps the controller off until the bus supply voltage exceeds 9V where internal digital soft starts get initiated to ramp up output. The LX2750 employs NMOS LDO controller. Other features include: 5V gate drive for HDRV signal, 12V gate drive for LDRV signal, programmable frequency, adaptive deadband control. n n FEATURES Single Input 12V Bus Voltage Excellent Dynamic Response with Selectable Feedforward Voltage Mode Control or Constant On Time Control Diode Emulation Mode Available Programmable Switching Frequency Up to 2MHz Internal Digital Soft Start Function Programmable Over Current Protection Triggers Hiccup NMOS LDO Controller Available FB UVLO Followed by Hiccup Feature in Both Controllers 5V High Side Driver and 12 V Low Side Driver Pb-free and RoHS Compliant n n n n n n n n n n n n APPLICATIONS Graphic Card on Board Converters On Board DC to DC such as 12V to 3.3V, 2.5V or 1.8V Set Top Box and LCD Display ASIC Power Supplies TYPICAL APPLICATION VIN1 +12V 15 7 VIN 10 BST VCC HDRV 14 SW 13 12 Connected to 5VREG Voltage mode Connected to GND Constant on time mode Connected to 5VREG synchronous mode Connected to GND Diode emulation mode VOUT1 +1.8V@8A PGOOD 9 FCCM 16 RT LX2750 8 MODE LDRV 11 2 FB COMP 6 VREF_OC LDO_DRV 1 3 5 REFIN GPIO 17 GND(PAD) LDO_FB 4 VOUT2 +1.1V Figure1 - Typical application of LX2750 ORDERING INFORMATION Device LX2750CLQ Temperature 0 to 70o C Package 3X3 MLPQ-16L Frequency 200kHz to 2MHz Pb-Free Yes Note: Available in Tape & Reel. Append the letters "TR" to the part number. (i.e. LX2750CLQ-TR) Rev. 1.0a 07/14/10 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 1 LX2750 ABSOLUTE MAXIMUM RATINGS 5VREG to GND & BST to SW voltage ................ -0.3V to 6V VIN, LDO_DRV to GND ...................................... -0.3V to 16V BST,HDRV to GND Voltage .............................. -0.3V to 21V SW to GND ....................................................... -2V to 16V LDRV to GND .................................................... -0.3V to VIN+0.3V All other pins ..................................................... -0.3V to VCC+0.3V Storage Temperature Range ............................... -65oC to 150oC Operating Junction Temperature Range ...............-40oC to 125oC ESD Susceptibility .............................................. 1000V CAUTION: Stresses above those listed in "ABSOLUTE MAXIMUM RATINGS", may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. PACKAGE INFORMATION 3x3 16-LEAD PLASTIC MLPQ θ JA ≈ 46o C/W SW 13 12 PGOOD 17 GND 11 LDRV 10 VCC 9 FCCM 5 REFIN 6 VREF_OC 7 VIN 8 MODE SYM VREF VIN from 10V to 16V Vin No switching,COMP=0.8V Switching with HDRV and LDRV open,COMP=1.8V 16 COMP 1 FB 2 15 14 LDO_DRV 3 LDO_FB 4 ELECTRICAL SPECIFICATIONS Unless otherwise specified, these specifications apply over VIN=12V and TA = 0 to 70oC. Typical values refer to TA = 25oC. PARAMETER REFOUT_OC Voltage REFOUT_OC Voltage Accuracy Supply Voltage(Vin) Vin V oltage Range Input Voltage Current(Static) Input Voltage Current (Dynamic) Rev. 1.0a 07/14/10 HDRV BST RT Test Condition Min 2 .45 -0.3 10 TYP 2.5 MAX 2.55 0.3 16 Units V % V mA mA 7 9 Microsemi Analog Mixed Signal Group 11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570 2 LX2750 PARAMET ER VIN UVL O V in-Threshold V in-Hysteresis 5V REG 5VREG Output 5VREG Max Current SS Soft Start time Oscillator (Rt) Frequency Ramp-feedforward gain Ramp Offset Max Duty Cycle Min Off Tim e Min Controlable On Time Rt Disable threshold Error Amplifiers Open Loop Gain (Note1) Gain Bandwidth (Note1) Input Bias Current Max Sourcing Current Max Sinking Current COMP High Voltage COMP Low Voltage SW zero cross comparator Offset voltage High Side Driver N Output Impedance , Sourcing Current (Note1) Output Impedance , Sinking Current (Note1) Low Side Driver Output Impedance, Sourcing Current (Note1) SYM V in_UVLO V in_Hyst Test Condition Vin Rising Vin Falling No switching Min TYP 9 8 5.4 50 5.2 1.3 MAX Units V V V mA mS mS 30 Tss_pwm Tss_con FS V RAMP F S=300kHz F S=350kHz,MODE=5V F S=350kHz,MODE=0V Rt=110k,MODE=5V 245 300 0.1 1 80 560 200 0.3 80 10 1 3 0.4 4.4 0.1 -2 359 kHz V/V V % nS nS V dB MHz nA mA mA V V mV ohm ohm Ib FB=0.7V, comp>=3V FB=0.9V,com p8V LDOFB=0.9V, LDODRV