Synchronous Step Down Controller

www.DataSheet4U.com SiP12202 New Product Vishay Siliconix Synchronous Step Down Controller DESCRIPTION SiP12202 is a synchronous step down controller designed for use in dc-dc converter circuits requiring output currents as high as 10 amperes. SiP12202 is designed to require a minimum number of external components, simplifying design and layout. It accepts input voltages from 2.7 V to 5.5 V, providing an adjustable output with voltage ranging from 0.6 V to 5.5 V. SiP12202 includes a combination Compensation/ Shutdown pin. Protection features include undervoltage lockout, Power Good output, output current limit, and thermal shutdown. SiP12202 is available in a lead (Pb)-free MLP-33-10 package and is specified to operate over the range of - 40 °C to 85 °C. FEATURES • 2.7 V to 5.5 V Input Voltage Range • Adjustable Output Voltage - 0.6 to 5.5 V • For Converter loads up to 10 A • High efficiency - 93% • Uses High Side P-Channel MOSFET • Uses Low Side N-Channel MOSFET • 500 kHz operation • Internal Soft Start • Power Good Indication • Shutdown Pin • Output Current Limit • Minimum External Components • MLP33-10 Package APPLICATIONS • • • • • Distributed Power Desktop & Notebook Computers Battery Operated Equipment Point of Load Regulation DSP Cores TYPICAL APPLICATION CIRCUIT VIN VIN VIN DH LX Power Good Compensation/ Shutdown PG DL COMP/SD VOUT FB AGND P AGNDPGND GND GND Document Number: 73542 S-52083–Rev. A, 10-Oct-05 www.vishay.com 1 SiP12202 Vishay Siliconix ABSOLUTE MAXIMUM RATINGS Parameter VIN, LX to GND FB, PG, Comp/SD to GND Power Dissipationa, b Maximum Junction Temperature Storage Temperature Notes a. Device mounted with all leads soldered or welded to PC board b. Derate 14 mW/°C above + 85 °C Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating/conditions for extended periods may affect device reliability. Limit 6 - 0.3 to 6 560 125 - 55 to + 150 Unit V mW °C New Product RECOMMENDED OPERATING RANGE Parameter Input Voltage Range Output Voltage Adjustment Range Operating Temperature Range Limit 2.7 to 5.5 0.6 to 5.5 - 40 to + 85 Unit V °C SPECIFICATIONS Parameter Controller Input Voltage Quiescent Current Switching Oscillator Frequency Oscillator Ramp Amplitude Feedback Voltage FB input Bias Current Transconductance Soft Start Inputs and Outputs SD Input Voltage Shutdown Current MOSFET Drivers Break-before-make-time Highside Driver Output Voltage On resistance Rise time - PFET Turn On Fall time - PFET Turn Off Lowside Driver Output Voltage On resistance Rise time - NFET Turn On Fall time - NFET Turn Off VDL RDSLH RDSLL trL tfL VIN = 4.5 V VIN = 4.5 V VIN = 5 V, CL = 2.7 nF VIN = 5 V, CL = 2.7 nF 4.5 5.5 0.85 83 6.6 8.2 1.4 V Ω Ω ns VDH RDSHH RDSHL trH tfH VIN = 4.5 V VIN = 4.5 V VIN = 5 V, CL = 2.7 nF VIN = 5 V, CL = 2.7 nF 4.5 1.3 2.8 64 8 1.9 4.4 V Ω Ω ns tBBM 30 ns VIL IIL 30 0.15 60 V µA fOSC ∆VOSC VFB IFB GM 2 4 TA = 25 °C 0.591 0.585 VIN Non Switching 400 2.7 0.6 500 1 0.600 0.609 0.615 100 5.5 1 600 V mA kHz V V nA mA/V ms Symbol Test Condition Unless Specified VIN = 5.0 Limits -40 to 85°C Mina Typb Maxa Unit www.vishay.com 2 Document Number: 73542 S-52083–Rev. A, 10-Oct-05 SiP12202 New Product SPECIFICATIONS Parameter Protection Under voltage lockout UVLO-Hysteresis Power Good PG Output Voltage PG Leakage Current PG Voltage Threshold PG Threshold Hysteresis Over Current Limit Thermal Shutdown Temperature Thermal Hysteresis MOSFET On Voltage Sense Threshold VDL With respect to VIN -335 Rising 165 20 -300 -265 °C °C mV VPGOL IPGOL VETH VEH ISINK = 0.5 mA 70 5 0.4 1 V µA %VOUT %VOUT VUVLO Rising 2.3 2.4 0.10 2.5 V Symbol Test Condition Unless Specified VIN = 5.0 Limits -40 to 85°C Mina Typb Maxa Unit Vishay Siliconix NOTES: a) The algebriac convention whereby the most negative value is a minimum and the most positive a maximum. b) Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing. PIN CONFIGURATION PIN DESCRIPTION Part Number 1 2 3 4 5, 10 6 7 8 9 Name COMP/SD FB AGND PG VIN DL PGND LX DH Feedback input Analog Ground Indicates that the output voltage is in regulation Input voltage for the power MOSFETs and their gate drive Lowside gate drive Power Ground Connection for the inductor node Highside gate drive Function Combination Compensation and Shut down pin ORDERING INFORMATION Part Number SiP12202DM-T1-E3 Eva Kit SiP12202DB Temperature Range -40 to 85 °C Temperature Range -40 to 85 °C Package MLP33-10 Board Surface Mount Document Number: 73542 S-52083–Rev. A, 10-Oct-05 www.vishay.com 3 SiP12202 Vishay Siliconix FUNCTIONAL BLOCK DIAGRAM SiP12202 New Product 0.45 V PG FB Vin Vin UVLO Over Temp Over Voltage DH Soft Start Shut Down Over Current Sense Comp LX FB GM PWM Comp 0.6 V OSC 500KHz ∆Vosc Gate Control Logic BBM Vin DL Pgnd SD/Comp Agnd DETAILED OPERATIONAL DESCRIPTION Enable/ON State: The COMP/SD pin has 10 µA pull up current to ensure auto startup as soon as the pin is released by the external pull down MOS. When the internal reference is ready, there will be a clamp current applied at COMPSD; this is to ensure the COMPSD pin will not go below 600 mV inadvertently due to the amplifier excursion or noise. The COMPSD has to go above 600 mV to enable the chip fully. Disable/Shutdown/Off State To disable the chip, the COMP/SD pin has to pulled below 150 mV typically and the external pull down MOSFET has to be able to sink at least 250 µA. Once the pin reaches a voltage below the 150 mV level, the chip will go into shutdown mode with only essential curcuitry alive and the current bias of the chip will be cut down to 30 µA level typically. Both High Side and Low Side Gates are off. UVLO: The chip enters into Under Voltage Lockout when VIN is below 2.3 V (typical). Both High Side Gate and Low Side Gate will be turned off. The chip will go out of UVLO mode when VIN is above 2.4 V (typical). Soft Start: Once the chip is out of shutdown and UVLO mode the soft start is initiated. The soft start is done accomplished by ramping up the internal reference. During soft start mode the chip can not enter into fault mode. If there is an over current condition (current limit condition), the High Side Gate will be turned off and the Low Side will be turned on. Once the soft start timing elapses, the chip enters into a normal state of operation. Output Over Voltage State: When the Output voltage goes above 1.083 times nominal Output Voltage, the High Side Gate will be turned off and the Low Side Gate will be on. The condition will persist until the Output voltage drops below the trigger voltage minus a hysteresis. Output Over Current State: The SiP12202 will enter a cycle by cycle over current condition when the voltage on the LX pin falls below VIN by 300 mV. During the over current condition the High Side MOSFET is turned off for the duration of the existing cycle. At the beginning of the next cycle the High Side MOSFET turns on and the LX voltage is measured again. If the over current condition still exists, the High Side MOSFET is turned off again. This is repeated seven consecutive times after which the IC will go into a fault state. If the over current condition is removed before seven consecutive cycles the IC reverts to normal operating mode. Document Number: 73542 S-52083–Rev. A, 10-Oct-05 www.vishay.com 4 SiP12202 New Product Fault State: The IC can only enter into Fault mode after the soft start mode has ended and seven consecutive over current condition cycles has occurred. Once it enters the Fault state, with the High Side MOSFET turned off and the Low Side MOSFET turned on, any occurring over current condition will be ignored. The Fault State will last for seven soft start cycles. After which the IC will enter Soft Start mode. If the over current condition is removed the IC will operate normally, otherwise the over current sequence is repeated. This fault scheme minimizes thermal stress on the external power MOSFET switches Over Temperature: When the temperature of the chip goes above 165 °C, the chip enters into over temperature shutdown. The High Side gate will be off and the Low Side gate will be on. Only system monitor circuitry will be active. Once the temperature of the chip drops below 145 °C, the chip enters into the normal operation mode. Power Good: Power Good State: When the output is above 0.75 times nominal output voltage, the PC signal will be high to indicate that the output voltage is available for external use. The PG pin requires a pull up resistor. Setting the Output Voltage: An output voltage between 0.8 V and (0.9 V x VIN) 0.6 V and VIN and can be configured by connecting FB pin to a resistive divider between the output and GND. Select resistor R2 in the 1 kΩ to 10 kΩ range. R1 is then given by: R1 = R2 FREQUENCY (kHz) Vishay Siliconix TYPICAL CHARACTERISTICS 100 95 90 Vout = 3.3 V EFFICIENCY (%) 85 80 75 70 65 60 55 Vout = 2.5 V Vin = 5.0 V 50 0 2 4 6 8 10 LOAD CURRENT (A) EFFICIENCY vs LOAD CURRENT 600 550 Vin = 5.0 V 500 450 Vin = 2.7 V 400 -45 -10 25 60 95 130 TEMPERATURE (°C) OSCILLATOR FREQUENCY Vs TEMPERATURE 0.615 (V V OUT FB −1 ) VOLTAGE ( V) 0.605 Vin = 2.7 V to 5.0 V where VFB = 0.6 V. VOUT 0.595 R1 FB R2 0.585 -45 -10 25 60 95 130 TEMPERATURE (°C) FEEDBACK THRESHOLD Vs TEMPERATURE 0.6 V Document Number: 73542 S-52083–Rev. A, 10-Oct-05 www.vishay.com 5 SiP12202 Vishay Siliconix TYPICAL CHARACTERISTICS -260 New Product 2.5 -280 2.45 Vin = 2.7 V VOLTAGE ( mV) VOLTAGE ( V) 130 -300 Vin = 5.0 V 2.4 -320 2.35 -340 -45 2.3 -10 25 60 95 -45 -10 25 60 95 130 TEMPERATURE (°C) CURRENT SENSE