MAX5099 19-4112 Rev 0 5/08 Dual, 2.2MHz, Automotive Synchronous Buck Converter with 80V Load-Dump Protection General Description Features The MAX5099 offers a dual-output, high-switching-fre- Wide 4.5V to 5.5V or 5.2V to 19V Input Voltage quency DC-DC buck converter with an integrated high- Range with 80V Load-Dump Protection side switch. The MAX5099 integrates two low-side MOSFET drivers to allow each converter to drive an Dual-Output DC-DC Converter with Integrated external synchronous-rectifier MOSFET. Converter 1 Power MOSFETs delivers up to 2A output current, and converter 2 can deliver up to 1A of output current. The MAX5099 inte- Adjustable Outputs from 0.8V to 0.9V IN grates load-dump protection circuitry that is capable of Output Current Capability Up to 2A and 1A handling load-dump transients up to 80V for automotive applications. The load-dump protection circuit utilizes Switching Frequency Programmable from 200kHz an internal charge pump to drive the gate of an external to 2.2MHz n-channel MOSFET. When an overvoltage or load- dump condition occurs, the series protection MOSFET Synchronization Input (SYNC) absorbs the high voltage transient to prevent damage to lower voltage components. Individual Converter Enable Input and Power- The DC-DC converter operates over a wide 4.5V to 19V Good Output operating voltage range. The MAX5099 operates 180 out-of-phase with an adjustable switching frequency to Low-I (7A) Standby Current (ON/OFF) Q minimize external components while allowing the ability Internal Digital Soft-Start and Soft-Stop to make trade-offs between the size, efficiency, and cost. The high switching frequency also allows these Short-Circuit Protection on Outputs and devices to operate outside the AM band for automotive Maximum Duty-Cycle Limit applications. These regulators can be protected against high voltage transients such as a load-dump Overvoltage Protection on Outputs with Auto condition by using the integrated overvoltage controller. Restart This device utilizes voltage-mode control for stable operation and external compensation, so that the loop Thermal Shutdown gain is tailored to optimize component selection and transient response. The MAX5099 has a maximum duty Thermally Enhanced 32-Pin TQFN Package cycle of 92.5% and is synchronized to an external clock Dissipates Up to 2.7W at +70C fed at the SYNC input. Additional features include internal digital soft-start, individual enable for each DC-DC regulator (EN1 and Ordering Information EN2), open-drain power-good outputs (PGOOD1 and PGOOD2), and shutdown input (ON/OFF). PART TEMP RANGE PIN-PACKAGE -40C to +125C Other features of the MAX5099 include overvoltage pro- MAX5099ATJ+ 32 TQFN-EP* tection and short-circuit (hiccup current limit) and ther- +Denotes a lead-free package. mal protection. The MAX5099 is available in a thermally *EP = Exposed pad. enhanced, exposed pad 5mm x 5mm, 32-pin TQFN package and operates over the automotive -40C to +125C temperature range. Applications Automotive AM/FM Radio Power Supply Pin Configuration appears at end of data sheet. Automotive Instrument Cluster Display Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLEDual, 2.2MHz, Automotive Synchronous Buck Converter with 80V Load-Dump Protection ABSOLUTE MAXIMUM RATINGS V+ to SGND............................................................-0.3V to +25V OSC, FSEL 1, COMP , SYNC, V+ to IN HIGH...........................................................-19V to +6V FB to SGND..............................................-0.3V to (V + 0.3V) L IN HIGH to SGND..................................................-0.3V to +19V DL to PGND ...........................................-0.3V to (VDRV + 0.3V) IN HIGH Maximum Input Current.......................................60mA SOURCE1, DRAIN1 Peak Current ..............................5A for 1ms BYPASS to SGND..................................................-0.3V to +2.5V SOURCE2, DRAIN2 Peak Current ..............................3A for 1ms GATE to V+.............................................................-0.3V to +12V V , BYPASS to L GATE to SGND.......................................................-0.3V to +36V SGND Short Circuit................... Continuous, Internally Limited SGND to PGND .....................................................-0.3V to +0.3V Continuous Power Dissipation (T = +70C) A V to SGND..................-0.3V to the Lower of +6V or (V+ + 0.3V) 32-Pin TQFN-EP (derate 34.5mW/C above +70C)..2759mW L VDRV to SGND.........................................................-0.3V to +6V Package Junction-to-Ambient BST1/VDD1, BST2/VDD2, DRAIN , Thermal Resistance ( ) (Note 1).............................29.0C/W JA PGOOD to SGND ..............................................-0.3V to +30V Package Junction-to-Case ON/OFF to SGND ...............................-0.3V to (IN HIGH + 0.3V) Thermal Resistance ( ) (Note 1) ..............................1.7C/W JC BST1/VDD1 to SOURCE1, Operating Temperature Range .........................-40C to +125C BST2/VDD2 to SOURCE2......................................-0.3V to +6V Storage Temperature Range ............................-65C to +150C SOURCE to SGND................................................-0.6V to +25V Junction Temperature......................................................+150C EN to SGND............................................................-0.3V to +6V Lead Temperature (soldering, 10s) ................................+300C Note 1: Package thermal resistances were obtained using the method described in JEDEC specifications. For detailed information on package thermal considerations refer to www.maxim-ic.com/thermal-tutorial. 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. ELECTRICAL CHARACTERISTICS (VDRV = V , V+ = V = IN HIGH = 5.2V or V+ = IN HIGH = 5.2V to 19V, EN = V , SYNC = GND, I = 0mA, PGND = SGND, L L L VL C = 0.22F (low ESR), C = 4.7F (ceramic), C = 1F (low ESR), C = 1F (ceramic), R = 3.9k, R = 10k, BYPASS VL V+ IN HIGH IN HIGH OSC T = -40C to +125C, unless otherwise noted.) (Note 2) J PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SYSTEM SPECIFICATIONS V+ = IN HIGH 5.2 19 Input Voltage Range V+ V V = V+ = IN HIGH, Figure 6 (Note 3) 4.5 5.5 L V+ Operating Supply Current I V unloaded, no switching, V = 1V 4.2 6.0 mA Q L FB V = 0V, PGOOD unconnected, EN V+ Standby Supply Current I 0.75 1.1 mA V+STBY V+ = V = 14V IN HIGH V+ = V = 5.2V 86 L V = 5V at 1.5A, OUT1 Efficiency % V = 3.3V at 0.75A, V+ = 12V 85 OUT2 f = 300kHz SW V+ = 16V 85 OVERVOLTAGE PROTECTOR IN HIGH Clamp Voltage IN HIGH I = 10mA 19 20 21 V SINK IN HIGH Clamp Load 1mA < I < 50mA 160 mV SINK Regulation V = V = V = 0V, EN PGOOD GATE IN HIGH Supply Current I 270 600 A IN HIGH V = V = 14V IN HIGH ON/OFF IN HIGH Standby Supply V = 0V, V = V + = ON/OFF PGOOD I 79 A IN HIGHSTBY Current unconnected, V = 14V IN HIGH V+ to IN HIGH Overvoltage V V = V+ - V , I = -1mA 1.20 1.85 2.50 V OV OV IN HIGH GATE Clamp 2 MAX5099