MAX5072 19-3503 Rev 2 2/06 2.2MHz, Dual-Output Buck or Boost Converter with POR and Power-Fail Output General Description Features The MAX5072 is a dual-output DC-DC converter with inte- 4.5V to 5.5V or 5.5V to 23V Input Supply Voltage grated high-side n-channel power MOSFETs. Each output Range can be configured either as a buck converter or a boost 0.8V (Buck) to 28V (Boost) Output Voltage converter. The MAX5072 is designed to manage the power requirements of xDSL modems. The wide 5.5V to Two Independent Output DC-DC Converters with 23V input voltage range allows for the use of inexpensive Internal Power MOSFETs AC adapters to power the device in xDSL modem appli- Each Output can be Configured in Buck or Boost cations. Each output is programmable down to 0.8V in the Mode buck mode and up to 28V in the boost mode with an out- put voltage accuracy of 1%. In the buck mode, convert- I and I of 2A and 1A (Respectively) in OUT1 OUT2 er 1 and converter 2 can deliver 2A and 1A, respectively. Buck Mode The output switching frequency of each converter can be 180 Out-of-Phase Operation programmed from 200kHz to 2.2MHz to avoid harmonics in the xDSL frequency band of operation. Each output Clock Output for Four-Phase Operation operates 180 out-of-phase, thus reducing input-capaci- Switching Frequency Programmable from 200kHz tor ripple current, size, and cost. A SYNC input facilitates to 2.2MHz external frequency synchronization. Moreover, a CLKOUT output provides out-of-phase clock signal with respect to Digital Soft-Start and Independent Converter converter 2, allowing four-phase operation using two Shutdown MAX5072 ICs in master-slave configuration. SYNC Input, Power-On Reset, Manual Reset, And The MAX5072 includes an internal digital soft-start that Power-Fail Output reduces inrush current, eliminates output-voltage over- shoot, and ensures monotonic rise in output voltage dur- Short-Circuit Protection (Buck)/Maximum Duty- ing power-up. The device includes a power-good output Cycle Limit (Boost) and power-on reset as well as manual reset. In addition, Thermal Shutdown each converter output can be shut down individually. The MAX5072 features adying gas output, which goes low Thermally Enhanced 32-Pin Thin QFN Package when the input voltage drops below a preprogrammed Dissipates up to 2.7W at +70C voltage. Protection features include output short-circuit Pin Configuration protection for buck mode and maximum duty-cycle limit for boost operation, as well as thermal shutdown. The MAX5072 is available in a thermally enhanced 32-pin TOP VIEW thin QFN package that can dissipate 2.7W at +70C ambi- ent temperature. The device is rated for operation over the 24 23 22 21 20 19 18 17 -40C to +85C extended, or -40C to +125C automotive temperature range. PGOOD1 25 16 MR Applications SOURCE1 26 15 BYPASS xDSL Modems 27 14 SOURCE1 VL xDSL Routers PGND 28 13 VL Point-of-Load DC-DC Converters MAX5072 SGND 29 12 V+ Ordering Information PGND 30 11 OSC SOURCE2 PFI PKG 31 10 PART TEMP RANGE PIN-PACKAGE CODE SOURCE2 32 9 SYNC 32 Thin QFN-EP* MAX5072ETJ -40C to +85C T3255-4 1234567 8 (5mm x 5mm) *EP = Exposed pad. THIN QFN Ordering Information continued at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE CLKOUT FSEL1 BST2/VDD2 BST1/VDD1 DRAIN2 DRAIN1 DRAIN2 DRAIN1 EN2 EN1 FB2 FB1 COMP2 COMP1 PFO RST2.2MHz, Dual-Output Buck or Boost Converter with POR and Power-Fail Output ABSOLUTE MAXIMUM RATINGS V+ to PGND............................................................-0.3V to +25V SOURCE2, DRAIN2 Peak Current ..............................3A for 1ms SGND to PGND .....................................................-0.3V to +0.3V VL, BYPASS to SGND Short Circuit............................Continuous VL to SGND...................-0.3V to the lower of +6V or (V+ + 0.3V) Continuous Power Dissipation (T = +70C) A BST1/VDD1, BST2/VDD2, DRAIN , PFO, RST, PGOOD1 to 32-Pin Thin QFN (derate 21.3mW/C above +70C).....2758mW* SGND .................................................................-0.3V to +30V Package Junction-to-Case Thermal Resistance (J ).......2C/W C BST1/VDD1 to SOURCE1, Operating Temperature Ranges: BST2/VDD2 to SOURCE2 ....................................-0.3V to +6V MAX5072ETJ (T to T )...........................-40C to +85C MIN MAX SOURCE to SGND................................................-0.6V to +25V MAX5072ATJ (T to T ).........................-40C to +125C MIN MAX EN to SGND ................................................-0.3V to (VL + 0.3V) Junction Temperature......................................................+150C CLKOUT, BYPASS, OSC, FSEL1, COMP1, Storage Temperature Range .............................-65C to +150C COMP2, PFI, MR, SYNC, FB to SGND....-0.3V to (VL + 0.3V) Lead Temperature (soldering, 10s) .................................+300C SOURCE1, DRAIN1 Peak Current ..............................5A for 1ms *As per JEDEC51 standard. 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 (V+ = VL = 5.2V or V+ = 5.5V to 23V, EN = VL, SYNC = GND, I = 0, PGND = SGND, C = 0.22F, C = 4.7F (ceramic), VL BYPASS VL R = 10k (circuit of Figure 1), T = T = T to T , unless otherwise noted.) (Note 1) OSC A J MIN MAX PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SYSTEM SPECIFICATIONS (Note 2) 5.5 23 Input Voltage Range V+ V VL = V+ 4.5 5.5 VL unloaded, no switching, Operating Supply Current I 2.2 1.2 mA Q V = 1V, V+ = 12V, R = 60k FB OSC EN = 0, MR, PFO, and PGOOD floating, 0.6 1.4 V+ = 12V, R = 60k ( MAX5072ETJ) OSC V+ Standby Supply Current I mA STBY EN = 0, MR, PFO, and PGOOD floating, 0.6 1.4 V+ = 12V, R = 60k ( MAX5072ATJ) OSC V+ = VL = 5V 82 V = 3.3V at 1.5A, OUT1 Efficiency V = 2.5V at 0.75A V+ = 12V 80 % OUT2 (f = 1.25MHz) SW V+ = 16V 78 STARTUP/VL REGULATOR VL Undervoltage Lockout Trip UVLO VL falling 3.95 4.1 4.25 V Level VL Undervoltage Lockout 175 mV Hysteresis VL Output Voltage VL V+ = 5.5V to 23V, I = 0 to 40mA 4.9 5.2 5.5 V SOURCE BYPASS OUTPUT I = 0, R = 60k ( MAX5072ETJ) 1.98 2.00 2.02 BYPASS OSC BYPASS Voltage V V BYPASS I = 0, R = 60k ( MAX5072ATJ) 1.975 2.00 2.025 BYPASS OSC BYPASS Load Regulation V 0 I 50A, R = 60k 02 10 mV BYPASS BYPASS OSC SOFT-START f OSC Digital Ramp Period Internal 6-bit DAC 2048 clock cycles Soft-Start Steps 64 steps 2 MAX5072