EVALUATION KIT AVAILABLE Click here for production status of specific part numbers. MAX20028 Step-Down Controller with Dual 2.1MHz Step-Down DC-DC Converters General Description Benefits and Features The MAX20028 power-management integrated circuit High-Efficiency Voltage DC-DC Controller Saves Power (PMIC) is a 2.1MHz, multichannel, DC-DC converter 3.5V to 36V Operating Supply Voltage designed for automotive applications. The device inte- Output Voltage: Pin Selectable, Fixed, or Resistor-Divider Adjustable grates three supplies in a small footprint. The device includes one high-voltage step-down controller (OUT1), 350kHz to 2.1MHz Operation 30A Quiescent Current with DC-DC designed to run directly from a car battery, and two low- voltage step-down converters (OUT2/OUT3), cascaded Controller Enabled from OUT1. Under no-load conditions, the MAX20028 Dual 2.1MHz DC-DC Converters with Integrated consumes only 30A of quiescent current, making it ideal FETs Saves Space for automotive applications. OUT2 and OUT3 are Cascaded from OUT1, The high-voltage synchronous step-down DC-DC controller Improving Efficiency 3A Output Current (OUT1) operates from a voltage up to 36V continuous and 0.8V to 3.95V Output Voltage is protected from load-dump transients up to 42V. There is a 25% Lower C and C Compared to the pin-selectable frequency option of either 2.1MHz or a factory- OUT2 OUT3 MAX16993 set frequency for 1.05MHz, 525kHz, 420kHz, or 350kHz. The Fixed or Resistor-Divider-Adjustable Output Voltage low-voltage, synchronous step-down DC-DC converters run 180 Out-of-Phase Operation directly from OUT1 and can supply output currents up to 3A. High Accuracy to Meet ASIL Specification The device provides a spread-spectrum enable input 1% FB Accuracy, 2% Output-Voltage Accuracy, (SSEN) to provide quick improvement in electromagnetic and 0.5% OV/UV Accuracy interference when needed. There is also a SYNC I/O for Excellent Load-Transient Performance providing either an input to synchronize to an external clock source or an output of the internally generated Robust for the Automotive Environment clock (see the Selector Guide for the different options Current-Mode Architecture with Forced-PWM and available). The device includes overtemperature Skip Modes of Operations shutdown and overcurrent limiting. The device also Frequency Synchronization Input/Output Reduces includes individual RESET1 outputs and individual enable System Noise inputs. The individual RESET1 outputs provide voltage Individual Enable Inputs and RESET1 Outputs monitoring for all output channels. Overtemperature and Short-Circuit Protection AECQ-100 Qualified The MAX20028 is available in a 32-pin (5mm x 5mm x 0.75mm) side-wettable TQFN-EP package and is speci- Simplified Schematic fied for operation over the -40C to +125C automotive BATP temperature range. BATP V SUP EN1 VDD EN3 DH1 Applications EN2 BST1 PV Automotive LX1 PV1 BIAS DL1 Industrial ADAS GND CS1 SSEN OUT1 SYNC1 FB1 MODE COMP1 CSEL1 PV 2:3 /4 RESET1, ERR LX2 LX3 OUT3 OUT2 Ordering Information and Selector Guide appear at end of PGND3 PGND2 data sheet. 19-7478 Rev 6 3/20MAX20028 Step-Down Controller with Dual 2.1MHz Step-Down DC-DC Converters Absolute Maximum Ratings V , EN1 to GND ...............................................-0.3V to +45V FB1, EN2, EN3 to GND........................................-0.3V to +6.0V SUP PV to GND............................................................-0.3V to +6.0V RESET , ERR to GND .........................................-0.3V to +6.0V PV1 to GND..........................................................-0.3V to +6.0V CS1 to OUT1 ........................................................-0.3V to +0.3V PV2 to GND, PV2 to PGND2 ...............................-0.3V to +6.0V CSEL1, SYNC, SSEN to GND .............................-0.3V to +6.0V PV3 to GND, PV3 to PGND3 ...............................-0.3V to +6.0V COMP1 to GND............................................. -0.3V to PV + 0.3V PGND2, PGND3 to GND .....................................-0.3V to +0.3V LX2, LX3 Output Short-Circuit Duration ....................Continuous LX1 to GND ...............................................-6.0V to V + 6.0V Continuous Power Dissipation (T = +70C) SUP A BST1 to LX1 .........................................................-0.3V to +6.0V TQFN (derate 34.5mW/C above +70C)...............2758.6mW DH1 to LX1 ...............................................-0.3V to BST1 + 0.3V Operating Temperature Range ..........................-40C to +125C BIAS to GND ........................................................-0.3V to +6.0V Junction Temperature ......................................................+150C DL1 to GND .................................................-0.3V to PV1 + 0.3V Storage Temperature Range .............................-65C to +150C LX2 to PGND2.............................................-0.3V to PV2 + 0.3V Lead Temperature (soldering, 10s) .................................+300C LX3 to PGND3.............................................-0.3V to PV3 + 0.3V Soldering Temperature (reflow) .......................................+260C OUT1OUT3, CS1 to GND ..................................-0.3V to +6.0V 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. Package Thermal Characteristics (Note 1) TQFN Junction-to-Ambient Thermal Resistance ( ) ......... 29C/W JA Junction-to-Case Thermal Resistance ( ) ............ 1.7C/W JC Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. Electrical Characteristics (V = 14V, V = V = V , V = V = V T = T = -40C to +125C, unless otherwise noted. Typical values are at SUP PV PV1 BIAS PV2 PV3 OUT1 A J T = +25C under normal conditions, unless otherwise noted.) (Note 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage Startup V V rising 4.25 4.5 4.75 V SUP,STARTUP SUP Threshold Supply Voltage Range V Normal operation, after Buck 1 startup 3.5 36 V SUP V = V = V = 0V 4 15 EN1 EN2 EN3 Supply Current I A SUP V = 5V, V = V = 0V (no load) 26 60 EN1 EN2 EN3 Oscillator Frequency f 2.0 2.1 2.2 MHz SW SYNC Input Frequency 1.7 2.4 MHz Range BIAS Regulator Voltage V 6V V 42V, no switchover 4.5 5.0 5.5 V BIAS SUP V falling 2.5 2.7 2.9 BIAS PV Power-On Reset V Hysteresis 0.45 Maxim Integrated 2 www.maximintegrated.com