MAX20012B

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Technical content

The MAX20012B is a dual-output, high-efficiency synchronous step-down controller IC that operates with a 3.0V to 5.5V input voltage range and provides a 0.5V to 1.5875V output voltage range. The controller architecture enables up to 12A of load current per phase. Channel one has an option to operate with two phases to deliver higher load current, making this device ideal for automotive point- of-load (PoL) and post-regulation applications. The IC achieves ±2% output error over load, line, and temperature ranges. The IC features a 2.2MHz fixed-frequency PWM mode for better noise immunity and load-transient response, and a pulse-frequency modulation mode (skip) for increased efficiency during light-load operation. The 2.2MHz frequency operation allows the use of all-ceramic capacitors and minimizes external components. The programmable spread-spectrum frequency modulation minimizes radiated electromagnetic emissions. The MAX20012B is offered with factory-preset output voltages (see the Selector Guide for options). The I interface supports dynamic voltage adjustment with pro - grammable slew rates for each channel. Other features include programmable soft-start, overcurrent, and over- temperature protections.

Applications

• Automotive Benefits and Features
• 2-Channel High-Efficiency DC-DC Controller in a Small Solution Size
• 3.0V to 5.5V Operating Supply Voltage
• OUT1 Supports 24A (with Two Phases)
• OUT2 Supports 12A
• High-Precision Regulator for Applications Processors
• ±2% Output-Voltage Accuracy
• Differential Remote Voltage Sensing
• I2C-Controlled Output Voltage: 0.5V to 1.27V in 10mV Steps
• 0.625V to 1.5875V in 12.5mV Steps
• Excellent Load-Transient Performance
• Low-Noise Features Reduce EMI
• 2.2MHz Operation
• Spread-Spectrum Option
• Frequency-Synchronization Input/Output
• Current-Mode, Forced-PWM, and Skip Operation
• Robust for the Automotive Environment
• Individual Enable Inputs and PGOOD Outputs
• Low RDS(ON) External FETs
• Overtemperature and Short-Circuit Protection
• 32-Pin (5mm x 5mm) TQFN with Exposed Pad
• -40°C to +125°C Operating Temperature Range
• AECQ-100 Qualified Ordering Information appears at end of data sheet. 19-100151; Rev 8; 8/19 MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller EVALUATION KIT AVAILABLE Click here for production status of specific part numbers.

PV1, PV2 CS1- EN1, EN2 CS1+ DH1 MAX20012B PG1, PG2 SYNC GND RS1+ SCL, SDA PGND1, PGND2 PV 0.1µH, 3.6mΩ BST1 LX1 VOUT1 3x 10µF 5.36kΩ 2.49kΩ 10nF RS1- 4x 47μF DL2 CS2- CS2+ DH2 RS2+ BST2 LX2 VOUT2 3x 10µF 5.36kΩ 2.49kΩ 10nF RS2- 4x 47μF VSUP VSUP MAX15492 GND VDD PWM SKIP BST DH LX DL PWM1X 0.1μF VSUP 2.49kΩ 5.36kΩ 10nF VOUT1 CS1X+ OPTIONAL 2ND PHASE 1μF 1kΩ 1μF 1kΩ VSUP VSUP 0.1μF 0.1μF 3x 10µF 0.1µH, 3.6mΩ 0.1µH, 3.6mΩ 2x 47µF MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 2 Typical Operating Circuit MAXIM INTEGRATED CONFIDENTIAL/DISTRIBUTE ONLY UNDER NDA

Continuous Power Dissipation (TA = +70°C) (Multilayer Board)

Electrical Characteristics

(VPV = VPV_ = 5V, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C under normal conditions, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage Range VIN_ Fully operational 3.0 5.5 V Undervoltage Lockout (UVLO) Rising 2.9 3 V Falling 2.6 2.7 UVLO Hysteresis 200 mV Supply Current (Skip Mode) IIN_ EN1 = high, EN2 = low, VCS1X+ = VPV_, VCS1 = 0V (Note 2) 570 µAEN1 = EN2 = high, VCS1X+ = VPV_, VCS1 = VCS2 = 0V (Note 2) 1100 Shutdown Supply Current ISHDN EN1 = EN2 = low 5 10 µA PACKAGE TYPE: 32-PIN TQFN Package Code T3255+6 Outline Number 21-0140 Land Pattern Number 90-0603 PACKAGE TYPE: 32-PIN SW TQFN Package Code T3255Y+6 Outline Number 21-100041 Land Pattern Number 90-100066 THERMAL RESISTANCE, FOUR-LAYER BOARD: Junction to Ambient (θ JA) 36°C/W Junction to Case (θJC) 3°C/W MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 3 Absolute Maximum Ratings 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. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.

Package Information

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Electrical Characteristics (continued) (VPV = VPV_ = 5V, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C under normal conditions, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS PWM Switching Frequency fSW Internally generated 2.0 2.2 2.4 MHz Spread Spectrum Δf/f CONFIG.SS = 1 +3 % Voltage Accuracy VOUT VCS_ = 0mV to 50mV, 3.0V ≤ VPV_ ≤ 5.5V (Note 2) 0.80V to 1.5875V -2 +2 % 0.50V to 0.79V -15 +15 mV High-Side Output-Drive Resistance Rising 1.5 Ω Falling 0.7 Low-Side Output-Drive Resistance Rising 0.7 Ω Falling 0.3 Peak Current-Limit Threshold VLIM Measured across VCS (Note 2) 60 mV Skip Current Threshold VSKIP Measured across VCS (Note 2 12 mV Maximum Duty Cycle PWM mode 90 99 % Minimum On-Time 35 ns LX_ Leakage Current VPV = VPV_ = 6V, LX_ = PGND_ or PV_, TA = +25°C 0.1 µA OUT2 Phase Shift (Note 3) 180 Degrees CS_- Pulldown Resistance VEN_ = 0V 5 Ω THERMAL OVERLOAD Thermal-Shutdown Temperature TJ rising 165 °C Hysteresis 15 °C POWER GOOD PG_ Overvoltage (OV) Threshold (Rising) Percentage of nominal output, blanked during slewing 0.5V < VOUT < 0.79V 105 108 111 0.8V < VOUT < 1.5875V 106 108 110 PG_ Undervoltage (UV) Threshold (Falling) Percentage of nominal output, blanked during slewing 0.5V < VOUT < 0.79V 89 92 95 0.8V < VOUT < 1.5875V 90 92 94 Active Timeout Period 256 Clocks UV/OV Propagation Delay 5 µs PG_ Output High Leakage Current TA = +25°C 1 µA PG_ Output Low Level 3.0V ≤ VPV_ ≤ 5.5V, sinking 2mA 0.2 V MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 4 MAXIM INTEGRATED CONFIDENTIAL/DISTRIBUTE ONLY UNDER NDA

Note 1: All units are 100% production tested at +25°C. All temperature limits are guaranteed by design. Note 2: V CS_ = (VCS_+) - (VCS_-). Note 3: Specifications are guaranteed by design, not production tested. Electrical Characteristics (continued) (VPV = VPV_ = 5V, TA = TJ = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C under normal conditions, unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DIGITAL INPUTS (EN_, ADDR) Input High Level VIH 1.5 V Input Low Level VIL 0.5 V Input Hysteresis 0.1 V Input Leakage Current 0V ≤ VPV ≤ 5.5V, TA = +25°C 1 μA Enable Time Rising EN_ to first rising DH_ 140 μs PWM1X Output Low VOL ISINK = 3mA 0.4 V Output High VOH VPV_ = VPV = 5.0V, ISOURCE = 3mA 4.2 V DIGITAL INPUT (SYNC) Input High Level VIH 1.8 V Input Low Level VIL 0.4 V Input Hysteresis 0.1 V Input Pulldown 100 kΩ Input Frequency Range 1.8 2.6 MHz SYNC OUTPUT (CONFIG.SO[1:0] = 10) Output Low VOL ISINK = 3mA 0.4 V Output High VOH VPV_ = VPV = 5.0V, ISOURCE = 3mA 4.2 V DIGITAL INPUTS (SDA, SCL) Input High Level VIH_I2C 1.2 V Input Low Level VIL_I2C 0.5 V Input Hysteresis 0.1 V Input Leakage Current 0V ≤ VPV ≤ 5.5V, TA = +25°C 1 µA I2C INTERFACE Clock Frequency fSCL 1 MHz Setup Time (Repeated) START tSU:STA (Note 3) 160 ns Hold Time (Repeated) START tHD:STA (Note 3) 160 ns SCL Low Time tLOW (Note 3) 160 ns SCL High Time tHIGH (Note 3) 60 ns Data Setup Time tSU:DAT (Note 3) 50 ns Data Hold Time tHD:DAT (Note 3) 0 70 ns Setup Time for STOP Condition tSU:STO (Note 3) 160 ns Spike Suppression 20 ns SDA Output Low VOL_SDA ISINK = 13mA 0.4 V MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 5 MAXIM INTEGRATED CONFIDENTIAL/DISTRIBUTE ONLY UNDER NDA

(TA = +25°C, unless otherwise noted.) 100 200 300 400 500 600 700 INPUT CURRENT (μA) INPUT VOLTAGE (V) SUPPLY CURRENT vs. INPUT VOLTAGE (SKIP), EN1 = 1 toc04 CONFIG BIT3 = 0 ILOAD = 0A EN1 = 1, EN2 = 0 100 0.001 0.01 0.1 1 10 100 EFFICIENCY (%) LOAD CURRENT (A) PWM OUT1 EFFICIENCY vs. LOAD CURRENT toc01 SKIP VIN = 5V 50mV/div (AC- COUPLED) 8.8A toc06 20μs/div VOUT OUT1 DUAL MODE LOAD-TRANSIENT RESPONSE (PWM) ILOAD -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 0 1 2 3 4 5 6 7 8 9 10 11 12 REGULATION (%) LOAD CURRENT (A) OUT1 LOAD REGULATION (PWM) VIN = 5V VOUT = 0.98V toc02 TA = +25°CTA = +125°C TA = -40°C -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 REGULATION (%) INPUT VOLTAGE (V) OUT1 LINE REGULATION (PWM) VOUT = 0.98V NO LOAD toc03 TA = +125°C TA = +25°C TA = -40°C 100 200 300 400 500 600 700 800 -40 -25 -10 5 20 35 50 65 80 95 110 125 INPUT CURRENT (μA) TEMPERATURE (°C) SUPPLY CURRENT vs. TEMPERATURE (SKIP), EN = 1 toc05 CONFIG BIT3 = 0 VIN = 5V ILOAD = 0A EN1 = 1, EN2 = 0 5V/div 5V/div toc07 40μs/div VOUT1 OUT1 0.1ΩLOAD STARTUP BEHAVIOR VEN1 VLX1 500mV/div 5V/div 200mV/div toc08 20μs/div VLX1 OUT1 DUAL MODE 0.2ΩLOAD STARTUP BEHAVIOR ILX1 VOUT1 2A/div MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller Maxim Integrated │ 6 www.maximintegrated.com Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.) -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 REGULATION (%) INPUT VOLTAGE (V) OUT2 LINE REGULATION (PWM) VOUT = 0.95V NO LOAD toc12 TA = +125°C TA = +25°C TA = -40°C 200mV/div 5A/div toc09 200μs/div VOUT1 OUT1 DUAL MODE SHUTDOWN (NO LOAD) VLX1 ILX1 5V/div VPG1 5V/div 50mV/div (AC- COUPLED) 8.5A toc15 10μs/div VOUT OUT2 LOAD-TRANSIENT RESPONSE (PWM) ILOAD 100 0.001 0.01 0.1 1 10 100 EFFICIENCY (%) LOAD CURRENT (A) PWM OUT2 EFFICIENCY vs. LOAD CURRENT (VOUT = 0.95V) toc10 SKIP VIN = 5V 10V/div 200mV/div toc16 40μs/div VLX2 OUT2 0.2ΩLOAD STARTUP BEHAVIOR VOUT2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0 0 1 2 3 4 5 6 7 8 9 10 11 12 REGULATION (%) LOAD CURRENT (A) OUT2 LOAD REGULATION (PWM) VIN = 5V VOUT = 0.95V toc11 TA = +125°C TA = +25°C TA = -40°C 500 600 700 800 900 1000 1100 1200 1300 1400 1500 INPUT CURRENT (μA) INPUT VOLTAGE (V) SUPPLY CURRENT vs. INPUT VOLTAGE (SKIP), EN1 = EN2 = 1toc13 CONFIG BIT3 = 0 ILOAD = 0A EN1 = 1, EN2 = 1 200 400 600 800 1000 1200 1400 -40 -25 -10 5 20 35 50 65 80 95 110 125 INPUT CURRENT (μA) TEMPERATURE (°C) SUPPLY CURRENT vs. TEMPERATURE (SKIP), EN1 = EN2 = 1 toc14 CONFIG BIT3 = 0 VIN = 5V ILOAD = 0A EN1 = 1, EN2 = 1 MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller Maxim Integrated │ 7 www.maximintegrated.com

(TA = +25°C, unless otherwise noted.) 2.00 2.05 2.10 2.15 2.20 2.25 2.30 2.35 2.40 -40 -25 -10 5 20 35 50 65 80 95 110 125 fSW (MHz) TEMPERATURE (°C) SWITCHING FREQUENCY vs. TEMPERATURE toc17 VIN = 5V CONFIG BIT3 = 1 NO LOAD 2V/div 500mV/div toc20 1ms/div VOUT SHORT CIRCUIT (PWM MODE) VPG VLX 5V/div 200mV/div toc19 200μs/div VOUT OUT2 SHUTDOWN (NO LOAD) VLX 5V/div VPG 5V/div 2V/div 2V/div toc22 400ns/div VLX SYNC FUNCTION (INPUT), SO = 00b VSYNC ILX 2A/div 2.10 2.12 2.14 2.16 2.18 2.20 2.22 2.24 2.26 2.28 2.30 0 1 2 3 4 5 6 7 8 9 10 11 12 fSW (MHz) LOAD CURRENT (A) SWITCHING FREQUENCY vs. LOAD CURRENT toc18 VIN = 5V CONFIG BIT3 = 1 2V/div 2V/div toc21 200ns/div VLX SYNC FUNCTION (OUTPUT), SO = 10b VSYNC ILX 5A/div 200mV/div toc23 40μs/div VOUT DVS RISING 0.8V TO 1.18V (0.1ΩLOAD) VLX 5V/div 200mV/div toc24 100μs/div VOUT DVS FALLING 1.18V TO 0.8V (0.1ΩLOAD) VLX 5V/div MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller Maxim Integrated │ 8 www.maximintegrated.com Typical Operating Characteristics MAXIM INTEGRATED CONFIDENTIAL/DISTRIBUTE ONLY UNDER NDA

(5mm x 5mm) TOP VIEW DL2 DH2 LX2 EN2 DH1 PV1 DL1 LX1 SDA SCL CS1X+ ADDR PWM1X SYNC BST2 BST1 PV EN1 GND 1718192021 54321 PV2 CS2- RS2- RS2+ 876 RS1+ RS1- CS1- 222324 PG1 CS1+ PGND1 CS2+ PGND2 PG2 10EP = GND PIN NAME FUNCTION

1 GND Analog Ground

2 PV Analog Input Supply. Connect a 1µF ceramic capacitor from PV to GND. Connect PV to PV1 and PV2 through a 10Ω resistor.

3 SDA I2C Data I/O

4 SCL I2C Clock Input

5 EN2 Active-High Digital Enable Input for DCDC2. Drive EN2 high for normal operation. Connect EN2 to GND if DCDC2 is not used.

6 RS2- DCDC2 Remote Voltage-Sense Negative Input

7 RS2+ DCDC2 Remote Voltage-Sense Positive Input

8 CS2- Current-Sense Negative Input for DCDC2. Connect CS2- to the negative side of the current-sense element. 9 CS2+ Current-Sense Positive Input for DCDC2. Connect CS2+ to the positive side of the current-sense element. See the Current-Limit/Short-Circuit Protection section. MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 9 Pin Description Pin Configuration

10 PG2

Open-Drain DCDC2 Reset Output. This output remains low for 120μs after the output has reached its regulation level (see the Electrical Characteristics table). To obtain a logic signal, pull up PG2 with an external resistor.

11 PGND2 Power Ground for DCDC2

12 DL2 Low-Side Gate Drive for DCDC2

13 PV2 Input-Voltage Pin for DCDC2. Bypass this pin with enough input capacitance to supply current to the buck controller. Connect PV1 and PV2 together externally. See the Input Capacitor section. 14 BST2 Bootstrap Capacitor for High-Side Driver of Buck 2. Connect a 0.1µF from LX2 to BST2.

15 DH2 High-Side Gate Drive for DCDC2

16 LX2 Inductor Connection for DCDC2. Connect LX2 to the switched side of the inductor. LX2 serves as the lower supply rail for the DH2 high-side gate driver.

17 SYNC

SYNC I/O. When configured as an input, connect SYNC to GND or leave unconnected to enable skip- mode operation under light loads. Connect SYNC to PV or an external clock to enable fixed-frequency forced-PWM mode operation. When configured as an output, connect SYNC to other devices’ SYNC inputs. 18 PWM1X PWM Output for Optional 2nd Phase of DCDC1. Connect to the MAX15492 PWM pin. If unused, leave PWM1X unconnected. 19 ADDR I2C Address Select. Connect to GND or PV to select between two different I2C addresses. See the Selector Guide for default I2C settings. 20 CS1X+ Current-Sense Positive Input for the 2nd Phase of DCDC1. Connect CS1X+ to the positive side of the current-sense element. To disable phase 2, short CS1X+ to PV. 21 EN1 Active-High Digital Enable Input for DCDC1. Drive EN1 high for normal operation. Connect EN1 to GND if DCDC1 is not used.

22 RS1- DCDC1 Remote Voltage-Sense Negative Input

23 RS1+ DCDC1 Remote Voltage-Sense Positive Input

24 CS1- Current-Sense Negative Input for DCDC1. Connect CS1- to the negative side of the current-sense element. 25 CS1+ Current-Sense Positive Input for DCDC1. Connect CS1+ to the positive side of the current-sense element. See the Current-Limit/Short-Circuit Protection section.

26 PG1

Open-Drain DCDC1 Reset Output. This output remains low for 120μs after the output has reached its regulation level (see the Electrical Characteristics table). To obtain a logic signal, pull up PG1 with an external resistor.

27 PGND1 Power Ground for DCDC1

28 DL1 Low-Side Gate Drive for DCDC1

29 PV1 Input-Voltage Pin for DCDC1. Bypass this pin with enough input capacitance to supply current to the buck controller. Connect PV1 and PV2 together externally. See the Input Capacitor section. 30 BST1 Bootstrap Capacitor for High-Side Driver of DCDC1. Connect a 0.1µF from LX1 to BST1.

31 DH1 High-Side Gate Drive of DCDC1

32 LX1 Inductor Connection for DCDC1. Connect LX1 to the switched side of the inductor. LX1 serves as the lower supply rail for the DH1 high-side gate driver. — EP Exposed Pad. Connect EP to ground. Connecting the exposed pad to ground does not remove the requirement for proper ground connections to PGND1, PGND2, and GND. The exposed pad is attached with epoxy to the substrate of the die, making it an excellent path to remove heat from the IC. MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 10 MAXIM INTEGRATED CONFIDENTIAL/DISTRIBUTE ONLY UNDER NDA

Figure 1. Internal Block Diagram

output error over load, line, and temperature ranges. enables system synchronization. current, and overtemperature protections (Figure 1). between the IC and the master at clock rates up to 1MHz. 2-wire interface timing diagram. transmitting the proper address followed by the data word. Repeated START (Sr) condition and a STOP (P) condition. always followed by an acknowledge clock pulse. operation, even on a noisy bus. Figure 2. I2C Timing Diagram

(Sr) condition is generated instead of a STOP condition. occurs in the same high pulse as a START condition. any form of clock stretching to hold down the clock line. Figure 3. START, STOP, and Repeated START Conditions Table 1. I2C Slave Addresses

1) The master sends a START command (S). 4) The master sends an 8-bit register pointer. 5) The slave acknowledges the register pointer. 6) The master sends a data byte. 7) The slave updates with the new data. Repeated START condition (Sr). protocol is not supported by the RTC functional block. 1) The master sends a START command. 4) The master sends an 8-bit register pointer. 5) The slave acknowledges the register pointer. 6) The master sends a data byte. register and the data becomes active. Figure 6. Write Byte Format

0 ASLAVE ADDRESSS

Figure 7. Write Register-Data Pair Format

Table 2. Register Map Table 3. Identification Register (ID) VMAX[6:0] Maximum Voltage Setting. If VID[] > VMAX[], then a fault is set and the actual voltage is capped by VMAX[]. See Table 10 for VID output-voltage selections.

Table 5. Tracking Mode Register (TCONFIG) Table 6. Configuration Register (CONFIG) 0 = Mode controlled by SYNC pin. When SYNC is output, device is always in FPWM mode. 1 = Forced-PWM Mode. Overrides SYNC skip mode setting when SYNC is an input.

Table 7. Status Register (STATUS) Table 8. Slew-Rate Register (SLEW) Table 9. Output-Voltage Register (VID) INTERR Internal Hardware Error: This bit is set to ‘1’ when ATE trimming and testing not complete. TRKERR Tracking Address Error: This bit is set to ‘1’ when ENTRK == 1 & VSTEP == 0. VRHOT Thermal Shutdown Indication: A thermal shutdown has occurred since the last time this register was read. UV VOUT Undervoltage: This bit indicates if the output is currently under the target voltage. OV VOUT Overvoltage: This bit indicates if the output is currently over the target voltage. VMERR VOUTMAX Error. Set to 1 if VID[] > VOUTMAX[] in normal mode, or TVID[] > VOUTMAX[] in tracking mode. VID[6:0] Target Voltage Setting. VOUT ramps at the programmed DVS ramp rate until it reaches programmed VID. See Table 10 for VID output-voltage selections. Note 1: VSTEP = ‘0’; when VSTEP = ‘1’, increase by a factor of 1.25. Note 2: Falling DVS slew rate is -1.375mV/μs.

Table 10. VID Output-Voltage Selection

Table 11. Tracking Voltage Register (TRACKVID) Table 12. TRACKVID Output-Voltage Selections TVID[5:0] Tracking VID: This is used to calculate the new VID when in tracking mode. See Table 12 for TRACKVID output-voltage selections.

The MAX20012B features a special voltage-tracking mode where the device listens to I 2C write commands targeted at LDO4 of the MAX20024 PMIC. Any time the CNFG1_L4.TV_L4[5:0] (register 0x2B) is updated, the value is copied to the TRACKVID register. When tracking is enabled (TCONFIG.ENTRK = 1 and CONFIG.VSTEP = 1), the TRACKVID value is used instead of the VID register to set the output voltage. The I 2C address of the MAX20024 PMIC must be selected in the TCONFIG register for tracking to work properly. PG Output The IC features an open-drain PGOOD output that asserts when the output voltage is between the PG_UV and PG_OV thresholds. PG_ is asserted after the power- good active timeout period. An additional 220μs (typ) PG_ delay exists following soft-start or DVS slewing. PG_ is deasserted after a UV/OV propagation delay if the output voltage is outside the PG_ UV/OV thresholds, or after the first DVS command after soft-start. Connect PG_ to a pul- lup supply with a 20kΩ resistor. Soft-Start The IC includes a programmable soft-start rate. Soft-start limits startup inrush current by forcing the output voltage to ramp up towards its regulation point. Dynamic Voltage Scaling The step-down regulators feature dynamic volt - age scaling (DVS) to allow loads to margin their supply voltage. DVS registers for OUT1 and OUT2 are programmed with VID[6:0]. The rising slew rate dur - ing DVS is adjustable with SR[3:0] (see Table 8). The falling slew rate during DVS is fixed at -1.375mV/μs for VSTEP = 0 and -1.719mV/μs for VSTEP = 1. The PG_ comparator is masked to prevent false PG_ interrupts during the DVS period. I 2C DVS commands should only be issued when the output voltage is no longer slewing and is in a stable state. Shutdown During shutdown, the output voltage is ramped down at the 1.375mV/µs slew rate. The CS- pulldown is enabled as needed to assist in the ramp down. When powering down in skip mode under light load, the falling ramp may be based on the RC discharge curve based on COUT and the 5Ω pulldown resistance. Spread-Spectrum Option The IC features spread-spectrum (SS) operation by vary - ing the internal operating frequency up by 3% relative to the internally generated operating frequency of 2.2MHz (typ). This function does not apply to external sync. Synchronization (SYNC) SYNC is an I2C-programmable I/O. When configured as an input and the FPWM bit = 0, driving SYNC low or unconnected places the converter in skip mode. Forcing SYNC logic-high places the IC in forced-PWM (FPWM) mode. Input triggering on the rising edge or falling edge is determined by the setting of registers SO[1:0], see Table 6. When SO[1:0] = 2, SYNC is configured as an output. The output clock is 180° out of phase with the internal clock. Current-Limit/Short-Circuit Protection The current-limit circuit uses differential current-sense inputs (CS_+ and CS_-) to limit the peak inductor current. If the magnitude of the current-sense signal exceeds the current-limit threshold (VLIM_ = 57.4mV (typ), 60mV (typ), 62.8mV (max)), the PWM controller turns off the high-side MOSFET. The high side turns on again once the inductor current drops below the valley current limit. The actual maximum load current is less than the peak current-limit threshold by an amount equal to half of the inductor ripple current. Therefore, the maximum load capability is a function of the current-sense resistance, inductor value, switching MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.comMaxim Integrated │ 22 MAXIM INTEGRATED CONFIDENTIAL/DISTRIBUTE ONLY UNDER NDA

current-sense configurations. 2.2MHz switching frequency) until the short is removed. in either skip mode or forced-PWM mode of operation. only when the output voltage falls below a set threshold. switch the IC to PWM mode when updating the VID. capacitance is required (for a total of 300µF). Figure 8. Current-Sense Configurations

Lossless Inductor DCR Sensing High-power applications that do not require highly accurate current-limit protection can reduce the overall power dissipation by connecting a series RC circuit across the inductor with an equivalent time constant: CSEQ DCR R1RR RR and: DCR EQ 1 2 L11R C RR = +  where RCSEQ is the required current-sense resistor and RDCR is the inductor’s series DC resistance. Use the inductance and R DCR values provided by the inductor manufacturer. Carefully observe the PCB layout guidelines to ensure that noise and DC errors do not corrupt the differential current-sense signals seen by CS_+ and CS_-. Place the sense network close to the device with short, direct traces, making a Kelvin-sense connection to the current-sense network. High-Side Gate-Drive Supply (BST1) The high-side MOSFET is turned on by closing an internal switch between BST1 and DH1 and transferring the bootstrap capacitor’s (at BST1) charge to the gate of the high-side MOSFET. This charge refreshes when the high-side MOSFET turns off and the LX1 voltage drops down to ground potential, taking the negative terminal of the capacitor to the same potential. At this time the bootstrap diode recharges the positive terminal of the bootstrap capacitor. The selected n-channel high-side MOSFET determines the appropriate boost-capacitance values (CBST_ in the Typical Operating Circuit) according to the following equation: = ∆ GBST_ BST1 QC V where Q G is the total gate charge of the high-side MOSFET and ΔV BST1 is the voltage variation allowed on the high-side MOSFET driver after turn-on. Choose ΔVBST1 such that the available gate-drive voltage is not significantly degraded (e.g., ΔVBST1 = 100mV to 300mV) when determining CBST_. The boost capacitor should be a low-ESR ceramic capacitor. A minimum value of 100nF works in most cases. CBST2 is calculated using the same method described for CBST1. Applications Information Input Capacitor The input filter capacitor reduces peak currents drawn from the power source and reduces noise and voltage ripple on the input caused by the circuit’s switching. The input capacitor RMS current requirement (I RMS) is defined by the following equation: OUT PV_ OUT RMS LOAD(MAX) PV_ V (V - V ) II V= IRMS has a maximum value when the input voltage equals twice the output voltage (V PV_ = 2V OUT), so I RMS(MAX) = ILOAD(MAX)/2. Choose an input capacitor that exhibits less than +10°C self-heating temperature rise at the RMS input current for optimal long-term reliability. The input-voltage ripple is comprised of ΔV Q (caused by the capacitor discharge) and ΔV ESR (caused by the ESR of the capacitor). Use low-ESR ceramic capacitors with high ripple-current capability at the input. Assume the contribution from the ESR and capacitor discharge equal to 50%. Calculate the input capacitance and ESR required for a specified input-voltage ripple using the following equations: ESRIN LOUT VESR II 2 ∆= ∆+ where: PV_ OUT OUT L PV_ SW (V - V ) V I V fL ∆= ×× and: OUTIN Q SW I D(1- D)C Vf ×= ∆× and: OUT PV_ VD V= IOUT is the maximum output current, D is the duty cycle. MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 24 MAXIM INTEGRATED CONFIDENTIAL/DISTRIBUTE ONLY UNDER NDA

Three key inductor parameters must be specified for operation with the MAX20012B: inductance value (L), inductor saturation current (I SAT), and DC resistance (RDCR). Use the following formula to determine the mini - mum inductor value: ( ) OUTPVMAX OUT PVMAX MIN SW OUTMAX INDMAX VV -V VL 1.3 fI K  where f SW1 is the operating frequency and 1.3 is a coefficient that accounts for inductance initial precision. KINDMAX is the maximum inductor current ripple. A good initial maximum inductor current ripple is 30% peak to peak (KINDMAX = 0.3). For proper operation, the chosen inductor value must be ≥ L MIN. The maximum inductor value recommended is twice the chosen value from the above formula. MOSFET Selection The gate drivers drive two external logic-level n-channel MOSFETs as the circuit switch elements. The key selection parameters to choose these MOSFETs are:

• Drain-to-Source On-Resistance (RDS(ON))
• Maximum Drain-to-Source Voltage (VDS(MAX))
• Minimum Threshold Voltage (VTH(MIN))
• Total Gate Charge (QG)
• Reverse Transfer Capacitance (CRSS)
• Power Dissipation Both n-channel MOSFETs must be logic-level types with guaranteed on-resistance specifications at V GS = 3.5V. The conduction losses at minimum input voltage should not exceed MOSFET package thermal limits or violate the overall thermal budget. Also ensure that the conduction losses plus switching losses at the maximum input volt - age do not exceed package ratings or violate the overall thermal budget. In particular, check that the dV/dt caused by DH_ turning on does not pull up the DL_ gate through its drain-to-gate capacitance. This is the most frequent cause of cross-conduction problems. Gate-charge losses are dissipated by the driver and do not heat the MOSFET. Therefore, the power dissipation in the IC due to drive losses must be checked. Both MOSFETs must be selected so that their total gate charge is low enough; therefore, PV/VOUT can power both drivers without overheating the IC: PDRIVE = VOUT x (QGTOTH + QGTOTL) x fSW1 Where QGTOTL is the low-side MOSFET total gate charge and QGTOTH is the high-side MOSFET total gate charge. Select MOSFETs with a QG_TOTAL of less than 15nC. The n-channel MOSFETs must deliver the average current to the load and the peak current during switching. Dual MOSFETs in a single package can be an economical solution. To reduce switching noise for smaller MOSFETs, use a series resistor in the DH_ path and additional gate capacitance. Contact the factory for guidance using gate resistors. Output Capacitor Use low-ESR ceramic capacitors on the output. Other capacitor types should be verified with a gain and phase analysis. In single-phase configuration, use a nominal value of 200µF; in dual-phase configuration, use a nominal value of 300µF. MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 25 MAXIM INTEGRATED CONFIDENTIAL/DISTRIBUTE ONLY UNDER NDA

Note: Insert the desired suffix option from the Selector Guide into the blank. /V denotes an automotive qualified part. +Denotes a lead(Pb)-free/RoHS-compliant package. SW = Side-wettable TQFN package *EP = Exposed pad. For variants with different options, contact factory. OPTION SUFFIX VOUT1 (V) VOUT2 (V) VMAX CONFIG VID SLEW I2C VMAX CONFIG VID SLEW I2C A/V+ 0x3B (1.08) 0x0C 0x36 (1.03) 0x04 0x74 0x43 (1.45) 0x8C 0x3B (1.35) 0x04 0x70 A/VY+ 0x3B (1.08) 0x0C 0x36 (1.03) 0x04 0x74 0x43 (1.45) 0x8C 0x3B (1.35) 0x04 0x70 B/V+ 0x4E (1.27) 0x08 0x47 (1.20) 0x03 0x74 0x3D (1.10) 0x08 0x33 (1.00) 0x03 0x70 C/V+ 0x4A (1.23) 0x08 0x31 (0.98) 0x03 0x74 0x4A (1.23) 0x08 0x2E (0.95) 0x03 0x70 E/V+ 0x2E (0.95) 0x0C 0x22 (0.83) 0x09 0x70 0x47 (1.20) 0x0C 0x3E (1.11) 0x09 0x74 F/V+ 0x4A (1.23) 0x08 0x21 (0.82) 0x03 0x74 0x4A (1.23) 0x08 0x21 (0.82) 0x03 0x70 F/VY+ 0x4A (1.23) 0x08 0x21 (0.82) 0x03 0x74 0x4A (1.23) 0x08 0x21 (0.82) 0x03 0x70 G/V+ 0x36 (1.03) 0x0C 0x33 (1.00) 0x03 0x70 0x36 (1.03) 0x0C 0x33 (1.00) 0x03 0x74 H/V+ 0x2A (0.91) 0x05 0x22 (0.83) 0x09 0x74 0x38 (1.05) 0x05 0x2F (0.96) 0x09 0x70 H/VY+ 0x2A (0.91) 0x05 0x22 (0.83) 0x09 0x74 0x38 (1.05) 0x05 0x2F (0.96) 0x09 0x70 J/V+ 0x33 (1.25) 0x84 0x0F (0.80) 0x00 0x74 0x27 (1.10) 0x84 0x17 (0.90) 0x00 0x70 K/V+ 0x2D (0.94) 0x08 0x24 (0.85) 0x09 0x74 0x48 (1.21) 0x08 0x3D (1.10) 0x09 0x70 L//V+ 0x2D (0.94) 0x0C 0x24 (0.85) 0x09 0x74 0x48 (1.21) 0x0C 0x3D (1.10) 0x09 0x70 PART TEMP RANGE PIN-PACKAGE MAX20012BATJ_/V+ -40°C to +125°C 32 TQFN-EP* MAX20012BATJ_/VY+ -40°C to +125°C 32 SW TQFN-EP* MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller www.maximintegrated.com Maxim Integrated │ 26

Ordering Information

0 9/17 Initial release — 1 1/18 Updated PG Output section 22 2 3/18 Updated Selector Guide 26 3 4/18 Updated Selector Guide 26 4 5/18 Updated Selector Guide 26 5 12/18 Updated Selector Guide 26 6 3/19 Changes to Table 6 on the Bit Description,and Spread Spectrum Option section, updated Selector Guide and Ordering Information section 18, 22, 26 7 5/19 Updated Package Information and Selector Guide 3, 26 8 8/19 Updated Selector Guide 26 Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. MAX20012B Automotive Low-Voltage 2-Channel Step-Down Controller © 2019 Maxim Integrated Products, Inc. │ 27

Revision History

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