MAX15027/MAX15028 General Description The MAX15027/MAX15028 low-dropout linear regulators operate from input voltages as low as 1.425V and deliver up to 1A of continuous output current with a typical dropout voltage of only 75mV. The output voltage is adjustable from 0.5V to VIN and is 2% accurate over load and line variations, from -40C to +125C. The MAX15028 features a BIAS input of 3V to 5.5V from an always-on power supply. The BIAS input current is reduced down to less than 2A during shutdown. These regulators use small, 1F ceramic input capacitors and 4.7F ceramic output capacitors to deliver 1A output current. High bandwidth provides excellent transient response and limits the output voltage deviation to 15mV for a 500mA load step, with only a 4.7F ceramic output capacitor, and the voltage deviations can be reduced further by increasing the output capacitor. These devices offer a logic-controlled shutdown input to reduce input current (IIN) consumption down to less than 5.5A in standby mode. Other features include a softstart to reduce inrush current, short-circuit protection, and thermal-overload protection. 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Features 1.425V to 3.6V Input Voltage Range Output Voltage Programmable from 0.5V to VIN Guaranteed Maximum 225mV Dropout at 1A Output Current 2% Output Accuracy Over Load, Line, and Temperature Stable with Ceramic Capacitors Fast Transient Response 60A Operating Bias Supply Current (MAX15028) 1.2A Shutdown Bias Supply Current (MAX15028) Short-Circuit and Thermal Protection -40C to +125C Operating Temperature Range Soft-Start Limits Inrush Current Thermally Enhanced 3mm x 3mm TDFN Package AEC-Q100 Qualified The MAX15028 features a BIAS input allowing a secondary supply to keep the LDO's internal circuitry alive if the voltage on IN goes to 0V. Both devices are fully specified from -40C to +125C and are available in a 10-pin thermally enhanced TDFN package (3mm x 3mm) that includes an exposed pad for optimal power dissipation. For a 500mA version of these LDOs, refer to the MAX15029/MAX15030 data sheet. Applications Automotive (Dead-Man LDO) Servers Storage Networking Base Stations Optical Modules ATE 19-4488; Rev 3; 8/16 Ordering Information appears at end of data sheet. Typical Operating Circuits and Pin Configurations appear at end of data sheet. MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Absolute Maximum Ratings IN, FB, SS, I.C. to GND........................................-0.3V to +4.0V BIAS to GND............................................................-0.3V to +6V EN to GND.............-0.3V to the lower of (VBIAS + 0.3V) or +6V OUT to GND............................................... -0.3V to (VIN + 0.3V) Output Short-Circuit Duration.....................................Continuous Continuous Power Dissipation (TA = +70C) 10-Pin TDFN, Multilayer Board (derate 24.4mW/C above +70C).............................1951mW Operating Junction Temperature Range........... -40C to +125C Maximum Junction Temperature......................................+150C Storage Temperature Range............................. -65C to +150C Lead Temperature (soldering, 10s).................................. +300C Soldering Temperature (reflow)........................................+260C 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) Junction-to-Ambient Thermal Resistance (JA)................ 41C/W Junction-to-Case Thermal Resistance (JC).....................9C/W Chip Information PROCESS: BiCMOS 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. Package Information 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 TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 10 TDFN-EP T1033+1 21-0137 90-0003 Electrical Characteristics (Circuit of Figure 1; VIN = 1.8V, VOUT = 1.2V, EN = IN for MAX15027, EN = BIAS for MAX15028, IOUT = 100mA, TA = TJ = -40C to +125C. Typical values are at TA = +25C, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS IN MAX15027 Input Voltage Range Undervoltage Lockout Undervoltage Lockout Hysteresis Quiescent GND Current Input Supply Current in Shutdown www.maximintegrated.com VIN VUVLO MAX15028 VIN rising, IOUT = 2mA 1.425 3.600 VBIAS = 3V to 5.5V 1.425 3.600 BIAS = IN 3.000 3.600 MAX15027 1.275 1.325 1.375 MAX15028 1.04 1.106 1.14 VUVLO_HYST IGND IIN_SD 50 V mV VIN = 1.425V to 3.6V, VOUT = 1.2V, IOUT = 1mA, VBIAS = 3.3V 160 275 410 VIN = 3.6V, VOUT = 3.3V, IOUT = 100mA 180 275 560 VIN = 3.3V, VOUT = 3.3V, IOUT = 500mA 170 315 470 0.1 5.5 VEN = 0V, TA = -40C to +85C V A A Maxim Integrated 2 MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Electrical Characteristics (continued) (Circuit of Figure 1; VIN = 1.8V, VOUT = 1.2V, EN = IN for MAX15027, EN = BIAS for MAX15028, IOUT = 100mA, TA = TJ = -40C to +125C. Typical values are at TA = +25C, unless otherwise noted.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 5.5 V 2.7 V BIAS (MAX15028) Input Voltage Range Undervoltage Lockout VBIAS VBIAS_UVLO Undervoltage Lockout Hysteresis Quiescent Input Supply Current Input Supply Current in Shutdown 3 VBIAS rising, IOUT = 2mA 2.3 IOUT = 2mA IBIAS IBIAS_SD 110 VEN = VBIAS EN = GND 2.5 20 mV 60 120 VIN = 0V, VOUT = 0V, VBIAS = 3.3V 1.2 2 VIN = 3.3V, VOUT = 0V, VBIAS = 3.3V 1.2 2 VIN = 3.3V, VOUT = 0V, VBIAS = 5V 1.5 3 A A OUT Output Voltage Range VOUT 0.5 Load Regulation IOUT = 1mA to 1A Line Regulation VIN = 1.425V to 3.6V, IOUT = 1mA Dropout Voltage (VIN - VOUT) VDO IOUT = 1A, VIN = 1.5V Output Current Limit ILIM VFB = 300mV Threshold Accuracy VFB VOUT = 0.5V to 3.3V, VIN = (VOUT + 0.3V) to 3.6V, IOUT = 1mA to 1A Input Current IFB VFB = 0.688V 3.3 V 0.01 mV/mA 4 mV 75 225 mV 1.4 1.7 2.0 A 0.489 0.499 0.509 mV 0.1 0.2 A FB EN/SOFT-START Enable Input Threshold (MAX15028) VIH Enable Input Threshold (MAX15027) VIH VIL VIL VBIAS = 5V VIN = 1.8V 1.05 0.4 1.05 0.4 V V Soft-Start Charging Current ISS 5 A Soft-Start Reference Voltage VSS 0.499 V 165 C 15 C THERMAL SHUTDOWN Thermal-Shutdown Threshold Thermal-Shutdown Hysteresis TJ rising Note 2: All devices are 100% production tested at TA = +25C. Limits over the operating temperature range are guaranteed by design and characterization. www.maximintegrated.com Maxim Integrated 3 MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Typical Operating Characteristics (Circuit of Figure 1, VIN = 1.8V, VOUT = 1.5V, IOUT = 1A, TA = +25C, unless otherwise noted.) 1.500 0.8 1.495 0.6 1.490 0.4 IOUT = 0 VBIAS = 3.3V 1.0 1.5 2.0 2.5 3.0 3.5 1.480 4.0 0 0 100 200 300 400 500 600 700 800 900 1000 VBIAS = 3.3V 0 0.5 1.0 1.5 2.0 2.5 3.0 INPUT VOLTAGE (V) MAX15028 BIAS CURRENT (IBIAS) vs. BIAS VOLTAGE (VBIAS) MAX15028 BIAS CURRENT (IBIAS) vs. OUTPUT CURRENT GROUND CURRENT vs. OUTPUT CURRENT 53 30 20 52 51 VBIAS = 5.5V 50 49 VBIAS = 3.3V 48 47 10 2 3 4 5 6 45 0 100 200 300 400 500 600 700 800 900 1000 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 LOAD CURRENT (A) 120 100 80 VIN = 1.4V 20 200 180 DROPOUT VOLTAGE (mV) 140 0 0.30 MAX15028 DROPOUT VOLTAGE vs. OUTPUT CURRENT MAX15027 toc07 DROPOUT VOLTAGE (mV) 160 40 0.32 OUTPUT CURRENT (mA) VBIAS = 3.3V 60 0.33 VBIAS = 3.3V MAX15028 DROPOUT VOLTAGE vs. OUTPUT CURRENT 180 0.34 0.31 BIAS VOLTAGE (V) 200 4.0 MAX15027 toc07 1 0.35 46 IOUT = 0 3.5 MAX15027 toc06 54 GROUND CURRENT (mA) 55 BIAS CURRENT (A) 40 0 0.1 OUTPUT CURRENT (mA) 50 0 0.2 INPUT VOLTAGE (V) MAX15027 toc04 60 0.5 0.3 1.485 MAX15027 toc05 0 MAX15027 toc03 1.510 1.505 1.0 0.2 BIAS CURRENT (A) 1.515 INPUT CURRENT (IIN) vs. INPUT VOLTAGE (VIN) 0.4 INTPUT CURRENT (mA) 1.2 VBIAS = 3.3V OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 1.4 0 1.520 MAX15027 toc01 1.6 MAX15028 OUTPUT VOLTAGE vs. OUTPUT CURRENT MAX15027 toc02 MAX15028 OUTPUT VOLTAGE vs. INPUT VOLTAGE VBIAS = 3.3V 160 140 120 100 80 60 40 VIN = 1.4V 20 0 100 200 300 400 500 600 700 800 900 1000 OUTPUT CURRENT (mA) www.maximintegrated.com 0 0 100 200 300 400 500 600 700 800 900 1000 OUTPUT CURRENT (mA) Maxim Integrated 4 MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = 1.8V, VOUT = 1.5V, IOUT = 1A, TA = +25C, unless otherwise noted.) POWER-UP RESPONSE POWER-DOWN RESPONSE MAX15027 toc09a MAX15027 toc09b VOUT 1V/div VOUT 1V/div VIN 2V/div VIN 2V/div IOUT = 500mA IOUT = 500mA 2ms/div 10s/div TURN-ON VIA ENABLE RESPONSE TURN-OFF VIA ENABLE RESPONSE MAX15027 toc10b MAX15027 toc10a VOUT 1V/div VOUT VEN 2V/div VEN 1V/div 2V/div IOUT = 500mA 2ms/div www.maximintegrated.com IOUT = 500mA 4s/div Maxim Integrated 5 MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Typical Operating Characteristics (continued) (Circuit of Figure 1, VIN = 1.8V, VOUT = 1.5V, IOUT = 1A, TA = +25C, unless otherwise noted.) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX15028 FB VOLTAGE (VFB) vs. TEMPERATURE MAX15027 toc11 0.510 MAX15027 toc12 50dB 0.508 10dB/div FB VOLTAGE (VFB) (V) 0.506 0.504 0.502 0.500 0.498 0.496 0.494 0.492 100Hz 0.490 1MHz VBIAS = 3.3V -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (C) OVERCURRENT THRESHOLD vs. TEMPERATURE 1.76 1.74 1.72 1.70 1.68 1.66 1.64 1.62 1.60 VBIAS = 3.3V -40 -20 0 20 40 60 80 100 120 140 TEMPERATURE (C) www.maximintegrated.com 80 MAX15027 toc14 1.78 CASE TEMPERATURE RISE (C) MAX15027 toc13 OVERCURRENT THRESHOLD (A) 1.80 CASE TEMPERATURE RISE vs. POWER DISSIPATION 70 60 50 40 30 20 10 0 0 0.5 1.0 1.5 2.0 2.5 POWER DISSIPATION (W) Maxim Integrated 6 MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Pin Configurations TOP VIEW TOP VIEW IN 1 IN 2 IN 3 I.C. 4 EN + MAX15027 EP 5 10 OUT IN 1 9 OUT IN 2 8 GND BIAS 3 7 FB I.C. 4 6 SS EN + OUT 9 OUT 8 GND 7 FB 6 SS MAX15028 EP 5 TDFN (3mm x 3mm) 10 TDFN (3mm x 3mm) Pin Description PIN NAME FUNCTION 1, 2 IN Regulator Input. 1.425V to 3.6V voltage range. Bypass to GND with at least 1F of ceramic capacitance. IN is high impedance when the LDO is shut down. -- 3 BIAS Internal Circuitry Supply Input. BIAS supplies the power for the internal circuitry. 3V to 5.5V voltage range. 4 4 I.C. Internally Connected. Connect I.C. directly to GND. 5 5 EN LDO Enable. Drive EN high to enable the LDO or connect to IN (BIAS for MAX15028) for always-on operation. Drive EN low to disable the LDO and place the IC in low-power shutdown mode. 6 6 SS Soft-Start Input. For typical operation, connect a 0.1F capacitor from SS to GND. The soft-start timing is dependent on the value of this capacitor. See the Soft-Start section. 7 7 FB Feedback Input. Connect FB to the center of a resistor-divider connected between OUT and GND to set the output voltage. See the Programming the Output Voltage section. 8 8 GND Ground 9, 10 9, 10 OUT Regulator Output. Bypass OUT to GND with at least 4.7F of ceramic capacitance for 1A load operation. -- -- EP MAX15027 MAX15028 1, 2, 3 www.maximintegrated.com Exposed Pad. Connect EP to GND and a large copper ground plane to facilitate package power dissipation. Maxim Integrated 7 MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Functional Diagram IN MAX15027 ONLY MAX15028 ONLY REF MAX15027 MAX15028 BIAS INTERNAL SUPPLY GENERATOR REF IN UVLO BIAS UVLO CONTROL LOGIC ERROR AMPLIFIER WITH SOFT-START EN OVERTEMPERATURE PROTECTION MOS DRIVER WITH ILIMIT P OUT SS FB GND www.maximintegrated.com Maxim Integrated 8 MAX15027/MAX15028 Detailed Description The MAX15027/MAX15028 low-dropout linear regulators operate from input voltages as low as 1.425V and deliver up to 1A of continuous output current with a maximum dropout voltage of only 225mV. The MAX15028 operates with an input voltage as low as 1.425V if the bias voltage (VBIAS) of 3V to 5.5V is available. The power is applied at IN while the control is provided through BIAS input. The current drawn by BIAS is negligible when the LDO goes into shutdown. This feature is especially useful in automotive applications where the BIAS input is derived from an always-on LDO that expects to provide minimal power during the key-off condition. The pMOS output stage can be driven from input voltages down to +1.425V without sacrificing stability or transient performance. The output voltage of all the regulators is adjustable from 0.5V to VIN and is 2% accurate over load and line variations, from -40C to +125C. Since these regulators have a pMOS output device, supply current is not a significant function of load or input headroom. Internal p-Channel Pass Transistor The devices feature a 75m (typ) p-channel MOSFET pass transistor. Unlike similar designs using pnp pass transistors, p-channel MOSFETs require no base drive, reducing quiescent current. pnp-based regulators also waste considerable current in dropout when the pass transistor saturates and use high base-drive currents under large loads. The devices do not suffer from these problems and consume only 275A (typ) of quiescent current under heavy loads, as well as in dropout. Short-Circuit/Thermal Fault Protection The devices are fully protected from a short circuit at the output through current limiting and thermal-overload circuitry. In the fault condition when the output is shorted to ground, the output current is limited to a maximum of www.maximintegrated.com 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input 2A. Under these conditions, the device quickly heats up. When the junction temperature reaches +165C (typ), the thermal-overload circuitry turns off the output, allowing the part to cool down. When the junction temperature cools to +150C (typ), the output turns back on and reestablishes regulation. Current limiting and thermal protection continue until the fault is removed. For continuous operation, do not exceed the absolute maximum junction-temperature rating of TJ = +150C. Soft-Start The devices feature a soft-start function that slowly ramps up the output voltage of the regulator based on the value of the capacitor (CSS) connected from SS to GND. Upon power-up, CSS is charged with a 5A (typ) current source through SS. The voltage at SS is compared to the internal 0.5V reference (VREF). The feedback voltage for regulation (VREG) is the lower of VSS or VREF. As VSS rises, the regulation voltage (VREG) rises at the same rate. Once VSS reaches and rises above VREF, the regulation voltage then tracks the reference voltage since it is the lower of VSS and VREF. The value of CSS determines the length of the soft-start time, tSS. Use the following formula to determine CSS. CSS = 10-5 x tSS where CSS is in farads and tSS is in seconds. Shutdown Mode The devices include an enable input. To shut down the IC, drive EN low. In shutdown mode, the current drawn by BIAS is less than 2A. This feature is extremely useful in an automotive application where the BIAS input is derived from an always-on LDO expecting to provide minimal dark current. For normal operation, drive EN high or connect EN to IN (BIAS for MAX15028) for continuous on operation. During shutdown, an internal 10k resistor is connected between OUT and GND. Maxim Integrated 9 MAX15027/MAX15028 Applications Information Programming the Output Voltage The MAX15027/MAX15028 feature an adjustable output voltage from 0.5V to VIN using two external resistors connected as a voltage-divider to FB as shown in Figure 1. The output voltage is set by the following equation: R1 V= OUT VFB 1 + R2 where typically VFB = 0.5V. Choose R2 to be 10k. Or, to optimize load-transient response for no load to full load transients, use the resistor-divider as a minimum load and choose R2 to be 500. To simplify resistor selection: V R1 = R2 OUT - 1 V FB Capacitor Selection and Regulator Stability Capacitors are required at the device's inputs and outputs for stable operation over the full temperature range and with load currents up to 1A. Connect a 1F capacitor between IN and ground and a 4.7F capacitor with low equivalent series resistance (ESR) between OUT and ground for 1A output current. The input capacitor (CIN) lowers the source impedance of the input supply. If input supply source impedance is high, place a larger input capacitor close to IN to prevent VIN sagging due to load transients. Smaller output capacitors can be used for output currents less than 1A. Calculate the minimum COUT as follows: 1F = C OUT I OUT(MAX) x 0.25A Operating Region and Power Dissipation The maximum power dissipation depends on the thermal resistance of the IC package and circuit board, the temperature difference between the die junction and ambient air, and the rate of airflow. The power dissipated in the device is PDISS = IOUT (VIN - VOUT). The package features an exposed thermal pad on its underside. This pad lowers the thermal resistance of the package by providing a direct heat conduction path from the die to the PCB. Connect the exposed backside pad and GND to the system ground using a large pad or ground plane and multiple vias to the ground plane layer. 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Noise, PSRR, and Transient Response The devices are designed to operate with low-dropout voltages and low quiescent currents while still maintaining good noise performance, transient response, and AC rejection (see the Typical Operating Characteristics for a plot of Power-Supply Rejection Ratio (PSRR) vs. Frequency). When operating from noisy sources, improved supplynoise rejection and transient response can be achieved by increasing the values of the input and output bypass capacitors and through passive filtering techniques. The MAX15027/MAX15028 load-transient response graphs (see the Typical Operating Characteristics) show two components of the output response: a DC shift from the output impedance due to the load current change, and the transient response. A typical transient overshoot for a step change in the load current from 300mA to 800mA is 15mV. Use ceramic output capacitors greater than 4.7F (up to 100F) to attenuate the overshoot. Layout Guidelines The TDFN package has an exposed thermal pad on its underside. This pad provides a low thermal resistance path for heat transfer into the PCB. This low thermally resistive path carries a majority of the heat away from the IC. The PCB is effectively a heatsink for the IC. The exposed pad should be connected to a large ground plane for proper thermal and electrical performance. The minimum size of the ground plane is dependent upon many system variables. To create an efficient path, the exposed pad should be soldered to a thermal landing, which is connected to the ground plane by thermal vias. The thermal landing should be at least as large as the exposed pad. ALWAYS-ON INPUT 3V TO 5.5V BIAS INPUT 1.2V TO 3.6V IN 1F OUTPUT OUT R1 MAX15028 ENABLE FB 4.7F I.C. R2 EN SHUTDOWN GND SS 0.1uF Figure 1. MAX15028 Typical Application Circuit www.maximintegrated.com Maxim Integrated 10 MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Typical Operating Circuits OUT INPUT 1.425V TO 3.6V OUTPUT 0.5V TO VIN ALWAYS-ON INPUT 3V TO 5.5V INPUT 1.425V TO 3.6V 1F IN 1F MAX15027 FB BIAS IN MAX15028 4.7F EN OUT OUTPUT 0.5V TO VIN FB 4.7F EN SS GND SS GND Ordering Information PART TEMP RANGE PINPACKAGE TOP MARK MAX15027ATB+T -40C to +125C 10 TDFN-EP* +AUD MAX15027ATB/V+T -40C to +125C 10 TDFN-EP* +AWC MAX15028ATB+T -40C to +125C 10 TDFN-EP* +AUE +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. *EP = Exposed pad. /V denotes an automotive qualified part. www.maximintegrated.com Maxim Integrated 11 MAX15027/MAX15028 1.425V to 3.6V Input, 1A Low-Dropout Regulators with BIAS Input Revision History REVISION NUMBER REVISION DATE 0 3/09 Initial release 1 5/10 Revised the Features, Ordering Information, and the Absolute Maximum Ratings. 2 1/15 Changed TOC10a label from 20s/div to 2ms/div 8/16 Rebranded data sheet; added new Package Thermal Characteristics section; corrected package code (from T1033-1 to T1033+1) in Package Information table and moved to pg 2; moved Ordering Information table to pg 11, Pin Configuration diagrams to pg 7, and Chip Information table to pg 2 3 PAGES CHANGED DESCRIPTION -- 1, 2 5 1, 2, 7, 10, 11 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated's website at www.maximintegrated.com. 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. (c) 2016 Maxim Integrated Products, Inc. 12