MAX38642AENT+

EVALUATION KIT AVAILABLE Click here to ask about the production status of specific part numbers. MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter General Description Benefits and Features The MAX38640–MAX38643 are a nanoPower family of ultra-low 330nA quiescent current buck (step-down) DCDC converters that operate from 1.8V to 5.5V input voltage and support load currents of up to 175mA, 350mA, 700mA with peak efficiencies of 96%. While in shutdown, there is only 5nA of shutdown current. The devices offer ultra-low quiescent current, small total solution size, and high efficiency throughout the load range. The MAX38640–MAX38643 are ideal for battery applications where long battery life is a must. ● Extends Battery Life • 330nA Ultra-Low Quiescent Supply Current • 5nA Shutdown Current • 96% Peak Efficiency and over 88% at 10µA The MAX38640–MAX38643 family utilizes a unique control scheme that allows ultra-low quiescent current and high efficiency over a wide output current range. The MAX38642 excludes active discharge resistor in shutdown, which allows the output to be regulated or held high by another source or by the charged output capacitor. The MAX38640–MAX38643 devices are offered in a space-saving 1.42mm x 0.89mm, 6-pin WLP (2x3 bump, 0.4mm pitch), as well as a 2mm x 2mm, 6-pin µDFN package. All parts are specified over the -40°C to +85°C extended temperature range. Applications ● Portable, Space-Constrained Consumer Products ● Wearable Devices, Ultra-Low-Power IoT, NB IoT, and Bluetooth® LE ● Single Li-ion (Li+) and Coin Cell Battery Products ● Wired or Wireless Industrial Products ● Easy to Use – Addresses Popular Operation • 1.8V to 5.5V Input Range • Single Resistor-Adjustable VOUT from 0.7V to 3.3V (A-Option) • Preprogrammed VOUT from 0.5V to 5.0V (B-Option) • ±1.75% Output Voltage Accuracy • Up to 175mA/350mA/700mA Load Current ● Protects System in Multiple Use Cases • Reverse-Current Blocking in Shutdown • Optional Active Discharge Feature ● Reduces Size and Increases Reliability • -40°C to +85°C Temperature Range • 2mm x 2mm, 6-pin µDFN Package • 1.42mm x 0.89mm, 0.4mm Pitch 6-pin (2 x 3) WLP Ordering Information appears at end of data sheet. Typical Operating Circuit 2.2µH INPUT 1.8V TO 5.5V IN CIN 10µF LX OUT OUTPUT 1.8V COUT 22µF MAX38640A RSEL EN Bluetooth is a registered trademark of Bluetooth SIG, Inc. 19-100410; Rev 6; 8/21 GND RSEL 768kΩ MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Absolute Maximum Ratings IN, EN, RSEL, NC, OUT to GND............................... -0.3V to +6V LX RMS Current WLP ............................. -1.6ARMS to +1.6ARMS LX RMS Current µDFN .................................. -1ARMS to +1ARMS LX to GND (Note 1) ........................................ -0.3V to VIN + 0.3V Continuous Power Dissipation—WLP (TA = +70°C) (Derate 10.5mW/°C above +70°C) ................................................ 840mW Continuous Power Dissipation—µDFN (TA = +70°C) (Derate 4.5mW/°C above +70°C) ...............................................357.8mW Operating Temperature Range .............................-40°C to +85°C Maximum Junction Temperature ...................................... +150°C Storage Temperature Range ..............................-65°C to +150°C Lead Temperature (soldering, 10 seconds) ......................+300°C Soldering Temperature (reflow) ........................................ +260°C Note 1: LX pin has internal clamps to GND and IN. These diodes may be forward biased during switching transitions. During these transitions, the max LX current should be within the Max RMS Current rating for safe operation. 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 Information 6 µDFN Package Code L622+1C Outline Number 21-0164 Land Pattern Number 90-0004 Thermal Resistance, Four-Layer Board: Junction to Ambient (θJA) 223.6°C/W Junction to Case (θJC) 122°C/W 6 WLP Package Code N60E1+2 Outline Number 21-100128 Land Pattern Number Refer to Application Note 1891 Thermal Resistance, Four-Layer Board: Junction to Ambient (θJA) 95.15°C/W 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 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. www.maximintegrated.com Maxim Integrated | 2 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Electrical Characteristics (VIN = 3.3V, VOUT = 1.8V, TA = -40°C to +85°C, CIN = 10µF, COUT = 22µF, unless otherwise specified. (Note 2)) PARAMETER Shutdown Current Input Voltage Range SYMBOL IIN_SD VIN_RANGE VUVLO Input Undervoltage Lockout VUVLO Output Voltage Range VOUT_RANGE CONDITIONS MIN VEN = 0V, TA = +25°C Guaranteed by output accuracy TYP MAX UNITS 0.005 0.1 µA 5.5 V 1.8 V 1.8 RSEL > 50kΩ (MAX38640A/1A/ 2A/3A), (MAX38640B/1B/ 2B/3B) VIN rising 1.75 Hysteresis 50 RSEL < 50kΩ (MAX38640A/1A/ 2A/3A) VIN rising 2.6 Hysteresis 125 Guaranteed by output accuracy -1.75 +1.75 % VOUT = 1.8V, VIN = 2.0V to 5.5V, IOUT = 10mA to 160mA ±1.5 Quiescent Supply Current into IN IQ_IN VEN = VIN, not switching VOUT = 106% of target voltage, VOUT TARGET = 2.5V, TA = +25°C 330 Quiescent Supply Current into OUT IQ_OUT VEN = VIN, not switching VOUT = 106% of target voltage, VOUT TARGET = 2.5V, TA = +25°C 10 6.5 dVOUT/dt VOUT = 1.8V, no load LX Leakage Current ILEAK_LX VLX = VIN = 5.5V, TA = +25°C Inductor Peak Current Limit IPEAK_LX High-Side RDSON Low-Side RDSON Zero-Crossing Threshold Enable Input Leakage Enable Voltage Threshold Active Discharge Resistance (MAX38640/ 1/3 Only) www.maximintegrated.com RDS_H RDS_L IZX_LX ILEAK_EN mV V VLREG Soft-Start Slew Rate % 660 mV/µs 2 100 800 1000 1200 MAX38641/MAX38642 400 500 600 MAX38640 225 250 300 MAX38643 95 150 MAX38641/ MAX38642 170 320 MAX38640 320 600 MAX38643 50 90 MAX38641/ MAX38642 80 160 MAX38640 150 290 VIN = 3.3V VOUT = 1.2V, percent of IPEAK_LX 5 VEN = 5.5V, TA = +25°C 100 0.8 1.2 VEN rising VEN_F VEN falling 0.4 0.7 ROUT_DIS VEN = 0V 50 85 nA mA mΩ mΩ % 0.1 VEN_R nA nA MAX38643 VIN = 3.3V V 5 VOUT_ACC DC Line Regulation 2.7 0.5 OUT falling, when LX begins switching above 1MHz, VOUT = 0.7V to 3.3V, VIN = 5.5V (Note 3) Output Accuracy mV 200 nA V Ω Maxim Integrated | 3 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Electrical Characteristics (continued) (VIN = 3.3V, VOUT = 1.8V, TA = -40°C to +85°C, CIN = 10µF, COUT = 22µF, unless otherwise specified. (Note 2)) PARAMETER SYMBOL CONDITIONS MIN Required Select Resistor Accuracy (MAX38640A/1A/2A/3A Only) RSEL Use the nearest ±1% resistor from Table 1 -1 Select Resistor Detection Time (MAX38640A/1A/2A/3A Only) tRSEL CSEL < 2pF Thermal Shutdown TSHUT TJ rising when output turns off 165 °C Thermal Shutdown Threshold TSHUT TJ falling when output turns on 150 °C 240 TYP 600 MAX UNITS +1 % 1320 µs Note 2: Limits over the specified operating temperature and supply voltage range are guaranteed by design and characterization, and production tested at room temperature only. Note 3: Output Accuracy in low-power mode (LPM) and does not include load, line, or ripple. www.maximintegrated.com Maxim Integrated | 4 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Typical Operating Characteristics (MAX38640AENT+, VIN = 3.6V, VOUT = 1.8V, L = 2.2μH, CIN = 10μF, COUT = 22μF, TA = +25°C, unless otherwise noted.) www.maximintegrated.com Maxim Integrated | 5 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Typical Operating Characteristics (continued) (MAX38640AENT+, VIN = 3.6V, VOUT = 1.8V, L = 2.2μH, CIN = 10μF, COUT = 22μF, TA = +25°C, unless otherwise noted.) www.maximintegrated.com Maxim Integrated | 6 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Typical Operating Characteristics (continued) (MAX38640AENT+, VIN = 3.6V, VOUT = 1.8V, L = 2.2μH, CIN = 10μF, COUT = 22μF, TA = +25°C, unless otherwise noted.) www.maximintegrated.com Maxim Integrated | 7 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Pin Configurations 6 µDFN IN 1 LX 2 GND 3 MAX3864xxELT+ 6 EN 5 OUT 4 RSEL/NC 6 WLP A 1 2 3 IN LX GND MAX3864xxENT+ B www.maximintegrated.com EN OUT RSEL/ NC Maxim Integrated | 8 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Pin Descriptions PIN MAX3864xxE LT+ MAX3864xxE NT+ NAME FUNCTION 1 A1 IN Regulator Supply Input. Connect to a voltage between 1.8V and 5.5V and bypass with a ceramic capacitor from IN to GND. 2 A2 LX Switching Node. Connect an inductor between LX and the regulator output. 3 A3 GND 4 B3 RSEL/NC Ground. MAX38640A/1A/2A/3A: Output Voltage Select Input. Connect a resistor from RSEL to GND to program the output voltage and IN undervoltage threshold based on Table 1. MAX38640B/1B/2B/3B: No Connect. Leave floating. 5 B2 OUT 6 B1 EN www.maximintegrated.com Output Voltage Sense Input. Connect to the load at a point where accurate regulation (output capacitor) is required to eliminate resistive metal drops. Enable Input. Force this pin high to enable the buck converter. Force this pin low to disable the part and enter shutdown. Maxim Integrated | 9 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Functional Diagram INPUT MAX38640A MAX38640B IN REVERSE BLOCKING CIN 10µF UVLO CURRENT SENSE EN MODULATOR THERMAL SHUTDOWN 0.6V REFERENCE REFERENCE RSEL (MAX38640A ONLY) LX OUT 2.2µH OUTPUT COUT 22µF OPTIONAL ACTIVE DISCHARGE UVLO AND TARGET OUTPUT SELECTOR RSEL GND www.maximintegrated.com Maxim Integrated | 10 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Detailed Description The MAX38640–MAX38643 are ultra-low IQ (330nA) buck converters that step down from 1.8V to 5.5V to wide range of output voltages between 0.5V and 5V. The output voltage is either programmable on the MAX38640A/1A/2A/3A versions using an external resistor or fixed for the MAX38640B/1B/2B/3B versions. The external RSEL resistor on the RSEL pin programs the output voltage upon startup for the MAX38640A/1A/2A/3A versions. The buck converter automatically switches between ultra-low-power mode (ULPM), low-power mode (LPM), and highpower mode (HPM) to better service the load, depending on the load current. The buck converter overregulates in ultralow-power mode to allow the output capacitor to handle the transient load currents. The device has 90% duty cycle limitation. Active discharge resistor in the MAX38640/MAX38641/MAX38643 pulls OUT to ground when the part is in shutdown. Active discharge has been strategically omitted for the MAX38642 to preserve the charge on the output capacitor in shutdown. Harvesting applications where the output is connected to a supercapacitor can take advantage of reversecurrent blocking feature to preserve the charge on the output capacitor even if the input were to fall below the output in shutdown. Applications where two MAX38642 buck converters are connected in parallel to drive the load can have the input of one of the buck converters to go to 0V in shutdown without dragging the output down or loading the other buck. Voltage Configuration The MAX38640A/1A/2A/3A includes an RSEL pin to configure the output voltage and input UVLO threshold on startup. Resistors with tolerance 1% (or better) should be chosen, with nominal values specified in Table 1. Table 1. MAX38640A/1A/2A/3A RSEL Selection Table TARGET OUTPUT VOLTAGE (V) RSEL (kΩ) INPUT UVLO THRESHOLD, RISING (V) 2.5 OPEN 1.75 2 909 1.75 1.8 768 1.75 1.5 634 1.75 1.3 536 1.75 1.25 452 1.75 1.2 383 1.75 1.15 324 1.75 1.1 267 1.75 1.05 226 1.75 1 191 1.75 0.95 162 1.75 0.9 133 1.75 0.85 113 1.75 0.8 95.3 1.75 0.75 80.6 1.75 0.7 66.5 1.75 3.3 56.2 2.6 3 47.5 2.6 2.8 40.2 2.6 www.maximintegrated.com Maxim Integrated | 11 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Table 1. MAX38640A/1A/2A/3A RSEL Selection Table (continued) TARGET OUTPUT VOLTAGE (V) RSEL (kΩ) INPUT UVLO THRESHOLD, RISING (V) 2.75 34 2.6 2.5 28 2.6 2 23.7 2.6 1.8 20 2.6 1.5 16.9 2.6 1.25 14 2.6 1.2 11.8 2.6 1.15 10 2.6 1.1 8.45 2.6 1 7.15 2.6 0.95 5.9 2.6 0.9 4.99 2.6 0.8 SHORT TO GND 2.6 The MAX38640B/1B/2B/3B has a fixed output voltage that is preprogrammed (no RSEL programming). Contact Maxim to order a part with other preprogrammed output voltage selections. The input UVLO threshold for MAX38640B/1B/2B/ 3B is 1.75V (typ, VIN rising) with 50mV hysteresis (typ). www.maximintegrated.com Maxim Integrated | 12 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Applications Information Inductor Selection The inductor value for the MAX38640–MAX38643 affects the ripple current, the transition point from low-power mode (LPM) to ultra-low-power mode (ULPM), and the overall efficiency performance. Based on the peak current limit required for different applications, it is recommended to select an inductor value based on Table 2. Table 2. Inductor Selection PEAK CURRENT, PART NUMBER INDUCTANCE RANGE (µH) 1.0A, MAX38643 1.0 to 1.5 500mA, MAX38641/MAX38642 2.2 250mA, MAX38640 2.2 to 4.7 Input Capacitor The input capacitor (CIN) reduces the peak current drawn from the battery or input power source and reduces the switching noise in the IC. The impedance of CIN at the switching frequency should be very low. Ceramic capacitors are recommended with their small size and low ESR. For most MAX38640 applications, use a 10µF ceramic capacitor with X5R or X7R temperature characteristics. For MAX38641–MAX38643 applications, using a 22µF ceramic input capacitor is recommended. When operating at VIN close to the UVLO, more input capacitance may be required to keep the input voltage ripple from tripping the UVLO protection. Output Capacitor The output capacitor (COUT) is required to keep the output voltage ripple small and to ensure loop stability. COUT must have low impedance at the switching frequency. Ceramic capacitors are recommended due to their small size and low ESR. Make sure the capacitor does not degrade its capacitance significantly over temperature and DC bias. Capacitors with X5R or X7R temperature characteristics typically perform well. A 22µF ceramic capacitor is recommended for most MAX38640 and MAX38641/MAX38642 applications. In case of low VOUT target levels when using the MAX38641/ MAX38642, two 22µF output capacitors are recommended. For MAX38643 applications, use two 22µF output capacitors. Enabling Device The device has a dedicated EN pin. This pin can be driven by a digital signal. It is recommended that the digital signal enables the device after VIN crosses the UVLO threshold. In applications where EN is tied to IN, the device is designed to be powered by fast VIN slew rates. If VIN slew rates are slower than 5V/ms, users must delay enabling the device until after VIN crosses the UVLO threshold. This can be done using a simple RC circuit, as shown in Figure 1. IN BAT54 REN EN CEN Figure 1. RC Circuit at EN www.maximintegrated.com Maxim Integrated | 13 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter PCB Layout and Routing High switching frequencies and large peak currents make PCB layout a very important part of the buck regulator design. Good design minimizes excessive electromagnetic interference (EMI) on the feedback paths and voltage gradients in the ground plane to avoid instability and regulation errors. The input capacitor (CIN) should be placed as close as possible to the IC pins IN and GND. Connect the inductor, CIN, and output capacitor (COUT) as close together as possible, and keep their traces short, direct, and wide. Connect the two GND pins under the IC and directly to the ground of COUT. Keep noisy traces, such as the LX node, as short as possible. The OUT pin should be connected to the output capacitor and this trace should be routed away from the main power path between the inductor and COUT. The OUT trace should also be routed away from noisy traces such as the LX line or other external noise sources. Refer to the MAX38640–MAX38643 evaluation kit for an example PCB layout and routing scheme. Ordering Information OUTPUT CURRENT (mA) ACTIVE DISCHARGE MAX38640AELT+ 175 Yes MAX38641AELT+ 350 Yes MAX38642AELT+ 350 No MAX38643AELT+ 700 Yes MAX38640BELT+* 175 Yes MAX38641BELT+* 350 Yes MAX38642BELT+* 350 No MAX38643BELT+* 700 Yes MAX38640BELT18+T 175 Yes MAX38640AENT+ 175 Yes MAX38641AENT+ 350 Yes MAX38642AENT+ 350 No MAX38643AENT+ 700 Yes MAX38640BENT+* 175 Yes MAX38642BENT+* 350 No MAX38643BENT+* 700 Yes MAX38641BENT135+ 350 Yes 1.35V Preprogrammed Output Voltage MAX38640BENT06+T 175 Yes 0.6V Preprogrammed Output Voltage MAX38640BENT21+T 175 Yes 2.1V Preprogrammed Output Voltage MAX38643BENT185+T 700 Yes 1.85V Preprogrammed Output Voltage MAX38641BENT12+T 350 Yes 1.2V Preprogrammed Output Voltage MAX38640BENT18+T 175 Yes 1.8V Preprogrammed Output Voltage PART NUMBER FEATURES PACKAGE 0.7V to 3.3V Resistor-Selectable Output Voltage Using RSEL Pin 6-pin, 2mm x 2mm μDFN 0.5V to 5V Preprogrammed Output Voltage 1.8V Preprogrammed Output Voltage 0.7V to 3.3V Resistor-Selectable Output Voltage Using RSEL Pin 0.5V to 5V Preprogrammed Output Voltage 0.4mm pitch, 6-pin (2x3) WLP *Future product—contact factory for availability. +Denotes a lead(Pb)-free/RoHS-compliant package. T = tape-and-reel. www.maximintegrated.com Maxim Integrated | 14 MAX38640–MAX38643 Tiny 1.8V to 5.5V Input, 330nA IQ, 700mA nanoPower Buck Converter Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 10/18 Initial release 1 1/19 Updated Typical Operating Characteristics, Pin Descriptions, Functional Diagram, Applications Information, and Ordering Information 5, 6, 8, 9, 13, 14 2 5/19 Updated title of data sheet and changed part number references, updated Typical Operating Characteristics 1, 3–5, 7, 9–15 3 4/20 Updated Ordering Information 4 9/20 Updated Ordering Information 5 3/21 Removed Table 2, updated Ordering Information 6 8/21 Updated Absolute Maximum Ratings, Electrical Characteristics, Functional Diagram, and Ordering Information DESCRIPTION — 14 14 12, 14 2, 3, 10, 14 For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html. 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. © 2021 Maxim Integrated Products, Inc.