EVALUATION KIT AVAILABLE Click here for production status of specific part numbers. MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module General Description The Himalaya series of voltage regulator ICs and power modules enable cooler, smaller, and simpler powersupply solutions. The MAXM17532 is a high-efficiency, synchronous, step-down DC-DC power module with integrated controller, MOSFETs, compensation components, and inductor that operates over a wide input-voltage range. The module operates from 4V to 42V input and delivers up to 100mA output current over a programmable output voltage from 0.9V to 5.5V. The module significantly reduces design complexity, manufacturing risks and offers a true “plug and play” power supply solution, reducing the time-to-market. The MAXM17532 employs peak-current-mode control architecture. To reduce input inrush current, the device offers a soft-start feature including the default soft-start time of 5.1ms. The MAXM17532 is available in a low profile, compact 10-pin 2.6mm x 3mm x 1.5mm uSLIC™ package. Applications ●● ●● ●● ●● ●● Industrial Sensors and Encoders 4-20mA Current-Loop Powered Sensors LDO Replacement HVAC and Building Control Battery-Powered Equipment Benefits and Features ●● Easy to use • Wide 4V to 42V Input • Adjustable 0.9V to 5.5V Output • ±1.75% Feedback Accuracy • Up to 100mA Output Current • Internally Compensated • All Ceramic Capacitors ●● High Efficiency • Fixed-Frequency PWM • Pulse Frequency Modulation (PFM) Mode to Enhance Light-Load Efficiency • Shutdown Current as Low as 1.2μA (typ) ●● Flexible Design • Programmable Soft-Start and Prebias Startup • Open-Drain Power Good Output (RESET Pin) • Programmable EN/UVLO Threshold ●● Robust Operation • Hiccup Overcurrent Protection • Overtemperature Protection • -40°C to +125°C Ambient OperatingTemperature / -40°C to +150°C Junction Temperature ●● Rugged • Complies with CISPR22 (EN55022) Class B Conducted and Radiated Emissions. • Passes Drop, Shock, and Vibration Standards– JESD22–B103, B104, B111 Ordering Information appears at end of data sheet. uSLIC is a trademark of Maxim Integrated Products, Inc. Typical Application Circuit VIN 24V CIN 2.2µF MAXM17532 IN EN/UVLO RESET RT/SYNC R3 69.8kΩ LX VOUT 5V, 100mA OUT GND R1 261kΩ FB SS MODE CIN = 2.2µF: C2012X7R1H225K125AC COUT = 10µF: GRM21BR70J106K 19-100038; Rev 5; 5/18 COUT 10µF R2 49.9kΩ MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Absolute Maximum Ratings IN, EN/UVLO to GND.............................................-0.3V to +48V LX to GND........................................................ -0.3V to IN +0.3V OUT to GND.............................................................-0.3V to +7V RT/SYNC, SS, FB, RESET, MODE to GND............-0.3V to +6V Output Short-Circuit Duration.....................................Continuous Junction Temperature (Note 1).........................................+150°C Storage Temperature Range............................. -55°C to +125°C Lead Temperature (soldering, 10s).................................. +260°C Soldering Temperature (reflow)........................................+260°C 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 PACKAGE TYPE: 10-PIN uSLIC Package Code M102A3+1 Outline Number 21-100094 Land Pattern Number 90-100027 THERMAL RESISTANCE FOUR-LAYER BOARD (Note 2) Junction to Ambient (θJA) 30.6°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. Note 1: Junction temperature greater than +125°C degrades operating lifetimes Note 2: Package thermal resistance measured on Evaluation Board, Natural convection. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial. www.maximintegrated.com Maxim Integrated │ 2 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Electrical Characteristics (VIN = 24V, VGND = 0V, VFB = 0.85V, VEN/UVLO = 1.5V, RT/SYNC = 69.8kΩ, LX = SS = RESET = unconnected, MODE = GND; TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages are referenced to GND, unless otherwise noted) (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 42 V µA INPUT SUPPLY (IN) Input Voltage Range Input Shutdown Current VIN 4 IIN-SH VEN/UVLO = 0V, TA = +25°C IQ-PFM VMODE = unconnected IQ-PWM VFB = Normal switching, VMODE = 0V, VOUT = 3.3V Input Supply Current 0.67 1.2 2.25 30 62 110 µA 800 1100 1950 MODULE OUTPUT PIN (OUT) Output Line Regulation Accuracy VIN = 4V to 42V, VOUT = 3.3V, ILOAD = 0 0.1 mV/V Output Load Regulation Accuracy Tested with IOUT = 0A and 100mA VOUT = 3.3V 0.3 mV/mA ENABLE/UVLO (EN/UVLO) VENR EN/UVLO Threshold VENF VEN-TRUESD EN/UVLO Leakage Current IEN VEN/UVLO rising 1.2 1.25 1.3 VEN/UVLO falling 1.1 1.15 1.2 V -100 +100 nA VEN = 0V, TA = +25°C, VLX = (VGND + 1V) to (VIN - 1V) VOUT = float -1 +1 µA No SS cap 4.4 5.1 5.8 ms VSS = 0.4V 4.7 5 5.3 µA MODE = OPEN 0.786 0.812 0.830 MODE = GND 0.786 0.8 0.814 VFB = 0.81V, TA = 25°C -100 VEN/UVLO falling, true shutdown VEN/UVLO = 1.3V, TA = +25°C 0.72 LX LX Leakage Current ILX-LKG SOFT-START (SS) Soft-Start Time SS Charging Current tSS ISS FEEDBACK (FB) FB Regulation Voltage FB Input Leakage Current VFB-REG IFB +120 V nA CURRENT LIMIT VOUT Current-Limit VOUT Current-Limit ISOURCE-LIMIT ISINK-LIMIT 100 MODE = OPEN 178 -74 MODE = GND mA -50 mA -1 OSCILLATOR (RT/SYNC) Switching Frequency www.maximintegrated.com fSW RRT = 422kΩ 85 100 120 RRT = 191kΩ 200 220 250 RRT = 130kΩ 295 322 350 RRT = 69.8kΩ 540 600 640 RRT = 45.3kΩ 813 900 973 kHz Maxim Integrated │ 3 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Electrical Characteristics (continued) (VIN = 24V, VGND = 0V, VFB = 0.85V, VEN/UVLO = 1.5V, RT/SYNC = 69.8kΩ, LX = SS = RESET = unconnected, MODE = GND; TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages are referenced to GND, unless otherwise noted) (Note 3) PARAMETER SYMBOL MAX UNITS 100 900 kHz SYNC Input Frequency 1.1 x fSW 900 kHz SYNC Pulse Minimum Off-Time 40 Switching Frequency Adjustable Range SYNC Rising Threshold Hysteresis CONDITIONS MIN See the Switching Frequency (RT/SYNC) section for details TYP ns VSYNC-H 1 1.22 1.48 VSYNC-HYS 0.115 0.18 0.265 Number of SYNC Pulses to Enable Synchronization 1 V Cycles MODE MODE PFM Threshold VMODE-PFM MODE Hysteresis VMODE-HYS 1.00 1.22 1.48 0.19 V V TIMING Minimum On-Time Maximum Duty Cycle tON-MIN DMAX 46 90 152 VFB = 0.98 x VFB-REG fSW ≤ 600kHz 90 94 98 600kHz < fSW < 900kHz, VFB = 0.98 x VFB-REG 87 92 ns % Hiccup Timeout 51 ms RESET FB Threshold for RESET Rising VFB-OKR VFB rising 93 95 97 % FB Threshold for RESET Falling VFB-OKF VFB falling 90 92 94 % RESET Delay after FB Reaches 95% Regulation RESET Output Level Low IRESET = 1mA RESET Output Leakage Current VFB = 1.01 x VFB-REG, TA = +25°C 2.08 ms 0.23 V 1 µA THERMAL SHUTDOWN Thermal-Shutdown Threshold Temperature rising Thermal-Shutdown Hysteresis 160 °C 20 °C Note 3: All limits are 100% tested at +25°C. Limits over temperature are guaranteed by design. www.maximintegrated.com Maxim Integrated │ 4 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Typical Operating Characteristics (VIN = 24V, VEN/UVLO = 1.5V, RT/SYNC = 69.8kΩ, MODE = GND, TA = +25°C unless otherwise noted) toc01 toc02 100 90 80 80 3.340 70 70 60 50 VIN = 24V 40 VIN = 36V VIN = 12V 60 30 20 10 10 20 40 60 80 VIN = 24V 40 20 0 VIN = 36V 50 30 100 LOAD AND LINE REGULATION (5V OUTPUT, PWM MODE) 5.05 toc04 OUTPUT VOLTAGE (V) 90 VIN = 12V 0 20 3.325 3.320 40 60 80 3.300 100 VIN = 36V 4.85 VIN = 12V 4.80 EFFICIENCY vs. LOAD CURRENT (5V OUTPUT PFM MODE) 80 VIN = 12V VIN = 24V VIN = 36V 40 30 4.70 10 0 10 20 30 40 50 60 70 80 90 100 LOAD AND LINE REGULATION (3.3V OUTPUT, PFM MODE) 3.50 70 60 VIN = 12V 50 VIN = 24V VIN = 36V 40 30 20 MODE = OPEN 1 10 LOAD CURRENT (mA) 10 100 MODE = OPEN 1 10 100 LOAD CURRENT (mA) LOAD AND LINE REGULATION (5V OUTPUT, PFM MODE) toc07 toc06 100 toc05 90 50 20 10 20 30 40 50 60 70 80 90 100 EFFICIENCY vs. LOAD CURRENT (3.3V OUTPUT PFM MODE) 60 4.75 0 LOAD CURRENT (mA) EFFICIENCY (%) EFFICIENCY (%) VIN = 24V VIN = 36V VIN = 12V 3.315 LOAD CURRENT (mA) LOAD CURRENT (mA) 5.20 toc08 SOFT-START FROM EN/UVLO (3.3V OUTPUT, 100MA LOAD CURRENT, PWM MODE) toc09 5.15 3.45 5.10 3.40 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 3.330 70 4.90 3.35 3.30 VIN = 12V VIN = 24V VIN = 36V 3.25 MODE = OPEN 3.20 3.335 80 4.95 VIN = 24V 3.305 90 5.00 toc03 3.310 LOAD CURRENT (mA) OUTPUT VOLTAGE (V) 3.350 3.345 EFFICIENCY (%) EFFICIENCY (%) 100 LOAD AND LINE REGULATION (3.3V OUTPUT, PWM MODE) EFFICIENCY vs. LOAD CURRENT (5V OUTPUT, PWM MODE) EFFICIENCY vs. LOAD CURRENT (3.3V OUTPUT, PWM MODE) 0 20 40 60 LOAD CURRENT (mA) 80 5.00 1V/div 4.95 VOUT VIN = 12V 4.90 VIN = 36V VIN = 24V 0 20 40 60 80 50mA/div 5V/div VRESET MODE = OPEN 4.80 LOAD CURRENT (mA) www.maximintegrated.com IOUT 4.85 100 5V/div VEN/UVLO 5.05 100 1ms/div Maxim Integrated │ 5 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Typical Operating Characteristics (continued) (VIN = 24V, VEN/UVLO = 1.5V, RT/SYNC = 69.8kΩ, MODE = GND, TA = +25°C unless otherwise noted) SHUTDOWN FROM EN/UVLO (5V OUTPUT, 100mA LOAD CURRENT, PWM MODE) SOFT-START FROM EN/UVLO (5V OUTPUT, 100mA LOAD CURRENT, PWM MODE) SOFT-START WITH 3V PREBIAS (5V OUTPUT, NO LOAD, PWM MODE) TOC11 toc10 toc12 VEN/UVLO 5V/div VEN/UVLO VOUT IOUT 2V/div VOUT IOUT 5V/div 5V/div VEN/UVLO 1V/di v 2V/div 50mA/div 5V/div VRESET 50mA/div VRESET 5V/div 1ms/div 1ms/div SOFT-START WITH 3V PREBIAS, (5V OUTPUT, 100mA LOAD CURRENT, PWM MODE) STEADY-STATE SWITCHING WAVEFORMS (5V OUTPUT, NO LOAD, PWM MODE) toc13 5V/div VOUT VRESET 1ms/div STEADY-STATE SWITCHING WAVEFORMS (5V OUTPUT, 0.1A LOAD CURRENT, PWM MODE) toc15 toc14 5V/div VOU VEN/UVLO VOUT VOUT (AC) 10mV/div T 2V/div (AC) 10mV/div 100mA/div IOUT 5V/div VLX 1ms/div AVERAGE CURRENT LIMIT (mA) 10V/div 210 200 190 TEMP = 25°C 180 TEMP = -40°C 170 610 600 590 5 10 15 20 25 30 INPUT VOLTAGE (V) 35 40 45 -40°C 25°C 580 85°C 570 560 0 toc18 620 TEMP = 85°C 220 SWITCHING FREQUENCY vs. INPUT VOLTAGE 630 230 160 www.maximintegrated.com toc17 240 50mV/div (ACCOUPLED) 10µs/div 2μs/div AVERAGE CURRENT LIMIT toc16 VLX 10V/div 2μs/div STEADY-STATE SWITCHING WAVEFORMS (VIN = 24V, VOUT = 5V, IOUT = 20mA, PFM) VOUT (AC) VLX 10V/div SWITCHING FREQUENCY (kHz) VRESET 0 5 10 15 20 25 30 35 40 45 INPUT VOLTAGE (V) Maxim Integrated │ 6 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Typical Operating Characteristics (continued) (VIN = 24V, VEN/UVLO = 1.5V, RT/SYNC = 69.8kΩ, MODE = GND, TA = +25°C unless otherwise noted) SHUTDOWN CURRENT vs. INPUT VOLTAGE LOAD CURRENT TRANSIENT RESPONSE (VIN = 24V, VOUT = 5V, IOUT = 0.05A TO 0.1A) toc19 3.0 toc20 SHUTDOWN CURRENT (µA) 2.5 25° 2.0 50mV/div (AC COUPLED) VOUT 1.5 1.0 0.5 TEMP = 25°C IOUT 0.0 0 7 14 21 28 35 42 50mA/div 100µs/div INPUT VOLTAGE (V) LOAD CURRENT TRANSIENT RESPONSE (VIN = 24V, VOUT = 3.3V, IOUT = 0.05A TO 0.1A) LOAD CURRENT TRANSIENT RESPONSE (VIN = 24V, VOUT = 5V, IOUT = 0A TO 0.05A) toc22 toc21 50mV/div (AC COUPLED) VOUT IOUT VOUT 50mV/div (AC COUPLED) IOUT 50mA/div 50mA/div 200µs/div 100µs/div LOAD CURRENT TRANSIENT RESPONSE (VIN = 24V, VOUT = 3.3V, IOUT = 0A TO 0.05A) LOAD CURRENT TRANSIENT RESPONSE (VIN = 24V, VOUT = 5V, IOUT = 25mA to 75mA) toc24 toc23 50mV/div (AC COUPLED) VOUT 50mA/div IOUT IOUT 50mA/div 200µs/div www.maximintegrated.com 100mV/div (ACCOUPLED) VOUT (AC) 200µs/div Maxim Integrated │ 7 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Typical Operating Characteristics (continued) (VIN = 24V, VEN/UVLO = 1.5V, RT/SYNC = 69.8kΩ, MODE = GND, TA = +25°C unless otherwise noted) EXTERNAL SYNCHRONIZATION WITH 900kHz CLOCK FREQUENCY (VIN = 24V, VOUT = 5V, IOUT = 0.1A) LOAD CURRENT TRANSIENT RESPONSE (VIN = 24V, VOUT = 3.3V, IOUT = 20mA to 75mA) toc26 toc25 100mV/div (ACCOUPLED) VOUT (AC) VLX 10V/div 50mA/div IOUT 2V/div VSYNC 200µs/div 2µs/div OVERLOAD PROTECTION OVERLOAD PROTECTION toc27 toc28 2V/div VOUT IOUT 100mA/div 20V/div LX 40µs/div 20ms/div BODE PLOT (VIN = 24V, VOUT = 3.3V, IOUT = 0.1A) toc29 40 PHASE 30 20 60 20 10 50 10 0 40 GAIN -10 30 -20 -30 20 fCR = 22.3kHz, PHASE MARGIN = 65.2° -40 103 104 FREQUENCY (Hz) www.maximintegrated.com 105 GAIN (dB) 70 PHASE (°) GAIN (dB) 30 toc30 40 80 PHASE 70 60 50 40 0 30 20 GAIN -10 10 -20 10 -30 0 -40 103 80 PHASE (°) BODE PLOT (VIN = 24V, VOUT = 5V, IOUT = 0.1A) 0 fCR = 26.4kHz, PHASE MARGIN = 59.8° 104 FREQUENCY (Hz) -10 -20 105 Maxim Integrated │ 8 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Pin Configuration LX 1 GND 2 MODE 3 RESET OUT + TOP VIEW 10 IN 9 EN/UVLO 8 RT/SYNC 4 7 SS 5 6 FB MAXM17532 ‘+’ INDICATES PIN 1 OF THE MODULE Pin Description PIN NAME PIN # LX 1 Switching Node. LX is high impedance when the device is in shutdown. Do not connect any external components to this pin. GND 2 Ground. Connect GND to the power ground plane. Connect all the circuit ground connections together at a single point. See the PCB Layout Guidelines section. MODE 3 PFM/PWM Mode Selection Input. Connect MODE to GND to enable the fixed-frequency PWM. Leave MODE unconnected for light-load PFM operation. RESET 4 Open-Drain Reset Output. Pull up RESET to an external power supply less than or equal to 5.5V with an external resistor. RESET pulls low if FB drops below 92% of its set value. RESET goes high 2ms after FB rises above 95% of its set value. OUT 5 Module output pin. Connect a capacitor from OUT to GND. See PCB Layout Guidelines section for more connection details. FB 6 Output Feedback Connection. Connect FB to a resistor-divider between OUT and GND to set the output voltage. SS 7 Soft-Start Capacitor Input. Connect a capacitor from SS to GND to set the soft-start time. Leave SS unconnected for default 5.1ms internal soft-start. RT/SYNC 8 Oscillator Timing Resistor Input. Connect a resistor from RT/SYNC to GND to program the switching frequency from 100kHz to 900kHz. See the Switching Frequency (RT/SYNC) section for details. An external pulse can be applied to RT/SYNC through a coupling capacitor to synchronize the internal clock to the external pulse frequency. EN/UVLO 9 Active-High, Enable/Undervoltage-Detection Input. Pull EN/UVLO to GND to disable the module output. Connect EN/UVLO to IN for always-on operation. Connect a resistor-divider between IN, EN/ UVLO, and GND to program the input voltage at which the module is enabled and turns on. IN 10 Power Module Input. Connect a ceramic capacitor from IN to GND for bypassing. Place the capacitor close to the IN and PGND pins. See Component Selection tables for more details. www.maximintegrated.com FUNCTION Maxim Integrated │ 9 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Functional Diagram MAXM17532 IN LDO VCC_INT HIGH-SIDE DRIVER OSCILLATOR RT/SYNC LX VCC_INT MODE 1.22V PEAK CURRENT MODE CONTROLLER 100µH OUT EN/UVLO LOW-SIDE DRIVER 1.25V GND SS RESET FB 0.76V Detailed Description The MAXM17532 high-voltage, synchronous step-down power module with integrated MOSFETs and inductor, operates over a 4V to 42V input voltage range. The module can deliver output current up to 100mA at output voltages of 0.9V to 5.5V. The feedback voltage is accurate to within ±1.75% over -40°C to +125°C. The device uses an internally-compensated, peak current mode control architecture. On the rising edge of the internal clock, the high-side pMOSFET turns on. An internal error amplifier compares the feedback voltage to a fixed internal reference voltage and generates an error www.maximintegrated.com PGOOD LOGIC voltage. The error voltage is compared to a sum of the current-sense voltage and a slope-compensation voltage by a PWM comparator to set the “on-time.” During the on-time of the pMOSFET, the inductor current ramps up. For the remainder of the switching period (off-time), the pMOSFET is kept off and the low-side nMOSFET turns on. During the off-time, the inductor releases the stored energy as the inductor current ramps down, providing current to the output. Under overload conditions, the cycleby-cycle current- limit feature limits inductor peak current by turning off the high-side pMOSFET and turning on the low-side nMOSFET. Maxim Integrated │ 10 MAXM17532 Mode Selection (MODE) The device features a MODE pin for selecting either forced-PWM or PFM mode of operation. If the MODE pin is left unconnected, the device operates in PFM mode at light loads. If the MODE pin is grounded, the device operates in a constant-frequency forced-PWM mode at all loads. The mode of operation cannot be changed on-the fly during normal operation of the device. In PWM mode, the inductor current is allowed to go negative. PWM operation is useful in frequency-sensitive applications and provides fixed switching frequency at all loads. However, the PWM mode of operation gives lower efficiency at light loads compared to PFM mode of operation. PFM mode disables negative inductor current and additionally skips pulses at light loads for high efficiency. In PFM mode, the inductor current is forced to a fixed peak of 72mA (typ) (IPFM) every clock cycle until the output rises to 102% (typ) of the nominal voltage. Once the output reaches 102% (typ) of the nominal voltage, both high-side and low-side FETs are turned off and the device enters hibernation mode until the load discharges the output to 101% (typ) of the nominal voltage. Most of the internal blocks are turned off in hibernation mode to save quiescent current. Once the output falls below 101% (typ) of the nominal voltage, the device comes out of hibernation mode, turns on all internal blocks, and again commences the process of delivering pulses of energy to the output until it reaches 102% (typ) of the nominal output voltage. The device naturally exits PFM mode when the inductor peak current increases to a magnitude approximately equal to IPFM. 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Undervoltage-Lockout Level section for details. If input UVLO programming is not desired, connect EN/UVLO to IN (see the Electrical Characteristics table for EN/UVLO rising and falling-threshold voltages). Driving EN/UVLO low disables both power MOSFETs, as well as other internal circuitry, and reduces IN quiescent current to below 1.2μA. The SS capacitor is discharged with an internal pulldown resistor when EN/UVLO is low. If the EN/UVLO pin is driven from an external signal source, a series resistance of minimum 1kΩ is recommended to be placed between the signal source output and the EN/UVLO pin, to reduce voltage ringing on the line. Switching Frequency (RT/SYNC) Switching frequency of the device can be programmed from 100kHz to 900kHz by using a resistor connected from RT/SYNC to GND. The switching frequency (fSW) is related to the resistor connected at the RT/SYNC pin (RT) by the following equation, where RT is in kΩ and fSW is in kHz: RT = 42000 f SW MAXM17532 47pF RT/SYNC CLOCK SOURCE RT Enable Input (EN/UVLO) and Soft-Start (SS) When EN/UVLO voltage increases above 1.25V (typ), the device initiates a soft-start sequence and the duration of the soft-start depends on the status of the SS pin voltage at the time of power-up. If the SS pin is not connected, the device uses a fixed 5.1ms (typ) internal soft-start to ramp up the internal error-amplifier reference. If a capacitor is connected from SS to GND, a 5μA current source charges the capacitor and ramps up the SS pin voltage. The SS pin voltage is used as a reference for the internal error amplifier. Such a reference ramp up allows the output voltage to increase monotonically from zero to the final set value independent of the load current. Figure 1. Synchronization to an External Clock EN/UVLO can be used as an input voltage UVLO adjustment input. An external voltage-divider between IN and EN/UVLO to GND adjusts the input voltage at which the device turns on or off. See the Setting the Input The RT/SYNC pin can be used to synchronize the device’s internal oscillator to an external system clock. The external clock should be coupled to the RT/SYNC www.maximintegrated.com VLOGIC-HIGH VLOGIC-LOW DUTY The switching frequency in ranges of 130kHz to 160kHz and 230kHz to 280kHz are not allowed for user programming to ensure proper configuration of the internal adaptive-loop compensation scheme. External Synchronization Maxim Integrated │ 11 MAXM17532 pin through a 47pF capacitor, as shown in Figure 1. The external clock logic high level should be higher than 3V, logic low level lower than 0.5V and the duty cycle of the external clock should be in the range of 10% to 70%. The RT resistor should be selected to set the switching frequency 10% lower than the external clock frequency. The external clock should be applied at least 500μs after enabling the device for proper configuration of the internal loop compensation. Reset Output (RESET) The device includes an open-drain RESET output to monitor output voltage. RESET should be pulled up with an external resistor to the desired external power supply less than or equal to 5.5V. RESET goes high impedance 2ms after the output rises above 95% of its nominal set value and pulls low when the output voltage falls below 92% of the set nominal output voltage. RESET asserts low during the hiccup timeout period. Startup Into a Pre-biased Output The device supports monotonic startup into a pre-biased output. When the module starts into a pre-biased output, both the high-side and low-side switches are turned off so that the module does not sink current from the output. High-side and low-side switches do not start switching until the PWM comparator commands the first PWM pulse, at which point switching commences. The output voltage is then smoothly ramped up to the target value in alignment with the internal reference. Such a feature is useful in applications where digital integrated circuits with multiple rails are powered. Operating Input-Voltage Range The maximum operating input voltage is determined by the minimum controllable on-time, while the minimum operating input voltage is determined by the maximum duty cycle and circuit voltage drops. The minimum and maximum operating input voltages for a given output voltage should be calculated as follows: = VIN(MIN) VOUT + (I OUT × 8.6) + (I OUT × 2.5) D MAX f for duty cycle, D > 0.3 : VIN(MIN) > 4.8 × VOUT − SW 42000 VOUT VIN(MAX) = t ON(MIN) × f SW www.maximintegrated.com 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module where, VOUT = Steady-state output voltage IOUT = Maximum load current fSW = Switching frequency (max) DMAX = Maximum duty cycle tON(MIN) = Worst case minimum controllable switch ontime (152ns). Overcurrent Protection (OCP), Hiccup Mode The device implements a HICCUP-type overload protection scheme to protect the inductor and internal FETs under output short-circuit conditions. When the overcurrent event occurs, the part enters hiccup mode. In this mode, the part is initially operated with hysteretic cycleby-cycle peak-current limit that continues for a time period equal to twice the soft-start time. The part is then turned off for a fixed 51ms hiccup timeout period. This sequence of hysteretic inductor current waveforms, followed by a hiccup timeout period, continues until the short/overload on the output is removed. Since the inductor current is bound between two limits, inductor current runway never happens. Thermal Shutdown Thermal shutdown limits the total power dissipation in the module. When the junction temperature exceeds +160°C, an on-chip thermal sensor shuts down the device, turns off the internal power MOSFETs, allowing the device to cool down. The device turns on after the junction temperature cools by approximately 20°C. Application Information FREQUENCY RANGE (kHZ) MINIMUM OUTPUT CAPACITANCE (µF) 100 to 130 50 VOUT 160 to 230 25 VOUT 280 to 900 17 VOUT Input Capacitor Selection Small ceramic input capacitors are recommended. The input capacitor reduces peak current drawn from the Maxim Integrated │ 12 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module power source and reduces noise and voltage ripple on the input caused by the switching circuitry. It is recommended to select the input capacitor of the module to keep the input-voltage ripple under 2% of the minimum input voltage, and to meet the maximum ripple-current requirements. Output Capacitor Selection Small ceramic X7R-grade output capacitors are recommended for the device. The output capacitor has two functions. It stores sufficient energy to support the output voltage under load transient conditions and stabilizes the device’s internal control loop. Usually the output capacitor is sized to support a step load of 50% of the maximum output current in the application, such that the output voltage deviation is less than 3%. Calculate the minimum required output capacitance from the following equations: It should be noted that dielectric materials used in ceramic capacitors exhibit capacitance loss due to DC bias levels and should be appropriately de-rated to ensure the required output capacitance is obtained in the application. Soft Start Capacitor Selection The device offers a 5.1ms internal soft-start when the SS pin is left unconnected. When adjustable soft-start time is required, connect a capacitor from SS to GND to program the soft-start time. The minimum soft-start time is related to the output capacitance (COUT) and the output voltage (VOUT) by the following equation: tSS > 0.05 x COUT x VOUT where tSS is in milliseconds and COUT is in µF. Soft-start time (tSS) is related to the capacitor connected at SS (CSS) by the following equation: CSS = 6.25 x tSS where tSS is in milliseconds and CSS is in nanofarads. Setting the Input Undervoltage-Lockout Level The device offers an adjustable input undervoltage-lockout level. Set the voltage at which the device turns on with a resistive voltage-divider connected from IN to GND (see Figure 2). Connect the center node of the divider to EN/ UVLO. Choose R1 to be 3.3MΩ max and then calculate R2 as follows: 1.25 × R 1 R2 = VINU − 1.25 VIN IN MAXM17532 R1 EN/UVLO R2 GND Figure 2. Adjustable EN/UVLO Network VOUT MAXM17532 R4 FB R5 GND Figure 3 Circuit for Setting the Output Voltage. Adjusting the Output Voltage The output voltage can be programmed from 0.9V to 5.5V. Different output voltage needs to use different switching frequency (see Table 1). Set the output voltage by connecting a resistor-divider from output to FB to GND (see Figure 3). Choose R5 in the range of 25kΩ to 100kΩ and calculate R4 with the following equation: V R4 = R5 × OUT − 1 0.8 where VINU is the voltage at which the device is required to turn on. www.maximintegrated.com Maxim Integrated │ 13 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Table 1. Selection Component Values VOUT (V) VIN (V) CIN fSW (kHz) RT (kΩ) R4 (kΩ) R5 (kΩ) COUT 0.9 4 to 26 2 x 1μF 1206 50V X7R 220 191 6.19 49.9 2 x 10μF 0805 6.3V X7R 1.2 4 to 35 2 x 2.2μF 1206 50V X7R 220 191 24.9 49.9 2 x 10μF 0805 6.3V X7R 1.5 4 to 32 2 x 2.2μF 1206 50V X7R 322 130 43.2 49.9 1 x 10μF 0805 6.3V X7R 1.8 4 to 39 2 x 2.2μF 1206 50V X7R 322 130 61.9 49.9 1 x 10μF 0805 6.3V X7R 2.5 4 to 41 2 x 2.2μF 0805 50V X7R 400 105 107 49.9 1 x 10μF 0805 6.3V X7R 3.3 6.5 to 42 1 x 1μF 0603 50V X7R 400 105 158 49.9 1 x 10μF 0805 6.3V X7R 3.3 6 to 36 1 x 2.2μF 1206 50V X7R 600 69.8 158 49.9 1 x 10μF 0805 6.3V X7R 5 10 to 42 1 x 2.2μF 0805 50V X7R 600 69.8 261 49.9 1 x 10μF 0805 6.3V X7R 5.5 10 to 42 1 x 2.2μF 0805 50V X7R 700 60 294 49.9 1 x 10μF 0805 6.3V X7R Transient Protection In applications where fast line transients or oscillations with a slew rate in excess of 15V/µs are expected during power-up or steady-state operation, the MAXM17532 should be protected with a series resistor that forms a low pass filter with the input ceramic capacitor (Figure 4). These transients can occur in conditions such as hot-plugging from a low-impedance source or due to inductive load switching and surges on the supply lines. 4.7Ω IN MAXM17532 CIN = 2.2µF GND Power Dissipation Ensure that the junction temperature of the devices do not exceed 125°C under the operating conditions specified for the power supply. At a particular operating condition, the power losses that lead to temperature rise of the device are estimated as follows: 1 = PLOSS POUT ( − 1) η P= V × OUT OUT I OUT where POUT is the output power, η is the efficiency of power conversion. See the Typical Operating Characteristics for the power-conversion efficiency or www.maximintegrated.com Figure 4. Circuit for Transient Protection measure the efficiency to determine the total power dissipation. The junction temperature (TJ) of the device can be estimated at any ambient temperature (TA) from the following equation: T= J T A + θ JA × PLOSS where θJA is the junction-to-ambient thermal impedance of the package. Maxim Integrated │ 14 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module PCB Layout Guidelines ●● Ensure that all feedback connections are short and direct Careful PCB layout (Figure 5) is critical to achieve clean and stable operation. The switching power stage requires particular attention. Follow these guidelines for good PCB layout: ●● Route high-speed switching node (LX) away from the signal pins For a sample PCB layout that ensures the first-pass success, refer to the MAXM17532 evaluation kit data sheet. ●● Place the input ceramic capacitor as close as possible to VIN and GND pins VIN CIN VOUT OUT IN MAXM17532 R1 LX EN/UVLO R2 R6 R4 RESET FB SS RT/SYNC MODE COUT R5 GND R3 CIN GND PLANE VIN PLANE + LX COUT 1 MAXM17532 10 IN R1 GND 2 9 EN/UVLO MODE 3 8 RT/SYNC RESET R6 4 7 SS 5 6 OUT R2 R3 FB R5 VOUT PLANE R4 GND PLANE VIAS TO BOTTOM SIDE GROUND PLANE Figure 5. Layout Guidelines www.maximintegrated.com Maxim Integrated │ 15 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Ordering Information PART TEMP RANGE PIN-PACKAGE MAXM17532AMB+ -40°C to +125°C 10-pin uSLIC MAXM17532AMB+T -40°C to +125°C 10-pin uSLIC +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. Chip Information PROCESS: BiCMOS www.maximintegrated.com Maxim Integrated │ 16 MAXM17532 4V to 42V, 100mA, Himalaya uSLIC Step-Down Power Module Revision History REVISION NUMBER REVISION DATE 0 5/17 Initial release 9/17 Updated all figures, and changed package type to uSLIC. Updated Benefits and Features, Absolute Maximum Ratings, Detailed Description, Enable Input (EN/ UVLO) and Soft-Start (SS), Operating Input-Voltage Range, Overcurrent Protection (OCP), Hiccup Mode, and Input Capacitor Selection sections. Updated Electrical Characteristics global characteristics, Pin Description table (pin 1 and pin 5), Table 1, Ordering Information, and Package Information table. Updated TOC01-TOC04 and TOC19, and added TOC22-TOC23. 1 1.1 2 2/18 2.1 PAGES CHANGED DESCRIPTION — 1–16 Added trademark information for uSLIC 1–2, 15 Updated the General Description, Applications, Benefits and Features, Absolute Maximum Ratings sections, and Package Information and Ordering Information table. 1–2, 15 Corrected typos 1 3/18 Updated the General Description and Benefits and Features sections. 1 4 4/18 Updated Benefits and Features, Electrical Characteristics table, Pin Description table, and TOC01–TOC04. Replaced Typical Application Circuit, Pin Configuration, Functional Diagram, and Figure 5. Added Mode Selection section, new TOC05– TOC08, TOC16 and TOC24–TOC25, and renumbered existing TOCs. 5 5/18 Updated the Electrical Characteristics table. 3 1, 3–10, 14 4 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. © 2018 Maxim Integrated Products, Inc. │ 17