Order Now Product Folder Support & Community Tools & Software Technical Documents LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 LMZM23601 36-V, 1-A Step-Down DC/DC Power Module in 3.8-mm × 3-mm Package 1 Features 3 Description • • The LMZM23601 integrated-inductor power module is specifically designed for space-constrained industrial applications. It is available in two fixed output voltage options of 5-V and 3.3-V, and an adjustable (ADJ) output voltage option supporting a 2.5-V to 15-V range. The LMZM23601 has an input voltage range of 4-V to 36-V and can deliver up to 1000-mA of output current. This power module is extremely easy to use, requiring only 2 external components for a 5-V or 3.3-V output design. All aspects of the LMZM23601 are optimized for performance driven and low EMI industrial applications with spaceconstrained needs. An open-drain, Power-Good output provides a true indication of the system status and negates the requirement for an additional supervisory component, saving cost and board space. Seamless transition between PWM and PFM modes along with a no-load supply current of only 28 µA ensures high efficiency and superior transient response for the entire load-current range. For easy output current scaling the LMZM23601 is pin-to-pin compatible with the 500-mA output current capable LMZM23600. 4-V to 36-V Wide Operating Input Voltage 2.5-V to 15-V Adjustable, and 3.3-V or 5-V Fixed Output Voltage Options 1-A Output Current Only Input and Output Capacitors Needed for 5-V and 3.3-V Output Designs 27-mm2 Solution Size With Single-Sided Layout 28-µA Supply Current at No Load 2-µA Shutdown Current Power-Good Flag External Frequency Synchronization MODE Selection Pin – Forced PWM Mode for Constant Frequency Operation – Auto PFM Mode for High Efficiency at Light Load Built-in Control Loop Compensation, Soft Start, Current Limit, and UVLO Miniature 3.8-mm × 3-mm × 1.6-mm Package Create a Custom Design Using the LMZM23601 With the WEBENCH® Power Designer 1 • • • • • • • • • • • Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM) MicroSiP™ (10) 3.80 mm × 3.00 mm 2 Applications LMZM23601 • • • • (1) For all available packages, see the orderable addendum at the end of the data sheet. Sensor Transmitters Test and Measurement Grid Infrastructure Space Constrained Applications space space space Single-Sided Layout Solution Size 24-V to 5-V, 1-A DC/DC Converter Schematic for Fixed Output Option 24-V to 5-V, 1-A DC/DC Converter DC-DC Module GND GND CIN VIN MODE/ SYNC CIN COUT VIN EN PGOOD FB VOUT VOUT COUT GND Copyright © 2017, Texas Instruments Incorporated 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Table of Contents 1 2 3 4 5 6 7 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Device Comparison ............................................... Pin Configuration and Functions ......................... Specifications......................................................... 7.1 7.2 7.3 7.4 7.5 7.6 7.7 8 Absolute Maximum Ratings ...................................... 5 ESD Ratings.............................................................. 5 Recommended Operating Conditions....................... 5 Thermal Information .................................................. 5 Electrical Characteristics........................................... 6 System Characteristics ............................................. 9 Typical Characteristics ............................................ 10 Detailed Description ............................................ 15 8.1 8.2 8.3 8.4 9 1 1 1 2 3 4 5 Overview ................................................................. Functional Block Diagram ....................................... Feature Description................................................. Device Functional Modes........................................ 15 15 15 20 Application and Implementation ........................ 21 9.1 Application Information............................................ 21 9.2 Typical Applications ................................................ 21 9.3 Do's and Don't's ...................................................... 32 10 Power Supply Recommendations ..................... 33 10.1 Supply Voltage Range .......................................... 33 10.2 Supply Current Capability ..................................... 33 10.3 Supply Input Connections ..................................... 33 11 Layout................................................................... 34 11.1 Layout Guidelines ................................................ 34 11.2 Layout Examples................................................... 35 12 Device and Documentation Support ................. 37 12.1 12.2 12.3 12.4 12.5 12.6 12.7 12.8 Device Support...................................................... Custom Design With WEBENCH® Tools ............. Documentation Support ........................................ Receiving Notification of Documentation Updates Community Resources.......................................... Trademarks ........................................................... Electrostatic Discharge Caution ............................ Glossary ................................................................ 37 37 37 37 37 38 38 38 13 Mechanical, Packaging, and Orderable Information ........................................................... 38 4 Revision History NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Original (December 2017) to Revision A • 2 Page First release of production-data data sheet; add links for WEBENCH................................................................................... 1 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 5 Device Comparison Table 1. LMZM23601 Device Options PART NUMBER LMZM23601SILR LMZM23601V3SILR LMZM23601V5SILR OUTPUT VOLTAGE PACKAGE QTY Adjustable 3000 3.3 V 3000 5V 3000 Adjustable 250 LMZM23601V3SILT 3.3 V 250 LMZM23601V5SILT 5V 250 LMZM23601SILT (1) (1) See Package Option Addendum for tape and reel details as well as links used to order parts. Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 3 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 6 Pin Configuration and Functions SIL Package 10-Pin MicroSiP Top View GND 1 MODE/SYNC 2 10 DNC 9 DNC 8 DNC Thermal Pad VIN 3 EN 4 7 FB PGOOD 5 6 VOUT Not to scale Pin Functions PIN NO. NAME 1 GND TYPE DESCRIPTION G Ground for all circuitry. Reference point for all voltages. 2 MODE/SY NC I This is a multifunction mode control input which is tolerant of voltages up to the input voltage. With this input tied LOW, the device is in Auto PFM mode with automatic transition between PFM and PWM with diode emulation at light load. This mode is recommended when the application requires high efficiency at light load. With this input tied HIGH, the device is in forced PWM mode. The device switches at the internal clock frequency. This mode is recommended when the application requires constant switching frequency across the entire load current. With a valid synchronization signal at this pin, the device switches in forced PWM mode at the external clock frequency and synchronized with it at the rising edge of the clock. Do not float this pin. 3 VIN P Input supply to the regulator. Connect a high-quality bypass capacitor(s) directly to this pin and the GND pin (pin 1). 4 EN I Enable input to the regulator. HIGH = ON, LOW = OFF. This pin can be connected to VIN. Do not float. 5 PGOOD O Open-drain, power-good output. Connect to a suitable voltage supply through a current limiting resistor. HIGH = power is good, LOW = fault. This output terminal is LOW when EN is LOW. 6 VOUT O Output voltage terminal. It is internally connected to one terminal of the integrated inductor. Connect an output filter capacitor from VOUT to GND and place the capacitor as close as possible to the VOUT pin. 7 FB I Feedback input to the regulator. If using the fixed 3.3-V or 5-V options of the device, connect this pin to the positive end of the output filter capacitor (the VOUT node). If using the adjustable output option of the device connect this to the feedback voltage divider and keep this node as small as possible on the board layout. 8 DNC O Do not connect. Leave floating. This pin provides access to the internal VCC voltage of the device. 9 DNC O Do not connect. Leave floating. This pin provides access to the internal BOOT voltage for the high side MOSFET driver. 10 DNC O Do not connect. Leave floating. This pin provides access to the internal SW voltage of the device. — G This terminal is internally connected to GND and provides a wide thermal connection from the IC to the PCB. Connect to electrical ground plane for adequate heat sinking. Thermal Pad G = Ground, I = Input, O = Output, P = Power 4 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 7 Specifications 7.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted) (1) MIN MAX UNIT VIN to GND –0.3 42 V SW to GND –0.3 VIN + 0.3 V BOOT to SW –0.3 3.6 V EN to GND –0.3 42 V FB to GND (3.3-V and 5-V options) –0.3 16 V FB to GND (ADJ option) –0.3 5.5 V PGOOD to GND –0.3 16 V 8 mA MODE/SYNC to GND –0.3 42 V VCC to GND -0.3 3.6 V Operating junction temperature, TJ –40 125 °C Storage temperature, Tstg –40 150 °C PGOOD sink current (1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. 7.2 ESD Ratings VALUE V(ESD) (1) (2) Electrostatic discharge Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins (1) ±2000 Charged device model (CDM), per JEDEC specification JESD22-C101, all pins (2) ±500 UNIT V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. 7.3 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) MIN VIN VOUT NOM MAX UNIT Input voltage 4 36 V Output voltage (5 V) 0 5 V Output voltage (3.3 V) Output voltage (ADJ) IOUT Output current (1 A) TJ Operating junction temperature 0 3.3 V 2.5 15 V 0 1 A –40 125 °C 7.4 Thermal Information LMZM2360x THERMAL METRIC (1) SIL (μSIP) UNIT 10 PINS RθJA Junction-to-ambient thermal resistance ΨJT ΨJB (1) 45 °C/W Junction-to-top characterization parameter 3 °C/W Junction-to-board characterization parameter 20 °C/W For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report. Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 5 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 7.5 Electrical Characteristics Limits apply over the recommended operating junction temperature range of -40°C to +125°C, unless otherwise stated. Minimum and maximum limits are ensured through test, design or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless otherwise stated, the following conditions apply: VIN = 24 V. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT FEEDBACK VFB Initial output voltage accuracy (3.3-V and 5-V fixed output) VIN = 4 V to 36 V, open loop –1.5% VFB Reference voltage (ADJ option) VIN = 4 V to 36 V, open loop 0.985 IFB Input current from FB to GND (ADJ option) FB = 1 V 1.5% 1 1.015 V 20 nA 7 µA CURRENT VIN = 12 V, VFB = +10%, VOUT = 5 V Operating quiescent current; measured at VIN pin IQ IB Bias current into the VOUT pin Shutdown quiescent current; measured at VIN pin ISD VIN = 12 V, VFB = +10%, VOUT = 5 V, TJ = 85°C 16 VIN = 12 V, VFB = +10%, VOUT = 5 V, TJ = 125°C 18 VIN = 24 V, VFB = +10%, VOUT = 5 V 12 µA VIN = 24 V, VFB = +10%, VOUT = 5 V, TJ = 85°C 24 VIN = 24 V, VFB = +10%, VOUT = 5 V, TJ = 125°C 26 VIN = 24 V, VFB = +10%, VOUT = 5 V, Mode = 0 V 48 EN = 0 V, VIN = 12 V, TJ = 25°C 1.8 EN = 0 V, VIN = 12 V, TJ = 85°C 80 3 EN = 0 V, VIN = 24 V, TJ = 25°C 5 EN = 0 V, VIN = 24 V, TJ = 85°C µA µA 10 UNDERVOLTAGE LOCKOUT (UVLO) VIN_UVLO Minimum input voltage to operate Rising 3.1 3.5 3.85 V VIN_UVLO_HYST UVLO hysteresis 0.2 0.25 0.3 V 6 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 Electrical Characteristics (continued) Limits apply over the recommended operating junction temperature range of -40°C to +125°C, unless otherwise stated. Minimum and maximum limits are ensured through test, design or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless otherwise stated, the following conditions apply: VIN = 24 V. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT POWER GOOD FLAG (PGOOD) VPGOOD_OV PGOOD upper threshold voltage Rising, % of Vout 103.5% 106.7% 109% VPGOOD_UV PGOOD lower threshold voltage Falling, % of Vout 92% 94.7% 97% VPGOOD_GUARD Magnitude of PGOOD lower threshold difference from steady state output voltage. Steady state output voltage PGOOD threshold read at the same TJ and VIN VPGOOD_HYST PGOOD hysteresis as a percent of output voltage set point VPGOOD_VALID Minimum input voltage for proper PGOOD function tRESET_FILTER Glitch filter time constant for PGOOD function VOL RPGOOD_RDSON Low-level PGOOD function output voltage 4% 1.4% 50-µA pullup to PGOOD pin, EN = 0 V, TJ = 25°C 1.0 1.5 V 190 µs 50-µA pullup to PGOOD pin, VIN = 1.5 V, EN = 0 V 0.4 0.5-mA pullup to PGOOD pin, VIN = 12 V, EN = 0 V 0.4 1-mA pullup to PGOOD pin, VIN = 12 V, EN = 3.3 V 0.4 RDSON of the PGOOD output pull down 50 110 V Ω SWITCHING FREQUENCY fSW Switching frequency VIN = 24 V, 5-V and 3.3-V fixed output options 675 750 825 VIN = 24 V, ADJ output options 890 1000 1090 VIN = 36 V, 5-V and 3.3-V fixed output options 750 VIN = 36 V, ADJ output options 800 kHz FREQUENCY SYNCHRONIZATION AND MODE fSYNC Sync frequency range DSYNC Sync input duty cycle range VMODE_HIGH MODE/SYNC input logic HIGH voltage to enter FPWM mode VMODE_LOW MODE/SYNC input logic LOW voltage to enter AUTO PFM mode IMODE MODE/SYNC leakage current tMODE 5-V and 3.3-V fixed output options VOUT + VDROPOUT < VIN < 36 V 500 825 ADJ output options VOUT + VDROPOUT< VIN < 28 V 700 1100 25% 75% 2.3 V < HIGH state input < 5.5 V kHz 1.5 V 0.4 VIN = 12 V, VMODE/SYNC = 3.3 V 1 VIN = 12 V, VMODE/SYNC = 12V 5 MODE transition time to FPWM VIN = 12 V, VOUT = 5 V, IOUT= 20 mA 300 MODE transition time to AUTO PFM VIN = 12 V, VOUT = 5 V, IOUT = 20 mA 300 V µA µs CURRENT LIMIT PROTECTION IL-HS high-side switch current limit Duty cycle approaches 0% IL-LS low-side switch current limit IL-ZC Zero-cross current limit MODE/SYNC = logic LOW IL-NEG Low-side reverse current limit (positive current ino the SW pin to GND) MODE/SYNC = logic HIGH 1.45 1 0.5 1.81 2.2 A 1.2 1.43 A –0.01 A 0.8 A Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 7 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Electrical Characteristics (continued) Limits apply over the recommended operating junction temperature range of -40°C to +125°C, unless otherwise stated. Minimum and maximum limits are ensured through test, design or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless otherwise stated, the following conditions apply: VIN = 24 V. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT POWER STAGE CHARACTERISTICS HS RDS-ON High-side MOSFET on-resistance 220 mΩ LS RDS-ON Low-side MOSFET on-resistance 200 mΩ tON-MIN Minimum high-side on-time IOUT = 500 mA 50 80 ns tOFF-MIN Minimum high-side off-time IOUT = 500 mA, ADJ 62 100 ns DMAX Maximum switch duty cycle L Integrated inductor - inductance LDCR Integrated inductor - DCR 5-V and 3.3-V fixed output options 93% ADJ option 91% While in frequency foldback 97% 10 µH 390 mΩ ENABLE VEN Enable input threshold voltage VEN_HYST Enable input threshold hysteresis VEN_WAKE Enable input wake-up threshold IEN Enable pin input current Rising 1.7 1.92 V 0.42 0.52 V 0.4 VIN = VEN = 12 V V 2.7 µA VCC REGULATOR VIN = 12 V, VOUT < 3.3 V 3.05 VIN = 12 V, VOUT ≥ 3.3V 3.15 VCC Internal VCC voltage VCC_UVLO Internal VCC voltage input UVLO VIN rising 2.23 VCC_UVLO_HYST Internal VCC voltage input UVLO hysteresis Hysteresis below VCC_UVLO 150 tSS Soft-start time Time for VREF to ramp from 0% to 90% 1.8 tEN_LV Turnon delay with low VIN VIN < 4.2 V 4 ms tEN Turnon delay VIN = 12 V 0.7 ms tW Short circuit wait time (hiccup time) 8.0 ms 155 °C 15 °C 2.73 V 3.25 V 240 mV 5.5 ms SOFT START 3.5 THERMAL PROTECTION TSD Thermal shutdown TSD_HYST Thermal shutdown hysteresis 8 Rising threshold Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 7.6 System Characteristics The following specifications apply to a typical applications circuit, with nominal component values. Specifications in the typical (TYP) column apply to TJ = 25°C. Specifications in the minimum (MIN) and maximum (MAX) columns apply to the case of typical components over the temperature range of TJ = –40°C to 125°C. These specifications are not ensured by production testing. PARAMETER TEST CONDITIONS MIN TYP MAX UNIT SUPPLY CURRENT IQ-VIN Input current to the DC-DC converter while in regulation VIN = 12 V, VOUT = 3.3 V, IOUT = 0 A, fixed output option, EN connected to VIN 25 VIN =12 V, VOUT = 5 V, IOUT = 0 A, fixed output option, EN connected to VIN 32 VIN =24 V, VOUT = 3.3 V, IOUT = 0 A, fixed output option, EN connected to VIN 24 VIN = 24 V, VOUT = 5 V, IOUT = 0 A, fixed output option, EN connected to VIN 28 µA EFFICIENCY Efficiency Typical efficiency 12-V input VIN =12 V, VOUT = 5 V, IOUT = 1 A 87% Efficiency Typical efficiency 12-V input VIN = 12 V, VOUT = 3.3 V, IOUT = 1 A 81% Efficiency Typical efficiency 24-V input VIN = 24 V, VOUT = 5 V, IOUT = 1 A 85% Efficiency Typical efficiency 24-V input VIN = 24 V, VOUT = 3.3 V, IOUT = 1 A 79% Efficiency Typical efficiency 24-V input VIN = 24 V, VOUT = 12 V, IOUT = 1 A 92% Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 9 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 7.7 Typical Characteristics VIN = 24 V, TA = 25°C (unless otherwise noted). Refer to default evaluation board layout and bill of materials. 3.5 70 VOUT = 3.3 V VOUT = 5.0 V 65 3.4 3.3 55 Output Voltage (V) Supply Current (PA) 60 50 45 40 35 30 3.2 3.1 3 2.9 2.8 25 IOUT = 1.0 A IOUT = 0.75 A IOUT = 0.5 A IOUT = 0.25 A 2.7 20 2.6 15 2.5 3.3 10 0 4 8 12 16 20 24 Input Voltage (V) 28 32 36 3.5 3.7 Fixed output voltage options Output voltage in regulation EN = VIN Load = Open 4.7 4.9 D033 Figure 2. Dropout Voltage 12.2 12 11.8 Output Voltage (V) Output Voltage (V) 4.5 VOUT = 3.3 V Figure 1. Input Supply Current 5.1 5 4.9 4.8 4.7 4.6 4.5 4.4 4.3 4.2 4.1 4 3.9 3.8 3.7 4.5 3.9 4.1 4.3 Input Voltage (V) D041 IOUT = 1.0 A IOUT = 0.75 A IOUT = 0.5 A IOUT = 0.25 A 4.7 4.9 5.1 5.3 5.5 5.7 Input Voltage (V) 5.9 6.1 6.3 11.6 11.4 11.2 11 10.8 10.6 IOUT = 1.0 A IOUT = 0.75 A IOUT = 0.5 A IOUT = 0.25 A 10.4 10.2 10 11 6.5 11.4 11.8 D035 VOUT = 5 V 12.2 12.6 13 Input Voltage (V) 13.4 13.8 D037 VOUT = 12 V Figure 3. Dropout Voltage Figure 4. Dropout Voltage 50 15.2 15 40 14.6 Emissions (dBPV/m) Output Voltage (V) 14.8 14.4 14.2 14 13.8 13.6 IOUT = 1.0 A IOUT = 0.75 A IOUT = 0.5 A IOUT = 0.25 A 13.4 13.2 13 14 30 20 10 CISPR11 Class A Limit CISPR11 Class B Limit Evaluation Board 0 14.4 14.8 15.2 15.6 16 Input Voltage (V) 16.4 VOUT = 15 V 16.8 0 100 D039 300 400 500 600 700 Frequency (MHz) 800 VIN = 24 V OUT = 5 V Default EVM Layout with added 3 × 100pF 0603 CIN Figure 5. Dropout Voltage 10 200 900 1000 D042 IOUT = 1 A Figure 6. Radiated EMI Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 Typical Characteristics (continued) VIN = 24 V, TA = 25°C (unless otherwise noted). Refer to default evaluation board layout and bill of materials. 75 Thermal Resistance to Ambient (qC/W) 50 Emissions (dBPV/m) 40 30 20 10 CISPR11 Class A Limit CISPR11 Class B Limit Evaluation Board 70 65 60 55 2-Layer 4-Layer 50 0 0 100 200 300 400 500 600 700 Frequency (MHz) 800 5 900 1000 VIN = 24 V IOUT = 1 A Default EVM BOM with GND Plane as Top Layer 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) Power Dissipation (W) Power Dissipation (W) 0.8 0.9 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 1 0 0.1 0.2 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) Power Dissipation (W) Power Dissipation (W) 40 D032 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 D018 Figure 10. Power Dissipation VIN = 6.5 V PFM VIN = 6.5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 0.1 35 VOUT = 12 V Figure 9. Power Dissipation 0 30 VIN = 15 V PFM VIN = 15 V FPWM VIN = 18 V PFM VIN = 18 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM D020 VOUT = 15 V 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 20 25 Board Area (cm2) Figure 8. Package Thermal Resistance vs Board Copper Area, No Air Flow VIN = 18 V PFM VIN = 18 V FPWM VIN = 22 V PFM VIN = 22 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 0 15 VOUT = 5 V Figure 7. Radiated EMI 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 10 D044 0.8 0.9 1 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 0 0.1 0.2 D014 VOUT = 5 V 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 D016 VOUT = 3.3 V Figure 11. Power Dissipation Figure 12. Power Dissipation Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 11 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Typical Characteristics (continued) VIN = 24 V, TA = 25°C (unless otherwise noted). Refer to default evaluation board layout and bill of materials. 1.1 1 1 0.9 0.9 0.8 0.8 Output Current (A) Output Current (A) 1.1 0.7 0.6 0.5 0.4 0.3 VIN = 5 V VIN = 12 V VIN = 18 V VIN = 24 V 0.2 0.1 0 30 40 50 0.6 0.5 0.4 0.3 0.1 120 0 30 130 Rθ = 58°C/W Power Dissipation (W) Output Current (A) 0.9 0.8 0.7 0.6 0.5 0.4 0.3 VIN = 12 V VIN = 18 V VIN = 24 V 40 50 60 70 80 90 100 110 Ambient Temperature (degrees C) VOUT = 5 V 120 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 130 130 D024 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 0 0.1 0.2 Rθ = 58°C/W 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 D012 VOUT = 2.5 V Figure 15. Ambient Temperature vs Output Current Figure 16. Power Dissipation 1.1 1 1 0.9 0.9 0.8 0.8 Output Current (A) Output Current (A) 120 Rθ = 58°C/W D026 1.1 0.7 0.6 0.5 0.4 0.3 0.2 0.7 0.6 0.5 0.4 0.3 0.2 VIN = 18 V VIN = 24 V 0.1 0 30 40 50 VOUT = 12 V VIN = 18 V VIN = 24 V VIN = 36 V 0.1 60 70 80 90 100 110 Ambient Temperature (degrees C) 120 130 0 30 40 50 D028 Rθ = 58°C/W VOUT = 15 V Figure 17. Ambient Temperature vs Output Current 12 60 70 80 90 100 110 Ambient Temperature (degrees C) Figure 14. Ambient Temperature vs Output Current 1 0 30 50 VOUT = 3.3 V Figure 13. Ambient Temperature vs Output Current 0.1 40 D022 1.1 0.2 VIN = 5 V VIN = 12 V VIN = 18 V VIN = 24 V 0.2 60 70 80 90 100 110 Ambient Temperature (degrees C) VOUT = 2.5 V 0.7 60 70 80 90 100 110 Ambient Temperature (degrees C) 120 130 D030 Rθ = 58°C/W Figure 18. Ambient Temperature vs Output Current Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 Typical Characteristics (continued) 1100 1100 1000 1000 900 900 Switching Frequency (kHz) Switching Frequency (kHz) VIN = 24 V, TA = 25°C (unless otherwise noted). Refer to default evaluation board layout and bill of materials. 800 700 600 500 400 300 200 VIN = 5V VIN = 12V VIN = 24 V 100 800 700 600 500 400 300 200 0 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 0 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 D047 VOUT = 3.3 V Figure 19. Auto PFM Mode Switching Frequency vs Output Current Figure 20. Auto PFM Mode Switching Frequency vs Output Current 1100 800 1000 Switching Frequency (kHz) 900 700 600 500 400 300 200 VIN = 5V VIN = 12V VIN = 24 V 100 900 800 700 600 500 400 300 200 VIN = 12V VIN = 24V 100 0 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 0 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 D049 VOUT = 5 V Figure 21. Auto PFM Mode Switching Frequency vs Output Current Figure 22. Auto PFM Mode Switching Frequency vs Output Current 1100 800 1000 Switching Frequency (kHz) 900 700 600 500 400 300 200 VIN = 12V VIN = 24V 100 0.1 D057 VOUT = 3.3 V Fixed Option Switching Frequency (kHz) 0.1 D045 VOUT = 2.5 V Switching Frequency (kHz) VIN = 5V VIN = 12V VIN = 24 V 100 900 800 700 600 500 400 300 200 100 VIN = 24V 0 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 0 0.1 0.2 0.3 D059 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 D051 VOUT = 12 V VOUT = 5 V Fixed Option Figure 23. Auto PFM Mode Switching Frequency vs Output Current Figure 24. Auto PFM Mode Switching Frequency vs Output Current Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 13 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Typical Characteristics (continued) 1100 1100 1000 1000 900 900 Switching Frequency (kHz) Switching Frequency (kHz) VIN = 24 V, TA = 25°C (unless otherwise noted). Refer to default evaluation board layout and bill of materials. 800 700 600 500 400 300 200 100 800 700 600 500 400 VOUT = 2.5V VOUT = 3.3V VOUT = 5.0V VOUT = 12V VOUT = 15V 300 200 100 VIN = 24V 0 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 4 6 D053 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Input Voltage (V) D055 VOUT = 15 V Figure 25. Auto PFM Mode Switching Frequency vs Output Current Figure 26. Switching Frequency vs Input Voltage for Adjustable Output Options at Full Load 1100 Switching Frequency (kHz) 1000 900 800 700 600 500 400 300 200 VOUT = 5.0 V FIXED VOUT = 3.3V FIXED 100 0 0 5 10 15 20 25 Input Voltage (V) 30 35 40 D061 Figure 27. Switching Frequency vs Input Voltage for Fixed Output Options at Full Load 14 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 8 Detailed Description 8.1 Overview The LMZM23601 is a 4-V to 36-V wide-input voltage range, low quiescent current, high-performance DC/DC module designed specifically for space-constrained industrial applications. The device is available in an adjustable output voltage option with 2.5-V to 15-V output range, as well as fixed 5-V and 3.3-V output options. The high level of integration and innovative packaging technology utilized in this power module makes it possible to design a 5-V or a 3.3-V 1-A DC/DC converter with only an input capacitor and an output capacitor in just 27 mm² of available board space. 8.2 Functional Block Diagram VIN ENABLE LOGIC EN VCC THERMAL PROTECTION MODE/SYNC OSCILLATOR INT. REG. BIAS UVLO HS CURRENT SENSE BOOT 1-V REFERENCE ERROR AMPLIFIER ADJ VOUT OPTION FB + + - PWM COMP. CONTROL LOGIC - MOSFET DRIVER VCC MOSFET DRIVER OR HS SW VOUT LS PFM MODE CONTROL FIXED VOUT OPTION LS CURRENT SENSE PGOOD POWER GOOD CONTROL GND Copyright © 2017, Texas Instruments Incorporated 8.3 Feature Description 8.3.1 Control Scheme The LMZM23601 power module utilizes peak-current-mode-control architecture. This enables the use of wide range of input voltages while maintaining constant switching frequency and good input and output transient response. The device can be used with 5-V, 12-V, or 24-V typical industrial input voltage rail. The short minimum on- and off-times ensure constant frequency regulation over a wide range of input to output voltage conversion ratios. The adjustable (ADJ) output voltage option operates at 1000-kHz switching frequency. The minimum onand off- times allow for a duty factor window of 5% to 91% at 1000-kHz switching frequency. If the input voltage exceeds approximately 28 V on the ADJ version, the frequency is smoothly reduced from 1000 kHz as a function of input voltage. The switching frequency reduction allows output voltage regulation and the current mode control to operate with a duty factor below 5%. The fixed 5-V and 3.3-V output options operate at 750 kHz nominal switching frequency and the frequency foldback at high input voltage is not active or needed. Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 15 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Feature Description (continued) The control architecture also uses frequency foldback at low input voltage in order to achieve low dropout voltage, maintaining output regulation as the input voltage falls close to output voltage. The frequency foldback at low input voltage is active for the ADJ as well as the 5-V and 3.3-V output options. The reduction in frequency is smooth and continuous and is activated as the off-time approaches the minimum value. Under these conditions, the LMZM23601 device operates much like a constant off-time converter allowing the maximum duty cycle to reach 97%. This feature allows output voltage regulation with very low dropout. The LMZM23601 features exceptional conversion efficiency at light load. As the load current is reduced, the LMZM23601 transitions to light-load mode if the MODE/SYNC terminal is pulled low. In light-load mode the device uses diode emulation to reduce the RMS inductor current and the switching frequency is reduced. The fixed voltage versions (3.3-V and 5-V) do not need an external voltage divider connected to FB, which results in saving two components and lower standby current when the load is in standby. As a result, the consumed supply current is only 24 µA (typical) with 24-V to 3.3-V conversion and 28 µA (typical) with 24-V to 5-V conversion, while the output is regulated with no load. 8.3.2 Soft-Start Function The LMZM23601 features an internally programmed soft-start time. The soft-start time is fixed internally at about 4 ms and is achieved by ramping the internal reference. The device starts up properly even if there is a voltage present on output before the activation of the LMZM23601. In such cases, there is no switching until the output voltage value programmed by the ramping reference voltage is above the pre-biased output value. Once the prebiased voltage level is reached by the reference ramp, the switching starts, and the output ramps up smoothly from the pre-biased value up to the final output voltage. 8.3.3 Enable and External UVLO Function Some applications may require a precision enable or custom input voltage lockout (UVLO) functionality. Setting up external UVLO based on the application needs would prevent the converter from trying to regulate the output voltage until after the input voltage has reached a desired minimum level. Such function can be used to lower the current demand from the input supply as the supply is still starting up. The LMZM23601 features a precision enable (EN) input terminal. The EN input logic has two internal thresholds. The first rising threshold is at 0.9V typical. Its purpose is to wake up the internal VCC regulator to bias the internal circuitry. The EN rising threshold to start switching is 1.8V (typical) with 0.5V (typical) hysteresis. A voltage divider from VIN to EN can be used to set the VIN voltage at which the regulator starts the voltage conversion. The EN terminal is rated for up to the input voltage and can be connected directly to VIN for an always-on operation. Pulling the EN pin below 0.4 V puts the LMZM23601 in shutdown mode. In shutdown mode and 12-V input voltage the LMZM23601 only consumes 1.8 µA (typical) of input current. 8.3.4 Current Limit The LMZM23601 devices features two current limits inside the IC. A coarse high side or peak current limit is provided to protect against faults. The high-side current limit limits the duration of the on-period of the high-side power MOSFET during a given clock cycle. A precision cycle-by-cycle valley current limit prevents excessive average output current. A new switching cycle is not initiated until the inductor current drops below the valley current limit. 16 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 Feature Description (continued) Vout Peak Valley Figure 28. Current Limit Operation During Output Short Circuit Figure 28 shows the response of the LMZM23601 device to a short circuit on the output: The peak current limit prevents excessive peak current while the valley current limit prevents excessive average inductor current. After a small number of cycles, hiccup mode is activated. 8.3.5 Hiccup Mode In order to prevent excessive heating and power consumption under sustained output short-circuit conditions, a hiccup mode operation is included in the control logic. If an over current condition is maintained on the output, the LMZM23601 device shuts off both power MOSFETs and waits for a hiccup interval, tW, of approximately 8 ms. After the wait period, the device restarts operation beginning with a soft-start time interval. Vout Figure 29. Hiccup Operation Figure 29 shows hiccup mode operation: The LMZM23601 attempts to restart periodically, following a hiccup wait interval. If the fault at the output is still present, another hiccup wait interval is initiated, followed by another restart attempt. This sequence continues until the output short circuit is removed. When the output short circuit is removed, the output ramps up during the next restart sequence. Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 17 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Feature Description (continued) 8.3.6 Power Good (PGOOD) Function The LMZM23601 has a built-in power-good signal presented at the PGOOD terminal. This signal indicates whether the output voltage is within the regulation window. The PGOOD terminal is an open-drain output that requires a pullup resistor to a nominal voltage source of 15 V or less. The absolute maximum PGOOD sink current is 8 mA. Typically, TI recommends a pullup resistor value between 10 kΩ and 100 kΩ. Refer to Electrical Characteristics for the power-good thresholds and hysteresis for undervoltage and overvoltage detection. 8.3.7 MODE/SYNC Function 8.3.7.1 Forced PWM Mode When constant frequency operation is more important than light load efficiency, the MODE/SYNC input of the LMZM23601 device must be pulled high or a valid synchronization input must be provided. This activates forcedPWM-mode operation. Once activated, this feature ensures that the switching frequency stays constant across the entire load current range, while operating between the minimum and maximum duty cycle limits. The diode emulation feature is turned off in this mode. This means that the device remains in CCM under light loads. The switching frequency in forced PWM mode is only reduced when the input voltage-to-output voltage ratio results in minimum on-time limitation (ADJ version only) or minimum off-time limitation near dropout. This feature may be activated and deactivated while the part is regulating without removing the load. This feature activates and deactivates gradually, preventing perturbation of output voltage. When in FPWM mode, a limited reverse current is allowed through the inductor allowing power to pass from the regulators output to its input. 8.3.7.2 Auto PFM Mode If the MODE/SYNC terminal is held low the LMZM23601 device enables automatic power-saving-mode transition at light load. With high load the LMZM23601 regulates the output using normal PWM operation. When the load is light, the control logic smoothly transitions to PFM operation and diode emulation. In this mode, the high side MOSFET is turned on for one or more pulses to provide energy to the load. The on-time of the high side in this mode depends on the input voltage level and a pre-programmed internal IPEAK-MIN current level. The higher the input voltage is, the shorter the on-time is. At this point, there is a longer off-time during which the output would still be in the regulation window because the load is light, and the output is not getting discharged as quickly. The duration of the off-time depends on the load current level. Lighter load results in longer off-time. This mode of operation results in excellent conversion efficiency at very light load. When auto-PFM mode is used, the output voltage at no load is approximately 1% higher than FPWM operation. 8.3.7.3 Dropout Mode When the input voltage level decreases and approaches the output voltage level, the buck regulator reaches its maximum duty cycle or minimum off-time requirement for each switching cycle. At this point the output is no longer regulated and follows the input voltage minus the voltage drops from VIN to VOUT. In order to maximize the input voltage range for which the output is still regulated, the LMZM23601 features frequency foldback at low input voltage. This operation extends the switching period and, for a given fixed minimum off-time, it prolongs the maximum duty cycle of the regulator. As a result, the output voltage can still be well regulated even as the input voltage level is very close to the output voltage. This feature can be useful for battery applications (maximizing the useful battery range) or in applications where large input voltage variations can be expected. 18 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 Feature Description (continued) 8.3.7.4 SYNC Operation It is often desirable to synchronize the switching frequency of multiple regulators in a single system. This technique results in better defined EMI behavior and can reduce the need for capacitance on some power rails. The LMZM23601 MODE/SYNC input allows synchronization to an external clock. The LMZM23601 implements an in-phase locking scheme – the rising edge of the clock signal provided to the input of the LMZM23601 device corresponds to turning on the high-side MOSFET device. This function is implemented using phase locking over a limited frequency range eliminating large glitches upon initial application of an external clock. The clock fed into the LMZM23601 device replaces the internal free-running clock but does not affect frequency foldback operation. The foldback function takes over and the output voltage continues to be well regulated using frequency reduction when duty factors outside of the normal duty cycle range are reached. When the device is synchronized to the lower end of the synchronization range the internal inductor will see higher peak currents. For high current ripple designs (for example, high input voltage and 12-V and 15-V output designs), the maximum current capability of the device may be derated. The device remains in FPWM mode and operates in CCM for light loads when synchronization input is provided. The MODE/SYNC function logic always prioritizes the proper regulation of the output voltage. Table 2 summarizes the MODE/SYNC function and the operating switching frequency with various conditions. See Typical Characteristics for frequency foldback vs input voltage behavior. Table 2. Switching Frequency and MODE/SYNC Function DEVICE ADJ Output Fixed 3.3-V Output or 5-V Output SWITCHING FREQUENCY MODE/SYNC LIGHT LOAD FULL LOAD VIN > 28 V IN DROPOUT MODE Logic LOW = Auto PFM Reduced (save power) Fixed 1000 kHz Reduced (maintain regulation) Reduced (maintain regulation) Logic HIGH = FPWM Fixed 1000 kHz Fixed 1000 kHz Reduced (maintain regulation) Reduced (maintain regulation) Valid FSYNC Input FSYNC FSYNC Reduced (maintain regulation) Reduced (maintain regulation) Logic LOW = Auto PFM Reduced (save power) Fixed 750 kHz Fixed 750 kHz Reduced (maintain regulation) Logic HIGH = FPWM Fixed 750 kHz Fixed 750 kHz Fixed 750 kHz Reduced (maintain regulation) Valid FSYNC Input FSYNC FSYNC FSYNC Reduced (maintain regulation) 8.3.8 Thermal Protection The LMZM23601 monitors its junction temperature (TJ) and shuts off if the it gets too hot. The thermal shutdown threshold for the junction is typically 155°C. Both, high-side and low-side power MOSFETs are turned off until the junction temperature has decreased under the hysteresis level, typically 15°C below the shutdown temperature. Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 19 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 8.4 Device Functional Modes 8.4.1 Shutdown The LMZM23601 device shuts down most internal circuitry and high-side and low-side power MOSFETs under any of the following conditions: 1. EN is low 2. VIN is below the falling UVLO threshold 3. Junction temperature exceeds TSD threshold The PGOOD flag remains operational with input voltage as low as 1.5 V. 8.4.2 FPWM Operation If MODE/SYNC is above the VMODE/SYNC high threshold or a valid synchronizing is applied to MODE/SYNC, constant frequency operation is maintained across load. The ADJ option of the device folds back the frequency when VIN exceeds 28 V typical so that the output voltage can be properly regulated. See Table 2 for all use cases and options. FPWM mode requires negative current be allowed in the inductor if the load is light. If a large negative load is present, operation is halted by a reverse current limit, IL-NEG. 8.4.3 Auto PFM Mode Operation If MODE/SYNC is below the VMODE/SYNC low threshold, reverse current in the inductor is not allowed. This feature is called diode emulation. While the load is heavy, the regulator uses PWM mode to control the output. If the load is light, the control logic transitions to PFM mode. The switching frequency is reduced, resulting in excellent energy savings while regulation is maintained. Because the frequency is reduced and switching pulses can come in groups, the output voltage ripple can increase slightly. Under this condition, the output ripple can be reduced by increasing the output capacitance. 20 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 9 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 9.1 Application Information The LMZM23601 device is a step-down power module, typically used to efficiently convert a high DC input voltage to a lower DC output voltage with a maximum output current of up to 1 A. The following sections describe a simple design procedure for creating a DC/DC converter design with these modules. 9.2 Typical Applications The LMZM23601 module requires very few external components for a complete DC/DC converter design. If the output voltage for the application is 3.3 V or 5 V, the fixed output voltage option of the LMZM23601 device can be used. In such cases, the design is as simple as adding only an input and an output capacitor. The adjustable output voltage version of the device allows the user to set the output voltage between 2.5 V and 15 V with the addition of two feedback resistors to the bill of materials. GND GND CIN VIN MODE/ SYNC VIN EN PGOOD FB VOUT VOUT COUT GND Copyright © 2017, Texas Instruments Incorporated Figure 30. Fixed 5-V or 3.3-V Typical Application Circuit Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 21 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Typical Applications (continued) GND GND CIN VIN MODE/ SYNC VIN RFBT EN FB RFBB VOUT VOUT PGOOD COUT GND Copyright © 2017, Texas Instruments Incorporated Figure 31. Adjustable 2.5-V to 15-V Output Typical Application Circuit 9.2.1 Design Requirements For this design example, use the parameters listed in Table 3 as the input parameters. Table 3. Design Parameters DESIGN PARAMETER VALUE Input voltage range 8 V to 36 V Output voltage 5V Output current range No load to 1 A COMMENT This range covers a typical 12-V or 24-V industrial supply Fixed or adjustable output voltage can be used 9.2.2 Detailed Design Procedure 9.2.2.1 Custom Design With WEBENCH® Tools Click here to create a custom design using the LMZM23601device with the WEBENCH® Power Designer. 1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements. 2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial. 3. Compare the generated design with other possible solutions from Texas Instruments. The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time pricing and component availability. In most cases, these actions are available: • Run electrical simulations to see important waveforms and circuit performance • Run thermal simulations to understand board thermal performance • Export customized schematic and layout into popular CAD formats • Print PDF reports for the design, and share the design with colleagues Get more information about WEBENCH tools at www.ti.com/WEBENCH. 22 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 9.2.2.2 Input Capacitor Selection The input capacitor selection and placement on the board layout is very important for any buck converter design. This component provides the pulsing high di/dt current every switching cycle and reduces the input voltage ripple seen by the buck converter. Use a good-quality 10-µF, 1210 (3225) case size, X5R or X7R ceramic capacitor with sufficient voltage rating on the input of the device. Alternatively, in applications with strict size constraints and more stable input voltage it is possible to use a 10-µF, 1206 (3216) case size or a parallel combination of 2 × 4.7-µF, 0805 (2012), X5R or X7R capacitors. Ceramic capacitors have a DC bias dependence on their effective capacitance and can de-rate their value significantly when used at higher bias voltage. TI recommends ceramic capacitors with ≥ 50-V rating when using the device with a 24-V input supply. Ceramic capacitors with ≥ 25-V rating are recommended when using the device with a 12-V input supply. Just like with any buck converter, place the input capacitor as close as possible and next to the LMZM23601. Connect the capacitor directly to the VIN (pin 3) and GND (pin 1) terminals of the device. This placement ensures that the area of the high di/dt current loop in the buck converter is kept to a minimum, resulting in the lowest possible inductance in the switching current path. The proper placement of the input capacitor in any buck converter helps to keep the output noise of the converter to a minimum. See Table 4 for several input capacitor choices. Table 4. Input Capacitor Selection VALUE VOLTAGE RATING CASE SIZE DIELECTRIC QUANTITY 10 µF 50 V 1210 (3225) X7R 10 µF 50 V 1210 (3225) X7R 10 µF 50 V 1206 (3216) 4.7 µF 50 V 0805 (2012) VENDOR PART NUMBER 1 TDK C3225X7R1H106M250AC 1 MuRata GRJ32ER71H106KE11 X5R 1 TDK C3216X5R1H106K160AB X5R 2 TDK C2012X5R1H475K125AB For this design example a single 10-µF, 50-V 1210 X7R capacitor is used. 9.2.2.3 Output Capacitor Selection TI recommends low-ESR ceramic capacitors for output capacitors. There is a requirement for minimum capacitance on the output of the LMZM23601 in order to ensure stable operation. The minimum output capacitance requirement depends on the output voltage setting. There is also a maximum capacitance value for stability and in order to limit the in-rush supply current. Excessive output capacitance can result in excessive current to be drawn from the input supply during startup. If the overcurrent condition is persistent during start-up, the over current protection of the LMZM23601 can activate and affect the normal output voltage ramp up. In extreme cases, the Hiccup Mode operation can be activated during start-up if the maximum output capacitance is exceeded. Refer to Table 5 for the minimum, recommended, and maximum output capacitance values for each output voltage. For this example with a 5-V output a 22-µF capacitor can be used. Table 5. Output Capacitor OUTPUT VOLTAGE MINIMUM OUTPUT CAPACITANCE RECOMMENDED OUTPUT CAPACITANCE MAXIMUM OUTPUT CAPACITANCE 2.5 V 47 µF 68 µF 390 µF 3.3 V 22 µF 33 µF 330 µF 5V 15 µF 22 µF 220 µF 12 V 10 µF 15 µF 200 µF 15 V 10 µF 15 µF 200 µF Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 23 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 9.2.2.4 Feedback Voltage Divider for Adjustable Output Voltage Versions GND GND CIN VIN MODE/ SYNC VIN RFBT EN FB RFBB VOUT VOUT PGOOD COUT GND Copyright © 2017, Texas Instruments Incorporated Figure 32. Adjustable 2.5-V to 15-V Output Typical Application Circuit The adjustable version of the LMZM23601 regulates the output voltage such that the FB node voltage is equal to the internal VREF voltage of 1 V. The output voltage is then set by a feedback voltage divider formed by two external resistors, RFBT and RFBB. VOUT = VREF u RFBB + RFBT RFBB (1) The range of adjustable output voltage is 2.5 V to 15 V. Choose a value for RFBT in the kΩ range, and calculate the bottom resistor RFBB using Equation 2: RFBT RFBB = VOUT 1 VREF (2) For this design example the output voltage is set to 5 V. The fixed 5-V output voltage option of the LMZM23601 can be used without any feedback resistors. If the adjustable output option is used for this design condition, the top feedback resistor RFBT can be set to 102 kΩ. The RFBB value results in 25.5 kΩ. 9.2.2.5 RPU - PGOOD Pullup Resistor The PGOOD terminal of the LMZM23601 is an open-drain output. If the application requires a power-good flag, use a 100-kΩ pullup resistor from the PGOOD terminal to an external voltage rail. If a power-good function is not necessary, the PGOOD terminal can be left floating. 24 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 9.2.2.6 VIN Divider and Enable If the application requires custom input UVLO level higher than the internal UVLO, a voltage divider can be connected from VIN to the EN terminal to set the turnon threshold. VIN RENT EN RENB GND Figure 33. Enable Divider to Set External UVLO Threshold Choose the top resistor RENB between 10 kΩ and 50 kΩ and calculate the RENT according to Equation 3. § VSTART · ¨¨ 1¸¸ u RENB © VEN ¹ RENT VSTOP § VEN _ HYST · ¸ VSTART u ¨¨1 VEN ¸¹ © where • • • • VSTART is the rising input voltage level at which switching starts. Choose this value based on the application requirements. VSTOP is the input voltage at which switching stops VEN is the rising threshold on EN; see Electrical Characteristics VEN_HYST is the hysteresis on the EN threshold; see Electrical Characteristics (3) Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 25 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 9.2.3 Application Curves Unless otherwise stated, the following conditions apply: VIN = 24 V, TA = 25°C. 9.2.3.1 VOUT = 5 V 100 90 80 Efficiency (%) 70 IOUT (500 mA/DIV) 60 50 VIN = 6.5V PFM VIN = 6.5V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 40 30 20 10 0 0.0001 0.001 0.01 0.1 Output Current (A) MODE = Low for Auto PFM Mode MODE = High for FPWM Mode 1 VOUT (50 mV/DIV) Time (500 µs/DIV) 10 D002 5-V Adjustable Output 5-V Adjustable Output 10% to 100% Load Step Figure 34. Efficiency MODE = High Figure 35. Load Transient VOUT Ripple (5 mV/DIV) VOUT Ripple (20 mV/DIV) 20MHz BW Time (1 µs/DIV) 5-V Adjustable Output IOUT = 1 A Time (1 µs/DIV) 5-V Adjustable Output Figure 36. Output Ripple 20 MHz BW 250MHz BW IOUT = 1 A Figure 37. Output Ripple 250-MHz BW 5.1 5.075 Output Voltage (V) 5.05 EN (2 V/DIV) 5.025 5 VOUT (2 V/DIV) 4.975 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 4.95 4.925 4.9 4.875 4.85 IOUT (500 mA/DIV) PGOOD (2 V/DIV) Time (2 ms/DIV) 4.825 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 D008 Figure 38. Line and Load Regulation 26 Submit Documentation Feedback Figure 39. Start-up With 24-V Input Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 9.2.3.2 VOUT = 3.3 V 100 90 80 IOUT (500 mA/DIV) Efficiency (%) 70 60 50 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 40 30 20 10 0 0.0001 0.001 0.01 0.1 Output Current (A) MODE = High for FPWM Mode MODE = Low for Auto PFM Mode 1 VOUT (50 mV/DIV) Time (500 µs/DIV) 10 D003 3.3-V Adjustable Output 3.3-V Adjustable Output 10% to 100% Load Step MODE = High Figure 41. Load Transient Figure 40. Efficiency VOUT Ripple (5 mV/DIV) VOUT Ripple (20 mV/DIV) 3.3-V Adjustable Output Time (1 µs/DIV) 20MHz BW Time (1 µs/DIV) IOUT = 1 A 3.3-V Adjustable Output Figure 42. Output Ripple 20-MHz BW 250MHz 20MHz BW IOUT = 1 A Figure 43. Output Ripple 250 MHz BW 3.38 3.36 EN (2 V/DIV) Output Voltage (V) 3.34 3.32 VOUT (2 V/DIV) 3.3 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 3.28 3.26 3.24 3.22 IOUT (500 mA/DIV) PGOOD (2 V/DIV) Time (2 ms/DIV) 3.2 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) MODE = High for FPWM Mode MODE = Low for Auto PFM Mode 0.8 0.9 1 D009 3.3-V Adjustable Output 3.3-V Adjustable Output Figure 44. Line and Load Regulation Toggle Enable Figure 45. Start-up With 24-V Input Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 27 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 9.2.3.3 VOUT = 12 V 100 90 80 Efficiency (%) 70 IOUT (500 mA/DIV) 60 50 VIN = 15V PFM VIN = 15V FPWM VIN = 18 V PFM VIN = 18 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 40 30 20 10 0 0.0001 0.001 0.01 0.1 Output Current (A) MODE = High for FPWM Mode MODE = Low for Auto PFM Mode 1 VOUT (100 mV/DIV) Time (500 µs/DIV) 10 D004 12-V Adjustable Output 12-V Adjustable Output 10% to 100% Load Step Figure 46. Efficiency MODE = High Figure 47. Load Transient VOUT Ripple (5 mV/DIV) VOUT Ripple (20 mV/DIV) 20MHz BW Time (1 µs/DIV) 12-V Adjustable Output IOUT = 1 A Time (1 µs/DIV) 12-V Adjustable Output Figure 48. Output Ripple 20-MHz BW 250MHz BW IOUT = 1 A Figure 49. Output Ripple 250-MHz BW 12.2 12.15 Output Voltage (V) 12.1 EN (2 V/DIV) 12.05 12 VOUT (5 V/DIV) 11.95 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 11.9 11.85 11.8 11.75 11.7 IOUT (500 mA/DIV) PGOOD (2 V/DIV) Time (2 ms/DIV) 11.65 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) MODE = High for FPWM Mode MODE = Low for Auto PFM Mode 0.8 0.9 1 D010 12-V Adjustable Output 12-V Adjustable Output Figure 50. Line and Load Regulation 28 Submit Documentation Feedback Toggle Enable Figure 51. Start-up With 24-V Input Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 9.2.3.4 VOUT = 15 V 100 90 80 IOUT (500 mA/DIV) Efficiency (%) 70 60 50 VIN = 18V PFM VIN = 18V FPWM VIN = 22 V PFM VIN = 22 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 40 30 20 10 0 0.0001 0.001 0.01 0.1 Output Current (A) MODE = High for FPWM Mode MODE = Low for Auto PFM Mode 1 VOUT (100 mV/DIV) Time (500 µs/DIV) 10 D006 15-V Adjustable Output 15-V Adjustable Output 10% to 100% Load Step Figure 53. Load Transient Figure 52. Efficiency VOUT Ripple (5 mV/DIV) VOUT Ripple (20 mV/DIV) 20MHz BW Time (1 µs/DIV) 15-V Adjustable Output IOUT = 1 A Time (1 µs/DIV) 15-V Adjustable Output Figure 54. Output Ripple 20-MHz BW Output Voltage (V) MODE = High 15.3 15.25 15.2 15.15 15.1 15.05 15 14.95 14.9 14.85 14.8 14.75 14.7 14.65 14.6 14.55 14.5 250MHz BW IOUT = 1 A Figure 55. Output Ripple 250-MHz BW EN (2 V/DIV) VOUT (10 V/DIV) VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) MODE = High for FPWM Mode MODE = Low for Auto PFM Mode 0.8 0.9 IOUT (500 mA/DIV) PGOOD (2 V/DIV) Time (2 ms/DIV) 1 D011 15-V Adjustable Output 15-V Adjustable Output Figure 56. Line and Load Regulation Toggle Enable Figure 57. Start-up with 24-V Input Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 29 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 9.2.3.5 VOUT = 2.5 V 100 90 80 IOUT (500 mA/DIV) Efficiency (%) 70 60 50 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 40 30 20 10 0 0.0001 0.001 0.01 0.1 Output Current (A) MODE = High for FPWM Mode MODE = Low for Auto PFM Mode 1 VOUT (20 mV/DIV) Time (500 µs/DIV) 10 D005 2.5-V Adjustable Output 2.5-V Adjustable Output 10% to 100% Load Step MODE = High Figure 59. Load Transient Figure 58. Efficiency VOUT Ripple (5 mV/DIV) VOUT Ripple (20 mV/DIV) 20MHz BW Time (1 µs/DIV) 2.5-V Adjustable Output IOUT = 1 A Time (1 µs/DIV) 2.5-V Adjustable Output Figure 60. Output Ripple 20-MHz BW 250MHz BW IOUT = 1 A Figure 61. Output Ripple 250-MHz BW 2.6 2.575 Output Voltage (V) 2.55 EN (2 V/DIV) 2.525 2.5 VOUT (2 V/DIV) 2.475 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 2.45 2.425 2.4 2.375 2.35 IOUT (500 mA/DIV) PGOOD (2 V/DIV) Time (2 ms/DIV) 2.325 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 1 D007 Figure 62. Line and Load Regulation 30 Submit Documentation Feedback Figure 63. Start-up with 24-V Input Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 100 100 90 90 80 80 70 70 Efficiency (%) Efficiency (%) 9.2.3.6 VOUT = 5 V and 3.3 V Fixed Output Options 60 50 VIN = 6.5V PFM VIN = 6.5V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 40 30 20 10 0 0.0001 0.001 0.01 0.1 0.2 0.5 1 Output Current (A) MODE = Low for Auto PFM Mode MODE = High for FPWM Mode 60 50 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 40 30 20 10 0 0.0001 2 3 5 710 0.001 5-V Fixed Output MODE = Low for Auto PFM Mode MODE = High for FPWM Mode Figure 64. Efficiency for VOUT = 5 V 5.1 Output Voltage (V) Output Voltage (V) 5.05 5.025 5 4.975 VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 4.95 4.9 4.875 4.85 4.825 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) 0.8 0.9 3.38 3.36 3.34 3.32 3.3 3.28 3.26 3.24 3.22 3.2 3.18 3.16 3.14 3.12 3.1 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) MODE = Low for Auto PFM Mode MODE = High for FPWM Mode 0.1 0.2 0.3 0.8 0.9 1 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 Figure 68. Power Dissipation for VOUT = 5 V 0.8 0.9 1 D071 VIN = 5.0 V PFM VIN = 5.0 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 0 0.1 D067 5-V Fixed Output 0.4 0.5 0.6 0.7 Output Current (A) Figure 67. Line and Load Regulation for VOUT = 3.3 V Power Dissipation (W) Power Dissipation (W) VIN = 6.5 V PFM VIN = 6.5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM 0 D065 3.3-V Fixed Output VIN = 5 V PFM VIN = 5 V FPWM VIN = 12 V PFM VIN = 12 V FPWM VIN = 24 V PFM VIN = 24 V FPWM VIN = 36 V PFM VIN = 36 V FPWM D073 Figure 66. Line and Load Regulation for VOUT = 5 V 1.5 1.4 1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 2 3 5 710 Figure 65. Efficiency for VOUT = 3.3 V 5.075 4.925 0.01 0.1 0.2 0.5 1 Output Current (A) D063 0.2 0.3 0.4 0.5 0.6 0.7 Output Current (A) MODE = Low for Auto PFM Mode MODE = High for FPWM Mode 0.8 0.9 1 D069 3.3-V Fixed Output Figure 69. Power Dissipation for VOUT = 3.3 V Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 31 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 9.3 Do's and Don't's • • • • • • • 32 Don't: Exceed the absolute maximum ratings of the device. Don't: Exceed the ESD ratings of the device. Don't: Exceed the recommended operating conditions. Don't: Allow the EN or MODE/SYNC terminals to float. Don't: Allow the output voltage to exceed the input voltage, nor go below ground. Do: Follow all of the guidelines and/or suggestions found in this data sheet, before committing your design to production. Do: Review your designs with TI Application Engineers on the E2E forum. Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 10 Power Supply Recommendations 10.1 Supply Voltage Range The voltage of the input supply must not exceed the absolute maximum ratings and the recommended operating conditions of the LMZM23601. 10.2 Supply Current Capability The input supply must be able to supply the required input current to the LMZM23601 converter. The required input current depends on the application's minimum input voltage, the required maximum output current, the output voltage, and the converter efficiency η for this condition. IIN t VOUT u IOUTMAX VINMIN u K (4) As an example, assuming that the adjustable output voltage version of the LMZM23601 is used for a 5-V, 1-A output converter design with 12-V minimum input voltage. The conversion efficiency for this condition is about 85%. The required input current from the supply would be 0.49 A, so an input power supply with ≥ 0.5 A current capability would be recommended. 10.3 Supply Input Connections Long input connection cables can cause issues with the normal operation of any buck converter. Some of the issues could be a voltage drop in the input voltage or stability probes because of the added series input inductance. 10.3.1 Voltage Drops Using long input wires to connect the supply to the input of any converter adds impedance in series with the input supply. This impedance can cause a voltage drop at the VIN pin of the converter when the output of the converter is loaded. If the input voltage is near the minimum input operating voltage for the design, this added voltage drop can cause the converter to drop out or reset. If long wires are used during testing, TI recommends adding some bulk (for example, electrolytic) capacitance at the input of the converter. 10.3.2 Stability The added inductance of long input cables together with the ceramic (and low ESR) input capacitor can result in an underdamped RLC network at the input of the buck converter. This circuit may cause instability, or overvoltage transients at the VIN pin each time the input supply is cycled on and off. If long wires are used, TI recommends adding some electrolytic bulk capacitance in parallel with the ceramic input capacitor. The ESR of the bulk capacitor improves the damping. Use an electrolytic capacitor with a capacitance at least four times larger than the ceramic input capacitance. CBULK t 4 u CCER (5) The required ESR from the bulk capacitor depends on the cable inductance. ESRBULK t LCABLE CCER (6) For example, two cables (one for VIN and one for GND), each 1 meter (approximately 3 feet) long with approximately 1-mm diameter (18 AWG), placed 1 cm (approximately 0.4 inch) apart forms a rectangular loop resulting in about 1.2 µH of inductance. The inductance in this example can be decreased to almost half if the input wires are twisted. Based on a 10-µF ceramic input capacitor, the recommended parallel CBULK is ≥ 40 µF. Using a 47-µF capacitor is sufficient. Based on about 1.2 µH of inductance and 10 µF of ceramic input capacitance, the recommended ESR of the bulk capacitor is 0.35 Ω or larger. See TI User Guide, Simple Success with Conducted EMI for DC/DC Converters for more details on input filter design. Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 33 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com 11 Layout 11.1 Layout Guidelines Good board layout is essential for the proper operation of any switching regulator. A poor layout can ruin an otherwise perfect schematic design. The good news is that it is relatively easy to achieve an optimized layout when using a module because some of the critical nodes for the board layout are internal to the device. To have a good layout with this module, the designer should follow these main objectives: 1. Minimize the inductance in the switching current path of the converter. The switching current path in the buck converter is formed by the input capacitor and the power switches (for example, MOSFETs). A common mistake in many buck converter layouts is placing the input capacitor far from the IC. This introduces inductance in the switching current path, which leads to high frequency ringing on the switching node, which results in high frequency noise coupled all the way to the output voltage. The input capacitor placement affects the amount of noise on the output in a buck converter. Place the input capacitor as close as possible, right next to the LMZM23601 ensures that the switching current path area is kept to a minimum. This results in the lowest possible inductance in the path of high di/dt current. 2. Protect any sensitive nodes in the converter design. The feedback node is usually a sensitive area of the converter and needs to be away from any noise sources. The fixed 5-V and 3.3-V output voltage versions of the LMZM23601 have the feedback resistors internal to the device, and the sensitive node is inside the module. However, if the adjustable option is used, then two feedback resistors are required to set the output voltage. A common mistake in many layouts is placing the divider close to the load, far from the device, and then using a long feedback trace back to the regulator. A long feedback trace can potentially pick up noise from other nearby circuits. TI recommends placing the feedback divider as close as possible to the LMZM23601 device so that the feedback node is as small as possible. 3. Provide enough copper for heat dissipation. The board copper provides a thermal resistance path for the heat to flow out of the package and dissipate into the environment. Place a dog-bone shape of ground (GND) copper under the module for proper heat sinking. Also, place thermal vias to provide a heat path to the other board layers. TI recommends an unbroken GND plane or GND area of copper on the top and bottom layers. 11.1.1 Thermal Design Thermal design is an important aspect of any power regulator design. Every supply will dissipate some power, and it is important to provide sufficient copper area for proper heat dissipation. The package thermal resistance curves vs PCB copper area along with the power dissipation curves in Typical Characteristics can be used to estimate the necessary copper area for the design. Consider Equation 7 and Figure 70. 125 ( F 6#_/#: 4à Q 2& (7) Thermal Resistance to Ambient (qC/W) 75 70 65 60 55 2-Layer 4-Layer 50 5 10 15 20 25 Board Area (cm2) 30 35 40 D032 Figure 70. Package Thermal Resistance vs Board Copper Area 34 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 Layout Guidelines (continued) As an example, consider a typical application of 24-V input 5-V output with 0.8 A of output current and estimate the required heat-sinking area. For this example consider a maximum ambient temperature TA_MAX of 75°C and no air flow or additional heat sinking besides the PCB layers. Calculate the maximum allowed package thermal resistance for this design specification. From Typical Characteristics, it can be seen that the power dissipation for 24-V input, 5-V output, and 0.8A load is 0.75 W. Based on Equation 7, for this power dissipation level and 75°C maximum ambient temperature, the maximum package thermal resistance must be less than 66.7°C/W. To achieve this thermal resistance with a 2layer board, the approximate area of the board copper should be at least 9 cm2. 11.2 Layout Examples INPUT CAPACITOR PLACED NEXT TO THE MODULE OUTPUT CAPACITOR MODULE GND GND GND EN VIN MODE VIN PG GND COPPER FOR HEAT SINKING FB VOUT VOUT FEEDBACK CONNECTION =THERMAL VIAS Figure 71. Layout Example With Fixed Output Version Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 35 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Layout Examples (continued) INPUT CAPACITOR PLACED NEXT TO THE MODULE BOTTOM FB RESISTOR TOP FB OUTPUT RESISTOR CAPACITOR MODULE GND GND GND EN VIN MODE VIN PG GND COPPER FOR HEAT SINKING FB VOUT MINIMIZE FB NODE VOUT =THERMAL VIAS Figure 72. Layout Example With Adjustable Output Version 36 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 LMZM23601 www.ti.com SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 12 Device and Documentation Support 12.1 Device Support 12.1.1 Third-Party Products Disclaimer TI'S PUBLICATION OF INFORMATION REGARDING THIRD-PARTY PRODUCTS OR SERVICES DOES NOT CONSTITUTE AN ENDORSEMENT REGARDING THE SUITABILITY OF SUCH PRODUCTS OR SERVICES OR A WARRANTY, REPRESENTATION OR ENDORSEMENT OF SUCH PRODUCTS OR SERVICES, EITHER ALONE OR IN COMBINATION WITH ANY TI PRODUCT OR SERVICE. 12.2 Custom Design With WEBENCH® Tools Click here to create a custom design using the LMZM23601 device with the WEBENCH® Power Designer. 1. Start by entering the input voltage (VIN), output voltage (VOUT), and output current (IOUT) requirements. 2. Optimize the design for key parameters such as efficiency, footprint, and cost using the optimizer dial. 3. Compare the generated design with other possible solutions from Texas Instruments. The WEBENCH Power Designer provides a customized schematic along with a list of materials with real-time pricing and component availability. In most cases, these actions are available: • Run electrical simulations to see important waveforms and circuit performance • Run thermal simulations to understand board thermal performance • Export customized schematic and layout into popular CAD formats • Print PDF reports for the design, and share the design with colleagues Get more information about WEBENCH tools at www.ti.com/WEBENCH. 12.3 Documentation Support 12.3.1 Related Documentation For related documentation request the following: Inverting Application for the LMZM23601 and LMZM23600 AN-2020 Thermal Design By Insight, Not Hindsight AN-1149 Layout Guidelines for Switching Power Supplies Constructing Your Power Supply – Layout Considerations AN-1229 Simple Switcher PCB Layout Guidelines (SNVA054) Using New Thermal Metrics Semiconductor and IC Package Thermal Metrics AN-1520 A Guide to Board Layout for Best Thermal Resistance for Exposed Pad Packages TI User Guide, Simple Success with Conducted EMI for DC/DC Converters 12.4 Receiving Notification of Documentation Updates To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper right corner, click on Alert me to register and receive a weekly digest of any product information that has changed. For change details, review the revision history included in any revised document. 12.5 Community Resources The following links connect to TI community resources. Linked contents are provided "AS IS" by the respective contributors. They do not constitute TI specifications and do not necessarily reflect TI's views; see TI's Terms of Use. Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 37 LMZM23601 SNVSAQ4A – DECEMBER 2017 – REVISED APRIL 2018 www.ti.com Community Resources (continued) TI E2E™ Online Community TI's Engineer-to-Engineer (E2E) Community. Created to foster collaboration among engineers. At e2e.ti.com, you can ask questions, share knowledge, explore ideas and help solve problems with fellow engineers. Design Support TI's Design Support Quickly find helpful E2E forums along with design support tools and contact information for technical support. 12.6 Trademarks MicroSiP, E2E are trademarks of Texas Instruments. WEBENCH is a registered trademark of Texas Instruments. All other trademarks are the property of their respective owners. 12.7 Electrostatic Discharge Caution These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. 12.8 Glossary SLYZ022 — TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 13 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. 38 Submit Documentation Feedback Copyright © 2017–2018, Texas Instruments Incorporated Product Folder Links: LMZM23601 PACKAGE OPTION ADDENDUM www.ti.com 9-Apr-2018 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) LMZM23601SILR PREVIEW uSiP SIL 10 3000 RoHS (In Work) & Green (In Work) Call TI Call TI -40 to 125 TXN6023EC 4B A A 4B LMZM23601SILT PREVIEW uSiP SIL 10 250 TBD Call TI Call TI -40 to 125 TXN6023EC 4B A A 4B LMZM23601V3SILR PREVIEW uSiP SIL 10 3000 TBD Call TI Call TI -40 to 125 TXN6200EC 4I A A 4I LMZM23601V3SILT PREVIEW uSiP SIL 10 250 TBD Call TI Call TI -40 to 125 TXN6200EC 4I A A 4I LMZM23601V5SILR PREVIEW uSiP SIL 10 3000 TBD Call TI Call TI -40 to 125 TXN6100EC 4H A A 4H LMZM23601V5SILT PREVIEW uSiP SIL 10 250 TBD Call TI Call TI -40 to 125 TXN6100EC 4H A A 4H PLMZM23601SILR ACTIVE uSiP SIL 10 3000 TBD Call TI Call TI -40 to 125 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 9-Apr-2018 Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. (6) Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. Addendum-Page 2 PACKAGE OUTLINE SIL0010A MicroSiP TM - 1.578 mm max height SCALE 3.500 MICRO SYSTEM IN PACKAGE 3.9 3.7 B A PIN 1 ID 3.1 2.9 PICK AREA NOTE 3 NOTE 4 TYP 1.578 MAX C 0.08 C SEATING PLANE 3.05 TYP EXPOSED THERMAL PAD 0.7 0.1 (0.05) TYP 11 5 6 6X 0.6 2.9 0.1 SYMM 2X 2.4 10X 10 1 PIN 1 ID 0.175 10X PKG 0.4 0.2 0.1 0.05 C A B C 0.75 0.55 4222635/C 01/2018 MicroSiP is a trademark of Texas Instruments NOTES: 1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. Pick and place nozzle 1.1 mm or smaller recommended. 4. Location, size and quantity of components are for reference only and could vary. 5. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance. www.ti.com EXAMPLE BOARD LAYOUT SIL0010A MicroSiP TM - 1.578 mm max height MICRO SYSTEM IN PACKAGE (0.7) 10X (0.65) 11 1 10 10X (0.3) SYMM (2.9) 8X (0.6) (1.03) 6 5 ( 0.2) VIA TYP (0.175) PKG (3.05) LAND PATTERN EXAMPLE 1:1 RATIO WITH PACKAGE SOLDER PADS SOLDER MASK DEFINED SCALE:20X 0.05 MIN ALL AROUND SOLDER MASK OPENING METAL UNDER SOLDER MASK (R0.05) TYP DETAIL NOT TO SCALE 4222635/C 01/2018 NOTES: (continued) 6. This package is designed to be soldered to a thermal pad on the board. For more information, see Texas Instruments literature number SLUA271 (www.ti.com/lit/slua271). 7. Vias are optional depending on application, refer to device data sheet. If any vias are implemented, refer to their locations shown on this view. It is recommended that vias under paste be filled, plugged or tented. www.ti.com EXAMPLE STENCIL DESIGN SIL0010A MicroSiP TM - 1.578 mm max height MICRO SYSTEM IN PACKAGE 3X (0.7) (R0.05) TYP 10X (0.65) 11 1 10X (0.3) 10 3X (0.833) SYMM 8X (0.6) (1.03) SOLDER MASK EDGE 5 6 EXPOSED METAL 2X (0.175) PKG (3.05) SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL PAD 11: 86% PRINTED SOLDER COVERAGE BY AREA SCALE:25X 4222635/C 01/2018 NOTES: (continued) 8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate design recommendations. www.ti.com IMPORTANT NOTICE Texas Instruments Incorporated (TI) reserves the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. 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