LTM8032

FEATURES n n n n n n n n n n LTM8032 Ultralow Noise EMC Compliant 36V, 2A DC/DC µModule DESCRIPTION The LTM®8032 is an electromagnetic compatible (EMC) 36V, 2A DC/DC μModule® buck converter designed to meet the radiated emissions requirements of EN55022. Conducted emission requirements can be met by adding standard filter components. Included in the package are the switching controller, power switches, inductor, filters and all support components. Operating over an input voltage range of 3.6V to 36V, the LTM8032 supports an output voltage range of 0.8V to 10V, and a switching frequency range of 200kHz to 2.4MHz, each set by a single resistor. Only the bulk input and output filter capacitors are needed to finish the design. The low profile package (2.82mm) enables utilization of unused space on the bottom of PC boards for high density point of load regulation. The LTM8032 is packaged in a thermally enhanced, compact (9mm × 15mm) and low profile (2.82mm) overmolded land grid array (LGA) package suitable for automated assembly by standard surface mount equipment. The LTM8032 is RoHS compliant. , LT, LTC, LTM and μModule are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Complete Step-Down Switch Mode Power Supply Wide Input Voltage Range: 3.6V to 36V 2A Output Current 0.8V to 10V Output Voltage Selectable Switching Frequency: 200kHz to 2.4MHz EN55022 Class B Compliant Current Mode Control (e4) RoHS Compliant Package with Gold Pad Finish Programmable Soft-Start Low Profile (9mm × 15mm × 2.82mm) Surface Mount LGA Package APPLICATIONS n n n n n Automotive Battery Regulation Power for Portable Products Distributed Supply Regulation Industrial Supplies Wall Transformer Regulation TYPICAL APPLICATION Ultralow Noise 5V/2A DC/DC μModule Regulator VIN* 7VDC TO 36VDC VIN FIN RUN/SS 2.2μF SHARE PGOOD AUX OUT 10μF VOUT 5V 2A EMISSIONS LEVEL (dBμV/m) 90 80 70 60 50 40 30 20 10 0 –10 0 100 200 300 400 500 600 700 800 900 1000 FREQUENCY (MHz) 8031 TA01b EN55022 CLASS B LIMIT LTM8032 EMI Performance LTM8032 BIAS RT SYNC GND ADJ 44.2k fSW = 700kHz *RUNNING VOLTAGE RANGE. SEE APPLICATIONS FOR START-UP DETAILS 47.5k 8032 TA01a 8032fa 1 LTM8032 ABSOLUTE MAXIMUM RATINGS (Note 1) PIN CONFIGURATION 1 A BANK 1 B C D E BANK 2 F G H J K BANK 3 L VIN FIN RUN/SS SYNC LGA PACKAGE 71-LEAD (9mm 15mm 2.82mm) TJMAX = 125°C, θJA = 15.8°C/W, θJC = 5.5°C/W θJA DERIVED FROM 6.35cm × 5.6 PCB WITH 4 LAYERS WEIGHT = 1.2g BIAS AUX RT SHARE ADJ PGOOD 2 TOP VIEW 3 4 5 VOUT 6 GND 7 VIN, FIN, RUN/SS Voltage..........................................40V ADJ, RT, SHARE Voltage .............................................5V VOUT, AUX .................................................................10V Current from AUX ................................................100mA PGOOD, SYNC ..........................................................30V BIAS ..........................................................................25V VIN + BIAS .................................................................56V Maximum Junction Temperature (Note 2)............. 125°C Solder Temperature (Note 3)................................. 245°C ORDER INFORMATION LEAD FREE FINISH LTM8032EV#PBF LTM8032IV#PBF LTM8032MPV#PBF TRAY LTM8032EV#PBF LTM8032IV#PBF LTM8032MPV#PBF PART MARKING* LTM8032V LTM8032V LTM8032MPV PACKAGE DESCRIPTION 71-Lead (9mm × 15mm × 2.82mm) LGA 71-Lead (9mm × 15mm × 2.82mm) LGA 71-Lead (9mm × 15mm × 2.82mm) LGA TEMPERATURE RANGE –40°C to 125°C –40°C to 125°C –55°C to 125°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ This product is only offered in trays. For more information go to: http://www.linear.com/packaging/ 8032fa 2 LTM8032 ELECTRICAL CHARACTERISTICS SYMBOL VIN VOUT IOUT IQ(VIN) PARAMETER Input DC Voltage Output DC Voltage Continuous Output DC Current VIN Quiescent Current 0.2A < IOUT ≤ 2A, RADJ Open 0.2A < IOUT ≤ 2A, RADJ = 21.6k VIN = 24V VRUN/SS = 0.2V VBIAS = 3V, Not Switching VBIAS = 0V, Not Switching VRUN/SS = 0.2V VBIAS = 3V, Not Switching VBIAS = 0V, Not Switching 10V ≤ VIN ≤ 36V, IOUT = 1A, VOUT = 3.3V VIN = 24V, 0.2A ≤ IOUT ≤ 2A, VOUT = 3.3V VIN = 24V, IOUT = 2A, VOUT = 3.3V RT = 113k l l The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 10V, VRUN/SS = 10V, VBIAS = 3V, unless otherwise specified. CONDITIONS l MIN 3.6 TYP 0.8 10 MAX 36 UNITS V V V 2 0.6 25 88 0.03 60 1 0.1 0.3 6 325 765 790 1.9 4 5 2.5 0.2 730 10 815 2.8 60 120 120 5 A μA μA μA μA μA μA % % mV kHz mV V μA μA V V mV μA μA V V μA dBμV dBμV dBμV IQ(BIAS) ΔVOUT VOUT fSW VADJ VBIAS(MIN) IADJ IRUN/SS VIH(RUN/SS) VIL(RUN/SS) VPG(TH) IPGO IPGSINK VSYNCIL VSYNCIH ISYNC(BIAS) VIN(RIPPLE) BIAS Quiescent Current l Line Regulation Load Regulation Switching Frequency Voltage at ADJ Pin Minimum BIAS Voltage for Proper Operation Current Out of ADJ Pin RUN/SS Pin Current RUN/SS Input High Voltage RUN/SS Input Low Voltage ADJ Voltage Threshold for PGOOD to Switch PGOOD Leakage PGOOD Sink Current SYNC Input Low Threshold SYNC Input High Threshold SYNC Pin Bias Current 550kHz Narrowband Conducted Emission 1MHz Narrowband Conducted Emission 3MHz Narrowband Conducted Emission VOUT(AC_RMS) Output Ripple (RMS) VRUN/SS = 0V, VADJ = 0V, VOUT = 1V VRUN/SS = 2.5V VPG = 30V VPG = 0.4V fSYNC = 550kHz fSYNC = 550kHz VSYNC = 0V, VBIAS = 0V VIN = 24V, VOUT = 3.3V, IOUT = 2A, fSW = 550kHz, 5μH LISN 0.7 200 0.1 800 1 0.5 0.1 89 69 51 Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTM8032E is guaranteed to meet performance specifications from 0°C to 125°C internal. Specifications over the –40°C to 125°C internal temperature range are assured by design, characterization and correlation with statistical process controls. LTM8032I is guaranteed to meet specifications over the full –40°C to 125°C internal operating temperature range. The LTM8032MP is guaranteed to meet specifications over the full –55°C to 125°C internal operating temperature range. Note that the maximum internal temperature is determined by specific operating conditions in conjunction with board layout, the rated package thermal resistance and other environmental factors. Note 3: See Linear Technology Application Note 100. 8032fa 3 LTM8032 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. 3.3VOUT Efficiency 100 90 80 EFFICIENCY (%) EFFICIENCY (%) 70 60 50 40 30 20 10 0 0.01 1 0.1 OUTPUT CURRENT (A) 5.5VIN 12VIN 24VIN 36VIN 10 8031 G01 5VOUT Efficiency 100 90 80 EFFICIENCY (%) 12VIN 24VIN 36VIN 1 0.1 OUTPUT CURRENT (A) 10 8031 G02 8VOUT Efficiency 100 90 80 70 60 50 40 30 20 10 0 0.01 1 0.1 OUTPUT CURRENT (A) 12VIN 24VIN 36VIN 10 8031 G03 70 60 50 40 30 20 10 0 0.01 Input Current vs Output Current, 3.3VOUT 1600 1400 INPUT CURRENT (mA) 1200 1000 800 600 400 200 0 0 1000 500 1500 OUTPUT CURRENT (mA) 2000 8032 G04 Input Current vs Output Current, 5VOUT 1200 1000 INPUT CURRENT (mA) 800 600 400 200 0 0 500 1000 1500 OUTPUT CURRENT (mA) 2000 8032 G05 Input Current vs Output Current, 8VOUT 1800 1600 INPUT CURRENT (mA) 1400 12VIN 24VIN 36VIN 5.5VIN 12VIN 24VIN 36VIN 12VIN 24VIN 36VIN 1200 1000 800 600 400 200 0 1 1000 500 1500 OUTPUT CURRENT (mA) 2000 8032 G06 Minimum Required Input Voltage vs Output Voltage, IOUT = 2A 14 12 INPUT VOLTAGE (V) INPUT VOLTAGE (V) 10 8 6 4 2 0 2 4 6 8 OUTPUT VOLTAGE (V) 10 8032 G07 Minimum Required Input Voltage vs Load Current, VOUT = 2.5V 5.0 4.5 INPUT VOLTAGE (V) 4.0 3.5 3.0 2.5 2.0 0 TO RUN TO START 500 1000 1500 LOAD CURRENT (mA) 2000 8032 G08 Minimum Required Input Voltage vs Load Current, VOUT = 3.3V 6.0 5.5 5.0 4.5 4.0 3.5 3.0 0 500 1000 1500 LOAD CURRENT (mA) 2000 8032 G09 TO RUN TO START RUN/SS ENABLED 8032fa 4 LTM8032 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. Minimum Required Input Voltage vs Load Current, VOUT = 5V 7.5 11.0 10.5 BIAS CURRENT (mA) INPUT VOLTAGE (V) 10.0 9.5 9.0 8.5 8.0 0 500 1000 1500 LOAD CURRENT (mA) 2000 8032 G11 Minimum Required Input Voltage vs Load Current, VOUT = 8V 30 25 20 15 10 5 0 Bias Current vs Output Current 3.3VOUT 5VOUT 8VOUT 7.0 INPUT VOLTAGE (V) 6.5 6.0 5.5 TO RUN TO START RUN/SS ENABLED 0 500 1500 1000 LOAD CURRENT (mA) 2000 8032 G10 TO RUN TO START RUN/SS ENABLED 5.0 0 500 1000 1500 OUTPUT CURRENT (mA) 2000 8032 G12 Output Current vs Input Voltage (Output Shorted) 3200 3000 OUTPUT CURRENT (mA) 2800 2600 2400 2200 2000 1800 1600 0 10 20 INPUT VOLTAGE (V) 8032 G13 Input Current vs Input Voltage (Output Shorted) 1200 1000 TEMPERATURE RISE (°C) OUTPUT CURRENT (mA) 800 600 400 200 0 0 10 20 30 INPUT VOLTAGE (V) 40 8032 G14 Temperature Rise vs Load Current, VOUT = 2.5V 35 30 25 20 15 10 5 0 0 500 1000 1500 2000 LOAD CURRENT (mA) 8032 G15 5VIN 12VIN 24VIN 36VIN 2500 30 40 Temperature Rise vs Load Current, VOUT = 3.3V 40 35 TEMPERATURE RISE (°C) 30 25 20 15 10 5 0 0 500 1000 5VIN 12VIN 24VIN 36VIN 2000 1500 LOAD CURRENT (mA) 2500 8032 G16 Temperature Rise vs Load Current, VOUT = 5V 40 35 TEMPERATURE RISE (°C) 30 25 20 15 10 5 0 0 500 1000 12VIN 24VIN 36VIN 2000 1500 LOAD CURRENT (mA) 2500 8032 G17 Temperature Rise vs Load Current, VOUT = 8V 50 45 TEMPERATURE RISE (°C) 40 35 30 25 20 15 10 5 0 0 500 12VIN 24VIN 36VIN 1500 2000 1000 LOAD CURRENT (mA) 2500 8032 G18 8032fa 5 LTM8032 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. EMISSIONS LEVEL (dBμV/m) 90 70 50 30 10 –10 0 100 200 300 400 500 600 700 800 900 1000 FREQUENCY (MHz) 8031 G20 VIN = 36V VOUT = 10V AT 2A EMISSIONS LEVEL (dBμV/m) Temperature Rise vs Load Current, VOUT = 10V 50 45 TEMPERATURE RISE (°C) 40 35 30 25 20 15 10 5 0 0 500 24VIN 36VIN 1500 2000 1000 LOAD CURRENT (mA) 2500 8032 G19 Radiated Emissions Radiated Emissions 90 70 50 30 10 –10 0 100 200 300 400 500 600 700 800 900 1000 FREQUENCY (MHz) 8031 G21 VIN = 13V VOUT = 10V AT 2A PIN FUNCTIONS VIN (Bank 3): The VIN pin supplies current to the LTM8032’s internal regulator and to the internal power switch. This pin must be locally bypassed with an external, low ESR capacitor of at least 2.2μF . FIN (K3, L3): Filtered Input. This is the node after the input EMI filter. Use this only if there is a need to modify the behavior of the integrated EMI filter or if VIN rises or falls rapidly; otherwise, leave these pins unconnected. See the Applications Information section for more details. GND (Bank 2): Tie these GND pins to a local ground plane below the LTM8032 and the circuit components. Return the feedback divider (RADJ) to this net. VOUT (Bank 1): Power Output Pins. Apply the output filter capacitor and the output load between these pins and GND pins. AUX (Pin H5): Low Current Voltage Source for BIAS. In many designs, the BIAS pin is simply connected to VOUT. The AUX pin is internally connected to VOUT and is placed adjacent to the BIAS pin to ease printed circuit board routing. Although this pin is internally connected to VOUT, do not connect this pin to the load. If this pin is not tied to BIAS, leave it floating. BIAS (Pin H4): The BIAS pin connects to the internal power bus. Connect to a power source greater than 2.8V. If the output is greater than 2.8V, connect this pin to AUX. If the output voltage is less, connect this to a voltage source between 2.8V and 25V. Also, make sure that BIAS + VIN is less than 56V. RUN/SS (Pin L5): Pull RUN/SS pin to less than 0.2V to shut down the LTM8032. Tie to 2.5V or more for normal operation. If the shutdown feature is not used, tie this pin to the VIN pin. RUN/SS also provides a soft-start function; see the Applications Information section. RT (Pin G7): The RT pin is used to program the switching frequency of the LTM8032 by connecting a resistor from this pin to ground. The Applications Information section of the data sheet includes a table to determine the resistance value based on the desired switching frequency. Minimize capacitance at this pin. SHARE (Pin H7): Tie this to the SHARE pin of another LTM8032 when paralleling the outputs. Otherwise, do not connect. 8032fa 6 LTM8032 PIN FUNCTIONS SYNC (Pin L6): This is the external clock synchronization input. Ground this pin for low ripple Burst Mode® operation at low output loads. Tie to a stable voltage source greater than 0.7V to disable Burst Mode operation. Do not leave this pin floating. Tie to a clock source for synchronization. Clock edges should have rise and fall times faster than 1μs. See synchronizing section in Applications Information. PGOOD (Pin K7): The PGOOD pin is the open-collector output of an internal comparator. PGOOD remains low until the ADJ pin is within 10% of the final regulation voltage. The PGOOD output is valid when VIN is above 3.6V and RUN/SS is high. If this function is not used, leave this pin floating. ADJ (Pin J7): The LTM8032 regulates its ADJ pin to 0.79V. Connect the adjust resistor from this pin to ground. The value of RADJ is given by the equation: R ADJ = 196.71 VOUT – 0.79 where RADJ is in kΩ. Burst Mode is a registered trademark of Linear Technology Corporation. BLOCK DIAGRAM FIN EMI FILTER VIN 4.7μH VOUT 249k 10μF AUX GND BIAS GND SHARE CURRENT MODE CONTROLLER RUN/SS SYNC RT PGOOD ADJ 8032 BD 8032fa 7 LTM8032 OPERATION The LTM8032 is a standalone nonisolated step-down switching DC/DC power supply. It can deliver up to 2A of DC output current with only bulk external input and output capacitors. This module provides a precisely regulated output voltage programmable via one external resistor from 0.8VDC to 10VDC. The input voltage range is 3.6V to 36V. Given that the LTM8032 is a step-down converter, make sure that the input voltage is high enough to support the desired output voltage and load current. A simplified Block Diagram is given on the previous page. The LTM8032 is designed with an input EMI filter and other features to make its radiated emissions compliant with several EMC specifications including EN55022 class B. Compliance with conducted emissions requirements may be obtained by adding a standard input filter. The LTM8032 contains a current mode controller, power switching element, power inductor, power Schottky diode and a modest amount of input and output capacitance. The LTM8032 is a fixed frequency PWM regulator. The switching frequency is set by simply connecting the appropriate resistor value from the RT pin to GND. An internal regulator provides power to the control circuitry. The bias regulator can draw power from the VIN pin, but if the BIAS pin is connected to an external voltage higher than 2.8V, bias power will be drawn from the external source (typically the regulated output voltage). This improves efficiency. The RUN/SS pin is used to place the LTM8032 in shutdown, disconnecting the output and reducing the input current to less than 1μA. To further optimize efficiency, the LTM8032 automatically switches to Burst Mode operation in light load situations. Between bursts, all circuitry associated with controlling the output switch is shut down reducing the input supply current to 50μA in a typical application. The oscillator reduces the LTM8032’s operating frequency when the voltage at the ADJ pin is low. This frequency foldback helps to control the output current during start-up and overload. The LTM8032 contains a power good comparator which trips when the ADJ pin is at 90% of its regulated value. The PGOOD output is an open-collector transistor that is off when the output is in regulation, allowing an external resistor to pull the PGOOD pin high. Power good is valid when the LTM8032 is enabled and VIN is above 3.6V. APPLICATIONS INFORMATION For most applications, the design process is straight forward, summarized as follows: 1. Look at Table 1 and find the row that has the desired input range and output voltage. 2. Apply the recommended CIN, COUT, RADJ and RT values. 3. Connect BIAS as indicated. As the integrated input EMI filter may ring in response to an application of a step input voltage, a bulk capacitance, series resistance or some clamping mechanism may be required. See the Hot-Plugging Safely section for details. While these component combinations have been tested for proper operation, it is incumbent upon the user to verify proper operation over the intended system’s line, load and environmental conditions. Capacitor Selection Considerations The CIN and COUT capacitor values in Table 1 are the minimum recommended values for the associated operating conditions. Applying capacitor values below those indicated in Table 1 is not recommended, and may result in undesirable operation. Using larger values is generally acceptable, and can yield improved dynamic response, if it is necessary. Again, it is incumbent upon the user to verify proper operation over the intended system’s line, load and environmental conditions. Ceramic capacitors are small, robust and have very low ESR. However, not all ceramic capacitors are suitable. X5R and X7R types are stable over temperature and applied voltage and give dependable service. Other types, including Y5V and Z5U have very large temperature and voltage coefficients of capacitance. In an application circuit they 8032fa 8 LTM8032 APPLICATIONS INFORMATION Table 1: Recommended Component Values and Configuration VIN 3.6V to 36V 3.6V to 36V 3.6V to 36V 3.6V to 36V 3.6V to 36V 3.6V to 36V 4.0V to 36V 4.3V to 36V 5.5V to 36V 7V to 36V 10.5V to 36V 3.6V to 15V 3.6V to 15V 3.6V to 15V 3.6V to 15V 3.6V to 15V 3.6V to 15V 4.0V to 15V 4.3V to 15V 5.5V to 15V 7V to 15V 9V to 24V 9V to 24V 9V to 24V 9V to 24V 9V to 24V 9V to 24V 9V to 24V 9V to 24V 9V to 24V 9V to 24V 10.5V to 24V 13V to 24V 18V to 36V 18V to 36V 18V to 36V 18V to 36V 18V to 36V 18V to 36V 18V to 36V 18V to 36V 18V to 36V 18V to 36V 18V to 36V 18V to 36V VOUT 0.82V 1.00V 1.20V 1.50V 1.80V 2.00V 2.20V 2.50V 3.30V 5.00V 8.00V 0.82V 1.00V 1.20V 1.50V 1.80V 2.00V 2.20V 2.50V 3.30V 5.00V 0.82V 1.00V 1.20V 1.50V 1.80V 2.00V 2.20V 2.50V 3.30V 5.00V 8.00V 10.00V 0.82V 1.00V 1.20V 1.50V 1.80V 2.00V 2.20V 2.50V 3.30V 5.00V 8.00V 10.00V CIN 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF 2.2μF COUT 200μF 1206 200μF 1206 147μF 1206 147μF 1206 100μF 1206 68μF 1206 68μF 1206 47μF 1206 22μF 1206 10μF 1206 10μF 1206 200μF 1206 200μF 1206 147μF 1206 147μF 1206 100μF 1206 68μF 1206 68μF 1206 47μF 1206 22μF 1206 10μF 1206 200μF 1206 200μF 1206 147μF 1206 147μF 1206 100μF 1206 68μF 1206 47μF 1206 22μF 1206 22μF 1206 10μF 1206 10μF 1206 10μF 1206 200μF 1206 200μF 1206 147μF 1206 147μF 1206 100μF 1206 68μF 1206 47μF 1206 22μF 1206 22μF 1206 10μF 1206 10μF 1206 10μF 1206 RADJ 5.62M 953k 487k 280k 196k 165k 140k 115k 78.7k 47.5k 27.4k 5.62M 953k 487k 280k 196k 165k 140k 115k 78.7k 47.5k 5.62M 953k 487k 280k 196k 165k 140k 115k 78.7k 47.5k 27.4k 21.5k 5.62M 953k 487k 280k 196k 165k 140k 115k 78.7k 47.5k 27.4k 21.5k BIAS ≥2.8V,