LTM8067 2.8VIN to 40VIN Isolated µModule DC/DC Converter FEATURES DESCRIPTION 2kVAC Isolated µModule Converter nn UL60950 Recognized File 464570 nn Wide Input Voltage Range: 2.8V to 40V nn Up to 450mA Output Current (V = 24V V IN , OUT = 5V) Output Adjustable from 2.5V to 24V nn Current Mode Control nn User Configurable Undervoltage Lockout nn Low Profile (9mm × 11.25mm × 4.92mm) BGA Package The LTM®8067 is a 2kVAC isolated flyback µModule® (power module) DC/DC converter. Included in the package are the switching controller, power switches, transformer, and all support components. Operating over an input voltage range of 2.8V to 40V, the LTM8067 supports an output voltage range of 2.5V to 24V, set by a single resistor. Only output and input capacitors are needed to finish the design. nn APPLICATIONS Isolated IGBT Gate Drive Industrial Sensors nn Industrial Switches nn Test and Measurement Equipment nn nn The LTM8067 is packaged in a thermally enhanced, compact (9mm × 11.25mm × 4.92mm) overmolded ball grid array (BGA) package suitable for automated assembly by standard surface mount equipment. The LTM8067 is available with SnPb or RoHS compliant terminal finish. L, LT, LTC, LTM, Linear Technology, the Linear logo and µModule are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 2kVAC Isolated µModule Regulator VIN VOUT RUN 2.2µF 22µF VOUTN FB 8.25k 600 VOUT 5V LTM8067 GND 8067 TA01a LOAD CURRENT (mA) VIN 2.8V TO 40V Maximum Output Current vs VIN Max Load Current vs VIN 400 200 0 0 10 20 VIN (V) 30 40 8067 TA01b 8067fa For more information www.linear.com/LTM8067 1 LTM8067 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) TOP VIEW VIN, RUN, BIAS .........................................................42V VOUT Relative to VOUTN..............................................25V VIN + VOUT (Note 2)....................................................48V GND to VOUT– Isolation (Note 3).......................... 2kV AC Maximum Internal Temperature (Note 4)............... 125°C Peak Solder Reflow Body Temperature.................. 245°C Storage Temperature.............................. –55°C to 125°C A B BANK 2 VOUTN C BANK 1 VOUT D E F BANK 5 VIN G BANK 4 GND RUN FB H 1 3 4 5 6 7 BGA PACKAGE 38-LEAD (11.25mm × 9mm × 4.92mm) TJMAX = 125°C, θJA = 20.8°C/W, θJCbottom = 5.1°C/W, θJCtop = 18.4°C/W, θJB = 5.3°C/W WEIGHT = 1.1g, θ VALUES DETERMINED PER JEDEC 51-9, 51-12 ORDER INFORMATION 2 http://www.linear.com/product/LTM8067#orderinfo PART MARKING* PAD OR BALL FINISH DEVICE CODE PACKAGE TYPE MSL RATING LTM8067EY#PBF SAC305 (RoHS) LTM8067Y e1 BGA 3 –40°C to 125°C LTM8067IY#PBF SAC305 (RoHS) LTM8067Y e1 BGA 3 –40°C to 125°C SnPb (63/37) LTM8067Y e0 BGA 3 –40°C to 125°C PART NUMBER LTM8067IY TEMPERATURE RANGE (SEE NOTE 4) Consult Marketing for parts specified with wider operating temperature ranges. *Device temperature grade is indicated by a label on the shipping container. Pad or ball finish code is per IPC/JEDEC J-STD-609. • Recommended LGA and BGA PCB Assembly and Manufacturing Procedures: www.linear.com/umodule/pcbassembly • Terminal Finish Part Marking: www.linear.com/leadfree • LGA and BGA Package and Tray Drawings: www.linear.com/packaging 2 8067fa For more information www.linear.com/LTM8067 LTM8067 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full internal operating temperature range, otherwise specifications are at TA = 25°C, RUN = 2V (Note 4). PARAMETER CONDITIONS Minimum Input DC Voltage RUN = 2V l VOUT DC Voltage RADJ = 15.4k RADJ = 8.25k RADJ = 1.78k l VIN Quiescent Current VRUN = 0V Not Switching MIN 4.75 TYP 2.5 5 24 7 MAX UNITS 2.8 V 5.25 V V V 3 µA mA VOUT Line Regulation 3V ≤ VIN ≤ 40V, IOUT = 0.1A, RUN = 2V 1 % VOUT Load Regulation 0.05A ≤ IOUT ≤ 0.3A, RUN = 2V 1 % VOUT Ripple (RMS) IOUT = 0.1A, 1MHz BW 30 mV Isolation Voltage (Note 3) 2 kV Input Short-Circuit Current VOUT Shorted 80 mA RUN Pin Input Threshold RUN Pin Falling RUN Pin Current VRUN = 1V VRUN = 1.3V 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: VIN + VOUT is defined as the sum of (VIN – GND) + (VOUT – VOUTN). Note 3: The LTM8067 isolation test voltage of either 2kVAC or its equivalent of 2.83kVDC is applied for one second. Note 4: The LTM8067E is guaranteed to meet performance specifications from 0°C to 125°C. Specifications over the –40°C to 125°C internal temperature range are assured by design, characterization and correlation 1.18 1.214 2.5 1.25 V 0.1 µA µA with statistical process controls. LTM8067I is guaranteed to meet specifications over the full –40°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. Test flowcharts are posted for viewing at: www.linear.com/quality 8067fa For more information www.linear.com/LTM8067 3 LTM8067 TYPICAL PERFORMANCE CHARACTERISTICS as in Table 1 (TA = 25°C). Efficiency vs Load Current, Efficiency vs Load Current, VOUT = 3.3V VOUT = 2.5VV Efficiency, OUT = 2.5V 80 0 50 100 150 200 250 LOAD CURRENT (mA) 300 60 50 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 40 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 50 40 350 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 0 50 Efficiency vs Load Current, VOUT = 8V OUT 85 85 100 200 300 400 LOAD CURRENT (mA) 65 55 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 0 EFFICIENCY (%) EFFICIENCY (%) EFFICIENCY (%) 45 500 100 200 300 400 LOAD CURRENT (mA) 500 600 Efficiency vs Load Current, VOUT = 15V OUT VIN = 5V VIN = 12V VIN = 24V VIN = 36V 0 50 Efficiency vs Load Current, VOUT = 24V OUT 100 65 VIN = 5V VIN = 12V VIN = 24V 25 50 75 100 LOAD CURRENT (mA) 250 65 55 300 125 8067 G07 VIN = 5V VIN = 12V VIN = 24V 0 50 100 150 200 LOAD CURRENT (mA) VOUT = 2.5V 125 Input Current vs Load Current VOUT = 3.3V 100 75 50 25 0 250 8068 G06 Input Current vs Load Current 75 0 100 150 200 LOAD CURRENT (mA) 75 8068 G05 INPUT CURRENT (mA) EFFICIENCY (%) 0 8068 G03 VOUT = 12VV OUT = 12V Efficiency, 8068 G04 4 40 75 55 55 VIN = 5V VIN = 12V VIN = 24V VIN = 36V Efficiency vs Load Current, 65 85 60 8067 G02 75 45 70 50 100 150 200 250 300 350 400 LOAD CURRENT (mA) 8067 G01 85 OUT 90 70 60 30 OUT 80 70 Efficiency vs Load Current, VOUT = 5V VIN = 5V VIN = 12V VIN = 24V VIN = 36V 0 50 100 150 200 250 LOAD CURRENT (mA) 300 350 8067 G08 INPUT CURRENT (mA) 80 Unless otherwise noted, operating conditions are 75 50 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 25 0 0 100 200 300 LOAD CURRENT (mA) 400 8067 G09 8067fa For more information www.linear.com/LTM8067 LTM8067 TYPICAL PERFORMANCE CHARACTERISTICS Unless otherwise noted, operating conditions are as in Table 1 (TA = 25°C). 180 120 60 0 0 100 200 300 400 LOAD CURRENT (mA) 500 Input Current vs Load Current VOUT = 8V OUT VIN = 5V VIN = 12V VIN = 24V VIN = 36V 300 200 100 0 600 0 100 8067 G10 Input Current vs Load Current VOUT = 15V 400 200 100 0 0 100 200 LOAD CURRENT (mA) 0 0 0 5 10 15 VOUT (V) 20 25 8067 G16 100 200 LOAD CURRENT (mA) 300 8067 G12 Input Current vs VIN, VOUT Shorted Input Current vs VIN, VOUT Shorted 200 150 100 50 0 50 100 LOAD CURRENT (mA) 0 150 0 10 8067 G14 400 Maximum Load CurrentINvs VIN 600 2.5VOUT 3.3VOUT MAXIMUM LOAD CURRENT (mA) 125 0 250 100 MAXIMUM LOAD CURRENT (mA) MAXIMUM LOAD CURRENT (mA) 250 0 500 200 Maximum Maximum Load Load Current Current vs vs VVOUT OUT 375 100 VIN = 5V VIN = 12V VIN = 24V 300 300 VIN = 5V VIN = 12V VIN = 24V 200 Input Current vs Load Current VOUT = 24V OUT 8067 G13 500 300 INPUT CURRENT (mA) VIN = 5V VIN = 12V VIN = 24V 300 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 8087 G11 INPUT CURRENT (mA) INPUT CURRENT (mA) 400 200 300 400 LOAD CURRENT (mA) Input Current vs Load Current VOUT = 12V 400 INPUT CURRENT (mA) 240 INPUT CURRENT (mA) 400 VIN = 5V VIN = 12V VIN = 24V VIN = 36V INPUT CURRENT (mA) 300 Input Current vs Load Current VOUT OUT = 5V 300 200 100 0 10 20 VIN (V) 30 40 8067 G17 20 VIN (V) 30 40 8067 G15 Maximum Current Max Load Load Current vs VINvs VIN 5VOUT 8VOUT 12VOUT 400 200 0 0 10 20 VIN (V) 30 40 8067 G18 8067fa For more information www.linear.com/LTM8067 5 LTM8067 TYPICAL PERFORMANCE CHARACTERISTICS Unless otherwise noted, operating conditions are as in Table 1 (TA = 25°C). 200 100 12VOUT 15VOUT 0 10 20 VIN (V) 30 20 10mV/DIV 15 10 5 DATA0 0 40 Frequency vs VOUT Load Current 400 350 250 5VIN 12VIN 24VIN 100 200 300 400 LOAD CURRENT (mA) 500 8068 G22 6 MAXIMUM LOAD CURRENT (mA) SWITCHING FREQUENCY (kHz) 450 0 0 6 8067 G19 Stock DC2357A Demo Board Stock DC2357A Demo Board 150 C5 = 470pF HP461 150MHz AMPLIFIER AT 40dB GAIN 12 VOUT1 (V) 18 400 0 LFM AIR FLOW 300 200 0 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 25 50 75 100 AMBIENT TEMPERATURE (°C) 8067 G21 8067 G20 Derating, 2.5VOUT OUT 100 2µs/DIV 24 MAXIMUM LOAD CURRENT (mA) 0 Output Noise and Ripple DC2357A, 200mA Load Current 25 MINIMUM LOAD CURRENT (mA) MAXIMUM LOAD CURRENT (mA) 300 Minimum Load Current vs VOUT Over Full Output Voltage Range Maximum Current Max Load Load Current vs VINvs VIN 125 8067 G23 Derating, 3.3V 3.3VOUT OUT Derating, 0 LFM AIR FLOW 300 200 100 0 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 25 50 75 100 AMBIENT TEMPERATURE (°C) 125 8067 G24 8067fa For more information www.linear.com/LTM8067 LTM8067 TYPICAL PERFORMANCE CHARACTERISTICS as in Table 1 (TA = 25°C). Derating, 8VOUT 450 MAXIMUM LOAD CURRENT (mA) 0 LFM AIR FLOW 450 300 0 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 25 50 75 100 AMBIENT TEMPERATURE (°C) 125 300 0 LFM AIR FLOW 300 150 0 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 25 50 75 100 AMBIENT TEMPERATURE (°C) 300 Derating, 15VOUT 150 0 LFM AIR FLOW 225 150 75 0 VIN = 5V VIN = 12V VIN = 24V VIN = 36V 25 0 LFM AIR FLOW 225 150 125 75 0 VIN = 5V VIN = 12V VIN = 24V, 36V 25 8067 G26 8067 G25 MAXIMUM LOAD CURRENT (mA) 150 Derating, 12VOUT Derating, 12VOUT OUT MAXIMUM LOAD CURRENT (mA) Derating, 5V 5VOUT Derating, OUT MAXIMUM LOAD CURRENT (mA) MAXIMUM LOAD CURRENT (mA) 600 Unless otherwise noted, operating conditions are 50 75 100 AMBIENT TEMPERATURE (°C) 125 8067 G28 50 75 100 AMBIENT TEMPERATURE (°C) 125 8067 G27 Derating, 24VOUT OUT 0 LFM AIR FLOW 120 90 60 30 0 VIN = 5V VIN = 12V, 24V, 36V 25 50 75 100 AMBIENT TEMPERATURE (°C) 125 8067 G29 8067fa For more information www.linear.com/LTM8067 7 LTM8067 PIN FUNCTIONS PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY. VOUT (Bank 1): VOUT and VOUTN comprise the isolated output of the LTM8067 flyback stage. Apply an external capacitor between VOUT and VOUTN. Do not allow VOUTN to exceed VOUT. VOUTN (Bank 2): VOUTN is the return for VOUT. VOUT and VOUTN comprise the isolated output of the LTM8067. In most applications, the bulk of the heat flow out of the LTM8067 is through the GND and VOUTN pads, so the printed circuit design has a large impact on the thermal performance of the part. See the PCB Layout and Thermal Considerations sections for more details. Apply an external capacitor between VOUT and VOUTN. GND (Bank 4): This is the primary side local ground of the LTM8067 primary. In most applications, the bulk of the heat flow out of the LTM8067 is through the GND and VOUTN pads, so the printed circuit design has a large impact on the thermal performance of the part. See the PCB Layout and Thermal Considerations sections for more details. RUN (Pin F3): A resistive divider connected to VIN and this pin programs the minimum voltage at which the LTM8067 will operate. Below 1.214V, the LTM8067 does not deliver power to the secondary. When RUN is less than 1.214V, the pin draws 2.5µA, allowing for a programmable hysteresis. Do not allow a negative voltage (relative to GND) on this pin. Tie this pin to VIN if it is not used. FB (Pins G7): Apply a resistor from this pin to GND to set the output voltage VOUTN relative to VOUTN, using the recommended value given in Table 1. If Table 1 does not list the desired VOUT value, the equation: ( ) RFB = 37.415 VOUT –0.955 kΩ may be used to approximate the value. To the seasoned designer, this exponential equation may seem unusual. The equation is exponential due to nonlinear current sources that are used to temperature compensate the regulation. Do not drive this pin with an external power source. VIN (Bank 5): VIN supplies current to the LTM8067’s internal regulator and to the integrated power switch. These pins must be locally bypassed with an external, low ESR capacitor. 8 8067fa For more information www.linear.com/LTM8067 LTM8067 BLOCK DIAGRAM VOUT VIN • • 0.1µF 1µF RUN CURRENT MODE CONTROLLER VOUTN FB GND 8067 BD 8067fa For more information www.linear.com/LTM8067 9 LTM8067 OPERATION The LTM8067 is a stand-alone isolated flyback switching DC/DC power supply that can deliver up to 450mA of output current at 5VOUT, 24VIN. This module provides a regulated output voltage programmable via one external resistor from 2.5V to 24V. The input voltage range of the LTM8067 is 2.8V to 40V. Given that the LTM8067 is a flyback converter, the output current depends upon the input and output voltages, so make sure that the input voltage is high enough to support the desired output voltage and load current. The Typical Performance Characteristics section gives several graphs of the maximum load versus VIN for several output voltages. The LTM8067 has a galvanic primary to secondary isolation rating of 2kV AC. For details please refer to the Isolation, Working Voltage and Safely Compliance section. The LTM8067 is a UL 60950 recognized component. The RUN pin is used to turn on or off the LTM8067, disconnecting the output and reducing the input current to 1μA or less. The LTM8067 is a variable frequency device. For a given input and output voltage, the frequency decreases as the load increases. For light loads, the current through the internal transformer may be discontinuous. A simplified block diagram is given. The LTM8067 contains a current mode controller, power switching element, power transformer, power Schottky diode and a modest amount of input and output capacitance. 10 8067fa For more information www.linear.com/LTM8067 LTM8067 APPLICATIONS INFORMATION For most applications, the design process is straight forward, summarized as follows: 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. 1.Look at Table 1 and find the row that has the desired input range and output voltage. 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 may have only a small fraction of their nominal capacitance resulting in much higher output voltage ripple than expected. 2.Apply the recommended CIN, COUT and RFB. 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. Bear in mind that the maximum output current may be limited by junction temperature, the relationship between the input and output voltage magnitude and polarity and other factors. Please refer to the graphs in the Typical Performance Characteristics section for guidance. A final precaution regarding ceramic capacitors concerns the maximum input voltage rating of the LTM8067. A ceramic input capacitor combined with trace or cable inductance forms a high-Q (underdamped) tank circuit. If the LTM8067 circuit is plugged into a live supply, the input voltage can ring to much higher than its nominal value, possibly exceeding the device’s rating. This situation is easily avoided; see the Hot-Plugging Safely section. 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 Table 1. Recommended Component Values for Specific VOUT Values VIN VOUT CIN COUT RFB 2.8V to 40V 2.5V 2.2µF, 50V, 1206 100µF, 6.3V, 1210 15.4k 2.8V to 40V 3.3V 2.2µF, 50V, 1206 47µF, 6.3V, 1210 11.8k 2.8V to 40V 5V 2.2µF, 50V, 1206 22µF, 16V, 1210 8.25k 2.8V to 37V 8V 2.2µF, 50V, 1206 22µF, 16V, 1210 5.23k 2.8V to 33V 12V 4.7µF, 50V, 1206 10µF, 50V, 1210 3.48k 2.8V to 30V 15V 4.7µF, 50V, 1206 4.7µF, 25V, 1210 2.8k 2.8V to 27V 18V 4.7µF, 50V, 1206 4.7µF, 25V, 1210 2.37k 2.8V to 21V 24V 4.7µF, 50V, 1206 4.7µF, 25V, 1210 1.78k Note: An input bulk capacitor is required. 8067fa For more information www.linear.com/LTM8067 11 LTM8067 APPLICATIONS INFORMATION Isolation, Working Voltage and Safety Compliance The LTM8067 isolation is 100% hi-pot tested by tying all of the primary pins together, all of the secondary pins together and subjecting the two resultant circuits to a high voltage differential for one second. This establishes the isolation voltage rating of the LTM8067 component. The isolation rating of the LTM8067 is not the same as the working or operational voltage that the application will experience. This is subject to the application’s power source, operating conditions, the industry where the end product is used and other factors that dictate design requirements such as the gap between copper planes, traces and component pins on the printed circuit board, as well as the type of connector that may be used. To maximize the allowable working voltage, the LTM8067 has two columns of solder balls removed to facilitate the printed circuit board design. The ball to ball pitch is 1.27mm, and the typical ball diameter is 0.78mm. Accounting for the missing columns and the ball diameter, the printed circuit board may be designed for a metal-to-metal separation of up to 3.03mm. This may have to be reduced somewhat to allow for tolerances in solder mask or other printed circuit board design rules. For those situations where information about the spacing of LTM8067 internal circuitry is required, the minimum metal to metal separation of the primary and secondary is 0.75mm. To reiterate, the manufacturer’s isolation voltage rating and the required working or operational voltage are often different numbers. In the case of the LTM8067, the isolation voltage rating is established by 100% hi-pot testing. The working or operational voltage is a function of the end product and its system level specifications. The actual required operational voltage is often smaller than the manufacturer’s isolation rating. The LTM8067 is a UL recognized component under UL 60950, file number 464570. The UL 60950 insulation category of the LTM8067 transformer is Functional. Considering UL 60950 Table 2N and the gap distances stated above, 3.07mm external and 1mm internal, the 12 LTM8067 may be operated with up to 250V working voltage in a pollution degree 2 environment. The actual working voltage, insulation category, pollution degree and other critical parameters for the specific end application depend upon the actual environmental, application and safety compliance requirements. It is therefore up to the user to perform a safety and compliance review to ensure that the LTM8067 is suitable for the intended application. Safety Rated Capacitors Some applications require safety rated capacitors, which are high voltage capacitors that are specifically designed and rated for AC operation and high voltage surges. These capacitors are often certified to safety standards such as UL 60950, IEC 60950 and others. In the case of the LTM8067, a common application of a safety rated capacitor would be to connect it from GND to VOUTN. To provide maximum flexibility, the LTM8067 does not include any components between GND and VOUTN. Any safety capacitors must be added externally. The specific capacitor and circuit configuration for any application depends upon the safety requirements of the system into which the LTM8067 is being designed. Table 2 provides a list of possible capacitors and their manufacturers. The application of a capacitor from GND to VOUTN may also reduce the high frequency output noise on the output. Table 2. Safety Rated Capacitors MANUFACTURER PART NUMBER DESCRIPTION Murata Electronics GA343DR7GD472KW01L 4700pF, 250V AC, X7R, 4.5mm × 3.2mm Capacitor Johanson Dielectrics 302R29W471KV3E-****-SC 470pF, 250V AC, X7R, 4.5mm × 2mm Capacitor Syfer Technology 1808JA250102JCTSP 100pF, 250V AC, C0G, 1808 Capacitor 8067fa For more information www.linear.com/LTM8067 LTM8067 APPLICATIONS INFORMATION PCB Layout Most of the headaches associated with PCB layout have been alleviated or even eliminated by the high level of integration of the LTM8067. The LTM8067 is nevertheless a switching power supply, and care must be taken to minimize electrical noise to ensure proper operation. Even with the high level of integration, you may fail to achieve specified operation with a haphazard or poor layout. See Figure 1 for a suggested layout. Ensure that the grounding and heat sinking are acceptable. A few rules to keep in mind are: 1. Place the RFB resistor as close as possible to its respective pin. 2.Place the CIN capacitor as close as possible to the VIN and GND connections of the LTM8067. 3.Place the COUT capacitor as close as possible to VOUT and VOUTN 4.Place the CIN and COUT capacitors such that their ground current flow directly adjacent to or underneath the LTM8067. 5. Connect all of the GND connections to as large a copper pour or plane area as possible on the top layer. Avoid breaking the ground connection between the external components and the LTM8067. 6. Use vias to connect the GND copper area to the board’s internal ground planes. Liberally distribute these GND vias to provide both a good ground connection and thermal path to the internal planes of the printed circuit board. Pay attention to the location and density of the thermal vias in Figure 1. The LTM8067 can benefit from the heat sinking afforded by vias that connect to internal GND planes at these locations, due to their proximity to internal power handling components. The optimum number of thermal vias depends upon the printed circuit board design. For example, a board might use very small via holes. It should employ more thermal vias than a board that uses larger holes. FB VOUT LTM8067 COUT1 VOUTN RUN CIN VIN THERMAL/INTERCONNECT VIAS 8067 F01 Figure 1. Layout Showing Suggested External Components, Planes and Thermal Vias 8067fa For more information www.linear.com/LTM8067 13 LTM8067 APPLICATIONS INFORMATION Hot-Plugging Safely θJA: Thermal resistance from junction to ambient The small size, robustness and low impedance of ceramic capacitors make them an attractive option for the input bypass capacitor of the LTM8067. However, these capacitors can cause problems if the LTM8067 is plugged into a live supply (see Linear Technology Application Note 88 for a complete discussion). The low loss ceramic capacitor combined with stray inductance in series with the power source forms an underdamped tank circuit, and the voltage at the VIN pin of the LTM8067 can ring to more than twice the nominal input voltage, possibly exceeding the LTM8067’s rating and damaging the part. If the input supply is poorly controlled or the user will be plugging the LTM8067 into an energized supply, the input network should be designed to prevent this overshoot. This can be accomplished by installing a small resistor in series to VIN, but the most popular method of controlling input voltage overshoot is adding an electrolytic bulk capacitor to the VIN net. This capacitor’s relatively high equivalent series resistance damps the circuit and eliminates the voltage overshoot. The extra capacitor improves low frequency ripple filtering and can slightly improve the efficiency of the circuit, though it can be a large component in the circuit. θJCbottom: Thermal resistance from junction to the bottom of the product case Thermal Considerations The LTM8067 output current may need to be derated if it is required to operate in a high ambient temperature. The amount of current derating is dependent upon the input voltage, output power and ambient temperature. The temperature rise curves given in the Typical Performance Characteristics section can be used as a guide. These curves were generated by the LTM8067 mounted to a 58cm2 4-layer FR4 printed circuit board. Boards of other sizes and layer count can exhibit different thermal behavior, so it is incumbent upon the user to verify proper operation over the intended system’s line, load and environmental operating conditions. For increased accuracy and fidelity to the actual application, many designers use FEA to predict thermal performance. To that end, the Pin Configuration section of the data sheet typically gives four thermal coefficients: 14 θJCtop: Thermal resistance from junction to top of the product case θJCboard: Thermal resistance from junction to the printed circuit board. While the meaning of each of these coefficients may seem to be intuitive, JEDEC has defined each to avoid confusion and inconsistency. These definitions are given in JESD 51-12, and are quoted or paraphrased as follows: θJA is the natural convection junction-to-ambient air thermal resistance measured in a one cubic foot sealed enclosure. This environment is sometimes referred to as still air although natural convection causes the air to move. This value is determined with the part mounted to a JESD 51-9 defined test board, which does not reflect an actual application or viable operating condition. θJCbottom is the junction-to-board thermal resistance with all of the component power dissipation flowing through the bottom of the package. In the typical µModule converter, the bulk of the heat flows out the bottom of the package, but there is always heat flow out into the ambient environment. As a result, this thermal resistance value may be useful for comparing packages but the test conditions don’t generally match the user’s application. θJCtop is determined with nearly all of the component power dissipation flowing through the top of the package. As the electrical connections of the typical µModule converter are on the bottom of the package, it is rare for an application to operate such that most of the heat flows from the junction to the top of the part. As in the case of θJCbottom, this value may be useful for comparing packages but the test conditions don’t generally match the user’s application. θJCboard is the junction-to-board thermal resistance where almost all of the heat flows through the bottom of the µModule converter and into the board, and is really the sum of the θJCbottom and the thermal resistance of the 8067fa For more information www.linear.com/LTM8067 LTM8067 APPLICATIONS INFORMATION bottom of the part through the solder joints and through a portion of the board. The board temperature is measured a specified distance from the package, using a two-sided, two-layer board. This board is described in JESD 51-9. A graphical representation of these thermal resistances is given in Figure 2. Given these definitions, it should now be apparent that none of these thermal coefficients reflects an actual physical operating condition of a µModule converter. Thus, none of them can be individually used to accurately predict the thermal performance of the product. Likewise, it would be inappropriate to attempt to use any one coefficient to correlate to the junction temperature vs load graphs given in the product’s data sheet. The only appropriate way to use the coefficients is when running a detailed thermal analysis, such as FEA, which considers all of the thermal resistances simultaneously. The die temperature of the LTM8067 must be lower than the maximum rating of 125°C, so care should be taken in the layout of the circuit to ensure good heat sinking of the LTM8067. The bulk of the heat flow out of the LTM8067 is through the bottom of the module and the BGA pads into the printed circuit board. Consequently a poor printed circuit board design can cause excessive heating, resulting in impaired performance or reliability. Please refer to the PCB Layout section for printed circuit board design suggestions. The blue resistances are contained within the µModule converter, and the green are outside. JUNCTION-TO-AMBIENT RESISTANCE (JESD 51-9 DEFINED BOARD) JUNCTION-TO-CASE (TOP) RESISTANCE JUNCTION CASE (TOP)-TO-AMBIENT RESISTANCE JUNCTION-TO-BOARD RESISTANCE CASE (BOTTOM)-TO-BOARD JUNCTION-TO-CASE RESISTANCE (BOTTOM) RESISTANCE AMBIENT BOARD-TO-AMBIENT RESISTANCE 8067 F02 µMODULE DEVICE Figure 2. Approximate Thermal Model of LTM8067 8067fa For more information www.linear.com/LTM8067 15 LTM8067 APPLICATIONS INFORMATION 12V Flyback Converter VIN 12V VOUT RUN 4.7µF VOUT 12V 10µF VOUTN FB 3.48k LTM8067 GND 8067 TA03a 200 100 0 –15V Inverting Regulator VIN 5V TO 31V 4.7µF VOUTN FB 2.8k LTM8067 GND 8067 TA04a VOUT –15V 20 VIN (V) 30 40 8067 TA03b 200 100 0 16 10 OUT 300 VOUT RUN 4.7µF 0 Maximum Load Current vs VIN MAXIMUM LOAD CURRENT (mA) VIN OUT 300 MAXIMUM LOAD CURRENT (mA) VIN Maximum Load Current vs VIN 0 10 20 VIN (V) 30 40 8067 TA04b 8067fa For more information www.linear.com/LTM8067 LTM8067 PACKAGE DESCRIPTION Pin Assignment Table (Arranged by Pin Number) PIN FUNCTION PIN FUNCTION PIN FUNCTION PIN FUNCTION PIN FUNCTION PIN B1 VOUTN C1 D1 E1 GND F1 A1 VOUTN A2 VOUN B2 VOUTN C2 D2 E2 GND F2 A3 VOUTN B3 VOUTN C3 D3 E3 GND F3 B4 VOUTN C4 D4 E4 GND F4 A4 VOUTN B5 VOUTN C5 D5 E5 GND F5 A5 VOUTN B6 VOUT C6 D6 E6 GND F6 A6 VOUT B7 VOUT C7 D7 E7 GND F7 A7 VOUT FUNCTION RUN GND GND GND GND PIN G1 G2 G3 G4 G5 G6 G7 FUNCTION PIN FUNCTION VIN H1 VIN VIN H2 VIN H3 GND H4 GND GND H5 GND GND H6 GND FB H7 GND PACKAGE PHOTO 8067fa For more information www.linear.com/LTM8067 17 4 For more information www.linear.com/LTM8067 E SUGGESTED PCB LAYOUT TOP VIEW 2.540 PACKAGE TOP VIEW 1.270 PIN “A1” CORNER 0.3175 0.000 0.3175 aaa Z 1.270 Y 4.445 3.175 1.905 0.635 0.000 0.635 1.905 3.175 4.445 D X 4.7625 4.1275 aaa Z 3.95 – 4.05 SYMBOL A A1 A2 b b1 D E e F G aaa bbb ccc ddd eee NOM 4.92 0.60 4.32 0.75 0.63 11.25 9.0 1.27 8.89 7.62 DIMENSIONS 0.15 0.10 0.20 0.30 0.15 MAX 5.12 0.70 4.42 0.90 0.66 NOTES DETAIL B PACKAGE SIDE VIEW TOTAL NUMBER OF BALLS: 38 MIN 4.72 0.50 4.22 0.60 0.60 DETAIL A b1 0.27 – 0.37 SUBSTRATE A1 ddd M Z X Y eee M Z DETAIL B MOLD CAP ccc Z A2 A Z (Reference LTC DWG # 05-08-1925 Rev A) Øb (38 PLACES) // bbb Z 18 2.540 b 3 F e SEE NOTES 7 5 4 3 2 1 DETAIL A PACKAGE BOTTOM VIEW 6 G H G F E D C B A PIN 1 DETAILS OF PIN #1 IDENTIFIER ARE OPTIONAL, BUT MUST BE LOCATED WITHIN THE ZONE INDICATED. THE PIN #1 IDENTIFIER MAY BE EITHER A MOLD OR MARKED FEATURE 4 7 TRAY PIN 1 BEVEL ! BGA 38 1212 REV A PACKAGE IN TRAY LOADING ORIENTATION LTMXXXXXX µModule PACKAGE ROW AND COLUMN LABELING MAY VARY AMONG µModule PRODUCTS. REVIEW EACH PACKAGE LAYOUT CAREFULLY 6. SOLDER BALL COMPOSITION IS 96.5% Sn/3.0% Ag/0.5% Cu 5. PRIMARY DATUM -Z- IS SEATING PLANE BALL DESIGNATION PER JESD MS-028 AND JEP95 3 2. ALL DIMENSIONS ARE IN MILLIMETERS 7 SEE NOTES NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M-1994 COMPONENT PIN “A1” BGA Package 38-Lead (11.25mm × 9.00mm × 4.92mm) LTM8067 PACKAGE DESCRIPTION Please refer to http://www.linear.com/product/LTM8067#packaging for the most recent package drawings. 8067fa 3.810 3.810 LTM8067 REVISION HISTORY REV DATE DESCRIPTION A 05/16 Corrected symbol of internal switch in block diagram from NPN transistor to N-channel MOSFET PAGE NUMBER 9 8067fa Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of itsinformation circuits as described herein will not infringe on existing patent rights. For more www.linear.com/LTM8067 19 LTM8067 TYPICAL APPLICATION 15V Floating 1GBT Gate Drive VIN VIN 12V VOUT RUN 15V 200mA 100VDC MOTOR POWER 4.7µF 4.7µF VOUTN FB 2.8k LTM8067 GND 8067 TA02a DESIGN RESOURCES SUBJECT DESCRIPTION µModule Design and Manufacturing Resources Design: • Selector Guides • Demo Boards and Gerber Files • Free Simulation Tools µModule Regulator Products Search Manufacturing: • Quick Start Guide • PCB Design, Assembly and Manufacturing Guidelines • Package and Board Level Reliability 1. Sort table of products by parameters and download the result as a spread sheet. 2. Search using the Quick Power Search parametric table. TechClip Videos Quick videos detailing how to bench test electrical and thermal performance of µModule products. Digital Power System Management Linear Technology’s family of digital power supply management ICs are highly integrated solutions that offer essential functions, including power supply monitoring, supervision, margining and sequencing, and feature EEPROM for storing user configurations and fault logging. RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTM8068 2kVAC Isolated µModule Converter with LDO Post Regulator 2.8V ≤ VIN ≤40V, 1.2V ≤ VOUT ≤ 18V; 20µVrms Output Ripple. UL60950 Regognized. LTM8047 725VDC, 1.5W Isolated µModule Converter 3.1V ≤ VIN ≤32V, 2.5V ≤ VOUT ≤ 12V LTM8048 725VDC, 1.5W Isolated µModule Converter with LDO Post Regulator 3.1V ≤ VIN ≤32V, 1.2V ≤ VOUT ≤ 12V; 20µVrms Output Ripple LTM8045 Inverting or SEPIC µModule DC/DC Convertor 2.8V ≤ VIN ≤18V, 2.5V ≤ VOUT ≤ 15V or -2.5V ≤ VOUT ≤ –15V, Up to 700mA LT8300 Isolated Flyback Convertor with 100VIN, 150V/260mA Power Switch 6V ≤ VIN ≤ 100V, No Opt-Isolator Required LT8301 Isolated Flyback Convertor with 65V/1.2A Power Switch 2.7V ≤ VIN ≤ 42V, No Opt-Isolator Required LT8302 Isolated Flyback Convertor with 65V/3.6A Power Switch 2.8V ≤ VIN ≤ 42V, No Opt-Isolator Required 20 8067fa Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/LTM8067 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTM8067 LT 0516 REV A • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2016