MP24971 1.5A, 50V, 100kHz, 5V Fixed Output StepDown Converter with Programmable Current Limit and Output Line-Drop Compensation The Future of Analog IC Technology DESCRIPTION FEATURES The MP24971 is a monolithic, step-down, switch-mode converter with a programmable output-current limit. It has a fixed 5V/1.5A continuous output over a wide input supply range, and has excellent load and line regulation. It has an internal 2ms-to-4ms softstart that prevents inrush current at start-up, and compensates for output line drop. MP24971 achieves a low EMI signature with well-controlled switching edges. It has fault-condition protections including hiccup-mode current limit protection, shortcircuit protection, output over-voltage protection, and thermal shutdown. The MP24971 requires a minimal number of readily-available standard external components, and is available in SOIC8 and SOIC8E packages. Wide 8V-to-50V Operating Input Range Output Over-Voltage Protection 5V Fixed Output 0.4Ω Internal Power MOSFET Internal 4ms Soft-Start Stable with Low-ESR Ceramic Output Capacitors Fixed 100kHz Frequency Low EMI Signature Thermal Shutdown Output Line-Drop Compensation Hiccup Circuit Limit and Short Circuit Protection Available in SOIC8 and SOIC8E Package APPLICATIONS USB Power Supplies Automotive Power Adapters Power Supplies for Linear Chargers All MPS parts are lead-free and adhere to the RoHS directive. For MPS green status, please visit MPS website under Products, Quality Assurance page. “MPS” and “The Future of Analog IC Technology” are registered trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION Efficiency vs. Output Current R1 0O C2 2.2µF VIN C1 220µF BST L1 33µH C8 C9 C7 100µF 22µF 0.1µF + Diode C3 0.1µF VOC GND R2 402kO MP24971 ISP GND ISN C5 10nF R3 1kO C6 10nF R4 1kO C10 0.1µF VOUT=5V VIN=12V 90 V OUT SW VIN VOS 95 RSENSE 66mO EFFICIENCY (%) C4 0.1µF 85 80 VIN=24V 75 70 65 VIN=50V 60 R5 0O 55 0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 OUTPUT CURRENT (A) MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 1 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER ORDERING INFORMATION Part Number MP24971DS* MP24971DN** Package SOIC8 SOIC8E Top Marking MP24971 MP24971 Operating Temperature (TJ) -40C to +125C -40C to +125C * For Tape & Reel, add suffix –Z (eg. MP24971DS–Z); For RoHS, compliant packaging, add suffix –LF (eg. MP24971DS–LF–Z). ** For Tape & Reel, add suffix –Z (eg. MP24971DN–Z); For RoHS, compliant packaging, add suffix –LF (eg. MP24971DN–LF–Z). PACKAGE REFERENCE SOIC8 ABSOLUTE MAXIMUM RATINGS (1) Input Voltage VIN .......................................... 60V VISN, VISP, VVOS ........................................ 0V to 8V |VISN -VISP| ........................................... 0V to 0.4V VSW ..................................... -0.3V to (VIN + 0.3V) VBST ................................................... VSW + 6.5V All Other Pins ...............................-0.3V to +6.5V Junction Temperature ...............................150°C Lead Temperature ....................................260°C Storage Temperature ............... -65°C to +150°C (2) Continuous Power Dissipation (TA = 25°C) SOIC8 ...................................................... 1.38W SOIC8E ...................................................... 2.5W ESD Susceptibility HBM (Human Body Mode).......................... 2kV SOIC8E Recommended Operating Conditions (3) Input Voltage VIN ................................. 8V to 50V Maximum Junction Temp. (TJ) ................ 125°C Thermal Resistance (4) θJA θJC SOIC8 ..................................... 90 ...... 45... °C/W SOIC8E .................................. 50 ...... 10... °C/W Notes: 1) Exceeding these ratings may damage the device. 2) The maximum allowable power dissipation is a function of the maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature TA. The maximum allowable continuous power dissipation at any ambient temperature is calculated by PD (MAX) = (TJ (MAX)-TA)/θJA. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal shutdown circuitry protects the device from permanent damage. 3) The device is not guaranteed to function outside of its operating conditions. 4) Measured on JESD51-7, 4-layer PCB. MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 2 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS VIN = 12V, TA = 25°C, unless otherwise noted. Parameters Symbol Output Voltage VOUT Output Over-Voltage Protection VOVP Switch-On Resistance Condition Min Typ Max Units 8V VIN 50V, RSENSE=0Ω 4.85 5 5.15 V 5.69 6 6.2 V 0.4 0.5 Ω 0.1 (5) 1 μA 3.5 4.4 5.2 A 70 100 140 kHz RDS(ON) Switch Leakage VISN = 6.5V, VSW = 0V Current Limit Oscillator Frequency fSW Bootstrap Voltage VBST - VSW Minimum On Time tON SW Rising Edge SW Falling Edge 4 50 100 250 ns tRISE 50 100 ns tFALL 85 150 ns 3.5 4.2 V Under-Voltage Lockout Threshold Rising Under-Voltage Lockout Threshold Hysteresis Load-Line Compensation Gain Current Sense Voltage Input Bias Current (ISN, ISP) Supply Current (Quiescent) Thermal Shutdown V 2.8 200 VVOC mV VISP-VISN=50mV 200 330 450 VISP-VISN=100mV 500 620 700 90 -1 100 -0.5 110 +1 mV μA 1.2 1.5 mA VISP-VISN VISN=5V IBIAS (ISN,ISP) VISP=VISN=5V VISN = VVOS = 5.5V 150 mV °C Note: 5) Guaranteed by design. MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 3 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER PIN FUNCTIONS Package Pin # 1 2 3 4 5 6 7 8 Name Description Supply Voltage. Operates from an unregulated 8V-to-50V input. Requires decoupling capacitor(s)—CIN—to limit voltage spikes. Drain of the internal power MOSFET; supplies power to the whole chip. Ground. Voltage reference of the regulated output voltage. GND node should be placed GND outside of the diode-to-CIN ground path to prevent switching current spikes from inducing Exposed voltage noise into the part. Connect exposed pad to GND plane for optimal thermal Pad performance. VOS Output Voltage Sense. Connect directly to the output. Output Line Drop Compensator. Connect to GND through a resistor to compensate for the VOC output voltage drop. Negative Current Sense Input. Used for limiting load current and for over-voltage ISN protection. Native 6V over-voltage protection threshold. ISP Positive Current Sense Input. Used for load current limiting. Bootstrap. Requires a capacitor to drive the power MOSFET gate above the supply voltage. Connected capacitor between SW and BST pins to form a floating supply across BST the power MOSFET driver. An on-chip regulator charges the external bootstrap capacitor. If the on-chip regulator is not powerful enough, add a diode from VIN or VOUT to charge the external boot-strap capacitor. VIN SW Switch Output. Output power supply. MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 4 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER TYPICAL CHARACTERISTICS IBIAS(ISP,ISN) vs. Temperature Current Limit vs. Temperature V =V =5V -0.45 ISP ISN -0.5 5.4 4.96 5.3 4.9575 5.2 -0.6 -0.65 -0.7 -0.75 -0.8 4.9525 5 4.9 4.8 4.945 4.6 4.9425 4.5 -20 10 40 4.4 -50 70 100 130 4.95 4.9475 4.7 -20 10 40 4.94 -50 70 100 130 VOVP vs. Temperature Frequency vs. Temperature 109 106 105 104 5.94 5.93 5.92 103 102 40 70 100 130 635 VVOC(mV) VOVP(V) 107 10 VISP-VISN=100mV 640 5.95 108 -20 VVOC vs. Temperature 5.96 110 FREQUENCY(kHz) 4.955 5.1 VVOS(V) CURRENT LIMIT(A) -0.55 -0.85 -50 VVOS vs. Temperature 630 625 620 5.91 101 -20 10 40 70 100 130 5.9 -50 VBST vs. Temperature 1220 4.1 4 VBST(V) 10 40 615 -50 70 100 130 104 1190 103.5 1160 1150 3.85 10 40 70 100 130 1130 -50 70 100 130 103 102.5 102 101.5 101 1140 -20 40 VISN=5V 105 1200 1170 3.9 10 104.5 1180 3.95 -20 VISP-VISN vs. Temperature Quiescent Current vs. Temperature 1210 4.05 3.8 -50 -20 VISP-VISN(mV) 100 -50 100.5 -20 10 40 70 100 130 100 -50 -20 10 40 MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 70 100 130 5 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS C1=220μF, C2=2.2μF, C8=22μF, C9=100μF, L=33μH, RSENSE=66mΩ, TA=25°C, unless otherwise noted. Output Line Drop Loop Gain with Efficiency vs. Compensation Phase Margin Output Current 4.95 VIN=24V 4.93 GAIN (dB) VOUT (V) 4.94 VIN=50V 4.92 4.91 4.9 0 0.2 0.4 0.6 0.8 1 1.2 1.4 IOUT (A) 95 40 160 90 30 120 20 80 10 40 0 0 -10 -40 -20 -80 -30 -120 -40 -160 -50 0.1 Load Regulation 1 10 100 FREQUENCY(kHz) -200 1000 VIN=12V 85 80 VIN=24V 75 70 65 VIN=50V 60 55 0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 IOUT (A) EMI Radiation Connect ISP, ISN to GND 90 4.96 VOUT=5V 200 50 VIN=12V VIN=12V, VOUT=5V, IOUT=1.5A Resistor Load PHASE (degree) 4.96 VIN=12V, VOUT=5V, IOUT=1.5A Resistor Load 80 VOUT (V) 4.955 VIN=24V VIN=12V 60 4.95 4.945 70 50 EN55022 40 VIN=50V 4.94 4.935 4.93 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 IOUT (A) 30 20 10 0 -10 30 100 FREQUENCY(MHz) 1000 MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 6 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS (continued) C1=220μF, C2=2.2μF, C8=22μF, C9=100μF, L=33μH, RSENSE=66mΩ, TA=25°C，unless otherwise noted. Steady State Steady State Power Ramp Up VIN=12V, VOUT=5V, IOUT=1.5A E-Load VIN=50V, VOUT=5V, IOUT=1.5A E-Load SW 10V/div VIN/AC 500mV/div SW 50V/div VIN/AC 1V/div VOUT/AC 20mV/div VOUT/AC 50mV/div IL 2A/div IL 2A/div VIN 10V/div SW 10V/div VOUT 5V/div IOUT 2A/div Power Ramp Down Short Circuit Enter Short Circuit Steady VIN=12V, VOUT=5V, IOUT=1.5A Resistor Load VIN=12V, VOUT=5V, IOUT=0.5A VIN=12V, VOUT=5V VIN 10V/div SW 10V/div SW 10V/div SW 10V/div VOUT 5V/div VOUT 500mV/div IL 2A/div IOUT 2A/div VOUT 5V/div IOUT 2A/div SW 10V/div VIN=12V, VOUT=5V, IOUT=1.5A Resistor Load Short Circuit Recovery Load Transient Response Over Voltage Protection VIN=12V, VOUT=5V, IOUT=0.5A VIN=12V, VOUT=5V, IOUT=0.3A-1.5A Slew Rate=6.4mA/ s VIN=12V, VOUT=5V, IOUT=1.5A Add an 6V External Power to ISN VOUT 200mV/div VISN 5V/div VOUT 5V/div SW 10V/div IOUT 2A/div VOUT 5V/div IOUT 2A/div IOUT 1A/div MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 7 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER FUNCTIONAL BLOCK DIAGRAM VIN CURRENT SENSE AMPLIFIER GND Σ REGULATOR 63mO BST RAMP REFERENCE NMOSFET REGULATOR OSCILLATOR DRIVER CLK RSENSE OUT SW S IN Q R PWM COMPARATOR 600mV 6.2uA 200mV JFET Hiccup Current Limit ISP X6 ISN RS1 RS2 VOS 1.23V OVP COMPARATOR C2 50pF R1 1704kO 10000kO RTOP 300kO JFET C1 1pF SS Circuit ERROR AMPLIFIER 800mV 10pF VOC RBOT 57.14kO RC Figure 1—Function Block Diagram MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 8 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER OPERATION Main Control Loop The MP24971 is a current-mode buck regulator where the output voltage of the error amplifier (EA) is proportional to the peak inductor current. When a cycle starts, SW is disconnected and the EA output voltage is higher than the current sense amplifier (CSA) output. The rising edge of the 100kHz CLK signal sets the RS flip-flop, which connects SW and the inductor to the input supply. The CSA amplifies the rising inductor current. The PWM comparator (PWMCOMP) compares sum of the CSA output and the ramp compensation (positive input) against the EA output (negative input). When the positive PWMCOMP input exceeds the negative PWMCOMP input, the RS flip-flop resets and the MP24971 reverts to its initial SW off state: Otherwise, the falling edge of the CLK resets the flip-flop. The EA amplifies the voltage difference between VOUT (connected through the VOS pin) and the 800mV reference: Because VOUT connects to the negative input of the EA, when VOUT drops below 5V, the EA output increases. Since the EA output voltage is proportional to the peak inductor current, an increase in inductor voltage increases current delivered to the output. An external Schottky Diode dissipates the inductor current when SW is off. Hiccup-Mode Current Limit Protection The ISP and ISN pins sense the output current information for current limit protection. Once the VSENSE exceeds the 100mV voltage limit threshold, the current limit loop will turn off the high-side MOSFET immediately. The internal soft-start circuit resets after the VOS voltage drops below 1.9V and VCOMP rises above 3V; at this point, the high side switch turns on and MP24971 restarts with a full soft start. This hiccup process repeats until the device stops detecting a fault. The current limit value can be lowered by an internal current source and external resistors connected to ISN and ISP pins when the output voltage drops below 200mV. This feature can greatly reduce the average short circuit current. Output Over-Voltage Protection The MP24971 has output over-voltage protection to prevent the output voltage from rising above a threshold of 6V—such as if the output sense is left open—and prevents any voltage damage to the circuit load. If the output voltage—as sensed by the ISN pin—rises above 6V, the high-side MOSFET will turn off immediately and part will be lathed off after a timer delay. Output-Line–Drop Compensation MP24971 is capable of compensating an output voltage drop—such as high impedance caused by a very long trace—to keep a constant 5V load-side voltage. Compensation feedback comes from the VOS pin and through the RTOP resistor. Program the load line compensation gain using a resistor connected to VOC pin, selected based on RSENSE and RTRACE (Figure 2) values. MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 9 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER APPLICATION INFORMATION Setting the Output Line Drop Compensation Long traces to the circuit load induce a voltage drop between VOUT and VLOAD. that can be described as: VDROP IOUT RTRACE Supplying an accurate and consistent load voltage over current-dependant trace resistance necessitates line-drop compeonsation. MP24971 offers a compensation method that adjusts the FB voltage slightly according to the load current. The relation between VOUT and VFB can be described by: (3) IOUT RSENSE 6 RTOP RC (4) The VLOAD is determined by: VLOAD 5V IOUT RSENSE 6 RTOP RC (5) IOUT RTRACE Load X6 ISN R TOP VFB VOS VOC RC RBOT Hiccup Current Limit 600mV 10000kO 10pF 0.8V ERROR AMPLIFIER Internal Block Selecting the Inductor For most applications, use a 10µH to 47µH inductor with a DC current rating of at least 125% of the maximum load current. For best efficiency, select an inductor with a DC resistance less than 200mΩ. For most designs, the inductance value can be determined by. L To maintain a VLOAD that is not variable with load current, balance the equation below: IOUT RSENSE 6 RTOP IOUT RTRACE (6) RC Where RTOP is 300kΩ. Simplifying, we find that RC comes out to: R 6 300k RC SENSE RTRACE VLOAD R TRACE ISP Figure 2—Output Line Drop Compensation Where, VFB is 0.8V. Then, the VOUT can be calculated by: VOUT 5V RTRACE1 RTRACE2 (1) Where R TRACE R TRACE1 R TRACE2 as seen in Figure 2. Then, the VLOAD is: VLOAD VOUT IOUT RTRACE (2) VOUT VFB I RSENSE 6 V FB OUT R TOP RBOT RC VOUT R SENSE SW (7) Where RSENSE is known and RTRACE can be tested or evaluated VOUT ( VIN VOUT ) VIN IL f OSC (8) Where ΔIL is the inductor ripple current. Choose inductor current ripple to equal approximately 30% of the maximum load current, 1.5A. Then maximum inductor peak current is: IL(MAX ) ILOAD I L 2 (9) Under light-load conditions below 100mA, use a larger inductor to improve efficiency. MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 10 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER Selecting the Input Capacitor An input capacitor reduces the surge current drawn from the input and any switching noise from the device. Chose a capacitor with a switching-frequency impedance less than the input source impedance. Use ceramic capacitors with X5R or X7R dielectrics for their low ESR and small temperature coefficients. A capacitor value of 4.7µF will suffice for most applications. Selecting the Output Capacitor An output capacitor limits the output voltage and ensures regulator loop stability. Chose an output capacitor with a low impedance at the switching frequency; preferably ceramic with X5R or X7R dielectrics. Setting the Current Limit The inductor’s DC resistance (DCR) sets the hiccup current limit. Use a sense resistor with high precision and accuracy for accurate sense measurement. The current limit at output short condition is: IOUT _ SL 100mV 6.2A RS1 RSENSE (13) SW Ra ISP Ca RS1 RS2 ISN (a) RSENSE SW RS1 ISP RS2 ISN In Figure 3a, the output current limit is: 100mV DCR Where Ra and Ca form a low pass filter. IOUT _ L (b) (10) Figure 3—Current Sensing Methods In Figure 3b, the output current limit is set as: IOUT _ L RSENSE SW 100mV RSENSE (11) Programming the Short Circuit Current Limit The hiccup current limit at output short condition can be programmed to be lower by external resisters (RS1, RS2, RS1=RS2), as shown in figure 4. ISP RS1 ISN When output voltage is lower than 200mV, the current limit is described by: IOUT _ SL R SENSE 6.2A RS1 100mV RS2 6.2uA 200mV (12) Figure 4—Short Circuit Current Limit MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 11 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER PC Board Layout The high frequency paths for VIN, SW and GND should be routed very close to the device with short, direct, and wide traces. Place the input capacitor as close as possible to the IN and GND pins. Place the external feedback resistors next to the FB pin. Keep the switching node SW short and away from the feedback network. 5V BS MP24971 10nF SW Figure 5—External Bootstrap Diode External Bootstrap Diode An external bootstrap diode helps improve the efficiency of the regulator when the system has a 5V fixed input or the power supply generates a 5V output. The bootstrap diode can be lowcost, such as an IN4148 or a BAT54. Design Example Below is a sample design that follows the application guidelines for the specifications below: Parameter Input Voltage Output Voltage Output Current Limit Output OVP Add a diode for high duty-cycle operation (when VOUT >65%). VIN Symbol VIN VOUT IOUT-L VOVP Value 8 - 50 5 1.5 6 Units V V A V Figure 6 shows the detailed application schematic. The Typical Performance Characteristics performance and circuit waveforms are all based on this design. For additional implentations, consult the Evaluation Board Data Sheets. D1 NS Vcc R1 0O C2 2.2µF VIN C1 100µ F BST C4 0.1µF L1 33µH C9 C8 C7 100µF 22µF 0.1µF VIN D2 B 360A C3 0.1µF R7 165O + R5 100O VOC R2 402kO MP24971 GND R6 100mO VOUT SW C10 NS C11 0.1µF GND ISP GND VOS ISN C5 10nF R3 1kO C6 10nF R4 1kO R8 0O Figure 6—Detailed Sample Application Schematic MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 12 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER PACKAGE INFORMATION SOIC8 0.189(4.80) 0.197(5.00) 8 0.050(1.27) 0.024(0.61) 5 0.063(1.60) 0.150(3.80) 0.157(4.00) PIN 1 ID 1 0.228(5.80) 0.244(6.20) 0.213(5.40) 4 TOP VIEW RECOMMENDED LAND PATTERN 0.053(1.35) 0.069(1.75) SEATING PLANE 0.004(0.10) 0.010(0.25) 0.013(0.33) 0.020(0.51) 0.0075(0.19) 0.0098(0.25) SEE DETAIL "A" 0.050(1.27) BSC SIDE VIEW FRONT VIEW 0.010(0.25) x 45o 0.020(0.50) GAUGE PLANE 0.010(0.25) BSC 0o-8o 0.016(0.41) 0.050(1.27) DETAIL "A" NOTE: 1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN BRACKET IS IN MILLIMETERS. 2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH , PROTRUSIONS OR GATE BURRS. 3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. 4) LEAD COPLANARITY(BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.004" INCHES MAX. 5) DRAWING CONFORMS TO JEDEC MS-012, VARIATION AA. 6) DRAWING IS NOT TO SCALE. MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 13 MP24971 –1.5A, 50V, 100kHz, 5V FIXED OUTPUT STEP-DOWN CONVERTER PACKAGE INFORMATION SOIC8E (EXPOSED PAD) 0.189(4.80) 0.197(5.00) 8 0.124(3.15) 0.136(3.45) 5 0.150(3.80) 0.157(4.00) PIN 1 ID 1 0.228(5.80) 0.244(6.20) 0.089(2.26) 0.101(2.56) 4 TOP VIEW B OTTOM VIEW SEE DETAIL "A" 0.013(0.33) 0.020(0.51) 0.051(1.30) 0.067(1.70) SEATING PLANE 0.000(0.00) 0.006(0.15) 0.0075(0.19) 0.0098(0.25) SID E VIEW 0.050(1.27) BSC FR ON T VIEW 0.010(0.25) x 45 o 0.020(0.50) GAUGE PLANE 0.010(0.25) BSC 0.024(0.61) 0.050(1.27) 0 o-8 o 0.016(0.41) 0.050(1.27) 0.063(1.60) D ETA IL " A" 0.103(2.62) 0.138(3.51) R EC OMMEN D ED LA N D PA TTER N 0.213(5.40) N OTE: 1) CONTROL DIMENSION IS IN INCHES. DIMENSION IN BRACKET IS IN MILLIMETERS. 2) PACKAGE LENGTH DOES NOT INCLUDE MOLD FLASH , PROTRUSIONS OR GATE BURRS. 3) PACKAGE WIDTH DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. 4) LEAD COPLANARITY(BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.004" INCHES MAX. 5) DRAWING CONFORMS TO JEDEC MS-012, VARIATION BA. 6) DRAWING IS NOT TO SCALE. NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications. Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MP24971 Rev. 1.01 www.MonolithicPower.com 1/6/2012 MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited. © 2012 MPS. All Rights Reserved. 14