MP1583 3A, 23V, 385KHz Step-Down Converter The Future of Analog IC Technology DESCRIPTION FEATURES The MP1583 is a step-down regulator with a built-in internal Power MOSFET. It achieves 3A of continuous output current over a wide input supply range with excellent load and line regulation. • • • • • • • • • • • • Current mode operation provides fast transient response and eases loop stabilization. Fault condition protection includes cycle-by-cycle current limiting and thermal shutdown. An adjustable soft-start reduces the stress on the input source at startup. In shutdown mode the regulator draws 20μA of supply current. The MP1583 requires a minimum number of external components, providing a compact solution. 3A Output Current Programmable Soft-Start 100mΩ Internal Power MOSFET Switch Stable with Low ESR Output Ceramic Capacitors Up to 95% Efficiency 20μA Shutdown Mode Fixed 385KHz Frequency Thermal Shutdown Cycle-by-Cycle Over Current Protection Wide 4.75V to 23V Operating Input Range Output Adjustable from 1.22V to 21V Under-Voltage Lockout APPLICATIONS • • • Distributed Power Systems Battery Chargers Pre-Regulator for Linear Regulators “MPS” and “The Future of Analog IC Technology” are Registered Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION Efficiency Curve OPEN = AUTOMATIC STARTUP 10μ F CERAMIC 2 7 8 IN BS SW EN MP1583 SS GND 4 10nF FB COMP 6 100 10nF 1 3 5 B330A 5.6nF 3.9kΩ 15μ H 10.5kΩ 10kΩ OUTPUT 2.5V 3A 22μ F CERAMIC VIN = 10V VOUT=5.0V 90 EFFICIENCY (%) INPUT 4.75V to 23V VOUT=2.5V 80 VOUT=3.3V 70 60 50 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 LOAD CURRENT (A) MP1583_EC01 MP1583 Rev. 3.1 6/20/2011 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 1 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER ORDERING INFORMATION Part Number* MP1583DN MP1583DP Package SOIC8E PDIP8 Top Marking MP1583DN MP1583DP Free Air Temperature (TA) –40°C to +85°C –40°C to +85°C * For Tape & Reel, add suffix –Z (e.g. MP8736DL–Z) For RoHS compliant packaging, add suffix –LF (e.g. MP8736DL–LF–Z) PACKAGE REFERENCE TOP VIEW SOIC8N/PDIP8 BS 1 8 SS IN 2 7 EN SW 3 6 COMP GND 4 5 FB EXPOSED PAD (SOIC8N ONLY) CONNECT TO PIN 4 MP1583_PD01 ABSOLUTE MAXIMUM RATINGS (1) Thermal Resistance Supply Voltage VIN .......................–0.3V to +28V Switch Voltage VSW ................. –1V to VIN + 0.3V Bootstrap Voltage VBS ....VSW – 0.3V to VSW + 6V FB, COMP and SS Pins.................–0.3V to +6V (2) Continuous Power Dissipation (TA = +25°C) SOIC8E...................................................... 2.5W PDIP8 ........................................................ 1.2W Junction Temperature ...............................150°C Lead Temperature ....................................260°C Storage Temperature ............. –65°C to +150°C SOIC8E .................................. 50 ...... 10... °C/W PDIP8 .................................... 104 ..... 45... °C/W Recommended Operating Conditions (3) Input Voltage VIN ............................4.75V to 23V Operating Junct. Temp (TJ)...... -40°C to +125°C MP1583 Rev. 3.1 6/20/2011 (4) θJA θJC 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 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 2 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS VIN = 12V, TA = +25°C, unless otherwise noted. Parameters Symbol Condition Shutdown Supply Current Supply Current VEN = 0V VEN = 2.8V, VFB =1.4V Feedback Voltage VFB Error Amplifier Voltage Gain AVEA Error Amplifier Transconductance GEA High-Side Switch On-Resistance Low-Side Switch On-Resistance High-Side Switch Leakage Current Current Limit Current Sense to COMP Transconductance Oscillation Frequency Short Circuit Oscillation Frequency Maximum Duty Cycle Minimum Duty Cycle EN Shutdown Threshold Voltage Enable Pull Up Current EN UVLO Threshold EN UVLO Threshold Hysteresis Soft-Start Period Min 4.75V ≤ VIN ≤ 23V Units 20 1.0 30 1.2 µA mA 400 ΔICOMP = ±10μA 500 VEN = 0V, VSW = 0V 4.0 GCS fS VFB = 0V VFB = 1.0V VFB = 1.5V VEN = 0V VEN Rising 335 25 0.9 1.1 2.37 CSS = 0.1µF Thermal Shutdown MP1583 Rev. 3.1 6/20/2011 Max 1.194 1.222 1.250 RDS(ON)1 RDS(ON)2 DMAX Typ 800 0.1 10 0 4.9 3.8 385 40 90 1.2 1.8 2.54 210 10 160 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. V V/V 1120 10 6.0 435 55 0 1.5 2.5 2.71 µA/V Ω Ω µA A A/V KHz KHz % % V µA V mV ms °C 3 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER TYPICAL PERFORMANCE CHARACTERISTICS Soft-Start Efficiency Curve 100 CSS Open, VIN = 10V, VOUT = 3.3V, 1.5A Resistive Load VIN = 7V VOUT=5.0V EFFICIENCY (%) 90 VOUT=2.5V 80 VOUT=3.3V 70 VOUT 2V/div. IL 1A/div. 60 50 VEN 5V/div. 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 LOAD CURRENT (A) MP1583-TPC02 MP1583-TPC01 VEN 5V/div. VEN 5V/div. VOUT 2V/div. VOUT 2V/div. IL 1A/div. IL 1A/div. 1ms/div. MP1583-TPC03 MP1583-TPC04 PIN FUNCTIONS Pin # 1 2 3 4 5 6 Name Description High-Side Gate Drive Bootstrap Input. BS supplies the drive for the high-side N-Channel MOSFET BS switch. Connect a 4.7nF or greater capacitor from SW to BS to power the high-side switch. Power Input. IN supplies the power to the IC. Drive IN with a 4.75V to 23V power source. Bypass IN IN to GND with a suitably large capacitor to eliminate noise on the input to the IC. See Input Capacitor Power Switching Output. SW is the switching node that supplies power to the output. Connect the SW output LC filter from SW to the output load. Note that a capacitor is required from SW to BS to power the high-side switch. GND Ground. (Note: For the SOIC8E package, connect the exposed pad on backside to Pin 4). Feedback Input. FB senses the output voltage and regulates it. Drive FB with a resistive voltage FB divider from the output voltage. The feedback threshold is 1.222V. See Setting the Output Voltage Compensation Node. COMP is used to compensate the regulation control loop. Connect a series COMP RC network from COMP to GND to compensate the regulation control loop. See Compensation MP1583 Rev. 3.1 6/20/2011 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 4 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER PIN FUNCTIONS (continued) Pin # Name Description 7 EN Enable/UVLO. A voltage greater than 2.71V enables operation. For complete low current shutdown the EN pin voltage needs to be at less than 900mV. When the voltage on EN exceeds 1.2V, the internal regulator will be enabled and the soft-start capacitor will begin to charge. The MP1583 will start switching after the EN pin voltage reaches 2.71V. There is 7V zener connected between EN and GND. If EN is driven by external signal, the voltage should never exceed 7V. 8 SS Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor from SS to GND to set the soft-start period. To disable the soft-start feature, leave SS unconnected. OPERATION The voltage at COMP is compared to the internally measured switch current to control the output voltage. The MP1583 is a current-mode step-down regulator. It regulates input voltages from 4.75V to 23V down to an output voltage as low as 1.222V, and is able to supply up to 3A of load current. The converter uses an internal N-Channel MOSFET switch to step-down the input voltage to the regulated output voltage. Since the MOSFET requires a gate voltage greater than the input voltage, a boost capacitor connected between SW and BS drives the gate. The capacitor is internally charged when SW is low. The MP1583 uses current-mode control to regulate the output voltage. The output voltage is measured at FB through a resistive voltage divider and amplified through the internal error amplifier. The output current of the transconductance error amplifier is presented at COMP where a RC network compensates the regulation control system. An internal 10Ω switch from SW to GND is used to insure that SW is pulled to GND when SW is low in order to fully charge the BS capacitor. IN 2 CURRENT SENSE AMPLIFIER INTERNAL REGULATORS OSCILLATOR 40/385KHz + 1.2V -- EN 7 -- 2.54V + FREQUENCY FOLDBACK COMPARATOR SHUTDOWN COMPARATOR SLOPE COMP 5V CLK -- + -1μ A LOCKOUT COMPARATOR + Σ S Q R Q CURRENT COMPARATOR 1 BS 3 SW 4 GND 7V 1.8V -- + -- 0.7V 1.222V 5 FB + ERROR AMPLIFIER GM = 800μ A/V 6 COMP 8 SS Figure 1—Functional Block Diagram MP1583 Rev. 3.1 6/20/2011 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 5 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER APPLICATION INFORMATION COMPONENT SELECTION Setting the Output Voltage The output voltage is set using a resistive voltage divider from the output voltage to the FB pin. The voltage divider divides the output voltage down to the feedback voltage by the ratio: V FB = VOUT R2 R1 + R 2 Where VFB is the feedback voltage and VOUT is the output voltage. Thus the output voltage is: VOUT = 1.22V × R1 = 8.18 × (VOUT − 1.22V )( kΩ ) For example, for a 3.3V output voltage, R2 is 10kΩ, and R1 is 17kΩ. Inductor The inductor is required to supply constant current to the output load while being driven by the switched input voltage. A larger value inductor will result in less ripple current and lower output ripple voltage. However, larger value inductors have a larger physical size, higher series resistance, and/or lower saturation current. A good rule for determining the inductance to use is to allow the inductor peak-to-peak ripple current to be approximately 30% of the maximum switch current limit. Also, make sure that the peak inductor current is below the maximum switch current limit. The inductance value can be calculated by: ⎛ V VOUT × ⎜⎜ 1 − OUT VIN f S × ΔI L ⎝ The peak inductor current can be calculated by: I LP = I LOAD + ⎛ V VOUT × ⎜⎜ 1 − OUT 2 × fS × L ⎝ V IN ⎞ ⎟⎟ ⎠ Where ILOAD is the load current. Table 1 lists a number of suitable inductors from various manufacturers. The choice of which inductor to use mainly depends on the price vs. size requirements and any EMI requirements. Table 1—Inductor Selection Guide R1 + R 2 R2 A typical value for R2 can be as high as 100kΩ, but a typical value is 10kΩ. Using that value, R1 is determined by: L= Choose an inductor that will not saturate under the maximum inductor peak current. Vendor/ Model Package Dimensions (mm) Core Type Core Material W L H CR75 Open Ferrite 7.0 7.8 5.5 CDH74 Open Ferrite 7.3 8.0 5.2 CDRH5D28 Shielded Ferrite 5.5 5.7 5.5 CDRH5D28 Shielded Ferrite 5.5 5.7 5.5 CDRH6D28 Shielded Ferrite 6.7 6.7 3.0 CDRH104R Shielded Ferrite 10.1 10.0 3.0 Sumida Toko D53LC Type A Shielded Ferrite 5.0 5.0 3.0 D75C Shielded Ferrite 7.6 7.6 5.1 D104C Shielded Ferrite 10.0 10.0 4.3 D10FL Open Ferrite 9.7 1.5 4.0 DO3308 Open Ferrite 9.4 13.0 3.0 DO3316 Open Ferrite 9.4 13.0 5.1 Coilcraft ⎞ ⎟⎟ ⎠ Where VIN is the input voltage, fS is the 385KHz switching frequency and ΔIL is the peak-to-peak inductor ripple current. MP1583 Rev. 3.1 6/20/2011 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 6 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER Output Rectifier Diode The output rectifier diode supplies the current to the inductor when the high-side switch is off. Use a Schottky diode to reduce losses due to the diode forward voltage and recovery times. The input capacitor can be electrolytic, tantalum or ceramic. When using electrolytic or tantalum capacitors, a small, high quality ceramic capacitor (i.e. 0.1μF) should be placed as close to the IC as possible. Choose a diode whose maximum reverse voltage rating is greater than the maximum input voltage, and whose current rating is greater than the maximum load current. Table 2 lists example Schottky diodes and manufacturers. When using ceramic capacitors, make sure that they have enough capacitance to provide sufficient charge to prevent excessive voltage ripple at the input. The input voltage ripple caused by capacitance can be estimated by: Table 2—Diode Selection Guide Diode SK33 SK34 B330 B340 MBRS330 MBRS340 Voltage/Current Manufacture Rating 30V, 3A 40V, 3A 30V, 3A 40V, 3A 30V, 3A 40V, 3A Diodes Inc. Diodes Inc. Diodes Inc. Diodes Inc. On Semiconductor On Semiconductor Input Capacitor The input current to the step-down converter is discontinuous, therefore a capacitor is required to supply the AC current to the step-down converter while maintaining the DC input voltage. Use low ESR capacitors for the best performance. Ceramic capacitors are preferred, but tantalum or low-ESR electrolytic capacitors will also suffice. Since the input capacitor absorbs the input switching current it requires an adequate ripple current rating. The RMS current in the input capacitor can be estimated by: I C 1 = I LOAD × VOUT ⎛⎜ VOUT × 1− V IN ⎜⎜⎝ V IN ⎞ ⎟ ⎟⎟ ⎠ The worst-case condition occurs at VIN = 2VOUT, where: I C1 = I LOAD 2 For simplification, choose an input capacitor whose RMS current rating is greater than half of the maximum load current. MP1583 Rev. 3.1 6/20/2011 ΔV IN = I LOAD VOUT ⎛ VOUT × × ⎜1 − f S × C1 VIN ⎜⎝ V IN ⎞ ⎟⎟ ⎠ Where C1 is the input capacitance value. Output Capacitor The output capacitor is required to maintain the DC output voltage. Ceramic, tantalum or low ESR electrolytic capacitors are recommended. Low ESR capacitors are preferred so as to keep the output voltage ripple low. The output voltage ripple can be estimated by: ΔVOUT = VOUT ⎛ VOUT × ⎜1 − f S × L ⎜⎝ VIN ⎞ ⎞ ⎛ 1 ⎟ ⎟⎟ × ⎜⎜ RESR + 8 × f S × C 2 ⎟⎠ ⎠ ⎝ Where L is the inductor value, C2 is the output capacitance value and RESR is the equivalent series resistance (ESR) value of the output capacitor. In the case of ceramic capacitors, the impedance at the switching frequency is dominated by the capacitance, which is the main cause for the output voltage ripple. For simplification, the output voltage ripple can be estimated by: ΔVOUT = ⎛ V × ⎜⎜ 1 − OUT VIN × L × C2 ⎝ VOUT 8× fS 2 ⎞ ⎟⎟ ⎠ In the case of tantalum or electrolytic capacitors, the ESR dominates the impedance at the switching frequency. For simplification, the output ripple can be approximated to: ΔVOUT = VOUT ⎛ VOUT ⎞ × ⎜1 − ⎟ × R ESR fS × L ⎝ VIN ⎠ www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 7 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER The MP1583 can be optimized for a wide range of capacitance and ESR values. Compensation Components The MP1583 employs current mode control for easy compensation and fast transient response. The system stability and transient response are controlled through the COMP pin. COMP is the output of the internal transconductance error amplifier. A series capacitor-resistor combination sets a pole-zero combination to control the characteristics of the control system. The DC gain of the voltage feedback loop is: AVDC = RLOAD × GCS × AVEA × VFB VOUT Where AVEA is the error amplifier voltage gain, GCS is the current sense transconductance and RLOAD is the load resistor value. The system has two poles of importance. One is due to the compensation capacitor (C3) and the output resistor of error amplifier while the other is due to the output capacitor and the load resistor. These poles are located at: f P1 = G EA 2π × C 3 × AVEA f P2 = 1 2π × C 2 × RLOAD is Where GEA transconductance. the error amplifier 1 = 2π × C 3 × R3 The system may have another zero of importance, if the output capacitor has a large capacitance and/or a high ESR value. The zero due to the ESR and capacitance of the output capacitor is located at: f ESR MP1583 Rev. 3.1 6/20/2011 1 = 2π × C 2 × RESR f P3 = the the to the 1 2π × C 6 × R 3 The goal of compensation design is to shape the converter transfer function to get a desired loop gain. The system crossover frequency (where the feedback loop has unity gain) is important. Lower crossover frequencies result in slower line and load transient responses, while higher crossover frequencies could cause system instability. A good standard is to set the crossover frequency to approximately one-tenth of the switching frequency. The switching frequency for the MP1583 is 385KHz, so the desired crossover frequency is around 38KHz. Table 3 lists the typical values of compensation components for some standard output voltages with various output capacitors and inductors. The values of the compensation components have been optimized for fast transient responses and good stability at given conditions. Table 3—Compensation Values for Typical Output Voltage/Capacitor Combinations (Please reference Fig. 3 and Fig. 4) The system has one zero of importance, due to the compensation capacitor (C3) and the compensation resistor (R3). This zero is located at: f Z1 In this case, a third pole set by compensation capacitor (C6) and compensation resistor (R3) is used compensate the effect of the ESR zero on loop gain. This pole is located at: VOUT C2 R3 C3 C6 2.5V 22μF Ceramic 3.9kΩ 5.6nF None 3.3V 22μF Ceramic 4.7kΩ 4.7nF None 5V 22μF Ceramic 7.5kΩ 4.7nF None 12V 22μF Ceramic 16.9kΩ 1.5nF None 2.5V 560μF Al. 30mΩ ESR 91kΩ 1nF 150pF 3.3V 560μF Al 30mΩ ESR 120kΩ 1nF 120pF 5V 470μF Al. 30mΩ ESR 100kΩ 1nF 120pF 12V 220μF Al. 30mΩ ESR 169kΩ 1nF 39pF www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 8 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER 4) Route SW away from sensitive analog areas such as FB. 5) Connect IN, SW, and especially GND respectively to a large copper area to cool the chip to improve thermal performance and long-term reliability. For single layer, do not solder exposed pad of the IC Where R3 is the compensation resistor value. If this is the case, then add the second compensation capacitor (C6) to set the pole fP3 at the location of the ESR zero. Determine C6 by the equation: C6 = C2 × R ESR R3 FB 5 6 SGND SGND C6 C3 R3 4 GND C5 f 1 < S 2π × C2 × R ESR 2 R1 R2 C4 3. Determine if the second compensation capacitor (C6) is required. It is required if the ESR zero of the output capacitor is located at less than half of the 385KHz switching frequency, or if the following relationship is valid: R4 COMP 4 2π × R3 × f C Ensure all feedback connections are short and direct. Place the feedback resistors and compensation components as close to the chip as possible. SW C3 > 3) 3 2. Choose the compensation capacitor (C3) to achieve the desired phase margin. For applications with typical inductor values, setting the compensation zero, fZ1, below one forth of the crossover frequency provides sufficient phase margin. Determine C3 by the following equation: Keep the connection of low-side MOSFET between SW pin and input power ground as short and wide as possible. EN 7 Where fC is the desired crossover frequency (which typically has a value no higher than 38KHz). 2) IN 2π × C2 × f C VOUT × G EA × G CS VFB Keep the path of switching current short and minimize the loop area formed by Input cap, high-side and low-side MOSFETs. 2 R3 = 1) SS/REF 8 1. Choose the compensation resistor (R3) to set the desired crossover frequency. Determine R3 by the following equation: PCB Layout Guide PCB layout is very important to achieve stable operation. Please follow these guidelines and take Figure2 and 3 for references. 1 BS To optimize the compensation components for conditions not listed in Table 2, the following procedure can be used. L1 C1 D1 PGND C2 Figure 2―PCB Layout (Single Layer) MP1583 Rev. 3.1 6/20/2011 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 9 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER C4 R4 FB 5 SGND 4 GND 6 SW 3 COMP EN 7 IN 2 SS/REF 8 1 BS R2 C2 R1 C3 C6 External Bootstrap Diode An external bootstrap diode may enhance the efficiency of the regulator, the applicable conditions of external BST diode are: R3 L1 z VOUT=5V or 3.3V; and z Duty cycle is high: D= VOUT >65% VIN In these cases, an external BST diode is recommended from the output of the voltage regulator to BST pin, as shown in Fig.4 External BST Diode IN4148 BST C1 D1 PGND MP1583 C5 Top Layer SW CBST L + COUT 5V or 3.3V Figure 4—Add Optional External Bootstrap Diode to Enhance Efficiency The recommended external BST diode is IN4148, and the BST cap is 0.1~1µF. Bottom Layer Figure 3―PCB Layout (Double Layer) MP1583 Rev. 3.1 6/20/2011 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 10 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER TYPICAL APPLICATION CIRCUITS C5 10nF INPUT 4.75V to 23V 2 OPEN = AUTOMATIC STARTUP C1 10μ F/25V CERAMIC 7 L1 15μ H 1 IN BS SW EN 3 R1 16.9kΩ MP1583 8 SS GND FB COMP 4 C4 10nF 5 6 C6 NS C3 4.7nF R3 4.7kΩ OUTPUT 3.3V 3A D1 R2 10kΩ C2 22μ F/10V Murata Figure 5—3.3V output 3A solution with Murata 22µF, 10V Ceramic Output Capacitor MP1583 Rev. 3.1 6/20/2011 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 11 MP1583 – 3A, 23V, 385KHz 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 BOTTOM 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) SIDE VIEW 0.050(1.27) BSC FRONT VIEW 0.010(0.25) x 45o 0.020(0.50) GAUGE PLANE 0.010(0.25) BSC 0.050(1.27) 0.024(0.61) 0o-8o 0.016(0.41) 0.050(1.27) 0.063(1.60) DETAIL "A" 0.103(2.62) 0.138(3.51) RECOMMENDED LAND PATTERN MP1583 Rev. 3.1 6/20/2011 0.213(5.40) 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 BA. 6) DRAWING IS NOT TO SCALE. www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 12 MP1583 – 3A, 23V, 385KHz STEP-DOWN CONVERTER PDIP8 0.387 (9.830) 0.367 (9.322) 0.325(8.255) 0.300(7.620) PIN 1 IDENT. 0.260 (6.604) 0.240 (6.096) 0.014 (0.356) 0.008 (0.200) 3°~11° Lead Bend 0.392(9.957) 0.332(8.433) 0.065 (1.650) 0.050 (1.270) 0.040 (1.016) 0.020 (0.508) 0.145(3.683) 0.134(3.404) 0.035 (0.889) 0.015 (0.381) 0.140(3.556) 0.120(3.048) 0.100 BSC(2.540) 0.021(0.533) 0.015(0.381) NOTE: 1) Control dimension is in inches . Dimension in bracket is millimeters. 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. MP1583 Rev. 3.1 6/20/2011 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2011 MPS. All Rights Reserved. 13