B130

TM MP1570 3A, 23V, 340KHz Synchronous Rectified Step-Down Converter The Future of Analog IC Technology TM DESCRIPTION The MP1570 is a monolithic synchronous buck regulator. The device integrates 100mΩ MOSFETS that provide 3A continuous load current over a wide operating input voltage of 4.75V to 23V. Current mode control provides fast transient response and cycle-by-cycle current limit. An adjustable soft-start prevents inrush current at turn-on. In shutdown mode, the output is actively discharged by transferring energy in the output capacitor to the input capacitor, dropping the supply current to 1µA. This device, available in an 8-pin SOIC package, provides a very compact system solution with minimal reliance on external components. FEATURES • • • • • • • • • • • • • • 3A Output Current Wide 4.75V to 23V Operating Input Range Integrated 100mΩ Power MOSFET Switches Output Adjustable from 1.23V to 20V Up to 95% Efficiency Programmable Soft-Start Stable with Low ESR Ceramic Output Capacitors Fixed 340KHz Frequency Cycle-by-Cycle Over Current Protection Input Under Voltage Lockout Thermally Enhanced 8-Pin SOIC Package Distributed Power Systems Pre-Regulator for Linear Regulators Notebook Computers APPLICATIONS EVALUATION BOARD REFERENCE Board Number EV1570DN-00A Dimensions 2.0”X x 1.5”Y x 0.5”Z “MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION INPUT 4.75V to 23V C5 10nF 100 95 7 8 2 IN EN 1 BS 3 SW Efficiency vs. Load Current VIN=9V EFFICIENCY (%) MP1570 SS GND 4 FB COMP 6 OUTPUT 3.3V 3A 90 85 80 75 70 65 60 0 VOUT=5V 0.5 1.0 1.5 2.0 2.5 3.0 3.5 LOAD CURRENT (A) MP1570-EC02 VIN=12V VIN=23V 5 C6 (optional) C3 3.3nF D1 B130 (optional) MP1570_TAC01 MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 1 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER PACKAGE REFERENCE ABSOLUTE MAXIMUM RATINGS (1) Supply Voltage VIN ....................... –0.3V to +26V Switch Voltage VSW ................. –1V to VIN + 0.3V Boost Voltage VBS ..........VSW – 0.3V to VSW + 6V All Other Pins................................. –0.3V to +6V Junction Temperature...............................150°C Lead Temperature ....................................260°C Storage Temperature .............–65°C to +150°C TOP VIEW BS IN SW GND 1 2 3 4 8 7 6 5 SS EN COMP FB Recommended Operating Conditions (2) MP1570_PD01-SOIC8N Input Voltage VIN ............................ 4.75V to 23V Output Voltage VOUT ...................... 1.23V to 20V Ambient Operating Temperature ... –40°C to +85°C Thermal Resistance Part Number* MP1570DN * Package SOIC8N (Exposed Pad) Temperature (3) SOIC8N .................................. 50 ...... 10... °C/W Notes: 1) Exceeding these ratings may damage the device. 2) The device is not guaranteed to function outside of its operating conditions. 3) Measured on approximately 1” square of 1 oz copper. θJA θJC –40° to +85°C For Tape & Reel, add suffix –Z (eg. MP1570DN–Z) For Lead Free, add suffix –LF (eg. MP1570DN–LF–Z) ELECTRICAL CHARACTERISTICS VIN = 12V, TA = +25°C, unless otherwise noted. Parameter Shutdown Supply Current Supply Current Feedback Voltage Feedback Overvoltage Threshold Error Amplifier Voltage Gain (4) Error Amplifier Transconductance High Side Switch On Resistance Low Side Switch On Resistance (4) High Side Switch Leakage Current Upper Switch Current Limit Lower Switch Current Limit COMP to Current Sense Transconductance Oscillation Frequency Short Circuit Oscillation Frequency Maximum Duty Cycle Minimum On Time (4) EN Shutdown Threshold Voltage EN Shutdown Threshold Voltage Hysteresis (4) Symbol Condition VEN = 0V VEN = 2.7V, VFB = 1.4V VFB AEA GEA RDS(ON)1 RDS(ON)2 VEN = 0V, VSW = 0V ∆IC = ±10µA 4.75V ≤ VIN ≤ 23V, VCOMP < 2V Min Typ 0.3 1.3 Max 3.0 1.5 1.258 1.6 1100 Units µA mA V V V/V µA/V mΩ mΩ µA A A A/V KHz KHz % ns V mV 1.202 1.4 550 1.230 1.5 400 820 100 100 0 5.8 0.9 5.4 340 110 90 220 1.5 220 4.0 From Drain to Source GCS Fosc1 Fosc2 DMAX VFB = 0V VFB = 1.0V VEN Rising 1.1 4.0 300 10 7.6 6.8 380 2.0 MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 2 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER ELECTRICAL CHARACTERISTICS (continued) VIN = 12V, TA = +25°C, unless otherwise noted. Parameter EN Lockout Threshold Voltage EN Lockout Hysteresis Input Under Voltage Lockout Threshold Input Under Voltage Lockout Threshold Hysteresis Soft-Start Current Soft-Start Period Thermal Shutdown (4) Note: 4) Guaranteed by design, not tested. Symbol Condition Min 2.2 Typ 2.5 210 4.05 210 Max 2.7 4.30 Units V mV V mV µA ms °C VIN Rising 3.80 VSS = 0V CSS = 0.1µF 6 20 160 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 12V, VOUT = 3.3V, TA = +25°C, unless otherwise noted. Load Transient Waveforms 1A - 2A STEP VOUT 50mV/div. VOUT 1V/div. IL 1A/div. IL 1A/div. MP1570-TPC01 MP1570-TPC02 VOUT 1V/div. IL 1A/div. VOUT 10mV/div. VIN 100mV/div. IL 1A/div. VSW 10V/div. 4ms/div. MP1570-TPC03 MP1570-TPC04 MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 3 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER PIN FUNCTIONS Pin # 1 2 Name Description High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel MOSFET BS switch. Connect a 0.01µF or greater capacitor from SW to BS to power the high side switch. Power Input. IN supplies the power to the IC, as well as the step-down converter switches. IN Drive IN with a 4.75V to 23V power source. Bypass 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 SW the 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 (Connect Exposed Pad to Pin 4) Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a FB resistive voltage divider from the output voltage. The feedback threshold is 1.230V. See Setting the Output Voltage. Compensation Node. COMP is used to compensate the regulation control loop. Connect a series RC network from COMP to GND to compensate the regulation control loop. In some COMP cases, an additional capacitor from COMP to GND is required. See Compensation Components. Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on EN the regulator, drive it low to turn it off. Pull up with 100kΩ resistor for automatic startup. Soft-start Control Input. SS controls the soft-start period. Connect a capacitor from SS to GND SS to set the soft-start period. A 0.1µF capacitor sets the soft-start period to 20ms. To disable the soft-start feature, leave SS unconnected. 3 4 5 6 7 8 BLOCK DIAGRAM + LATCH 1.5V OSCILLATOR FB 5 0.3V S R SS 8 1.23V + + ERROR AMPLIFIER + Q Q 3 SW + 100/340KHz OVP RAMP CLK 1 BS CURRENT SENSE AMPLIFIER 2 + 5V IN CURRENT COMPARATOR COMP 6 EN 7 2.5V + + INTERNAL REGULATORS 1.5V SHUTDOWN COMPARATOR MP1570_BD01 4 EN OK LOCKOUT COMPARATOR 1.2V OVP IN < 4.05V IN GND Figure 1—Functional Block Diagram MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 4 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER OPERATION FUNCTIONAL DESCRIPTION The MP1570 is a synchronous rectified, current-mode, step-down regulator. It regulates input voltages from 4.75V to 23V down to an output voltage as low as 1.230V, and supplies up to 3A of load current. The MP1570 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 transconductance error amplifier. The voltage at COMP pin is compared to the switch current measured internally to control the output voltage. The converter uses internal N-Channel MOSFET switches to step-down the input voltage to the regulated output voltage. Since the high side MOSFET requires a gate voltage greater than the input voltage, a boost capacitor connected between SW and BS is needed to drive the high side gate. The boost capacitor is charged from the internal 5V rail when SW is low. When the MP1570 FB pin exceeds 20% of the nominal regulation voltage of 1.230V, the over voltage comparator is tripped and latched; the COMP pin and the SS pin are discharged to GND, forcing the high-side switch off. Latch cannot be cleared unless the EN or IN pin is reset. Following discharge, the MP1570 actively recycles the energy stored in the output capacitor. Initially the low-side synchronous rectifier turns on. Once the internal, negative 900mA current limit is reached, the low-side switch turns off, forcing inductor current to flow through the high-side switch body diode. The inductor current is recycled back into the input as an energy saving feature. This cycle continues until the output voltage is discharged below 10% of the initial regulation voltage (0.123V at FB), at which time the low-side switch turns off. APPLICATIONS INFORMATION COMPONENT SELECTION Setting the Output Voltage The output voltage is set using a resistive voltage divider from the output voltage to FB pin. The voltage divider divides the output voltage down to the feedback voltage by the ratio: VFB = VOUT R2 R1 + 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: R1 = 8.18 × ( VOUT − 1.23 )(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 that will result in lower output ripple voltage. However, the larger value inductor will 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 peak-to-peak ripple current in the inductor to be approximately 30% of the maximum switch current limit. Also, make sure that the Thus the output voltage is: VOUT = 1.23 × R1 + R2 R2 Where VFB is the feedback voltage and VOUT is the output voltage. MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 5 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER peak inductor current is below the maximum switch current limit. The inductance value can be calculated by: L= ⎞ VOUT ⎛ V × ⎜1 − OUT ⎟ ⎜ fS × ∆I ⎝ VIN ⎟ ⎠ Where VIN is the input voltage, fS is the 340KHz switching frequency, and ∆IL is the peak-topeak inductor ripple current. Choose an inductor that will not saturate under the maximum inductor peak current. The peak inductor current can be calculated by: ILP = ILOAD + ⎛ VOUT V × ⎜1 − OUT 2 × fS × L ⎜ VIN ⎝ ⎞ ⎟ ⎟ ⎠ Optional Schottky Diode During the transition between high-side switch and low-side switch, the body diode of the lowside power MOSFET conducts the inductor current. The forward voltage of this body diode is high. An optional Schottky diode may be paralleled between the SW pin and GND pin to improve overall efficiency. Table 2 lists example Schottky diodes and their Manufacturers. Table 2—Diode Selection Guide Part Number B130 SK13 MBRS130 Voltage/Current Rating 30V, 1A 30V, 1A 30V, 1A Vendor Diodes, Inc. Diodes, Inc. International Rectifier Where ILOAD is the load current. Table 1 lists a number of suitable inductors from various manufacturers. The choice of which style inductor to use mainly depends on the price vs. size requirements and any EMI requirement. Table 1—Inductor Selection Guide Package Dimensions (mm) W L H 7.0 7.8 7.3 8.0 5.5 5.7 5.5 5.7 6.7 6.7 10.1 10.0 5.0 5.0 5.5 5.2 5.5 5.5 3.0 3.0 3.0 5.1 4.3 4.0 3.0 5.1 Vendor/ Model Sumida CR75 CDH74 CDRH5D28 CDRH5D28 CDRH6D28 CDRH104R Toko D53LC Type A D75C D104C D10FL Coilcraft DO3308 DO3316 Core Type Open Open Shielded Shielded Shielded Shielded Shielded Shielded Shielded Open Open Open Core Material Ferrite Ferrite Ferrite Ferrite Ferrite Ferrite Ferrite Ferrite Ferrite Ferrite Ferrite Ferrite 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 may also suffice. Choose X5R or X7R dielectrics when using ceramic capacitors. Since the input capacitor (C1) absorbs the input switching current it requires an adequate ripple current rating. The RMS current in the input capacitor can be estimated by: IC1 = ILOAD × VOUT ⎛ VOUT ⎞ ⎟ ×⎜1− VIN ⎜ VIN ⎟ ⎝ ⎠ The worst-case condition occurs at VIN = 2VOUT, where: IC1 = ILOAD 2 7.6 7.6 10.0 10.0 9.7 1.5 9.4 9.4 13.0 13.0 For simplification, choose the input capacitor whose RMS current rating greater than half of the maximum load current. MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 6 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER 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. When using ceramic capacitors, make sure that they have enough capacitance to provide sufficient charge to prevent excessive voltage ripple at input. The input voltage ripple caused by capacitance can be estimated by: ∆VIN = ⎛ ILOAD V V × OUT × ⎜1 − OUT ⎜ f S × C1 VIN VIN ⎝ ⎞ ⎟ ⎟ ⎠ The characteristics of the output capacitor also affect the stability of the regulation system. The MP1570 can be optimized for a wide range of capacitance and ESR values. Compensation Components MP1570 employs current mode control for easy compensation and fast transient response. The system stability and transient response are controlled through the COMP pin. COMP pin 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 given by: A VDC = R LOAD × G CS × A VEA × VFB VOUT 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 to keep the output voltage ripple low. The output voltage ripple can be estimated by: ∆VOUT = VOUT ⎛ V × ⎜1 − OUT fS × L ⎜ VIN ⎝ ⎞ ⎞⎛ 1 ⎟ ⎟ × ⎜ R ESR + ⎟⎜ 8 × f S × C2 ⎟ ⎠⎝ ⎠ Where AVEA is the error amplifier voltage gain, 400V/V; GCS is the current sense transconductance, 5.4A/V; RLOAD is the load resistor value. The system has 2 poles of importance. One is due to the compensation capacitor (C3) and the output resistor of error amplifier, and the other is due to the output capacitor and the load resistor. These poles are located at: fP1 = fP2 = GEA 2π × C3 × A VEA 1 2π × C2 × R LOAD Where 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. The output voltage ripple is mainly caused by the capacitance. For simplification, the output voltage ripple can be estimated by: ∆VOUT = VOUT 8 × fS 2 ⎛ V × ⎜1 − OUT ⎜ VIN × L × C2 ⎝ ⎞ ⎟ ⎟ ⎠ is the Where, GEA transconductance, 800µA/V. error amplifier 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: ∆VOUT = VOUT ⎛ V × ⎜1 − OUT fS × L ⎜ VIN ⎝ ⎞ ⎟ × R ESR ⎟ ⎠ 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 = 1 2π × C3 × R3 MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 7 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER 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: fESR = 1 2π × C2 × R ESR Table 3—Compensation Values for Typical Output Voltage/Capacitor Combinations VOUT 1.8V 2.5V 3.3V 5V 12V 1.8 2.5V 3.3V 5V 2.5V 3.3V 5V 12V L 4.7µH 4.76.8µH 6.810µH 1015µH 1522µH 4.7µH 4.76.8µH 6.810µH 1015µH 4.76.8µH 6.810µH 1015µH 1522µH C2 100µF Ceramic 47µF Ceramic 22µFx2 Ceramic 22µFx2 Ceramic 22µFx2 Ceramic 100µF SP-CAP 47µF SP-CAP 47µF SP-CAP 47µF SP CAP 560µF Al. 30mΩ ESR 560µF Al 30mΩ ESR 470µF Al. 30mΩ ESR 220µF Al. 30mΩ ESR R3 5.6kΩ 4.7kΩ 5.6kΩ 7.5kΩ 10kΩ 10kΩ 5.6kΩ 6.8kΩ 10kΩ 10kΩ 10kΩ 15kΩ 15kΩ C3 3.3nF 4.7nF 3.3nF 3.3nF 1.2nF C6 None None None None None In this case (as shown in Figure 2), a third pole set by the compensation capacitor (C6) and the compensation resistor (R3) is used to compensate the effect of the ESR zero on the loop gain. This pole is located at: fP 3 = 1 2π × C6 × R3 2.2nF 100pF 3.3nF 2.2nF 2.2nF 7.5nF 10nF 7.5nF 10nF None None None 1.5nF 1.5nF 1nF 390pF 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 the unity gain is important. Lower crossover frequencies result in slower line and load transient responses, while higher crossover frequencies could cause system unstable. A good rule of thumb is to set the crossover frequency to approximately one-tenth of the switching frequency. Switching frequency for the MP1570 is 340KHz, so the desired crossover frequency is 34KHz. 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. To optimize the compensation components for conditions not listed in Table 2, the following procedure can be used. 1. Choose the compensation resistor (R3) to set the desired crossover frequency. Determine the R3 value by the following equation: R3 = 2π × C2 × f C VOUT × G EA × G CS VFB Where fC is the desired crossover frequency, 34KHz. MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 8 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER 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 the C3 value by the following equation: C3 > 4 2π × R3 × f C BS External Bootstrap Diode It is recommended that an external bootstrap diode be added when the system has a 5V fixed input or the power supply generates a 5V output. This helps improve the efficiency of the regulator. The bootstrap diode can be a low cost one such as IN4148 or BAT54. 5V 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 340KHz switching frequency, or the following relationship is valid: f 1 65%) and high VIN is the case, then add the second compensation capacitor (C6) to set the pole fP3 at the location of the ESR zero. Determine the C6 value by the equation: C6 = C2 × R ESR R3 output voltage (VOUT>12V) applications. TYPICAL APPLICATION CIRCUITS INPUT 4.75V to 23V C5 10nF 2 IN 7 EN 1 BS 3 SW OUTPUT 2.5V 3A MP1570 8 SS GND 4 FB COMP 6 5 C6 (optional) C3 3.3nF D1 B130 (optional) MP1570_F03 Figure 3—MP1570 with AVX 47µF, 6.3V Ceramic Output Capacitor MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 9 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER C5 10nF INPUT 4.75V to 23V 7 2 IN EN 1 BS 3 SW OUTPUT 2.5V 3A MP1570 8 SS GND 4 FB COMP 6 5 C6 (optional) C3 3.3nF D1 B130 (optional) MP1570_F04 Figure 4—MP1570 with Panasonic 47µF, 6.3V Solid Polymer Output Capacitor B130 INPUT 6V C5 10nF 2 IN 7 EN 1 BS 3 SW OUTPUT 5V 3A MP1570 8 SS GND 4 FB COMP 6 5 C6 (optional) C3 3.3nF D1 B130 (optional) MP1570_F05 Figure 5—MP1570 Application Circuit with VIN = 6V and VO = 5V MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 10 TM MP1570 – 3A, 23V, 340KHz SYNCHRONOUS RECTIFIED, STEP-DOWN CONVERTER PACKAGE INFORMATION SOIC8N (EXPOSED PAD) PIN 1 IDENT. 0.229(5.820) 0.244(6.200) NOTE 4 0.150(3.810) 0.157(4.000) 0.0075(0.191) 0.0098(0.249) SEE DETAIL "A" NOTE 2 0.013(0.330) 0.020(0.508) 0.050(1.270)BSC 0.011(0.280) x 45o 0.020(0.508) 0o-8o 0.016(0.410) 0.050(1.270) DETAIL "A" .028 NOTE 3 0.189(4.800) 0.197(5.000) 0.053(1.350) 0.068(1.730) 0.049(1.250) 0.060(1.524) SEATING PLANE 0.001(0.030) 0.004(0.101) .050 0.200 (5.07 mm) 0.140 (3.55mm) 0.060 Land Pattern NOTE: 1) Control dimension is in inches. Dimension in bracket is millimeters. 2) Exposed Pad Option (N-Package) ; 2.31mm -2.79mm x 2.79mm - 3.81mm. Recommend Solder Board Area: 2.80mm x 3.82mm = 10.7mm 2 (16.6 mil2) 3) The length of the package does not include mold flash. Mold flash shall not exceed 0.006in. (0.15mm) per side. With the mold flash included, over-all length of the package is 0.2087in. (5.3mm) max. 4) The width of the package does not include mold flash. Mold flash shall not exceed 0.10in. (0.25mm) per side. With the mold flash included, over-all width of the package is 0.177in. (4.5mm) max. 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. MP1570 Rev. 1.5 1/31/2006 www.MonolithicPower.com MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2006 MPS. All Rights Reserved. 11