AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n General Description The AME5250A is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. Capable of delivering 1A output current over a wide input voltage range from 2.5V to 5.5V. Supply current with no load is 400µA and drops to<1µA in shutdown.The 2.5V to 5.5V input Voltage range makes the AME5250A ideally suited for single Li-Ion batterypowered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems. PWM pulse skipping mode operation provides very low output ripple voltage for noise sensitive applications. At very light load, the AME5250A will automatically skip pulses in pulse skip mode operation to maintain output regulation. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The AME5250A is available in small DFN-6D & QFN-16C packages. Other features include soft start, lower internal reference voltage with 2% accuracy, over temperature protection, and over current protection. n Applications l l l l l Cellular Telephones Personal Information Appliances Wireless and DSL Modems MP3 Players Portable Instruments n Typical Application 2.2µH VIN IN AME5250 A CIN 4.7µF CER EN Rev.A.03 OUT Figure 1. High Efficiency Step-Down Converter VIN 2.5V to 5.5V n Features High Efficiency: Up to 95% Shutdown Mode Draws <1µA Supply Current 2.5V to 5.5V Input Range Adjustable Output From 0.6V to VIN 1.0V, 1.2V, 1.5V, 1.6V, 1.8V, 2.5V and 3.3V Fixed/Adjustable Output Voltage l 1A Output Current l Low Dropout Operation: 100% Duty Cycle l No Schottky Diode Required l 1.5MHz Constant Frequency PWM Operation l Small DFN-6D & QFN-16C Packages l All AME’ s Lead Free Product Meet RoHS Standard GND COUT 10µF CER Fixed Output Voltage 2.2µH IN l l l l l VOUT SW SW AME5250 A CIN 4.7µF CER EN CFWD FB GND VOUT 1.8V R1 1000mA 150K COUT 10µF CER R2 75K VOUT =VFB (R1+R2)/R2 Adjustable Output Voltage Figure 2. 1.8V at 1000mA Step-Down Requlator CFWD: 22pF~220pF 1 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Function Block Diagram Constant Off -time Mode Select Slope COMP VIN IN 3 PWM COMP FB/ OUT 6 0.6V 0. 6V VREF SW LOGIC 4 0. 55V UVDET Soft Start EN 2 OSC NMOS COMP IRCOM P GND 5 Figure 3. Founction Block Diagram 2 Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Pin Configuration 10 9 AME5250A 16 3 15 2 14 1 11 13 AME5250A 12 8 4 7 5 6 6 AME5250A-AVYxxx 1. NC 2. EN 3. IN 4. SW 5. GND 6. FB/OUT QFN-16C (3mmx3mmx0.75mm) Top View 5 DFN-6D (2mmx2mmx0.75mm) Top View 1 2 3 4 AME5250A-AWExxx 9. IN 1. GND 10. IN 2. GND 11. IN 3. GND 12. IN 4. FB/OUT 13. SW 5. GND 14. SW 6. NC 15. SW 7. EN 16. NC 8. NC * Die Attach: Conductive Epoxy * Die Attach: Conductive Epoxy Note: The area enclosed by dashed line represents Exposed Pad and connect to GND. n Pin Description Pin Number Rev.A.03 Pin Name Pin Description DFN QFN 1 6, 8, 16 NC No connection. Not internally connected. Can left floating or connected to GND. 2 7 EN Enable Control Input, active high. 3 9, 10, 11, 12 IN Input Supply Voltage Pin. Bypass this pin with a capacitor as close to the device as possible. 4 13, 14, 15 SW Switch Node Connection to Inductor. 5 1, 2, 3, 5 GND Ground. Tie directly to ground plane. 6 4 FB/OUT Output voltage Feedback input. 3 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Ordering Information AME5250A - x x x xxx Output Voltage Number of Pins Package Type Pin Configuration & Special Feature Pin Configuration & Special Feature A (DFN-6D) A (QFN-16C) 4 1. 2. 3. 4. 5. 6. NC EN IN SW GND FB/OUT 1. GND 2. GND 3. GND 4. FB/OUT 5. GND 6. NC 7. EN 8. NC 9. IN 10. IN 11. IN 12. IN 13. SW 14. SW 15. SW 16. NC Package Type V: DFN W: QFN Number of Pins Y: 6 E: 16 Output Voltage 100: 120: 150: 160: 180: 250: 330: ADJ: 1.0V 1.2V 1.5V 1.6V 1.8V 2.5V 3.3V Adjustable Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Absolute Maximum Ratings Parameter Symbol Maximum V IN -0.3 to 6.5 V EN , VOUT -0.3 to VIN VSW -0.3 to VIN Input Supply Voltage EN, VOUT Voltage SW Voltage Unit V B* ESD Classification Caution: Stress above the listed absolute maximum rating may cause permanent damage to the device. * HBM B: 2000V~3999V n Recommended Operating Conditions Parameter Symbol Rating Unit Supply Voltage Voltage VIN 2.5 to 5.5 V Ambient Temperature Range TA -40 to +85 o C Junction Temperature Range TJ -40 to +125 o C Rev.A.03 5 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Thermal Information Parameter Package Die Attach Thermal Resistance* (Junction to Case) Thermal Resistance (Junction to Ambient) Symbol Maximum θJ C 85 o DFN-6D Conductive Epoxy θJA 160 Internal Power Dissipation PD 625 Thermal Resistance* (Junction to Case) θJ C 67 Thermal Resistance (Junction to Ambient) Unit mW o QFN-16C Internal Power Dissipation Solder Iron (10Sec)** Conductive Epoxy θJA 149 PD 670 350 C/W C/W mW o C * Measure θJC on backside center of Exposed Pad. ** MIL-STD-202G 210F 6 Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Electrical Specifications VIN=3.6V, VOUT=2.5V, VFB=0.6V, L=2.2µH, CIN=4.7µF, COUT=10µF, TA=25oC, IMAX=1A unless otherwise specified. Parameter Input voltage Symbol Test Condition VIN VIN=2.5 to 5.5V, in PWM mode For Fixed Output Voltage Min Typ Max Units 2.5 5.5 V -3 3 % VFB VIN-0.2 V 0.612 V 50 nA Output Voltage Accuracy ∆VOUT Adjustable Output Range Vout Feedback Voltage VFB For Adjustable OutputVoltage 0.588 Feedback Pin Bias Current IFB VFB=VIN -50 Quiescent Current IQ IOUT=0mA, VFB=1V 0.4 0.5 mA Shutdown Current ISHDN VEN=GND 0.1 1 µA Switch Frequency fOSC 1.5 1.8 MHz 1.2 0.6 High-side Switch On-Resistance RDS,ON, LHI ISW=200mA, VIN=3.6V 0.28 Ω Low-side Switch On-Resistance RDS,ON, LO ISW=200mA, VIN=3.6V 0.25 Ω Switch Current Limit ISW,CL VIN=2.5 to 5.5V 1.4 1.6 A EN High (Enabled the Device) VEN,HI VIN=2.5 to 5.5V 1.5 EN Low (Shutdown the Device) VEN,LO VIN=2.5 to 5.5V Input Undervoltage Lockout VUVLO rising edge Input Undervoltage Lockout Hysteresis VUVLO,HYST Thermal Shutdown Temperature OTP Maximum Duty Cycle DMAX SW Leakage Current Rev.A.03 V 0.4 Shutdown, temperature increasing 1.8 V 0.1 V o 160 -1 C % 100 EN=0V, VIN=5.0V VSW=0V or 5.0V V 1 µA 7 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Detailed Description Main Control Loop The AME5250A uses a constant frequency, current mode step-down architecture. Both the main (P-channel MOSFET) and synchronous (N-channel MOSFET) switches are intermal. During normal operation, the internal top power MOSFET is turned on each cycle when the oscillator sets the RS latch, and turned off when the current comparator resets the RS latch. While the top MOSFET is off, the bottom MOSFET is turned on until either the inductor current starts to reverse as indicated by the current reversal comparator IRCMP. Pulse Skipping Mode Operation At light loads, the inductor current may reach zero or reverse on each pulse.The bottom MOSFET is turned off by the current reversal comparator, IRCMP, and the switch voltage will ring. This is discontinuous mode operation, and is normal behavior for the switching regulator. Short-Circuit Protection When the output is shorted to ground, the frequency of the oscillator is reduced to about 180KHz. This frequency foldback ensures that the inductor current hsa more time do decay, thereby preventing runaway. The oscillator’ s frequency will progressively increase to 1.5MHz when VFB or VOUT rises above 0V. Dropout Operation As the input supply voltage decreases to a value approaching the output voltage, the duty cycle increases toward the maximum on-time. Further reduction of the supply voltage forces the main switch to remain on for more than one cycle until it reaches 100% duty cycle. The output voltage will then be determined by the input voltage minus the voltage drop across the P-channel MOSFET and the inductor. 8 n Application Information The basic AME5250A application circuit is shown in Typical Application Circuit. External component selection is determined by the maximum load current and begins with the selection of the inductor value and followed by CIN and COUT. Inductor Selection For a given input and output voltage, the inductor value and operating frequency determine the ripple current. The ripple current DIL increases with higher VIN and decreases with higher inductance. ∆I L = V 1 × VOUT (1 − OUT ) VIN f ×L A reasonable starting point for setting ripple current is ∆IL=0.4(lmax). The DC current rating of the inductor should be at least equal to the maximum load current plus half the ripple current to prevent core saturation. For better efficiency, choose a low DC-resistance inductor. CIN and COUT Selection The Input capacitance, CIN is needed to filter the trapezoidal current at the source of the top MOSFET. To prevent large voltage transients, a low ESR input capacitorsized for the maximum RMS current must be used. The maximum RMS capacitor current is given by: I RMS = I OUT ( MAX ) × VI N VOUT × −1 VIN VOUT This formula has a maximum at VIN=2VOUT, where IRMS=IOUT/2. This simple worst-case condition is commonly used for design because even significant deviations do not offer much relief. Note that the capacitor manufacturer ripple current ratings are often based on 2000 hours of life. This makes it advisable to further derate the capacitor, or choose a capacitor rated at a higher temperature than required. Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A The selection of COUT is determined by the effective series resistance(ESR) that is required to minimize voltage ripple and load step transients. The output ripple, VOUT, is determined by: ∆VOUT ≅ ∆I L ESR + 1 8 fCOUT Using Ceramic Input and Output Capacitors Higher values, lower cost ceramic capacitors are now becoming available in smaller case sizes. Their high ripple current, high voltage rating and low ESR make them ideal for switching regulator applications. However, care must be taken when these capacitors are used at the input and output. When a ceramic capacitor is used at the input and the power is supplied by a wall adapter through long wires, a load step at the output can induce ringing at the input, VIN. At best, this ringing can couple to the output and be mistaken as loop instability. At worst, a sudden inrush of current through the long wires can potentially cause a voltage spike at VIN large enough to damage the part. Thermal Considerations In most applications the AME5250A does not dissipate much heat due to its high efficiency. But, in applications where the AME5250A is running at high ambient temperature with low supply voltage and high duty cycles, such as in dropout, the heat dissipated may exceed the maximum junction temperature of the part. If the junction temperature reaches approximately 160OC, both power switches will be turned off and the SW node will become high impedance. To avoid the AME5250A from exceeding the maximum junction temperature, the user will need to do some thermal analysis. The goal of the thermal analysis is to determine whether the power dissipated exceeds the maximum junction temperature of the part. The temperature rise is given by: TR = ( PD)(θ JA ) Where PD is the power dissipated by the regulator and θJA is the thermal resistance from the junction of the die to the ambient temperature. Output Voltage Programming The output voltage is set by an external resistive divider according to the following equation: VOUT = V REF × 1 + R1 R2 Where VREF equals to 0.6V typical. The resistive divider allows the FB pin to sense a fraction of the output voltage as shown in Figure 4. 0.6V ≤ V OUT ≤ 5.5V R1 FB AME5250A R2 GND Figure 4. Setting the AME5250A Output Voltage Rev.A.03 9 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A VIN 2.5V to 5.5V 2.2µH IN CIN 4.7µF CER VIN 2.5V to 5.5V GND FB 150K 150K SW AME5250A CFWD COUT 10µF CER CIN 4.7µF CER VOUT 1.6V 2.2µH IN SW AME5250A EN VOUT 1.2V EN GND FB CFWD 150K 90K COUT 10µF CER Figure 5. 1.2V Step-Down Regulator Figure 8. 1.6V Step-Down Regulator CFWD: 22pF~220pF CFWD: 22pF~220pF VIN 3.3V to 5.5V 2.2µH IN CIN 4.7µF CER VIN 3.6V to 5.5V GND FB COUT 10µF CER CIN 4.7µF CER EN VOUT 3.3V SW AME5250A CFWD 150K 100K 2.2µH IN SW AME5250A EN VOUT 1.5V GND FB CFWD 150K 33.3K COUT 10µF CER Figure 6. 1.5V Step-Down Regulator Figure 9. 3.3V Step-Down Regulator CFWD: 22pF~220pF CFWD: 22pF~220pF VIN 2.7V to 5.5V 2.2µH IN SW AME5250A CIN 4.7µF CER EN VOUT 2.5V GND FB CFWD 150K 47.3K COUT 10µF CER Figure 7. 2.5V Step-Down Regulator CFWD: 22pF~220pF 10 Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A PC Board Layout Checklist When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the AME5250A. These items are also illustrated graphically in Figures 10 and Figures 11 . Check the following in your layout: 1. The power traces, consisting of the GND trace, the SW trace and the VIN trace should be kept short, direct and wide. 2. Does the VFB pin connect directly to the feedback resistors? The resistive divider R2/R1 must be connected between the (+) plate of COUT and ground. 3. Does the (+) plate of CIN connect to VIN as closely as possible? This capacitor provides the AC current to the internal power MOSFETs. 4. Keep the switching node, SW, away from the sensitive VFB node. 5. Keep the (-) plates of CIN and COUT as close as possible. VIN CIN L1 IN AME5250A EN VOUT SW C1 R1 COUT FB VIN CIN L1 IN VOUT SW AME5250A EN COUT OUT COUT NC GND R2 Figure 10. AME5250A Adjustable Voltage Regulator Layout Diagram Rev.A.03 NC GND Figure 11. AME5250A Fixed Voltage Regulator Layout Diagram 11 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Application Information External components selection Supplier Inductance (µ µH) Current Rating (mA) DCR (mΩ Ω) Dimensions (mm) TAIYO YUDEN 2.2 1480 60 3.00 x 3.00 x 1.50 NR 3015 GOTREND 2.2 1500 58 3.85 x 3.85 x 1.80 GTSD32 Sumida 2.2 1500 75 4.50 x 3.20 x 1.55 CDRH2D14 Sumida 4.7 1000 135 4.50 x 3.20 x 1.55 CDRH2D14 TAIYO YUDEN 4.7 1020 120 3.00 x 3.00 x 1.50 NR 3015 GOTREND 4.7 1100 146 3.85 x 3.85 x 1.80 GTSD32 Series Table 1. Recommended Inductors Capacitance (µ µH) Package TDK 4.7 603 C1608JB0J475M MURATA 4.7 603 GRM188R60J475KE19 TAIYO YUDEN 4.7 603 JMK107BJ475RA TAIYO YUDEN 10 603 JMK107BJ106MA TDK 10 805 C2012JB0J106M MURATA 10 805 GRM219R60J106ME19 MURATA 10 805 GRM219R60J106KE19 TAIYO YUDEN 10 805 JMK212BJ106RD Supplier Part Number Table 2. Recommended Capacitors for CIN and COUT 12 Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Characterization Curve Efficiency vs. Output Current Efficiency vs. Output Current 100 100 90 90 VIN = 2.7V 70 60 50 40 30 20 V OUT = 2.5V 50 40 30 1 10 100 VOUT = 2.5V 0 1 1000 Efficiency vs. Output Current Efficiency vs. Output Current 90 VIN = 2.7V Efficiency (%) 80 70 60 50 40 30 VOUT = 1.5V 10 1 100 60 50 40 30 20 COUT = 10µF L = 2.2µH 10 VIN = 3.6V 70 VOUT = 1.5V 10 0 1000 Output Current (mA) 1 Efficiency vs. Output Current 100 90 90 Efficiency (%) 70 60 50 40 30 V OUT = 1.2V 100 Output Current (mA) 1000 60 50 40 30 VOUT = 1.2V 10 10 100 VIN = 5.5V 70 20 COUT = 10µF L = 2.2µH 10 1 10 Output Current (mA) 80 VIN = 2.5V 20 COUT = 10µF L = 2.2µH Efficiency vs. Output Current 100 80 Efficiency (%) 1000 100 20 Rev.A.03 100 Output Current (mA) 80 0 10 COUT = 10µF L = 2.2µH Output Current (mA) 90 Efficiency (%) 60 10 COUT = 10µF L = 2.2µH 100 0 70 20 10 0 VIN = 3.6V 80 Efficiency (%) Efficiency (%) 80 1000 0 1 10 COUT = 10µF L = 2.2µH 100 1000 Output Current (mA) 13 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Characterization Curve Frequency vs. Temperature 1.90 0.615 1.85 1.80 1.75 Frequency (MHz) Reference Voltage (V) Reference Voltage vs. Temperature 0.620 0.610 0.605 0.600 0.595 0.590 VIN = 3.6V 0.585 0.580 -50 -25 0 +25 +50 +75 +100 1.70 1.65 1.60 1.55 1.50 1.45 1.40 1.35 1.30 1.10 +125 Output Current (mA) Frequency vs. Supply Voltage -50 -25 1.70 1.90 1.65 1.89 1.60 1.88 1.55 1.50 1.45 1.40 1.35 1.30 1.25 1.20 1.10 2.5 +75 +100 +125 1.87 1.86 1.85 1.84 1.83 1.82 1.81 1.80 1.79 3.0 3.5 4.0 4.5 5.0 1.77 0 5.5 100 Current Limit (A) -10 +5 300 400 500 600 700 800 900 1000 Current Limit vs. Temperature VIN = 3.3V VOUT = 1.2V -25 200 Output Current (mA) Current Limit vs. Temperature Current Limit (A) +50 VOUT = 1.8V VIN = 3.6V VIN (V) +20 +35 +50 +65 Temperature ( C) o 14 +25 1.78 1.15 3.0 2.9 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 -40 +0 Output Current (mA) Output Voltage vs. Output Current Output Voltage (V) Frequency (MHz) VIN = 3.6V 1.25 1.20 1.15 +80 +95 +110 +125 3.0 2.9 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 -40 VIN = 3.6V VOUT = 1.2V -25 -10 +5 +20 +35 +50 +65 +80 +95 +110 +125 Temperature ( C) o Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Characterization Curve Current Limit (A) Current Limit vs. Temperature 3.0 2.9 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 2.0 1.9 1.8 1.7 1.6 1.5 1.4 1.3 -40 Light Load Mode Output Voltage Ripple VIN = 5.0V VOUT = 1.2V -25 -10 +5 +20 +35 +50 +65 +80 o Temperature ( C) +95 +110 +125 400nS/Div VIN = 3.6V VOUT = 1.8V IOUT = 50mA 1) VSW= 2V/div 2) VOUT = 10mV/Div 3) IL = 500mA/Div Heavy Load Mode Output Voltage Ripple 400nS/Div Rev.A.03 Load Step 40µS/Div VIN = 3.6V VOUT = 1.2V IOUT = 1A VIN = 3.6V VOUT = 1.8V IOUT = 0A~1A~0A 1) VSW= 2V/div 2) VOUT = 10mV/Div 3) IL = 500mA/Div 1) VOUT= 100mV/Div 2) IOUT = 500mA/Div 15 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Characterization Curve Load Step Load Step 40µS/Div 40µS/Div VIN = 3.6V VOUT = 1.8V IOUT = 50mA~1A~50mA VIN = 3.6V VOUT = 1.8V IOUT = 200mA~1A~200mA 1) VOUT= 100mV/Div 2) IOUT = 500mA/Div 1) VOUT= 100mV/Div 2) IOUT = 500mA/div Power On from EN Power Off from EN 400µS/Div 50µS/Div VOUT = 1.2V IOUT = 1A 1) EN= 2V/Div 2) VOUT = 500mV/Div 3) IL = 1A/Div 16 VIN = 3.6V VOUT = 1.8V IOUT = 1A 1) EN = 2V/Div 2) VOUT = 2V/Ddiv 3) IL = 500mA/Div Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Tape and Reel Dimension DFN-6D (2mmx2mmx0.75mm) P PIN 1 W AME AME Carrier Tape, Number of Components Per Reel and Reel Size Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size DFN-6D (2x2x0.75mm) 8.0±0.1 mm 4.0±0.1 mm 3000pcs 180±1 mm QFN-16C (3mmx3mmx0.75mm) P PIN 1 W AME AME Carrier Tape, Number of Components Per Reel and Reel Size Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size QFN-16C (3x3x0.75mm) 12.0±0.1 mm 4.0±0.1 mm 3000pcs 330±1 mm Rev.A.03 17 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Package Dimension DFN-6D (2mmx2mmx0.75mm) e b D E L E1 PIN 1 IDENTIFICATION D1 TOP VIEW A BOTTOM VIEW G1 REAR VIEW G SYMBOLS A INCHES MIN MAX MIN MAX 0.700 0.800 0.028 0.031 D 1.900 2.100 0.075 0.083 E 1.900 2.100 0.075 0.083 e 18 MILLIMETERS 0.650 TYP 0.026 TYP D1 1.100 1.650 0.043 0.065 E1 0.600 1.050 0.024 0.041 b 0.180 0.350 0.007 0.014 L 0.200 0.450 0.008 0.018 G 0.178 0.228 0.007 0.009 G1 0.000 0.050 0.000 0.002 Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Package Dimension QFN-16C (3mmx3mmx0.75mm) e b E1 E k L D D1 PIN 1 IDENTIFICATION Bottom View A3 A A1 Top View Real View Real View SYMBOLS INCHES MIN MAX MIN MAX A 0.700 0.800 0.028 0.031 A1 0.000 0.050 0.000 0.002 A3 0.203REF. 0.008REF. D 2.924 3.076 0.115 0.121 E 2.924 3.076 0.115 0.121 D1 1.600 1.800 0.063 0.071 E1 1.600 1.800 0.063 0.071 k b e L Rev.A.03 MILLIMETERS 0.200MIN. 0.180 0.280 0.500TYP. 0.324 0.476 0.008MIN. 0.007 0.011 0.020TYP. 0.013 0.019 19 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Lead pattern DFN-6D (2mmx2mmx0.75mm) 0.350 BSC 0.800 BSC 1.200 BSC 0.600 BSC 0.650 BSC 1.300 BSC N1 Note: 1. Lead pattern unit description: BSC: Basic. Represents theoretical exact dimension or dimension target. 2. Dimensions in Millimeters. 3. General tolerance +0.05mm unless otherwise specified. 20 Rev. A.03 AME 1A, 1.5MHz Synchronous Step-Down Converter AME5250A n Lead pattern QFN-16C (3mmx3mmx0.75mm) 0.330 BSC 0.625 BSC 0.500 BSC 2.150 BSC 1.800 BSC N1 1.800 BSC Note: 1. Lead pattern unit description: BSC: Basic. Represents theoretical exact dimension or dimension target. 2. Dimensions in Millimeters. 3. General tolerance +0.05mm unless otherwise specified. Rev.A.03 21 www.ame.com.tw E-Mail: [email protected] Life Support Policy: These products of AME, Inc. are not authorized for use as critical components in life-support devices or systems, without the express written approval of the president of AME, Inc. AME, Inc. reserves the right to make changes in the circuitry and specifications of its devices and advises its customers to obtain the latest version of relevant information. AME, Inc. , January 2014 Document: 1283-DS5250A-A.03 Corporate Headquarter AME, Inc. 2F, 302 Rui-Guang Road, Nei-Hu District Taipei 114, Taiwan. Tel: 886 2 2627-8687 Fax: 886 2 2659-2989