SEMTECH SC4520

SC4520 3A Step-Down Switching Regulator with Adjustable Switching Frequency POWER MANAGEMENT Features Description The SC4520 is a current mode switching regulator with ‹ Wide operating voltage range: 4.4V to 24V an integrated switch and an adjustable frequency with ‹ Integrated 3 Amp switch enable function. The integrated switch allows for cost- ‹ 100kHz to 600kHz adjustable frequency operation effective, low power solutions with a peak switch current ‹ Current mode control of 3 amps. An adjustable high frequency of 100kHz to ‹ Precision enable threshold 600kHz provides for fast dynamic response and ‹ SO-8 EDP package. Lead-free product, fully WEEE instantaneous duty cycle adjustment as the input varies, and RoHS compliant making the device ideal for CPE applications where the input is a wall plug power. Low shutdown current also Applications makes the this device an excellent choice for portable ‹ XDSL modems applications where conserving battery life is of prime ‹ CPE equipment concern. ‹ DC-DC point of load applications ‹ Portable equipment ‹ Digtial consumer electronics Typical Application Circuit D1 C1 1 L1 BST 2 3 V IN SW V IN OUT 5 6 Enable EN SC4520 FB R1 8 7 C2 C3 FSET COMP D2 GND 4 Rosc R2 C4 R3 Revision: December 13, 2006 1 www.semtech.com SC4520 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Exposure to Absolute Maximum rated conditions for extended periods of time may affect device reliability. Pl arameter Ss ymbo Ls imit Unit IV nput Supply Voltage -V 0.3 to +28 IN Boost Pin Above V (V - V)61V SW BST SW BV oost Pin Voltage -V 0.3 to +32 BST EV N Pin Voltage -V 0.3 to +24 EN FV B Pin Voltage -V 0.3 to +6 FB FI B Pin Current 1A m FB FV SET Pin Voltage +V 3 FSET (1) Thermal Impedance Junction to Ambient 3W 6.5 °C/ θ JA Me aximumJT unction Temperatur 1C 50 ° J ST torage Temperature Range -C 65 to +150 ° STG LT ead Temperature (Soldering) 10 sec 3C 00 ° LEAD ED SD Rating (Human Body Model) E2 S kV Note: (1) Minimum pad size. Electrical Characteristics Unless specified: V = 12V, V = 0.8V, V = V + 5V, EN = tied to V , SW = open. IN COMP BST IN IN T = T = -40°C to 125°C. A J Pl arameter Ss ymbo Cn ondition Mp i Tx yMs a Unit (1) OV perating Input Voltage 24 V IN MI aximum Switch Current Limit 3A .0 SW Of scillator Frequency R = 82.5k Ω 20 5030 03z 5 kH OSC OSC Of scillator Frequency Range 10 00 6z 0 kH OSC SV witch On Voltage Drop I=0 3A 2V 2 m D(SW) SW VUV ndervoltage Lockout 34 .9 4V . IN UVLO VUV VLO Hysteresis 6V 0 m IN HYST VSI upply Current V=3 1V 5A .5 m IN Q FB SI tandby Current V=0 0V 2A 5 µ Q(OFF) EN  2006 Semtech Corp. 2 www.semtech.com SC4520 POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified: V = 12V, V = 0.8V, V = V + 5V, EN = tied to V , SW = open. IN COMP BST IN IN T = T = -40°C to 125°C. A J PL ARAMETER SS YMBO CN ONDITION MP I TX YMS A UNIT FI B Input Current -1 0.25 -A µ FB Feedback Voltage 08 .78406 . 0V .81 (1) Feedback Voltage Line 4.4V < V < 24V +V 3 mV/ IN Regulation (2) FB to V Voltage Gain 0.9V ≤ V ≤20 .0V 10 53V 5 V/ COMP COMP FB to V Δ I = ± 10µA 50 0080 51o 30 µMh COMP COMP (2) Transconductance VPV in Source Current =0 0.6V 701A 1 µ COMP FB VPV in Sink Current =0 1.0V -0 7 -A 11 µ COMP FB V Pin to Switch Current V=3 1.25V 4V . A/ COMP COMP Transconductance V Pin Maximum D6 uty cycle = 0% 0V . COMP Switching Threshold VOV CP Threshold r2 ising V COMP COMP VHV iccup Retry Threshold f5 alling 0V .2 COMP COMP MV aximum Switch Duty Cycle = 1.2V, I = 400mA,8% 5 COMP SW R = 0 OSC Minimum Boost Voltage 2V .7 (2) Above Switch BI oost Current =0 1A 151A m SW I=0 3A 35 4 SW Enable Input Threshold V 13 .1 15 . 1V . ETH Voltage EI nable Output Bias CurrentE8 N = 50mV below threshold µA EOL IE0 N = 50mV below threshold 1A µ EOH Notes: (1) The required minimum input voltage for a regulated output depends on the output voltage and load condition. (2) Guaranteed by design.  2006 Semtech Corp. 3 www.semtech.com SC4520 POWER MANAGEMENT Pin Configurations Ordering Information (1)(2) Part Number Package TOP VIEW SP C4520SETRT SO-8 ED SD C4520EVB EVALUATION BOAR BST 1 8 FSET Notes: IN 2 7 COMP (1) Only available in tape and reel packaging. A reel contains 2500 devices. SW 3 6 FB GND 4 5 EN (2) Lead-free product. This product is WEEE and RoHS compliant. (SO-8 EDP) Pin Descriptions Pe in #Pn in Nam Pin Functio 1T BS This pin provides power to the internal NPN switch. The minimum turn on voltage for this switch is 2.7V. 2N I Pin IN delivers all power required by control and power circuitry. This pin sees high di/dt during switching. A decoupling capacitor should be attached to this pin as close as possible. 3W S Pin SW is the emitter of the internal switch. The external freewheeling diode should be connected as close as possible to this pin. 4D GN All voltages are measured with respect to this pin. The decoupling capacitor and the freewheeling diode should be connected to GND as short as possible. 5N E This is the chip enable input. The regulator is switched on if EN is high, and it is off if EN is low. The regulator is in standby mode when EN is low, and the input supply current is reduced to a few microamperes. 6BF. Feedback input for adjustable output controllers 7P COM This is the output of the internal error amplifier and input of the peak current comparator. A compensation network is connected to this pin to achieve the specified performance. 8T FSE Frequency setting pin. An external resistor connected from this pin to GND, sets the oscillator frequency. -L THERMA Pad for heatsinking purposes. Connect to ground plane using multiple vias. Not connected PAD internally.  2006 Semtech Corp. 4 www.semtech.com SC4520 POWER MANAGEMENT Block Diagram + + IN IN + + Is Is IS ISE EN N + + 40m 40m SL SLO OP PE E COM COMP P BST BST + + PW PWM M S S FB FB - - Q Q PO POW WE ER R EA EA R R TR TRA AN NSI SIST STO OR R SW SW Is Is 1V 1V UV UVL LO O RE REFE FER RE ENCE NCE EN EN SO SOF FT T S ST TAR ART T GND GND OL OL HI HICCUP CCUP 0. 0.7V 7V SL SLO OP PE E FB FB SL SLO OP PE E C CO OM MP P O OS SC CI ILLA LLAT TO OR R FSET FR FREQ EQU UE EN NC CY Y CLK CLK SYNC SYNC Typical Characteristic - OCP Limit SC4519H OCP Limit vs Duty Cycle Rosc = 0 7 6.5 6 5.5 5 ILIM @-40C 4.5 ILIM @25C ILIM @125C 4 3.5 3 2.5 2 0 2040 6080 100 Duty Cycle (%)  2006 Semtech Corp. 5 www.semtech.com Current Limit (A) SC4520 POWER MANAGEMENT Application Information Oscillator The SC4520 is a current mode buck converter regulator. The external resistor connected to the FSET pin sets the SC4520 has an internal fixed-frequency clock. The PWM frequency from 100kHz to 600kHz. SC4520 uses two feedback loops that control the duty cycle of the internal power switch. The error amplifier Frequency vs R OSC functions like that of the voltage mode converter. The 700 output of the error amplifier works as a switch current 600 reference. This technique effectively removes one of the 500 double poles in the voltage mode system. With this, it is 400 much simpler to compensate a current mode converter 300 to have better performance. The current sense amplifier 200 in the SC4520 monitors the switch current during each cycle. Overcurrent protection (OCP) is triggered when the 100 current limit exceeds the upper limit of 3A, detected by a 0 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 voltage on COMP greater than about 2V. When an OCP Rosc - kOhm fault is detected, the switch is turned off and the external COMP capacitor is discharged at the rate of dv/dt = 3µA/ UVLO C . Once the COMP voltage has fallen below 250mV, comp the part enters a normal startup cycle. C is the total comp When the EN pin is pulled and held above 1.8V, the voltage capacitance value attached to COMP. In the case of on Pin IN determines the operation of the SC4520. As sustained overcurrent or dead-short, the part will V increases during power up, the internal circuit senses continually cycle through the retry sequence as described IN V and keeps the power transistor off until V reaches above, at a rate dependent on the value of Ccomp. During IN IN 4.4V. start up, the voltage on COMP rises roughly at the rate of dv/dt = 120µA/C . Therefore, the retry time for a comp Load Current sustained overcurrent can be approximately calculated as: The peak current I in the switch is internally limited. PEAK 2V 2V For a specific application, the allowed load current I T = C • + C • retry comp comp OMAX 120uA 3uA will change if the input voltage drifts away from the original design as given for continuous current mode: Figure 1 shows the voltage on COMP during a sustained V ⋅(1− D) O overcurrent condition. I = 3 − OMAX 2 ⋅L ⋅ f s Where: f = switching frequency, S V = output voltage and O D = duty ratio, V / V O IN V = input voltage. IN Figure 1. Voltage on COMP for Startup and OCP Enable Pulling and holding the EN pin below 0.4V activates the shut down mode of the SC4520 which reduces the input supply current to less than 150µA. During the shut down mode, the switch is turned off. The SC4520 is turned on if the EN pin is pulled high.  2006 Semtech Corp. 6 www.semtech.com Frequency - kHz SC4520 POWER MANAGEMENT Application Information (Cont.) Figure 2 shows the theoretical maximum load current V ⋅ (V − V ) O I O L = for the specific cases. In a real application, however, the V ⋅ f ⋅δ ⋅ I I s OMAX allowed maximum load current also depends on the layout Where: and the air cooling condition. Therefore, the maximum fs = switching frequency, load current may need to be degraded according to the δ = ratio of the peak to peak inductor current to the thermal situation of the application. output load current and V = output voltage. O The peak to peak inductor current is: Maximum Load Current vs Input Voltage I =δ • I p−p OMAX L=10uH After the required inductor value is selected, the proper selection of the core material is based on the peak 2.900 2.880 inductor current and efficiency specifications. The core 2.860 must be able to handle the peak inductor current I 2.840 PEAK Vo=2.5V 2.820 without saturation and produce low core loss during the 2.800 Vo=3.3V high frequency operation. 2.780 Vo=5V 2.760 I 2.740 p−p I = I + PEAK OMAX 2.720 2 2.700 The power loss for the inductor includes its core loss and 46 8 10 12 14 16 18 copper loss. If possible, the winding resistance should Vi (V) be minimized to reduce inductor’s copper loss. The core must be able to handle the peak inductor current I PEAK without saturation and produce low core loss during the Figure 2. Theoretical maximum load current curves high frequency operation. The core loss can be found in the manufacturer’s datasheet. The inductor’s copper loss Inductor Selection can be estimated as follows: 2 The factors for selecting the inductor include its cost, P = I ⋅ R LRMS COPPER WINDING efficiency, size and EMI. For a typical SC4520 application, Where: the inductor selection is mainly based on its value, I is the RMS current in the inductor. This current can LRMS saturation current and DC resistance. Increasing the be calculated as follows: inductor value will decrease the ripple level of the output 1 2 voltage while the output transient response will be I = I ⋅ 1+ ⋅δ LRMS OMAX 12 degraded. Low value inductors offer small size and fast transient responses while they allow large ripple currents, Output Capacitor Selection poor efficiencies and require more output capacitance for low output ripple. The inductor should be able to Basically there are two major factors to consider in handle the peak current without saturating and its copper selecting the type and quantity of the output capacitors. resistance in the winding should be as low as possible to The first one is the required ESR (Equivalent Series minimize its resistive power loss. A good trade-off among Resistance) which should be low enough to reduce the its size, loss and cost is to set the inductor ripple current output voltage deviation during load changes. The second to be within 15% to 30% of the maximum output current. one is the required capacitance, which should be high enough to hold up the output voltage. Before the SC4520 The inductor value can be determined according to its regulates the inductor current to a new value during a operating point under its continuous mode and the switching frequency as follows:  2006 Semtech Corp. 7 www.semtech.com Iomax (A) SC4520 POWER MANAGEMENT Application Information (Cont.) load transient, the output capacitor delivers all the 1 T = ⋅ D W max additional current needed by the load. The ESR and ESL f s of the output capacitor, the loop parasitic inductance Where: between the output capacitor and the load combined f = the switching frequency and s with inductor ripple current are all major contributors to Dmax = maximum duty ratio, 0.85 for the SC4520. the output voltage ripple. Surface mount ceramic capacitors are recommended. The required minimum capacitance for the boost capacitor will be: Input Capacitor Selection I B C = ⋅ T boost W The input capacitor selection is based on its ripple current V D level, required capacitance and voltage rating. This capacitor must be able to provide the ripple current Where: drawn by the converter. For the continuous conduction I = the boost current and B mode, the RMS value of the input capacitor current V = discharge ripple voltage. D I can be calculated from: CIN(RMS) With f = 600kHz, V = 0.5V and I = 0.045A, the required V ⋅ (V − V ) O I O s D B I = I ⋅ CIN OMAX (RMS) 2 minimum capacitance for the boost capacitor is: V I This current gives the capacitor’s power loss through its I 1 0.045 1 B C = ⋅ ⋅D = ⋅ ⋅0.85 = 128nF boost max R as follows: V f 0.5 600k D s CIN(ESR) 2 P = I • R The internal driver of the switch requires a minimum 2.7V CIN (RMS) CIN CIN(ESR) to fully turn on that switch to reduce its conduction loss. The input ripple voltage mainly depends on the input If the output voltage is less than 2.7V, the boost capacitor capacitor’s ESR and its capacitance for a given load, input can be connected to either the input side or an voltage and output voltage. Assuming that the input independent supply with a decoupling capacitor. But the current of the converter is constant, the required input Pin BST should not see a voltage higher than its maximum capacitance for a given voltage ripple can be calculated rating. by: D ⋅ (1 − D) Freewheeling Diode Selection C = I ⋅ IN OMAX fs ⋅ (ΔV − I ⋅ R ) I OMAX CIN (ESR) Where: This diode conducts during the switch’s off-time. The diode ΔV = the given input voltage ripple. should have enough current capability for full load and I short circuit conditions without any thermal concerns. Because the input capacitor is exposed to the large surge Its maximum repetitive reverse block voltage has to be current, attention is needed for the input capacitor. If higher than the input voltage of the SC4520. A low tantalum capacitors are used at the input side of the forward conduction drop is also required to increase the converter, one needs to ensure that the RMS and surge overall efficiency. The freewheeling diode should be ratings are not exceeded. For generic tantalum turned on and off fast with minimum reverse recovery capacitors, it is suggested to derate their voltage ratings because the SC4520 is designed for high frequency at a ratio of about two to protect these input capacitors. applications. SS23 Schottky rectifier is recommended for certain applications. The average current of the diode, Boost Capacitor and its Supply Source Selection I _ can be calculated by: D AVG The boost capacitor selection is based on its discharge I = I ⋅(I − D) D-AVG omax ripple voltage, worst case conduction time and boost current. The worst case conduction time T can be w estimated as follows:  2006 Semtech Corp. 8 www.semtech.com SC4520 POWER MANAGEMENT Application Information (Cont.) Where: Thermal Considerations R – Load and L C – Output capacitor. There are three major power dissipation sources for the SC4520. The internal switch conduction loss, its switching The goal of the compensation design is to shape the loop loss due to the high frequency switching actions and the to have a high DC gain, high bandwidth, enough phase base drive boost circuit loss. These losses can be margin, and high attenuation for high frequency noises. estimated as: Figure 3 gives a typical compensation network which 10 2 −3 P = I ⋅R ⋅D +10.8 ⋅10 ⋅I ⋅ V + ⋅I ⋅D ⋅(V ) offers 2 poles and 1 zero to the power stage: total o on o I o boost 1000 Where: SC SC SC SC4 4 4 45 5 5 52 2 2 20 0 1 1 L1 L1 L1 L1 Vo Vou ut t I = load current; 2 2 2 2 3 3 3 3 O IN IN IN IN SW SW SW SW 5 5 6 6 R = on-equivalent resistance of the switch; C C C C on R1 R1 R1 R1 EN EN EN EN FB FB FB FB V = input voltage or output based on the boost circuit 8 8 7 7 BOOST FSET FSET CO CO CO COM M M MP P P P connection. 4 4 C4 C4 C4 C4 R2 R2 R2 R2 The junction temperature of the SC4520 can be C5 C5 C5 C5 further determined by: R3 R3 R3 R3 D2 D2 D2 D2 T = T +θ ⋅P J A JA total θ is the thermal resistance from junction to ambient. JA Its value is a function of the IC package, the application Figure 3. Compensation network provides 2 poles and layout and the air cooling system. 1 zero. The freewheeling diode also contributes a significant The compensation network gives the following portion of the total converter loss. This loss should be characteristics: minimized to increase the converter efficiency by using s Schottky diodes with low forward drop (V ). 1+ F ω R 2 Z P = V ⋅I ⋅(1− D) G (s) =ω ⋅ ⋅g ⋅ diode F o COMP 1 m s R + R 1 2 s ⋅(1+ ) ω P2 Loop Compensation Design Where: 1 The SC4520 has an internal error amplifier and requires ω = 1 C + C a compensation network to connect between the COMP 4 5 pin and GND pin as shown in Figure 3. The compensation 1 ω = network includes C4, C5 and R3. R1 and R2 are used to Z R ⋅C 3 4 program the output voltage according to: C + C 4 5 R ω = 1 P2 V = 1.2 •(1+ ) R ⋅C ⋅C O 3 4 5 R 2 Assuming the power stage ESR (equivalent series resistance) zero is an order of magnitude higher than The loop gain will be given by: the closed loop bandwidth, which is typically one tenth of s the switching frequency, the power stage control to output 1 + R R 1 ω −3 L 2 Z transfer function with the current loop closed (Ridley T(s) = G (s)⋅G (s) = 3.655 ⋅10 ⋅ ⋅ ⋅ COMP VD s s C R + R s 4 1 2 (1+ ) ⋅(1+ ) model) for the SC4520 will be as follows: ω ω P1 P2 4.3 ⋅R L Where: G (s) = VD s 1+ 1 1 ω = p1 R ⋅ C R ⋅ C L L  2006 Semtech Corp. 9 www.semtech.com GN GN GN GND D D D B B B BS S S ST T T T SC4520 POWER MANAGEMENT Application Information (Cont.) One integrator is added at origin to increase the DC gain. 2. Start the PCB layout by placing the power components ω is used to cancel the power stage pole ω so that the first. Arrange the power circuit to achieve a clean Z P1 loop gain has –20dB/dec rate when it reaches 0dB line. power flow route. Put all power connections on one ω is placed at half switching frequency to reject high side of the PCB with wide copper filled areas if P2 frequency switching noises. Figure 4 gives the asymptotic possible. diagrams of the power stage with current loop closed 3. The V bypass capacitor should be placed next to IN and its loop gain. the V and GND pins. IN 4. The trace connecting the feedback resistors to the output should be short, direct and far away from any noise sources such as switching node and switching Loop gain T(s) components. 5. Minimize the loop including input capacitor, the ω p1 Power stage SC4520 and freewheeling diode D . This loop passes 2 high di/dt current. Make sure the trace width is wide ω ω C P2 enough to reduce copper losses in this loop. ω Z 6. Maximize the trace width of the loop connecting the inductor, freewheeling diode D and the output 2 capacitor. 7. Connect the ground of the feedback divider and the Figure 4. Asymptotic diagrams of power stage with compensation components directly to the GND pin current loop closed and its loop gain. of the SC4520 by using a separate ground trace. 8. Connect Pin 4 to a large copper area to remove the The design guidelines for the SC4520 applications are IC heat and increase the power capability of the as following: SC4520. A few feedthrough holes are required to connect this large copper area to a ground plane to 1. Set the loop gain crossover corner frequency ω for C further improve the thermal environment of the given switching corner frequency ω = 2πf C C SC4520. The traces attached to other pins should 2. Place an integrator at the origin to increase DC and be as wide as possible for the same purpose. low frequency gains. 3. Select ω such that it is placed at ω to obtain a Z P1 -20dB/dec rate to go across the 0dB line. 4. Place a high frequency compensator pole ω (ω = πf ) to get the maximum attenuation of P2 P2 s the switching ripple and high frequency noise with the adequate phase lag at ω C. Layout Guidelines: In order to achieve optimal electrical and thermal performance for high frequency converters, special attention must be paid to the PCB layouts. The goal of layout optimization is to identify the high di/dt loops and minimize them. The following guidelines should be used to ensure proper operation of the converters. 1. A ground plane is suggested to minimize switching noises and trace losses and maximize heat transferring.  2006 Semtech Corp. 10 www.semtech.com SC4520 POWER MANAGEMENT Application Information (Cont.) Design Example: 16V to 5V at 2A D3 D3 C1 C1 0. 0.2 22 2u u V V =1 =16V 6V IN IN L1 L1 V V =5 =5V V o o 2 2 3 3 IN IN SW SW 8. 8.2 2u uH H C2 C2 C3 C3 4. 4.7 75 5k k 5 5 6 6 R1 R1 10u 10u 10u 10u S SC C4 4520 520 EN EN FB FB R4 R4 52. 52.3k 3k 8 8 7 7 F FSET SET COM COMP P Ro Ros sc c=0 =0 C4 C4 R2 R2 3. 3.3 3n n 10k 10k C5 C5 180p 180p R3 R3 3. 3.4k 4k D2 D2 Bill of Materials Iy temQe tRe eferenc Vr alu Part No./Manufacture 11CR 1 0y .22uF, 25V, 0805, X7 Visha 22CV 2, C3 1c 0u, 1210, X5R, 25 Panasoni 31CV 4 3y .3n, 0805, X7R, 25 Visha 41CF 5 180p 51D3 1 1N4148WS, SOD-32 61D3 2 S3 S3 Fairchild P/N: SS3 71LH 1 82 .2u COOPER P/N:DR125-8R 81RK 1 52.3 91Rk 2 10 11 0Rk 3 3.4 11 1Rk 4 4.75 11 2R0 osc 11 3U0 1 Sh C452 Semtec Unless specified, all resistors have 1% precision with 0603 package. Resistors are +/-1% and all capacitors are +/-20%  2006 Semtech Corp. 11 www.semtech.com 4 4 1 1 GN GND D BS BST T SC4520 POWER MANAGEMENT Outline Drawing - SOIC-8L EDP A D e DIMENSIONS N INCHES MILLIMETERS DIM MIN NOM MAX MIN NOM MAX - - A .053 .069 1.35 1.75 2X E/2 .000 - .005 0.00 - 0.13 A1 A2 .049 - .065 1.25 - 1.65 E1 E b .012 - .020 0.31 - 0.51 c .007 - .010 0.17 - 0.25 D .189 .193 .197 4.80 4.90 5.00 12 E1 .150 .154 .157 3.80 3.90 4.00 E .236 BSC 6.00 BSC ccc C e .050 BSC 1.27 BSC 2X N/2 TIPS e/2 F .116 .120 .130 2.95 3.05 3.30 H .085 .095 .099 2.15 2.41 2.51 B - - h .010 .020 0.25 0.50 L .016 .028 .041 0.40 0.72 1.04 D L1 (.041) (1.05) N 8 8 aaa C 01 0° - 8° 0° - 8° A2 A aaa .004 0.10 SEATING bbb .010 0.25 PLANE C A1 ccc .008 0.20 bxN bbb C A-B D h F EXPOSED PAD h H H c GAGE PLANE 0.25 L 01 (L1) DETAIL A SEE DETAIL A SIDE VIEW NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. DATUMS AND TO BE DETERMINED AT DATUM PLANE -A- -B- -H- 3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. 4. REFERENCE JEDEC STD MS-012, VARIATION BA. Land Pattern - SOIC-8L EDP E SOLDER MASK D DIMENSIONS DIM INCHES MILLIMETERS (.205) (5.20) C Z (C) D .134 3.40 G F E .201 5.10 F .101 2.56 G .118 3.00 Y P .050 1.27 X .024 0.60 THERMAL VIA P Y .087 2.20 Ø 0.36mm X Z .291 7.40 NOTES: 1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY. CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR COMPANY'S MANUFACTURING GUIDELINES ARE MET. 2. REFERENCE IPC-SM-782A, RLP NO. 300A. 3. THERMAL VIAS IN THE LAND PATTERN OF THE EXPOSED PAD SHALL BE CONNECTED TO A SYSTEM GROUND PLANE. FAILURE TO DO SO MAY COMPROMISE THE THERMAL AND/OR FUNCTIONAL PERFORMANCE OF THE DEVICE. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804  2006 Semtech Corp. 12 www.semtech.com