SEMTECH SC4519

SC4519 600kHz, 3A Step-Down Switching Regulator POWER MANAGEMENT Features Description The SC4519 is a current mode switching regulator with ‹ Integrated 3 Amp switch an integrated switch, operating at 600kHz with separate ‹ 600kHz frequency of operation sync and enable functions. The integrated switch allows ‹ Current mode controller for cost effective low power solutions (peak switch current ‹ Synchronizable to higher frequency up to 1.2MHz 3 amps). The sync function allows customers to ‹ 6µA low shutdown current synchronize to a faster clock in order to avoid frequency ‹ SOIC-8L-EDP Lead-free package. This product is beating in noise sensitive applications. High frequency fully WEEE and RoHS compliant of operation allows for very small passive components. Current mode operation allows for fast dynamic response Applications and instantaneous duty cycle adjustment as the input ‹ XDSL modems varies (ideal for CPE applications where the input is a ‹ CPE equipment wall plug power). ‹ DC-DC point of load applications The low shutdown current makes it ideal for portable ‹ Portable equipment applications where battery life is important. The SC4519 is a 600kHz switching regulator synchronizable to a faster frequency from 750kHz to 1.2MHz. Typical Application Circuit D1 C1 1 L1 BST 2 3 VIN VOUT IN SW SC4519 R1 5 6 Enable EN FB 8 7 C2 C3 SYNC COMP D2 GND 4 C4 R2 R3 Revision: April 18, 2007 1 www.semtech.com SC4519 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 (1) IV nput Supply Voltage -0.3 to +24 V 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 +16 EN FV B Pin Voltage -V 0.3 to +6 FB FI B Pin Current 1A m FB SI YNC Pin Current 1A m SYNC (2) Thermal Impedance Junction to Ambient 3W 6.5 °C/ θ JA OT perating Ambient Temperature Range -C 40 to +85 ° A 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 Notes: (1) For proper operation of device, V should be within maximum Operating Input Voltage as defined in Electrical IN Characteristics. (2) Minimum pad size. Electrical Characteristics Unless specified: V = 12V, V = 0.8V, V = V + 5V, EN = tied to V , SYNC = 0, SW = open. IN COMP BST IN IN T = T = -40°C to 85°C. A J Pl arameter Ss ymbo Cn ondition Mp i Tx yMs a Unit (1) OV perating Input Voltage 16 V IN MI aximum Switch Current Limit 3A .0 SW Of scillator Frequency 50 5060 07z 5 kH OSC SV witch On Voltage Drop I=0 3A 3V 3 m D(SW) SW o VUV ndervoltage Lockout T = 25C023 .6 V IN UVLO A VSI upply Current V = V+0 17% 15 . mA IN Q FB OUT(NOM) SI tandby Current V = 0V, V = V = 16V, V=5 0V 4A5 µ Q(OFF) EN IN BOOST SW  2007 Semtech Corp. 2 www.semtech.com SC4519 POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified: V = 12V, V = 0.8V, V = V + 5V, EN = tied to V , SYNC = 0, SW = open. IN COMP BST IN IN T = T = -40°C to 85°C. A J PL ARAMETERSS YMBO CN ONDITION MP I TX YMS A UNIT FI B Input Current -0 0.25-A 0.5 µ FB Feedback Voltage 12 .17614 .1V .22 (2) Feedback Voltage Line 3V < V < 16V +V 3 mV/ IN Regulation (3) FB to V Voltage Gain 0.4V ≤ V ≤00 .9V 10 5 35 COMP COMP FB to V Δ I = ± 10µA 50 0080 51o 30 µMh COMP COMP (3) Transconductance VPV in Source Current = V-0 17% 701A 1 µ COMP FB OUT(NOM) VPV in Sink Current = V+0 17% 701A 1 µ COMP FB OUT(NOM) V Pin to Switch Current 2V .5 A/ COMP Transconductance V Pin Maximum D5 uty cycle = 0% 0V .3 COMP Switching Threshold VPI in Threshold =9 3A 0V . COMP SW MV aximum Switch Duty Cycle = 1.2V, I=5 400mA8% COMP SW Minimum Boost Voltage I = 3A, 0°C ≤ T ≤ 85°C and 17 .8 2V . SW A (3) Above Switch I = 2.5A, T < 0°C SW A BI oost Current =0 1A 151A m SW I = 3A, 0°C ≤ T ≤ 85°C and 35 0 4 SW A I = 2.5A, T < 0°C SW A  2007 Semtech Corp. 3 www.semtech.com SC4519 POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified: V = 12V, V = 0.8V, V = V + 5V, EN = tied to V , SYNC = 0, SW = open. IN COMP BST IN IN T = T = -40°C to 85°C. A J PL ARAMETER SS YMBO CN ONDITION MP I TX YMS A UNIT EV nable Input Threshold Voltage 3V IH V 0V .4 IL EI nable Input Bias Current E5 N = 60mV above threshold 2A . µ IL IE5 N = 100mV below threshold 1A5 µ IH SYNC Threshold Voltage 1V .5 (4) SYNC Input Frequency 70 50 1z 20 kH SV YNC Pin Resistance =0 0.5V 2kΩ SYNC Notes: (1) The device may not function properly outside its operating input voltage range. (2) The required minimum input voltage for a regulated output depends on the output voltage and load condition. (3) Guaranteed by design. (4) For SYNC applications, please contact factory.  2007 Semtech Corp. 4 www.semtech.com SC4519 POWER MANAGEMENT Pin Configurations Ordering Information (1)(2) Part Number Package TOP VIEW SP C4519STRT SOIC-8L-ED Sd C4519EVB Evaluation Boar BST 1 8 SYNC Notes: IN 2 7 COMP (1) Only available in tape and reel packaging. A reel SW 3 6 FB contains 2500 devices. GND 4 5 EN (2) Lead free product. This product is WEEE and RoHS compliant. (SOIC-8L-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. 8C SYN This is synchronous control pin used to synchronize the internal oscillator to an external pulse control signal. When not used, it should be connected to GND. -L THERMA Pad for heatsinking purposes. Connect to ground plane using multiple vias. Not connected PAD internally.  2007 Semtech Corp. 5 www.semtech.com SC4519 POWER MANAGEMENT Block Diagram + + IN IN + + Is Is I ISEN SEN + + 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 REF FE ER 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 FR FREQ EQU UE EN NC CY Y CLK CLK SYNC SYNC  2007 Semtech Corp. 6 www.semtech.com SC4519 POWER MANAGEMENT Application Information The SC4519 is a current mode buck converter regulator. Oscillator SC4519 has an internal fixed-frequency clock. The Its internal free running oscillator sets the PWM frequency SC4519 uses two feedback loops that control the duty at 600kHz for the SC4519 without any external cycle of the internal power switch. The error amplifier components to program the frequency. An external clock functions like that of the voltage mode converter. The with a duty cycle from 20% to 80% connected to the output of the error amplifier works as a switch current SYNC pin activates synchronous mode. The frequency reference. This technique effectively removes one of the of the external clock can be from 750kHz to 1.2MHz. double poles in the voltage mode system. With this, it is much simpler to compensate a current mode converter UVLO to have better performance. The current sense amplifier in the SC4519 monitors the switch current during each When the EN pin is pulled and held above 1.8V, the voltage cycle. Overcurrent protection (OCP) is triggered when the on Pin IN determines the operation of the SC4519. As current limit exceeds the upper limit of 3A, detected by a VIN increases during power up, the internal circuit senses voltage on COMP greater than about 2V. When an OCP VIN and keeps the power transistor off until VIN reaches fault is detected, the switch is turned off and the external 2.6V. COMP capacitor is quickly discharged using an internal npn transistor. Once the COMP voltage has fallen below Load Current 250mV, an internal timer prevents any operation for 50µs, after which the part enters a normal startup cycle. The peak current I in the switch is internally limited. PEAK In the case of sustained overcurrent or dead-short, the For a specific application, the allowed load current I OMAX part will continually cycle through the retry sequence as will change if the input voltage drifts away from the original described above, at a rate dependent on the value of design as given for continuous current mode: Ccomp. During start up, the voltage on COMP rises roughly V ⋅(1− D) O I = 3 − at the rate of dv/dt=120µA/C . C is the total OMAX comp comp 2 ⋅L ⋅ f s capacitance value attached to COMP. Therefore, the retry Where: time for a sustained overcurrent can be approximately fs = switching frequency, calculated as: Vo = output voltage and 2V D = duty ratio, VO/VI T =C ⋅ +50us retry comp 120uA V = input voltage. I Figure 1 shows the voltage on COMP during a sustained Figure 2 shows the theoretical maximum load current overcurrent condition. for the specific cases. In a real application, however, the allowed maximum load current also depends on the layout 2V and the air cooling condition. Therefore, the maximum load current may need to be derated according to the thermal situation of the application. 250mV 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 SC4519 which reduces the input supply current to less than 10µA. During the shut down mode, the switch is turned off. The SC4519 is turned on if the EN pin is pulled high.  2007 Semtech Corp. 7 www.semtech.com SC4519 POWER MANAGEMENT Application Information (Cont.) The peak to peak inductor current is: I =δ • I p−p OMAX Maximum Load Current vs Input Voltage After the required inductor value is selected, the proper L=10uH selection of the core material is based on the peak inductor current and efficiency specifications. The core 2.900 must be able to handle the peak inductor current I 2.880 PEAK 2.860 without saturation and produce low core loss during the 2.840 Vo=2.5V high frequency operation. 2.820 2.800 Vo=3.3V I p−p 2.780 I = I + Vo=5V PEAK OMAX 2.760 2 2.740 The power loss for the inductor includes its core loss and 2.720 2.700 copper loss. If possible, the winding resistance should 46 8 10 12 14 16 18 be minimized to reduce inductor’s copper loss. The core Vi (V) must be able to handle the peak inductor current I PEAK without saturation and produce low core loss during the high frequency operation. The core loss can be found in Figure 2. Theoretical maximum load current curves the manufacturer’s datasheet. The inductor’s copper loss can be estimated as follows: Inductor Selection 2 P = I ⋅ R LRMS COPPER WINDING Where: The factors for selecting the inductor include its cost, I is the RMS current in the inductor. This current can efficiency, size and EMI. For a typical SC4519 application, LRMS be calculated as follows: the inductor selection is mainly based on its value, saturation current and DC resistance. Increasing the 1 2 I = I ⋅ 1+ ⋅δ LRMS OMAX inductor value will decrease the ripple level of the output 12 voltage while the output transient response will be degraded. Low value inductors offer small size and fast Output Capacitor Selection transient responses while they allow large ripple currents, poor efficiencies and require more output capacitance Basically there are two major factors to consider in for low output ripple. The inductor should be able to selecting the type and quantity of the output capacitors. handle the peak current without saturating and its copper The first one is the required ESR (Equivalent Series resistance in the winding should be as low as possible to Resistance) which should be low enough to reduce the minimize its resistive power loss. A good trade-off among output voltage deviation during load changes. The second its size, loss and cost is to set the inductor ripple current one is the required capacitance, which should be high to be within 15% to 30% of the maximum output current. enough to hold up the output voltage. Before the SC4519 regulates the inductor current to a new value during a The inductor value can be determined according to its load transient, the output capacitor delivers all the operating point under its continuous mode and the additional current needed by the load. The ESR and ESL switching frequency as follows: of the output capacitor, the loop parasitic inductance V ⋅ (V − V ) between the output capacitor and the load combined O I O L = V ⋅ f ⋅δ ⋅ I I s OMAX with inductor ripple current are all major contributors to the output voltage ripple. Surface mount ceramic Where: capacitors are recommended. fs = switching frequency, δ = ratio of the peak to peak inductor current to the Input Capacitor Selection output load current and V = output voltage. O The input capacitor selection is based on its ripple current level, required capacitance and voltage rating. This  2007 Semtech Corp. 8 www.semtech.com Iomax (A) SC4519 POWER MANAGEMENT Where: Application Information (Cont.) I = the boost current and B capacitor must be able to provide the ripple current V = discharge ripple voltage. D drawn by the converter. For the continuous conduction mode, the RMS value of the input capacitor current With f = 600kHz, V = 0.5V and I =0.045A, the required s D B I can be calculated from: minimum capacitance for the boost capacitor is: CIN(RMS) V ⋅ (V − V ) I 1 0.045 1 O I O B I = I ⋅ C = ⋅ ⋅D = ⋅ ⋅0.85 = 128nF CIN OMAX boost max (RMS) 2 V f 0.5 600k V I D s The internal driver of the switch requires a minimum 2.7V This current gives the capacitor’s power loss through its to fully turn on that switch to reduce its conduction loss. R as follows: CIN(ESR) If the output voltage is less than 2.7V, the boost capacitor 2 P = I CIN • R (RMS) CIN CIN(ESR) can be connected to either the input side or an The input ripple voltage mainly depends on the input independent supply with a decoupling capacitor. But the capacitor’s ESR and its capacitance for a given load, input Pin BST should not see a voltage higher than its maximum voltage and output voltage. Assuming that the input rating. current of the converter is constant, the required input capacitance for a given voltage ripple can be calculated Freewheeling Diode Selection by: D ⋅ (1 − D) This diode conducts during the switch’s off-time. The diode C = I ⋅ IN OMAX fs ⋅ (ΔV − I ⋅ R ) should have enough current capability for full load and I OMAX CIN (ESR) short circuit conditions without any thermal concerns. Where: Its maximum repetitive reverse block voltage has to be ΔV = the given input voltage ripple. I higher than the input voltage of the SC4519. A low forward conduction drop is also required to increase the Because the input capacitor is exposed to the large surge overall efficiency. The freewheeling diode should be current, attention is needed for the input capacitor. If turned on and off fast with minimum reverse recovery tantalum capacitors are used at the input side of the because the SC4519 is designed for high frequency converter, one needs to ensure that the RMS and surge applications. SS23 Schottky rectifier is recommended ratings are not exceeded. For generic tantalum for certain applications. The average current of the diode, capacitors, it is suggested to derate their voltage ratings I _ can be calculated by: D AVG at a ratio of about two to protect these input capacitors. I = I ⋅(I − D) D-AVG omax Boost Capacitor and its Supply Source Selection Thermal Considerations The boost capacitor selection is based on its discharge ripple voltage, worst case conduction time and boost There are three major power dissipation sources for the current. The worst case conduction time T can be SC4519. The internal switch conduction loss, its switching w estimated as follows: loss due to the high frequency switching actions and the base drive boost circuit loss. These losses can be 1 T = ⋅ D W max estimated as: f s 10 Where: 2 −3 P = I ⋅R ⋅D + 10.8 ⋅10 ⋅I ⋅ V + ⋅I ⋅D ⋅(V ) total o on o I o boost 1000 f = the switching frequency and s Where: Dmax = maximum duty ratio, 0.85 for the SC4519. I = load current; O R = on-equivalent resistance of the switch; The required minimum capacitance for the boost on V = input voltage or output based on the boost circuit capacitor will be: BOOST connection. I B C = ⋅ T boost W V D The junction temperature of the SC4519 can be further determined by:  2007 Semtech Corp. 9 www.semtech.com SC4519 POWER MANAGEMENT Application Information (Cont.) T = T +θ ⋅P J A JA total SC4519 L1 Vout 2 3 IN SW θ is the thermal resistance from junction to ambient. JA C 5 6 R1 EN FB Its value is a function of the IC package, the application 8 7 SYNC COMP layout and the air cooling system. C4 R2 C5 The freewheeling diode also contributes a significant R3 D2 portion of the total converter loss. This loss should be minimized to increase the converter efficiency by using Schottky diodes with low forward drop (V ). F P = V ⋅I ⋅(1− D) diode F o Figure 3. Compensation network provides 2 poles and 1 zero. Loop Compensation Design The compensation network gives the following The SC4519 has an internal error amplifier and requires characteristics: a compensation network to connect between the COMP s pin and GND pin as shown in Figure 3. The compensation 1+ ω R Z 2 network includes C4, C5 and R3. R1 and R2 are used to G (s) =ω ⋅ ⋅ g ⋅ COMP 1 m s R + R 1 2 program the output voltage according to: s ⋅ (1+ ) ω P2 R 1 V = 1.2 •(1+ ) O Where: R 2 1 Assuming the power stage ESR (equivalent series ω = 1 C + C 4 5 resistance) zero is an order of magnitude higher than the closed loop bandwidth, which is typically one tenth of 1 ω = Z the switching frequency, the power stage control to output R ⋅ C 3 4 transfer function with the current loop closed (Ridley C + C 4 5 model) for the SC4519 will be as follows: ω = P2 R ⋅ C ⋅ C 3 4 5 2.5 ⋅ R L G (s) = VD s 1+ 1 The loop gain will be given by: R ⋅ C L s Where: 1+ R R 1 ω −3 L 2 Z R – Load and T(s) = G (s) ⋅ G (s) = 2.125⋅10 ⋅ ⋅ ⋅ COMP VD L s s C R + R s 4 1 2 (1+ ) ⋅ (1+ ) C – Output capacitor. ω ω P1 P2 Where: The goal of the compensation design is to shape the loop 1 to have a high DC gain, high bandwidth, enough phase ω = p1 R ⋅ C L margin, and high attenuation for high frequency noises. Figure 3 gives a typical compensation network which offers 2 poles and 1 zero to the power stage: One integrator is added at origin to increase the DC gain. ω is used to cancel the power stage pole ω so that the Z P1 loop gain has –20dB/dec rate when it reaches 0dB line. ω is placed at half switching frequency to reject high P2 frequency switching noises. Figure 4 gives the asymptotic diagrams of the power stage with current loop closed and its loop gain.  2007 Semtech Corp. 10 www.semtech.com 4 1 GND BST SC4519 POWER MANAGEMENT Application Information (Cont.) Layout Guidelines: Mag Mag In order to achieve optimal electrical and thermal performance for high frequency converters, special L Loop oop g ga ain in T T( (s s) ) attention must be paid to the PCB layouts. The goal of layout optimization is to identify the high di/dt loops and ω ω p1 p1 minimize them. The following guidelines should be used Po Pow we er r s st ta ag ge e to ensure proper operation of the converters. ω ω ω ω C C P2 P2 ω ω 1. A ground plane is suggested to minimize switching ω ω Z Z noises and trace losses and maximize heat transferring. 2. Start the PCB layout by placing the power components first. Arrange the power circuit to achieve a clean power flow route. Put all power connections on one Figure 4. Asymptotic diagrams of power stage with side of the PCB with wide copper filled areas if current loop closed and its loop gain. possible. 3. The V bypass capacitor should be placed next to IN the V and GND pins. IN 4. The trace connecting the feedback resistors to the The design guidelines for the SC4519 applications are output should be short, direct and far away from any as following: noise sources such as switching node and switching components. 1. Set the loop gain crossover corner frequency ω for C 5. Minimize the loop including input capacitor, the given switching corner frequency ω = 2πf C C SC4519 and freewheeling diode D . This loop passes 2 2. Place an integrator at the origin to increase DC and high di/dt current. Make sure the trace width is wide low frequency gains. enough to reduce copper losses in this loop. 3. Select ω such that it is placed at ω to obtain a Z P1 6. Maximize the trace width of the loop connecting the -20dB/dec rate to go across the 0dB line. inductor, freewheeling diode D and the output 2 4. Place a high frequency compensator pole capacitor. ω (ω = πf ) to get the maximum attenuation of P2 P2 s 7. Connect the ground of the feedback divider and the the switching ripple and high frequency noise with compensation components directly to the GND pin the adequate phase lag at ω C. of the SC4519 by using a separate ground trace. 8. Connect Pin 4 to a large copper area to remove the IC heat and increase the power capability of the SC4519. A few feedthrough holes are required to connect this large copper area to a ground plane to further improve the thermal environment of the SC4519. The traces attached to other pins should be as wide as possible for the same purpose.  2007 Semtech Corp. 11 www.semtech.com SC4519 POWER MANAGEMENT Application Information (Cont.) Design Example: 16V to 5V at 2A D3 C1 0.22u V =16V L1 IN V =5V o 2 3 IN SW 8.2uH C3 C2 4.75k 10u 5 6 R1 10u EN FB R4 31.6k 8 7 SYNC COMP SC4519 C4 R2 R2 3.3n 10k 10k C5 180p R3 3.4k 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 31.6 91Rk 2 10 11 0Rk 3 3.4 11 1Rk 4 4.75 11 2U9 1 Sh C451 Semtec Unless specified, all resistors have 1% precision with 0603 package. Resistors are +/-1% and all capacitors are +/-20%  2007 Semtech Corp. 12 www.semtech.com 4 1 GND BST SC4519 POWER MANAGEMENT Application Information (Cont.) (COMPONENT - BOTTOM) (COMPONENT - TOP) SC4518 8 8 (PCB - TOP) (PCB - BOTTOM)  2007 Semtech Corp. 13 www.semtech.com SC4519 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 - - A1 .000 .005 0.00 0.13 - - 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 (.041) (1.05) L1 N 8 8 aaa C - - 01 0° 8° 0° 8° A2 A aaa .004 0.10 SEATING bbb .010 0.25 PLANE ccc C A1 .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. REFERENCE JEDEC STD MS-012, VARIATION BA. 4.  2007 Semtech Corp. 14 www.semtech.com SC4519 POWER MANAGEMENT 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 .201 5.10 E 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  2007 Semtech Corp. 15 www.semtech.com