SEMTECH SC4519H

SC4519H 600kHz, 3A Step-Down Switching Regulator POWER MANAGEMENT Features Description The SC4519H 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 ‹ Precision enable threshold synchronize to a faster clock in order to avoid frequency ‹ SO-8 EDP package. Lead free product, fully WEEE beating in noise sensitive applications. High frequency 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 wall plug power). ‹ CPE equipment ‹ DC-DC point of load applications The low shutdown current makes it ideal for portable ‹ Portable equipment applications where battery life is important. The SC4519H 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 IN SW VOUT SC4519H R1 5 6 Enable EN FB 8 7 C2 SYNC COMP C3 D2 GND 4 C4 R2 R3 Revision: December 12, 2007 1 www.semtech.com SC4519H 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 +28 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 +24 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 36.5 °C/W θ JA OT perating Ambient Temperature Range -C 40 to +85 ° A Me aximumJT unction Temperatur +C 150 ° 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) ThetaJA is calculated from a package in still air, mounted to 3" x 4.5", 4 layer FR4 PCB with thermal vias under exposed pad per JESD51 standards. 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 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 T=5 25°C, D = 50% 35 . 5A . SW A Of scillator Frequency 50 0060 07z 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 V UVLO Hysteresis 6V 0 m IN VSI upply Current V=3 1V 5 mA IN Q FB SI tandby Current V=0 0V 10 0 1A 5 µ Q(OFF) EN  2007 Semtech Corp. 2 www.semtech.com SC4519H 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 125°C. A J PL ARAMETERSS 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 (2) Feedback Voltage Line 4.4V < V < 24V +V 3 mV/ IN Regulation (3) FB to V Voltage Gain 0.9V ≤ V ≤20 .0V 10 53V 5 V/ COMP COMP FB to V 50 0080 51o 30 µMh Δ I = ± 10µA COMP COMP (3) 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=5 1.25V A/V 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=5 400mA8% COMP SW Minimum Boost Voltage 2V .7 (3) Above Switch BI oost Current =0 1A 151A m SW I=0 3A 35 4 SW  2007 Semtech Corp. 3 www.semtech.com SC4519H 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 125°C. A J PL ARAMETER SS YMBO CN ONDITION MP I TX YMS A UNIT EV nable Input Threshold Voltage 17 .115 .2 1V . ETH EI nable Output Bias Current E8 N = 50mV below threshold µA EOL IE0 N = 50mV above threshold 1A µ EOH SYNC Threshold Voltage 1V .5 (4) SYNC Input Frequency 80 00 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) Please contact factory for SYNC applications.  2007 Semtech Corp. 4 www.semtech.com SC4519H POWER MANAGEMENT Pin Configurations Ordering Information (1)(2) Part Number Package TOP VIEW SP C4519HSETRT SO-8 ED (3) SC4519HEVB EVALUATION BOARD BST 1 8 SYNC Notes: IN 2 7 COMP (1) Only available in tape and reel packaging. A reel contains 2500 devices. SW 3 6 FB (2) Lead free product. This product is WEEE and GND 4 5 EN RoHS compliant. (3) Consult factory for all other available options. (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. 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 SC4519H 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 OL OL GND GND 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 CLK CLK FR FREQ EQU UE EN NC CY Y SYNC SYNC Typical Characteristic - OCP Limit SC4519H OCP Limit vs Duty Cycle 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 (%)  2007 Semtech Corp. 6 www.semtech.com Current Limit (A) SC4519H POWER MANAGEMENT Application Information The SC4519H is a current mode buck converter regulator. Oscillator SC4519H has an internal fixed-frequency clock. The Its internal free running oscillator sets the PWM frequency SC4519H uses two feedback loops that control the duty at 600kHz for the SC4519H 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 700kHz 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 SC4519H 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 SC4519H. As current limit exceeds the upper limit of 3A, detected by a V increases during power up, the internal circuit senses IN voltage on COMP greater than about 2V. When an OCP V and keeps the power transistor off until V reaches IN IN fault is detected, the switch is turned off and the external 4.4V. COMP capacitor is discharged at the rate of dv/dt = 3µA/ C . Once the COMP voltage has fallen below 250mV, Load Current comp the part enters a normal startup cycle. C is the total comp capacitance value attached to COMP. In the case of The peak current I in the switch is internally limited. PEAK sustained overcurrent or dead-short, the part will For a specific application, the allowed load current I OMAX continually cycle through the retry sequence as described will change if the input voltage drifts away from the original above, at a rate dependent on the value of Ccomp. During design as given for continuous current mode: start up, the voltage on COMP rises roughly at the rate of V ⋅(1− D) O dv/dt = 120µA/C . Therefore, the retry time for a I = 3 − OMAX comp 2 ⋅L ⋅ f s sustained overcurrent can be approximately calculated as: Where: fs = switching frequency, 2V 2V T = C • + C • Vo = output voltage and retry comp comp 120uA 3uA D = duty ratio, VO/VI V = input voltage. I Figure 1 shows the voltage on COMP during a sustained overcurrent condition. Figure 2 shows the theoretical maximum load current for the specific cases. In a real application, however, the allowed maximum load current also depends on the layout and the air cooling condition. Therefore, the maximum load current may need to be derated according to the thermal situation of the application. 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 SC4519H which reduces the input supply current to less than 150µA. During the shut down mode, the switch is turned off. The SC4519H is turned on if the EN pin is pulled high.  2007 Semtech Corp. 7 www.semtech.com SC4519H 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 SC4519H LRMS be calculated as follows: application, the inductor selection is mainly based on its value, saturation current and DC resistance. Increasing 1 2 I = I ⋅ 1+ ⋅δ LRMS OMAX the inductor value will decrease the ripple level of the 12 output voltage while the output transient response will be degraded. Low value inductors offer small size and Output Capacitor Selection fast transient responses while they allow large ripple currents, poor efficiencies and require more output Basically there are two major factors to consider in capacitance for low output ripple. The inductor should selecting the type and quantity of the output capacitors. be able to handle the peak current without saturating The first one is the required ESR (Equivalent Series and its copper resistance in the winding should be as low Resistance) which should be low enough to reduce the as possible to minimize its resistive power loss. A good output voltage deviation during load changes. The second trade-off among its size, loss and cost is to set the one is the required capacitance, which should be high inductor ripple current to be within 15% to 30% of the enough to hold up the output voltage. Before the maximum output current. SC4519H regulates the inductor current to a new value during a load transient, the output capacitor delivers all The inductor value can be determined according to its the additional current needed by the load. The ESR and operating point under its continuous mode and the ESL of the output capacitor, the loop parasitic inductance switching frequency as follows: between the output capacitor and the load combined V ⋅ (V − V ) O I O with inductor ripple current are all major contributors to L = V ⋅ f ⋅δ ⋅ I I s OMAX the output voltage ripple. Surface mount ceramic capacitors are recommended. Where: fs = switching frequency, Input Capacitor Selection δ = ratio of the peak to peak inductor current to the output load current and The input capacitor selection is based on its ripple current V = output voltage. O level, required capacitance and voltage rating. This  2007 Semtech Corp. 8 www.semtech.com Iomax (A) SC4519H POWER MANAGEMENT Application Information (Cont.) 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 s D B V ⋅ (V − V ) O I O I = I ⋅ CIN OMAX minimum capacitance for the boost capacitor is: (RMS) 2 V I I 1 0.045 1 B This current gives the capacitor’s power loss through its C = ⋅ ⋅D = ⋅ ⋅0.85 = 128nF boost max V f 0.5 600k D s R as follows: CIN(ESR) The internal driver of the switch requires a minimum 2.7V 2 P = I CIN • R (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: Freewheeling Diode Selection D ⋅(1− D) C = I ⋅ IN OMAX fs ⋅(ΔV −I ⋅R ) I OMAX CIN (ESR) This diode conducts during the switch’s off-time. The diode Where: should have enough current capability for full load and ΔV = the given input voltage ripple. short circuit conditions without any thermal concerns. I Its maximum repetitive reverse block voltage has to be Because the input capacitor is exposed to the large surge higher than the input voltage of the SC4519H. A low current, attention is needed for the input capacitor. If forward conduction drop is also required to increase the tantalum capacitors are used at the input side of the overall efficiency. The freewheeling diode should be converter, one needs to ensure that the RMS and surge turned on and off fast with minimum reverse recovery ratings are not exceeded. For generic tantalum because the SC4519H is designed for high frequency capacitors, it is suggested to derate their voltage ratings applications. SS23 Schottky rectifier is recommended at a ratio of about two to protect these input capacitors. for certain applications. The average current of the diode, I _ can be calculated by: D AVG Boost Capacitor and its Supply Source Selection I = I ⋅(I − D) D-AVG omax The boost capacitor selection is based on its discharge Thermal Considerations ripple voltage, worst case conduction time and boost current. The worst case conduction time T can be w There are three major power dissipation sources for the estimated as follows: SC4519H. The internal switch conduction loss, its 1 T = ⋅ D switching loss due to the high frequency switching actions W max f s and the base drive boost circuit loss. These losses can Where: be estimated as: f = the switching frequency and s 10 2 −3 Dmax = maximum duty ratio, 0.85 for the SC4519H. P = I ⋅R ⋅D +10.8 ⋅10 ⋅I ⋅ V + ⋅I ⋅D ⋅(V ) total o on o I o boost 1000 Where: The required minimum capacitance for the boost I = load current; capacitor will be: O R = on-equivalent resistance of the switch; on I B C = ⋅ T V = input voltage or output based on the boost circuit boost W BOOST V D connection.  2007 Semtech Corp. 9 www.semtech.com SC4519H POWER MANAGEMENT Application Information (Cont.) The junction temperature of the SC4519H can be further determined by: SC4519H L1 Vout 2 3 IN SW T = T +θ ⋅ P J A JA total C 5 6 R1 EN FB 8 7 SYNC COMP θ is the thermal resistance from junction to ambient. JA C4 R2 Its value is a function of the IC package, the application C5 layout and the air cooling system. R3 D2 The freewheeling diode also contributes a significant portion of the total converter loss. This loss should be minimized to increase the converter efficiency by using Figure 3. Compensation network provides 2 poles and Schottky diodes with low forward drop (V ). F 1 zero. P = V ⋅I ⋅(1− D) diode F o The compensation network gives the following Loop Compensation Design characteristics: s The SC4519H has an internal error amplifier and requires 1+ ω R a compensation network to connect between the COMP Z 2 G (s) =ω ⋅ ⋅ g ⋅ COMP 1 m s R + R pin and GND pin as shown in Figure 3. The compensation 1 2 s ⋅ (1+ ) ω P2 network includes C4, C5 and R3. R1 and R2 are used to program the output voltage according to: Where: R 1 1 V = 0.8 •(1+ ) ω = O 1 R C + C 2 4 5 Assuming the power stage ESR (equivalent series 1 ω = Z resistance) zero is an order of magnitude higher than R ⋅ C 3 4 the closed loop bandwidth, which is typically one tenth of C + C 4 5 the switching frequency, the power stage control to output ω = P2 R ⋅ C ⋅ C 3 4 5 transfer function with the current loop closed (Ridley model) for the SC4519H will be as follows: 5 ⋅R L G (s) = The loop gain will be given by: VD s 1+ 1 s 1+ R ⋅ C R R 1 ω L −3 L 2 Z T(s) = G (s) ⋅ G (s) = 4.25 ⋅10 ⋅ ⋅ ⋅ COMP VD s s C R + R s 4 1 2 (1+ ) ⋅(1+ ) Where: ω ω P1 P2 R – Load and L Where: C – Output capacitor. 1 ω = p1 R ⋅ C The goal of the compensation design is to shape the loop L to have a high DC gain, high bandwidth, enough phase margin, and high attenuation for high frequency noises. One integrator is added at origin to increase the DC gain. Figure 3 gives a typical compensation network which ω is used to cancel the power stage pole ω so that the Z P1 offers 2 poles and 1 zero to the power stage: 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 BST GND SC4519H POWER MANAGEMENT Application Information (Cont.) Layout Guidelines: Mag In order to achieve optimal electrical and thermal Loop gain T(s) performance for high frequency converters, special ω p1 attention must be paid to the PCB layouts. The goal of Power stage layout optimization is to identify the high di/dt loops and ω ω C P2 minimize them. The following guidelines should be used ω to ensure proper operation of the converters. ω Z 1. A ground plane is suggested to minimize switching noises and trace losses and maximize heat transferring. Figure 4. Asymptotic diagrams of power stage with 2. Start the PCB layout by placing the power components current loop closed and its loop gain. first. Arrange the power circuit to achieve a clean power flow route. Put all power connections on one side of the PCB with wide copper filled areas if possible. 3. The V bypass capacitor should be placed next to The design guidelines for the SC4519H applications are IN the V and GND pins. as following: IN 4. The trace connecting the feedback resistors to the output should be short, direct and far away from any 1. Set the loop gain crossover corner frequency ω for C noise sources such as switching node and switching given switching corner frequency ω = 2πf C C components. 2. Place an integrator at the origin to increase DC and 5. Minimize the loop including input capacitor, the low frequency gains. SC4519H and freewheeling diode D . This loop 2 3. Select ω such that it is placed at ω to obtain a Z P1 passes high di/dt current. Make sure the trace width -20dB/dec rate to go across the 0dB line. is wide enough to reduce copper losses in this loop. 4. Place a high frequency compensator pole 6. Maximize the trace width of the loop connecting the ω (ω = πf ) to get the maximum attenuation of P2 P2 s inductor, freewheeling diode D and the output 2 the switching ripple and high frequency noise with capacitor. the adequate phase lag at ω C. 7. Connect the ground of the feedback divider and the compensation components directly to the GND pin of the SC4519H 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 SC4519H. A few feedthrough holes are required to connect this large copper area to a ground plane to further improve the thermal environment of the SC4519H. The traces attached to other pins should be as wide as possible for the same purpose.  2007 Semtech Corp. 11 www.semtech.com SC4519H POWER MANAGEMENT Application Information (Cont.) Design Example: 16V to 5V at 2A D3 D3 D3 C1 C1 C1 0. 0. 0.2 2 22 2 2u u u L1 L1 L1 V V =1 =16 6V V IN IN V V =5 =5V V o o 2 2 2 3 3 3 IN IN IN SW SW SW 8. 8. 8.2u 2u 2uH H H C3 C3 C2 C2 C2 4. 4. 4.7 75 5k k 5 5 5 6 6 6 R1 R1 R1 10 10u u 10 10 10u u u SC SC SC4519H 4519H 4519H EN EN EN FB FB FB R4 R4 R4 52.3k 8 8 8 7 7 7 SYN SYN SYNC C C COM COM COMP P P C4 C4 C4 R2 R2 R2 R2 R2 R2 3. 3. 3.3 3 3n n n 10 10 10k k k k k k C5 C5 18 180 0p p R3 R3 R3 3. 3. 3.4 4 4k k k D2 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 2UH 1 Sh C4519 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 4 4 1 1 1 GND GND GND BST BST BST SC4519H POWER MANAGEMENT Application Information (Cont.) (COMPONENT - BOTTOM) (COMPONENT - TOP) SC4518 8 8 (PCB - TOP) (PCB - BOTTOM)  2007 Semtech Corp. 13 www.semtech.com SC4519H 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 .150 .154 .157 3.80 3.90 4.00 E1 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) aaa C N 8 8 - - 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) A DETAIL 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 C (.205) (5.20) 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  2007 Semtech Corp. 14 www.semtech.com