SEMTECH SC2608A

SC2608A Simple, Synchronous Voltage Mode PWM Controller POWER MANAGEMENT Description Features ‹ +5V or +12V input voltage The SC2608A is a versatile voltage-mode PWM control- ler designed for use in step down DC/DC power supply ‹ 250kHz operation applications. A simple, fixed frequency, highly efficient ‹ High efficiency (>90%) buck regulator can be implemented using the SC2608A ‹ 1.5% Reference voltage accuracy with minimal external components. The input voltage ‹ Hiccup mode over current protection range is from +5V to +12V. Internal level shift and drive ‹ Robust output drive circuitry eliminates the need for an expensive P-channel, ‹ R Current sensing for protection DS(ON) high-side MOSFET. The small device footprint allows for ‹ Industrial temperature range compact circuit design. ‹ SO-8 package ‹ Integrated boot strap diode SC2608A features include temperature compensated ‹ Thermal Shut down voltage reference, triangle wave oscillator, current limit ‹ Fully WEEE and RoHS Compliant comparator, and an externally compensated error ampli- fier. Current limit is implemented by sensing the voltage drop across the bottom MOSFET R . DS(ON) Applications The SC2608A operates at a fixed frequency of 250kHz ‹ Termination supplies providing an optimum compromise between efficiency , ‹ Low cost microprocessor supplies external component size, and cost. ‹ Peripheral card supplies ‹ Industrial power supplies SC2608A has a thermal protection circuit, which is ‹ High density DC/DC conversion O activated if the junction temperature exceeds 150 C. Typical Application Circuit SC2608A SC2608 sense COMP/SS SENSE +12V/+5V/+3.3V +12V GND VCC DL PHASE VOUT DH BST sense Figure 1 1 Revision 2: April, 2006 www.semtech.com ������� ���������������� ������������������������ ����������������������������������������������������������������������������������������������������������������������������������������������������� ��������������������������������������������������������� ��������� �� ����� �� ����� ���� � �� ��� �� �� �� ��� �� ����� �� �� ��� �� ��� �� �� ������� ����� �� ��� �� � �� ��� ������� �� �� ����� �� �� ������� �� �� ��� �� � �� ��� ������� �� ��� �� � ����� �� ��� �� � � �*�)(!’ &� " �!�#� %$�#�"�� �� �! � � �� ��+ �� � � �*�)(!’ &� " �!�#� %$�#�"�� �� �(,"��� ��� ��+ �� � �.�)!�"�- ��(.�)!�$)� &!�-� � ��� �� ���� � % � �� ��)!-� ��(.�)!�$)� &!�-� �/� �� ���� � ��� ��� &!�"�- ��$(!� ��01 ��0�’� �� �� 2� ������������������������������������������������������������������� �������������!"��#���������������������$����%�&����%�&� ������������������������������������������������������������������� �������������!%#���������������������$����%�&����%�&� �������������������������� � ������������������� � �!"����� #�� � �!"����� �$�$���%� �% � �"& �� �� ����� ����� ���� � � �� �������� �� ���� �� �������� �� � �� � �� � ���� ����� ������ �� $..’1 ��’�!-� �� 3� �� �� �4 $..’1 �$))��� �5/ �3�� (� �� ���� ����� ��������� 6� ��0,!#2 ��’�!-� �3���5�##5��3/� �7 3�77�� 3 �� 37� 6� � � � � 5 � 5 7� � � � � ��� � 5 � 5 ����7�� 3 � �� �� �)!� #��0$#�!�#� �� ( ( �� .�� ���. �� �!"� /� � 0 � 44 �.$� �"! �$))��� �� $� 6� �4 $�.$� �"�2 �$))��� � ; �3:�9 �<� �3�� �� �� $ �4�8 ����� ���� �4 $�.$� ��$)#� �$))��� � 5 �3��9 �<� �3�� �� � $ ��=&�� ����� ���� � ��������������� ��������������������� ������� ���������������� �������������������������� � ������������������� ���������� ��� ���������� ������������� ����� �� �� ����� ����� ���� � � �� �������� �� ���� �� �������� �� � �� � �� � ���� ���������� �� ����������������� �� ������ �� � �� � �� � �� ��� !� � ������������ &%���$�$( ��%’� �� % �#" �� !� � �������������� &%���$�$( ��%’� �� % � �� +) �*� � )�������� �� ����� (. +-, ������ ������� )0 �����/������������� � 2&���� �( %’�- % )� �1 � �&%��65��4 3� )0 7����/������������� �� %’ �% � ��%��65��4 )7 3� - )9 �!�5�/����8� � �� �:��� ;�����:������%� �5 � 7 )9 7!�5�/����8� � �� �:��� &�����:������%� �5 � 7 )� ��<8� � �� �����%� (5 � <� )� 7+��� � ��8� � &� %���$���$��%’� &5 � � �= ������� ����� 8� ���������� &$ %��� �$ �� ��%’� #� &��#� ;� #� ;� 8!0� � �� #3=) ���� ��-�> ���������� �0 �������������� �$’ �%�� �- �!� ��+� �0 ������������ �2’ �%�� #- � �=" ��+� ����� �����!� ��� ��� � ?� �7�8���5���< #&�$8 $(��A;� % &; % &� % �� @ �#����� �#����"� � �8 B��8� ��������8�������� ��� � �8� � ��������������� ��������������������� SC2608A POWER MANAGEMENT Gate Drive Timing Diagram Figure 2 Block Diagram VCC BST LEVEL DH OSC SHIFT S PHASE REF 0.8V NON-OVERLAP RQ TIMING E/A + 0 PWM VCC - Vcc SENSE OCP & DL UVLO GND OCP PHASE 0 0 + - 0 COMP/SS Figure 3 4 www.semtech.com © 2006 Semtech Corp. - + SC2608A POWER MANAGEMENT Pin Configuration Ordering information (1) Top View DevicePT ackage Temp Range ( ) J (2) O SC2608ASTRT S5 O-8 -40 to 12 C 8 1 BST PHASE Sd C2608AEVB Evaluation Boar DH 2 7 COMP/SS Notes: (1) Only available in tape and reel packaging. A reel con- tains 2500 devices. 3 SENSE GND 6 (2) This device is fully WEEE and RoHS Compliant DL VCC 4 5 (8-Pin SO-8) Pin Descriptions PPn Pn Piiiin n Pin P PPe PePn iiiiin n n n n N N N N Na a a a am m m m me e e P PPn Pn Piiiiin n n n n F F F F Fu u u u un n n n nc c c c ct t t t tiiiiio o o o on n # # # # # 1TB. S Bootstrap for high side driver 2HD. High side driver output 3DG. N Ground 4LD. Low side driver output 5CV. C Chip bias supply pin 6eS. ens Output voltage sense input Error amplifier output. Connect compensation network to GND. The compensation capacitor COMP/SS 7 serves as soft start capacitor. By pulling this pin low will disable the output. 8E PHAS Connect this pin to the switching node between the MOSFETs. 5 www.semtech.com © 2006 Semtech Corp. SC2608A POWER MANAGEMENT Theory of Operation Synchronous Buck Converter Synchronous Buck Converter Synchronous Buck Converter Synchronous Buck Converter Synchronous Buck Converter outputs remain in the off state whenever the supply volt- The output voltage of the synchronous converter is set age drops below the set threshold. Lockout occurs if V CC and controlled by the output of the error amplifier. The falls below 4.1V typ. inverting input of the error amplifier receives its voltage from the SENSE pin. The non-inverting input of the error Soft Start Soft Start Soft Start Soft Start Soft Start amplifier is connected to an internal 0.8V reference. The The SC2608A provides a soft start function to prevent large error amplifier output is connected to the compensation inrush currents upon power-up or hiccup retry. If both COMP pin. The error amplifier generates a current proportional and SENSE pins are low (<300mV), the device enters soft to (0.8V-Vsense), which is the COMP pin output current start mode, and the compensation capacitor is slowly (Transconductance ~ 7mS). The voltage on the COMP charged by an internal 6uA current source. When the COMP pin is the integral of the error amplifier current. The COMP pin reaches 300mV, the low side FET is switched on in order voltage is the non-inverting input of the PWM compara- to refresh the bootstrap capacitor, and begin PWM from a tor and controls the duty cycle of the MOSFET drivers. known state. As the COMP pin rises above 800mV, PWM The compensation network controls the stability and tran- begins at minimum duty cycle. sient response of the regulator. The larger capacitor, the slower COMP voltage changes, and slower the duty COMP continues to charge, slowly sweeping the device cycle changes. through the duty cycle range until FB reaches the regulation point of 800mV. Once FB reaches the regulation point, the The non-inverting input voltage of the PWM comparator soft start current is switched off, and the strong error amp is the triangular ramp signal generated from the oscillator. is enabled, providing a glitch-free entrance into closed loop The peak-to-peak voltage of the ramp is 1V, this is a operation. The overcurrent comparator is still active during parameter used in control loop calculation. When the soft start mode, and will override soft start in the event oscillator ramp signal rises above the COMP voltage, the that an overcurrent is detected, such as startup into a comparator output goes high and the PWM latch is reset. dead short. This pulls DH low, turning off the high-side MOSFET. Af- ter a short delay (dead time), DL is pulled high, turning on R R R R R Current Limiting Current Limiting Current Limiting Current Limiting Current Limiting DS(ON) DS(ON) DS(ON) DS(ON) DS(ON) the low-side MOSFET. The oscillator also produces a set In case of a short circuit or overload, the low-side (LS) FET pulse for the PWM latch to turn off the low-side MOSFET, will conduct large currents. To protect the regulator in this After a delay time, DH is pulled high to turn on the high- situation, the controller will shut down the regulator and side MOSFET. The delay time is determined by a begin a soft start cycle later. While the LS driver is on,the monostable on the chip. Phase voltage is compared to the OCP trip voltage. If the phase voltage is lower than OCP trip voltage, an over cur- The triangle wave minimum is about 0.8V, and the maxi- rent condition is detected. The low-side R sense is imple- dson mum is about 1.8V. Thus, if Vcomp = 0.7V, high side duty mented at end of each LS-FET turn-on duration. The mini- cycle is the minimum (~0%) , but if Vcomp is 1.8V, duty mum turn-on time of the LS-FET is set to be 400nS. This cycle is at maximum ( ~90%).The internal oscillator uses an will ensure the sampled signal is noise free by giving enough on-chip capacitor and trimmed precision current sources time for the switching noise to die down. to set the oscillation frequency to 250kHz. Figure 1 shows a 2.5V output converter. If the Vout <2.5V, then the SENSE OCP Hiccup OCP Hiccup OCP Hiccup OCP Hiccup OCP Hiccup voltage < 0.8V. In this case the error amplifier will be sourc- In the event that an overcurrent is detected, the SC2608A ing current into the COMP pin so that COMP voltage and latches the fault and begins a hiccup cycle. Switching is duty cycle will gradually increase.If Vout > 2.5V, the error immediately stopped, and the drivers are set to a tristate amplifier will sink current and reduce the COMP voltage, so condition (Both DH and DL are low). COMP is slowly that duty cycle will decrease.The circuit will be in steady discharged to 300mV with an internal 6uA current source, state when Vout =2.5V , Vsense = 0.8V, Icomp = 0. The providing a long cooldown time to keep power dissipation COMP voltage and duty cycle depend on Vin. low in the event of a continuous dead short. Once COMP and SENSE both fall below the 300mV threshold, the part U Under V nder Voltage Lock oltage Lockout out U U Under V nder V nder Voltage Lock oltage Lock oltage Lockout out out re-enables the 6uA soft start current , and the device begins The under voltage lockout circuit of the SC2608A as- a normal startup cycle again. sures that both high-side and low-side MOSFET driver 6 www.semtech.com © 2006 Semtech Corp. SC2608A POWER MANAGEMENT Applications Information (Cont.) 1 G = A note to the user is needed: The device cannot restart pwm V ramp until both COMP and SENSE are low, to prevent start up where the ramp amplitude is fixed at 1 volts. into a charged output. In the event of an overcurrent The total control loop-gain can then be derived as condition, the output is quickly discharged by the load, follows: therefore bringing SENSE below the 300mV threshold. If ⎛V ⎞ 1+sRC bg c o the COMP pin is pulled low by an external device (such as ⎜ ⎟ T() s =G •G •V • •H() s• m pwm in c ⎜ ⎟ V ⎛ ⎞ ⎛ ⎞ L R ⎝ o⎠ 2 c an open-drain logic gate used for system shutdown), and 1+s⎜RC + ⎟+s LC⎜1+ ⎟ c o o ⎜ ⎟ ⎜ ⎟ R R ⎝ o⎠ ⎝ o⎠ SENSE is high(above 300mV) while COMP is low, then the 1 SC2608A turns on the low side FET to discharge the output H() s = c 1 before changing to shutdown or soft-start mode. The low + sC i 1 R+ side FET turns off when SENSE drops below 300mV and sC the converter remains in the tri-state condition until COMP The task here is to properly choose the compensation is released. Although this shutdown technique can be used network for a nicely shaped loop-gain Bode plot. The successfully on the SC2608A, the system designer using following design procedures are recommended to accom- COMP for external shutdown will need to consider the load plish the goal: on the low side FET when discharging the output capacitor (1) Calculate the corner frequency of the output filter: bank. For large capacitor bank, this peak current can be 1 F = o quite large as it is limited only by the R of the low side 2π LC DS(ON) o FET. Fortunately the duration of this event is quite short, (2) Calculate the ESR zero frequency of the output filter and has been shown in the lab to have no detrimental effect capacitor: 1 on the performance of the external FETs. F = esr 2πR C c o Disabling the output by pulling down COMP/SS pin is only recommended when the output capacitor bank is not too (3) Check that the ESR zero frequency is not too high. large. F SW F < esr 5 Compensation Network Design Compensation Network Design Compensation Network Design Compensation Network Design Compensation Network Design If this condition is not met, the compensation structure may not provide loop stability. The solution is to add some electrolytic capacitors to the output capacitor bank E/A G_PWM to correct the output filter corner frequency and the ESR L R1 zero frequency. In some cases, the filter inductance may VBG R Rc Ro also need to be adjusted to shift the filter corner 0.8V Ci VIN frequency. It is not recommended to use only high fre- Co R2 C quency multi-layer ceramic capacitors for output filter. (4) Choose the loop gain cross over frequency (0 dB fre- quency). It is recommended that the crossover frequency is always less than one fifth of the switching frequency : Fig. 4. SC2608A small signal model. 1 F = •F X _OVER SW The control model of SC2608A is depicted in Fig. 4. 5 This model can also be used to generate loop gain Bode If the transient specification is not stringent, it is better plots. The bandgap reference is 0.8V and trimmed to to choose a crossover frequency that is less than one +/-1% accuracy. The desired output voltage can be tenth of the switching frequency for good noise immunity. achieved by setting the resistive divider network, R1 and The resistor in the compensation network can then be R2. The error amplifier is transconductance type with fixed calculated as: 2 gain of: 0.007 A F ⎛ ⎞ 1 ⎛F ⎞ ⎛ ⎞ V X _OVER G = esr o ⎜ ⎟ m ⎜ ⎟ ⎜ ⎟ R= • • • V ⎜ ⎟ ⎜ ⎟ ⎜ ⎟ G •V •G F F V pwm in m ⎝ o⎠ ⎝ esr ⎠ bg ⎝ ⎠ The compensation network includes a resistor and a ca- when pacitor in series, which terminates the output of the F sw F < F < error amplifier to the ground. o esr 5 The PWM gain is inversion of the ramp amplitude, and this gain is given by: 7 www.semtech.com © 2006 Semtech Corp. SC2608A POWER MANAGEMENT Applications Information (Cont.) (5) The compensation capacitor is determined by choos- An example is given below to demonstrate the proce- ing the compensator zero to be about one fifth of the dure introduced above. output filter corner frequency: C =4400uF V =12V o in F R =0.009Ω o V =2.5V c F = o zero 5 V =0.8V I =15A bg o V =1V F =250KHz 1 ramp sw C= L=2.2uH G =0.007A/V 2πR•F m zero SC2608A soft start time is determined by the set C =1nF i compensation capacitor. Capacitance can be adjusted set to R =1.5KΩ R =1.33KΩ c c to satisfy the soft start requirement. set to C=100nF C=327.95nF (6) The final step is to generate the Bode plot by using for suitable soft start time the simulation model in Fig. 4 or using the equations pro- vided here with Mathcad. The phase margin can then be checked using the Bode plot. Loop Gain Mag (dB) 100 50 mag() i 0 50 3 4 5 6 . . . . 10 100 1 10 1 10 1 10 1 10 F i Loop Gain Phase (Degree) 0 45 phase() i 90 135 180 3 4 5 6 . . . . 10 100 1 10 1 10 1 10 1 10 F i Fig. 5. Bode plot of the loop 8 www.semtech.com © 2006 Semtech Corp. SC2608A POWER MANAGEMENT Typical Performance Characteristics V ref vs. Tem perature Frequency vs. Temperature 0.83 270 260 0.82 250 0.81 240 0.80 230 0.79 220 -50 -25 0 25 50 75 100 125 -50-25 0 25 50 75100 125 o o Temperature ( C) Temperature ( C) I_limit vs. Temperature UV LO vs. Temperature 390 4.25 380 4.20 370 4.15 360 350 4.10 340 4.05 330 320 4.00 -50-25 0 25 50 75100 125 -50 -25 0 25 50 75 100 125 o o Temperature ( C) Temperature ( C) Gate driver dead tim e vs. Tem perature Icc vs. Tem perature 40 15 14 13 30 12 11 10 20 9 8 10 7 -50 -25 0 255075 100 125 -50 -25 0 255075 100 125 o o Temperature ( C) Temperature ( C) 9 www.semtech.com © 2006 Semtech Corp. Gate driver dead time (ns) Vref(V) I_limit trip (mV) Icc (mA) UVLO (V) Frequency (kHz) SC2608A POWER MANAGEMENT Application Information T T T T Typical Application Schematic ypical Application Schematic ypical Application Schematic ypical Application Schematic ypical Application Schematic +12V/+5V/+3.3V Q1 C1 C2 C3 R1 2R2 C4 U1 2.5VOUT/15A 100pF 8 1 Phase BST C5 L11.2uH 7 2 1uF/16V Q2 C7 C8 C9 C10 C11 COMP/SS DH R4 R3 R2 1k C6 68nF 6 3 1R 1k Sense SENSE GND Sense 5 4 C12 +12V VCC DL R6 2.2n R5 1k C13 SC2608A 1uF/16V 1R VOUT=0.8V X (R3+R6)/R6 Bill of Materials Bill of Materials Bill of Materials Bill of Materials Bill of Materials Iy temQe uantitRt eferencPr ar Vende 11CV 1 4y .7uF/16 An 22CV 2,C31J 500uF/16 Panasonic F 31CV 4 1y 00pF/50 An 42CV 5,C13 1y uF/16 An 51CV 6 6y 8nF/25 An 62CV 7,C82J 200uF/6.3 Panasonic F 73CV 9,C10,C114y .7uF/6.3 An 81CF 12 2y .2n An 91LH 1 1y .2u An 11 0 QA 1 In PD09N03L Infineo 11 1 QA 2 In PD13N03L Infineo 11 2 R2 1 2y R An 11 3 RK 2 1y An 12 4 R% 3,R6 1y K, 1 An 12 5 R0 4,R5 1y R An 11 6 UA 1 SH C2608 SEMTEC 10 www.semtech.com © 2006 Semtech Corp. IPB13N 03LA IPB09N 03LA 4.7uF /16V 2200uF /6.3V 1500uF /16V 2200uF /6.3V 1500uF /16V 4.7uF /6.3V 4.7uF /6.3V 4.7uF /6.3V SC2608A POWER MANAGEMENT Typical Performance Characteristics Start up Efficiency V. S. Load Current Vi Vin n 95 94 Com Comp p/ / S SS S 93 92 91 90 DL DL 89 88 87 VO VO 86 85 0 2 4 6 8 1012 1416 1820 Over Current Protection (21A DC tripped) Transient Response Vi Vin n COM COMP P/SS /SS Co Com mp p/ S / SS S VOUT VOUT DL DL IL( IL(1 10 0A A/DIV) /DIV) VO VO 5 -18 A step load OCP HICCUP Gate waveforms Vi Vin n DH DH Com Comp p/ SS / SS P Ph ha as se e n node ode DL DL DL DL VO VO 15 A sustain loading 11 www.semtech.com © 2006 Semtech Corp. SC2608A POWER MANAGEMENT Application Information T T T T Typical DDR VDDQ Application Schematic ypical DDR VDDQ Application Schematic ypical DDR VDDQ Application Schematic ypical DDR VDDQ Application Schematic ypical DDR VDDQ Application Schematic 5VDual Q1 C1 C2 C3 C4 R1 2.2R C5 U1 1.8VOUT/24A 100pF 8 1 Phase BST L1 C6 7 2 Q2 C8 C9 C10 C11 C12 1.2uH/40A C13 COMP/SS DH 1uF/16V R4 R3 R2 68nF C7 6 3 2R2 1k 1.27k Sense SENSE GND Sense 5 4 C14 5VDual VCC DL 1n R5 D1 1k C15 BAT54H SC2608A 1uF/16V D2 1N4148 +12V Bill of Materials Bill of Materials Bill of Materials Bill of Materials Bill of Materials Iy temQe uantitRt eferencPr ar Vende 14CV 1,C11,C12,C134y .7uF/6.3 An 23CV 2,C3,C41J 500uF/6.3 Panasonic F 31CV 5 1y 00pF/50 An 42CV 6,C15 1y uF/16 An 51CV 7 6y 8nF/25 An 63CV 8,C9,C101J 800uF/6.3 Panasonic F 71CV 14 1y nF/50 An 81DH 1 By AT54 An 91D8 2 1y N414 An 11 0 LA 1 1y .2uH/40 An 11 1QA 1 In PD09N03L Infineo 11 2QA 2 In PD09N03L Infineo 12 3 R2 1,R4 2y R An 11 4 RK 2 1y An 11 5 R% 3 1y .27K, 1 An 11 6 R% 5 1y K, 1 An 11 7 UA 1 SH C2608 SEMTEC 12 www.semtech.com © 2006 Semtech Corp. IP B 09N 03LA IP B 09N 03LA 4.7uF /16V 1500uF /16V 1800uF /6.3V 1800uF /6.3V 1500uF /16V 1800uF /6.3V 1500uF /16V 4.7uF /6.3V 4.7uF /6.3V 4.7uF /6.3V SC2608A POWER MANAGEMENT Application Information T T T T Typical High In ypical High In ypical High In ypical High In ypical High Input V put V put V put V put Voltage Application Schematic oltage Application Schematic oltage Application Schematic oltage Application Schematic oltage Application Schematic 20VIN Q1 C1 C2 R1 0R R2 U1 5R1 C3 L1 5VOUT/8A 10pF/Opt. 8 1 Phase BST C4 2.2uH 7 2 1uF/16V Q2 COMP/SS DH R5 R3 R4 C6 C7 C8 1K C5 68n 5.25K 6 3 2R2 Sense SENSE GND R6 1KR/1206 5 4 C9 Vin VCC DL Sense 1n R7 SC2608A C10 C11 1k 2.2nF D1 1KR/1206 1uF/16V 8.2V R7 Bill of Materials Bill of Materials Bill of Materials Bill of Materials Bill of Materials Iy temQe uantitRt eferencPr ar Vende 11CV 1 4y .7uF/25 An 21CV 2 1J 000uF/25 Panasonic F 31C. 3 1y 0pF/50V , Opt An 42CV 4,C11 1y uF/16 An 51CV 5 6y 8nF/16 An 61CV 6 2J 200uF/6.3 Panasonic F 72CV 7,C8 4y .7uF/6.3 An 81CV 9 1y nF/50 An 91CV 10 2y .2nF/50 An 11 0 DV 1 Zy ener 8.2 An 11 1 LA 1 2y .2uH/15 An 11 2QA 1 In PD13N03L Infineo 11 3QA 2 In PD13N03L Infineo 11 4 RR 1 0y An 11 5 RR 2 5y .1 An 12 6 R% 3,R7 1y .K, 1 An 11 7 R2 4 2y R An 11 8 R% 5 5y .25K, 1 An 12 9 R6 6,R7 1y KR, 120 An 21 0 UA 1 SH C2608 SEMTEC 13 www.semtech.com © 2006 Semtech Corp. IPD13N03LA IPD13N03LA 4.7uF/25V 1000uF/25V 2200uF/6.3V 4.7uF/6.3V 4.7uF/6.3V SC2608A POWER MANAGEMENT Outline Drawing - SO-8 DIMENSIONS INCHES MILLIMETERS A DIM MIN NOM MAX MIN NOM MAX D e - - A .053 .069 1.35 1.75 N - - A1 .004 .010 0.10 0.25 - - A2 .049 .065 1.25 1.65 - - b .012 .020 0.31 0.51 2X E/2 c - - .007 .010 0.17 0.25 .189 .193 .197 4.80 4.90 5.00 E1 E D E1 .150 .154 .157 3.80 3.90 4.00 E .236 BSC 6.00 BSC e .050 BSC 1.27 BSC 12 h .010 - .020 0.25 - 0.50 ccc C L .016 .028 .041 0.40 0.72 1.04 2X N/2 TIPS e/2 L1 (.041) (1.04) N 8 8 - - B 01 0 8 0 8 aaa .004 0.10 bbb .010 0.25 D ccc .008 0.20 aaa C h A2 A SEATING PLANE h C A1 H bxN bbb C A-B D c GAGE PLANE 0.25 L 01 (L1) SEE DETAIL A DETAIL A SIDE VIEW NOTES: 1. CO NTRO LLING DIM ENSIO N S ARE IN M ILLIM ETERS (ANG LES IN DEG REES). 2. DATUM S -A- AND -B- TO BE DETERM INED AT DATUM PLANE -H- 3. DIM EN SION S "E1" AND "D" DO NO T INCLUDE M O LD FLASH, PR OTRUSIO NS O R G ATE BURRS. 14 www.semtech.com © 2006 Semtech Corp. SC2608A POWER MANAGEMENT Land Pattern - SO-8 X DIMENSIONS DIM INCHES MILLIMETERS (.205) (5.20) C G .118 3.00 (C) G Z P .050 1.27 X .024 0.60 Y .087 2.20 Y .291 7.40 Z P 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. Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804 15 www.semtech.com © 2006 Semtech Corp.