LM2608ATL-1.8

LM2608 NSC | Alldatasheet

Document overview

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Technical content

Features

n Sub-miniature 10-pin thin Micro SMD package n Only four tiny surface-mount external components required n Uses small ceramic capacitors n Internal soft start n Current and Thermal shutdown protection n No external compensation required

Applications

Typical Application Circuit 20036602 December 2002 LM2608 400mA Sub-miniature, High Efficiency, Programmable DC-DC Converter with Linear Mode © 2003 National Semiconductor Corporation DS200366 www.national.com

Ordering Information

Order Number Package Type NSC Package Marking (*) Supplied As 10-Pin Micro SMD LM2608ATL-1.3 10-bump Wafer Level Chip Scale (Micro SMD) XYTT IS43A 250 Units, Tape and Reel LM2608ATL-1.8 XYTT IS44A 250 Units, Tape and Reel LM2608ATLX-1.3 XYTT IS43A 3000 Units, Tape and Reel LM2608ATLX-1.8 XYTT IS44A 3000 Units, Tape and Reel (*) XY - denotes the date code marking (2 digit) in production (*) TT - refers to die run/lot traceability for production (*) I - pin one indication (*) S - product line designator Note the Package Marking may change over the course of production LM2608 www.national.com 2

Pin Number (*) Pin Name Function A1 FB Feedback Analog Input. Connect to the output at the output filter capacitor (Figure 1) B1 VSEL Output Voltage Selection Input. Set this digital input to: VDD for 1.8V output voltage (1.5V for LM2608ATL-1.3) SGND for 1.5V output voltage (1.3V for LM2608ATL-1.3) C1 VREF External Reference Input. Drive this analog input with a 1.35V reference to set the output voltage. The LM2608 uses an internal reference while in LDO mode. (see Note 5 in the Electrical Characteristics table for further information.) D1 SYNC/MODE Synchronization Input. Use this digital input for frequency synchronization or mode control. Set: SYNC/MODE = high for low-noise 600kHz PWM mode SYNC/MODE = low for low-current LDO mode SYNC/MODE = 500kHz - 1MHz external clock for synchronization to an external clock in PWM mode. See Synchronization and Operating Modesin the Device Informationsection. D2 EN Enable Input. Set this Schmitt trigger digital input high for normal operation. D3 PGND Power Ground C3 SW Switching Node connection to the internal PFET switch and NFET synchronous rectifier. Connect to an inductor with a saturation current rating that exceeds the max. Switch Peak Current Limit specification of the LM2608 ( Figure 1) B3 PVIN Power Supply Input to the internal PFET switch. Connect to the input filter capacitor (Figure 1). A3 VDD Analog Supply Input. If board layout is not optimum, an optional 0.1µF ceramic capacitor is suggested (Figure 1) A2 SGND Analog and Control Ground (*) Note that the pin numbering scheme for the Micro SMD package was revised in April,2002 to conform to JEDEC standard. Only the pin numbers were revise d. No changes to the physical location of the inputs/outputs were made. For reference purpose, the obsolete numbering had FB as pin 1, VSEL as pin 2, VREF as pin 3, SYNC as pin 4, EN as pin 5, PGND as pin 6, SW as pin 7, PVIN as pin 8, VDD as pin 9 and SGND as pin 10. LM2608 www.national.com3

Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. PVIN, VDD, to SGND −0.2V to +6V PGND to SGND −0.2V to +0.2V EN, SYNC/MODE, VSEL to SGND −0.2V to +6V FB, SW (GND −0.2V) to (VDD +0.2V) Storage Temperature Range −45˚C to +150˚C Lead temperature (Soldering, 10 sec.) 260˚C Junction Temperature (Note 2) −25˚C to 125˚C Minimum ESD Rating Human body model, C = 100pF, R = 1.5 kΩ ±2.0kV Thermal Resistance (θJA) LM2608ATL(Note 3) 140˚C/W

Electrical Characteristics

Specifications with standard typeface are for T A =T J = 25˚C, and those in bold face type apply over the full Operating Tem- perature Range (TA =T J = −25˚C to +85˚C). Unless otherwise specified, PVIN = VDD = EN = SYNC = 3.6V, VSEL = 0V, VREF = 1.35V. Symbol Parameter Conditions Min Typ Max Units VIN Input Voltage Range (Note PVIN = VDD, VSEL = V IN 2.8 5.5 V VFB Feedback Voltage PWM Mode SYNC/MODE = V IN(Note 5) LM2608ATL-1.3, VSEL = 0V 1.287 1.30 1.313 VLM2608ATL-1.3, VSEL = V IN 1.485 1.50 1.515 LM2608ATL-1.8, VSEL = 0V 1.485 1.50 1.515 LM2608ATL-1.8, VSEL = V IN 1.782 1.80 1.818 VFB, LIN Feedback Voltage LIN Mode (SYNC/MODE =0V) V IN= 3.6V IOUT = 100µA LM2608ATL-1.3, VSEL = 0V 1.261 1.30 1.339 V LM2608ATL-1.3, VSEL = V IN 1.455 1.50 1.545 LM2608ATL-1.8, VSEL = 0 1.455 1.50 1.545 LM2608ATL-1.8, VSEL = V IN 1.746 1.80 1.854 ∆VOUT_LDO Line Regulation I OUT = 100µA 0.1 %/V Load Regulation V IN= 3.6V, IOUT = 10µA to 1.5mA 1.0 %/mA VHYST OVP Comparator Hysteresis Voltage (Note 6) PWM Mode 45 75 mV I SHDN Shutdown Supply Current EN = 0V 0.02 3 µA IQ, PWM DC Bias Current into VDD (PWM Mode) F B=2 V SYNC/MODE =VIN 590 725 µAIQ, LIN DC Bias Current into VDD (LDO Mode) SYNC/MODE = 0V, IOUT =0m A 20 30 RDSON (P) Pin-Pin Resistance for P FET 370 500 m Ω RDSON (N) Pin-Pin Resistance for N FET 330 500 m Ω RDSON , TC FET Resistance Temperature Coefficient 0.5 %/C ISC, LDO Short Circuit (LDO) V OUT = GND SYNC/MODE = 0V 3 6 8 mA Ilim Switch Peak Current Limit (Note 7) LM2608ATL-1.3 383 460 518 mALM2608ATL-1.8 510 620 690 VEN_H EN Positive Going Threshold Voltage (Note 8) 0.80 1.3 V V EN_L EN Negative Going Threshold Voltage (Note 8) 0.4 0.75 V LM2608 www.national.com 4

Electrical Characteristics (Continued) Specifications with standard typeface are for T A =T J = 25˚C, and those in bold face type apply over the full Operating Tem- perature Range (TA =T J = −25˚C to +85˚C). Unless otherwise specified, PVIN = VDD = EN = SYNC = 3.6V, VSEL = 0V, VREF = 1.35V. Symbol Parameter Conditions Min Typ Max Units VSYNC_H SYNC/MODE Positive Going Threshold Voltage 0.85 1.3 V VSYNC_L SYNC/MODE Negative Going Threshold Voltage 0.4 0.80 V VSEL_H VSEL Positive Going Threshold Voltage 0.80 1.3 V VSEL_L VSEL Negative Going Threshold Voltage 0.4 0.75 V ISEL VSEL Pull Down Current VSEL = 1.2V 0.70 2 µA IREF Input current into VREF pin 15 150 nA fsync SYNC/MODE Clock Frequency Range (Note 9) 500 1000 kHz F OSC Internal Oscillator Frequency LM2608ATL-1.3/1.8, PWM Mode 510 610 690 kHz Tmin Minimum ON-Time of P FET Switch in PWM Mode 200 ns Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings are conditions for which the device is intended to be functional, but parameter specifications may not be guaranteed. For guaranteed specifications and associated test conditions, see the Min and Max limits and Conditions in the Electrical Characteristics table. Electrical Characteristics table limits are guaranteed by production testing, design or corr elation using standard Statistical Quality Control methods. Typical (Typ) specifications are mean or average values from characterization at 25˚C and are not guaranteed. Note 2: Thermal shutdown will occur if the junction temperature exceeds the 150˚C maximum junction temperature of the device. Note 3: Thermal resistance specified with 2 layer PCB(0.5/0.5 oz. cu). Note 4: The LM2608 is designed for cell phone applications where turn-on after system power-up is controlled by the system processor and internal UVLO (Under Voltage LockOut) circuitry is unnecessary. The LM2608 has no UVLO circuitry and should be kept in shutdown by holding the EN pin low until the input volt age exceeds 2.8V. Although the LM2608 exhibits safe behavior while enabled at low input voltages, this is not guaranteed. Note 5: The LM2608 PWM mode output voltage precision is ±1% when operating from an external 1.35V reference voltage. Note 6: The hysteresis voltage is the minimum voltage swing on FB that causes the internal feedback and control circuitry to turn the internal PFET switch on an d then off, during test mode. Note 7: Current limit is built-in, fixed, and not adjustable. If the current limit is reached while the output is pulled below about 0.7V, the internal PFET swi tch turns off for 2.5 µs to allow the inductor current to diminish. Note 8: EN is a Schmitt trigger digital input with logic thresholds that are independent of supply voltage at the VDD pin. Note 9: SYNC driven with an external clock switching between VDD and GND. When an external clock is present at SYNC, the IC is forced into PWM mode at the external clock frequency. The LM2608 synchronizes to the rising edge of the external clock. LM2608 www.national.com5

Typical Operating Characteristics LM2608ATL, Circuit of Figure 1,V IN = 3.6V, T A = 25˚C, L1 = 10 µH, unless otherwise noted. Quiescent Supply Current vs Supply Voltage (PWM MODE) Quiescent Supply Current vs Supply Voltage (LDO MODE) 20036644 20036606 Output Voltage vs Supply Voltage (PWM MODE) Output Voltage vs Supply Voltage (PWM MODE) 20036645 20036646 Shutdown Quiescent Current vs Temperature PWM Output Voltage vs Output Current 20036607 20036652 LM2608 www.national.com 6

Typical Operating Characteristics LM2608ATL, Circuit of Figure 1,V IN = 3.6V, T A = 25˚C, L1 = 10 µH, unless otherwise noted. (Continued) PWM Output Voltage vs Output Current PWM Output Voltage vs Output Current 20036614 20036613 LDO Output Voltage vs Supply Voltage (VOUT = 1.5V) LDO Output Voltage vs Supply Voltage (VOUT = 1.8V) 20036611 20036612 LDO Output Voltage vs Output Current LDO Output Voltage vs Output Current 20036616 20036615 LM2608 www.national.com7

Typical Operating Characteristics LM2608ATL, Circuit of Figure 1,V IN = 3.6V, T A = 25˚C, L1 = 10 µH, unless otherwise noted. (Continued) LDO Output Voltage vs Output Current LDO Short Circuit Output Current 20036617 20036618 Maximum LDO Output Current Maximum LDO Output Current 20036619 20036620 Switching Frequency vs Temperature (PWM Mode) Efficiency vs Output Current withDiode 20036621 20036650 LM2608 www.national.com 8

Typical Operating Characteristics LM2608ATL, Circuit of Figure 1,V IN = 3.6V, T A = 25˚C, L1 = 10 µH, unless otherwise noted. (Continued) Efficiency vs Output Current without Diode Efficiency vs Output Current without Diode 20036651 20036622 Efficiency vs Output Current with Diode Efficiency vs Output Current Without Diode 20036642 20036623 Efficiency vs Output Current with Diode PWM Load Transient Response 20036643 20036648 LM2608 www.national.com9

Typical Operating Characteristics LM2608ATL, Circuit of Figure 1,V IN = 3.6V, T A = 25˚C, L1 = 10 µH, unless otherwise noted. (Continued) PWM Load Transient Response PWM Load Transient Response 20036636 20036637 LDO Load Transient Response LDO Load Transient Response 20036632 20036633 PWM Line Transient Response LDO Line Transient Response 20036639 20036638 LM2608 www.national.com 10

Typical Operating Characteristics LM2608ATL, Circuit of Figure 1,V IN = 3.6V, T A = 25˚C, L1 = 10 µH, unless otherwise noted. (Continued) LDO Line Transient Response LDO Start-up Response 20036649 20036640 LDO to PWM Mode Change 20036641 LM2608 www.national.com11

91% for a 100mA load with 1.8V output, 2.8V input. duces battery consumption to 0.02µA (typ.). age selection pin eliminates external feedback resistors. pacitors for reduced board area. through the inductor to the output filter capacitor and load. average voltage at the SW pin. FIGURE 1. Typical Operating Circuit

lating the energy per cycle to control power to the load. for the increase in the load. FIGURE 2. Simplified Functional Diagram

PWM Operation (Continued) LDO Operation Connecting the SYNC/MODE pin to SGND sets the LM2608 to Linear mode operation. While in LDO (Low Dropout regu- lator) mode, the output voltage is regulated by the internal LDO to supply up to 3mA. This is done by using an internal pass transistor and an error amplifier to sense the output voltage and maintain the desired output voltage. During LDO mode, the PFET and NFET network switch off to reduce quiescent current. Operating Mode Selection (SYNC/MODE Pin) The SYNC/MODE digital input pin is used to select between PWM and LDO operating modes. Set SYNC/MODE high (above 1.3V) for 600kHz PWM operation. Set SYNC/MODE low (below 0.4V) to select LDO mode to reduced current consumption when the system is in standby. The LM2608 has an over-voltage protection feature that may activate if the device is left in PWM mode under low-load conditions to prevent the output voltage from rising too high. See Over- voltage Protection, for more information. Select modes with the SYNC/MODE pin using a signal with a slew rate faster than 5V/100µs. Use a comparator Schmitt trigger or logic gate to drive the SYNC/MODE pin. Do not leave the pin floating or allow it to linger between logic levels. These measures will prevent output voltage errors that could otherwise occur in response to an indeterminate logic state. Frequency Synchronization (SYNC/MODE Pin) The SYNC/MODE input can also be used for frequency synchronization. To synchronize the LM2608 to an external clock, supply a digital signal to the SYNC/MODE pin with a voltage swing exceeding 0.4V to 1.3V. During synchroniza- tion, the LM2608 initiates cycles on the rising edge of the clock. When synchronized to an external clock, it operates in PWM mode. The device can synchronize to an external clock over frequencies from 500kHz to 1MHz. Use the following waveform and duty-cycle guidelines when applying an external clock to the SYNC/MODE pin. The duty cycle can be between 30% and 70%. Clock under/overshoot should be less than 100mV below GND or above VDD. When applying noisy clock signals, especially sharp edged signals from a long cable during evaluation, terminate the cable at its characteristic impedance; add an RC filter to the SYNC pin, if necessary, to soften the slew rate and over/ undershoot. Note that sharp edged signals from a pulse or function generator can develop under/overshoot as high as 10V at the end of an improperly terminated cable. Overvoltage Protection The LM2608 has an over-voltage comparator that prevents the output voltage from rising too high when the device is left in PWM mode under low-load conditions. Otherwise, the output voltage could rise out of regulation from the minimum energy transferred per cycle due to the 200nS minimum on-time of the PFET switch while in PWM mode. When the output voltage rises by 45mV over its regulation threshold, the OVP comparator inhibits PWM operation to skip pulses until the output voltage returns to the regulation threshold. In over voltage protection, output voltage and ripple increase slightly. Shutdown Mode Setting the EN input low, to SGND, places the LM2608 in a 0.02µA (typ) shutdown mode. During shutdown, the PFET switch, NFET synchronous rectifier, reference, control and bias of the LM2608 are turned off. Setting EN high to VDD enables normal operation. While turning on, soft start is activated. EN is a Schmitt trigger digital input with thresholds that are independent of the input voltage at VDD. EN must be set low to turn off the LM2608 during undervolt- age conditions when the supply is less than the 2.8V mini- mum operating voltage. The LM2608 is designed for mobile phones and similar applications where power sequencing is determined by the system controller and internal UVLO (Un- der Voltage LockOut) circuitry is unnecessary. The LM2608 PWM Mode Switching Waveform 20036624 FIGURE 3. LM2608 www.national.com 14

Shutdown Mode (Continued) has no UVLO circuitry. Although the LM2608 exhibits good behavior while enabled at low input voltages, this is not guaranteed. Internal Synchronous Rectification The LM2608 uses an internal NFET as a synchronous rec- tifier to improve efficiency by reducing rectifier forward volt- age drop and associated power loss. In general, synchro- nous rectification provides a significant improvement in efficiency whenever the output voltage is relatively low com- pared to the voltage drop across an ordinary rectifier diode. Under moderate and heavy loads, the internal NFET syn- chronous rectifier is turned on during the inductor current down-slope in the second part of each cycle. The synchro- nous rectifier is turned off prior to the next cycle, or when the inductor current ramps near zero at light loads. The NFET is designed to conduct through its intrinsic body diode during transient intervals before it turns on, eliminating the need for an external diode. Current Limiting A current limit feature allows the LM2608 to protect itself and external components during overload conditions. Current limiting is implemented using an independent internal com- parator. In PWM mode, cycle-by-cycle current limiting is normally used. If an excessive load pulls the output voltage down to approximately 0.7V, then the device switches to a timed current limit mode. In timed current limit mode the internal P-FET switch is turned off after the current compara- tor trips and the beginning of the next cycle is inhibited for 2.5µs to force the instantaneous inductor current to ramp down to a safe value. Timed current limit prevents the loss of current control seen in some products when the output volt- age is pulled low in serious overload conditions. Current Limiting and PWM Mode Transient Response Considerations The LM2608 was designed for fast response to moderate load steps. Harsh transient conditions during loads above 300mA can cause the inductor current to swing up to the maximum current limit, resulting in PWM mode jitter or insta- bility from activation of the current limit comparator. To avoid this jitter or instability, do not power-up or start the LM2608 into a full load (loads near or above 400mA). Do not change operating modes or output voltages when operating at a full load. Avoid extremely sharp and wide-ranging load steps to full load, such as from <30mA to >350mA. Pin Selectable Output Voltage The LM2608 features pin-selectable output voltage to elimi- nate the need for external feedback resistors. The output can be set to 1.3V, 1.5V or 1.8V by configuring the VSEL pin. See Setting the Output Voltagein the Application Information section for further details. Soft-Start The LM2608 is designed to be started in LDO mode. Under these conditions, the output voltage will increase at a rate determined by the LDO current limit and the output capacitor and load. This ramp time is typically in the mS range. The LM2608 may be started in PWM mode as well. Under these conditions, the reference voltage for the error amp is ramped up in about 100µs and the output voltage will follow. In this way, the input inrush current and output voltage overshoot can be minimized. Thermal Shutdown Protection The LM2608 has thermal shutdown protection in PWM mode to protect from short-term misuse and overload conditions. When the junction temperature exceeds 150˚C, the device shuts down and re-starts in soft start after the temperature drops below 130˚C. Prolonged operation in thermal overload conditions may damage the device and is considered bad practice.

Application Information

SETTING THE OUTPUT VOLTAGE The LM2608 features pin-selectable output voltage to elimi- nate the need for external feedback resistors. Select an output voltage of 1.3V, 1.5V or 1.8V by configuring the VSEL pin, as directed in Table 1. TABLE 1. VSEL Output Voltage Selection Settings TABLE 2. Suggested Inductors and Their Suppliers

TABLE 2. Suggested Inductors and Their Suppliers (Continued) TABLE 3. Suggested Capacitors and Their Suppliers and a 22µF, X7R or X5R ceramic output filter capacitor. tors. Table 3lists suggested capacitors and suppliers. transient load changes and reduces output voltage ripple. tance and sufficiently low ESR to perform these functions. tors is a major factor in voltage ripple.

Application Information (Continued) MICRO SMD PACKAGE ASSEMBLY AND USE Use of the Micro SMD package requires specialized board layout, precision mounting and careful reflow techniques, as detailed in National Semiconductor Application Note AN- 1112. Refer to the section Surface Mount Technology (SMT) Assembly Considerations. For best results in assembly, alignment ordinals on the PC board should be used to facilitate placement of the device. Since Micro SMD packag- ing is a new technology, all layouts and assembly means must be thoroughly tested prior to production. In particular, proper placement, solder reflow and resistance to thermal cycling must be verified. The 10-Bump package used for the LM2608 has 300micron solder balls and requires 10.82mil (0.275mm) pads for mounting on the circuit board. The trace to each pad should enter the pad with a 90˚ entry angle to prevent debris from being caught in deep corners. Initially, the trace to each pad should be 6 mil wide, for a section 6 mil long or longer, as a thermal relief. Then each trace should neck up to its optimal width over a span of 11 mils or more, so that the taper extends beyond the edge of the package. The important criterion is symmetry. This ensures the solder bumps on the LM2608 re-flow evenly and that the device solders level to the board. In particular, special attention must be paid to the pads for bumps D3, C3, B3, A3 and A2. Because PVIN and PGND are typically connected to large copper planes, inad- equate thermal reliefs can result in late or inadequate reflow of these bumps. The pad style used with Micro SMD package must be the NSMD (non-solder mask defined) type. This means that the solder-mask opening is larger than the pad size or 14.7mils for the LM2608. This prevents a lip that otherwise forms if the solder-mask and pad overlap. This lip can hold the device off the surface of the board and interfere with mount- ing. See Applications Note AN-1112 for specific instructions. BOARD LAYOUT CONSIDERATIONS PC board layout is an important part of DC-DC converter design. Poor board layout can disrupt the performance of a DC-DC converter and surrounding circuitry by contributing to EMI, ground bounce, and resistive voltage loss in the traces. These can send erroneous signals to the DC-DC converter IC, resulting in poor regulation or instability. Poor layout can also result in reflow problems leading to poor solder joints between the Micro SMD package and board pads. Poor solder joints can result in erratic or degraded performance. Good layout for the LM2608 can be implemented by follow- ing a few simple design rules: 1. Place the LM2608 on 10.82mil pads for Micro SMD package. As a thermal relief, connect to each pad with a 6mil wide trace (Micro SMD), 6mils long or longer, then incrementally increase each trace to its optimal width over a span so that the taper extends beyond the edge of the package. The important criterion is symmetry to ensure re-flow occurs evenly (see Micro SMD Package Assembly and Use). 2. Place the LM2608, inductor and filter capacitors close together and make the traces short. The traces between these components carry relatively high switching cur- rents and act as antennas. Following this rule reduces radiated noise. Place the capacitors and inductor within 0.2in (5mm) of the LM2608. 3. Arrange the components so that the switching current loops curl in the same direction. During the first part of each cycle, current flows from the input filter capacitor, through the LM2608 and inductor to the output filter capacitor and back through ground, forming a current loop. In the second part of each cycle, current is pulled up from ground, through the LM2608 by the inductor, to the output filter capacitor and then back through ground, forming a second current loop. Routing these loops so the current curls in the same direction prevents mag- netic field reversal between the two part-cycles and reduces radiated noise. 4. Connect the ground pins of the LM2608 and filter ca- pacitors together using generous component-side cop- per fill as a pseudo-ground plane. Then, connect this to the ground-plane (if one is used) with several vias. This reduces ground-plane noise by preventing the switching currents from circulating through the ground plane. It also reduces ground bounce at the LM2608 by giving it a low-impedance ground connection. 5. Use wide traces between the power components and for power connections to the DC-DC converter circuit. This reduces voltage errors caused by resistive losses across the traces. 6. Route noise sensitive traces, such as the voltage feed- back path, away from noisy traces between the power components. The voltage feedback trace must remain close to the LM2608 circuit and should be routed away from noisy components. This reduces EMI radiated onto the DC-DC converter’s own voltage feedback trace. 7. Place noise sensitive circuitry, such as radio IF blocks, away from the DC-DC converter, CMOS digital blocks and other noisy circuitry. Interference with noise- sensitive circuitry in the system can be reduced through distance. In mobile phones, for example, a common practice is to place the DC-DC converter on one corner of the board, arrange the CMOS digital circuitry around it (since this also generates noise), and then place sensitive preamplifiers and IF stages on the diagonally opposing corner. Often, the sensitive circuitry is shielded with a metal pan and power to it is post-regulated to reduce conducted noise, using low- dropout linear regulators, such as the LP2966. LM2608 www.national.com17

Physical Dimensions inches (millimeters) unless otherwise noted NOTES: UNLESS OTHERWISE SPECIFIED 1. EPOXY COATING 2. 63Sn/37Pb EUTECTIC BUMP 3. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD. 4. PIN A1 IS ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION. 5. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS PACKAGE HEIGHT. 6. REFERENCE JEDEC REGISTRATION MO-211. VARIATION BD. 10-Bump Micro SMD Package The dimensions for X1, X2 and X3 are as given: X3 = 0.600+/− 0.075mmLIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Americas Customer Support Center Email: new.feedback@nsc.com Tel: 1-800-272-9959 National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 National Semiconductor Asia Pacific Customer Support Center Email: ap.support@nsc.com National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: jpn.feedback@nsc.com Tel: 81-3-5639-7560 www.national.com LM2608 400mA Sub-miniature, High Efficiency, Programmable DC-DC Converter with Linear Mode National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the righ t at any time without notice to change said circuitry and specifications.