MIC4680 1A 200kHz SuperSwitcher™ Buck Regulator General Description Features The MIC4680 SuperSwitcher™ is an easy-to-use fixed or adjustable output voltage step-down (buck) switch-mode voltage regulator. The 200kHz MIC4680 achieves up to 1.3A of continuous output current over a wide input range in a 8-pin SOIC. The MIC4680 is available in 3.3V and 5V fixed output versions or adjustable output down to 1.25V. The MIC4680 has an input voltage range of 4V to 34V, with excellent line, load, and transient response. The regulator performs cycle-by-cycle current limiting and thermal shutdown for protection under fault conditions. In shutdown mode, the regulator draws less than 2µA of standby current. The MIC4680 SuperSwitcher™ regulator requires a minimum number of external components and can operate using a standard series of inductors and capacitors. Frequency compensation is provided internally for fast transient response and ease of use. The MIC4680 is available in the 8-pin SOIC with a –40°C to +125°C junction temperature range. • • • • • • • • • • • SOIC-8 package with up to 1.3A output current All surface mount solution Only 4 external components required Fixed 200kHz operation 3.3V, 5V, and adjustable output versions Internally compensated with fast transient response Wide 4V to 34V operating input voltage range Less than 2µA typical shutdown-mode current Up to 90% efficiency Thermal shutdown Overcurrent protection Applications • • • • • • • • Simple 1A high-efficiency step-down (buck) regulator Replacement of TO-220 and TO-263 designs Efficient pre-regulator (5V to 2.5V, 12V to 3.3V, etc.) On-card switching regulators Positive-to-negative converter (inverting buck-boost) Simple battery charger Negative boost converter Higher output current regulator using external FET Typical Application +6V to +34V C1 15µF 35V SHUTDOWN ENABLE Power SOIC-8 MIC4680-3.3BM 2 1 IN SHDN SW 3 FB 4 L1 68µH GND 5–8 D1 B260A or SS26 Fixed Regulator Circuit 3.3V/1A C2 220µF 16V +5V to +34V C1 15µF 35V SHUTDOWN ENABLE Power SOIC-8 2 1 MIC4680BM IN SW SHDN FB GND 5–8 3 L1 2.5V/1A 68µH R1 3.01k 4 D1 B260A or SS26 R2 2.94k C2 220µF 16V Adjustable Regulator Circuit SuperSwitcher is a trademark of Micrel, Inc. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com March 2008 M9999-032808 Micrel, Inc. MIC4680 Ordering Information Part Number Standard Pb-Free Voltage Junction Temp. Range Package MIC4680BM MIC4680YM Adj. –40°C to +125°C 8-Pin SOIC MIC4680-3.3BM MIC4680-3.3YM 3.3V –40°C to +125°C 8-Pin SOIC MIC4680-5.0BM MIC4680-5.0YM 5.0V –40°C to +125°C 8-Pin SOIC Pin Configuration SHDN 1 8 GND IN 2 7 GND SW 3 6 GND FB 4 5 GND 8-Pin SIOC (M) Pin Description Pin Number Pin Name 1 SHDN 2 VIN Supply Voltage (Input): Unregulated +4V to +34V supply voltage. 3 SW Switch (Output): Emitter of NPN output switch. Connect to external storage inductor and Shottky diode. 4 FB Feedback (Input): Connect to output on fixed output voltage versions, or to 1.23V-tap of voltage-divider network for adjustable version. 5–8 GND March 2008 Pin Function Shutdown (Input): Logic low enables regulator. Logic high (>1.6V) shuts down regulator. Ground 2 M9999-032808 Micrel, Inc. MIC4680 Absolute Maximum Ratings(1) Operating Ratings(2) Supply Voltage (VIN)(3) ..................................................+38V Shutdown Voltage (VSHDN)............................. –0.3V to +38V Steady-State Output Switch Voltage (VSW) ....................–1V Feedback Voltage [Adjustable] (VFB) ...........................+12V Storage Temperature (Ts) .........................–65°C to +150°C EDS Rating(5) Supply voltage (VIN)(4)....................................... +4V to +34V Junction Temperature (TJ) ....................................... +125°C Package Thermal Resistance(6) SIOC (θJA)..........................................................63°C/W Electrical Characteristics VIN = 12V; ILOAD = 500mA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C, Note 7; unless noted. Parameter Condition Min Typ Max Units (±1%) (±1%) 1.217 1.205 1.230 1.243 1.255 V V 8V ≤ VIN ≤ 34V, 0.1A ≤ ILOAD ≤ 1A, VOUT = 5V 1.193 1.180 1.230 1.267 1.280 V V MIC4680 [Adjustable] Feedback Voltage Maximum Duty Cycle VFB = 1.0V Output Leakage Current VIN = 34V, VSHDN = 5V, VSW = 0V 50 500 µA VIN = 34V, VSHDN = 5V, VSW = –1V 4 20 mA VFB = 1.5V 7 12 mA Quiescent Current 93 97 % MIC4680-3.3 Output Voltage (±1%) (±3%) 3.266 3.201 3.3 3.333 3.399 V V 6V ≤ VIN ≤ 34V, 0.1A ≤ ILOAD ≤ 1A 3.168 3.135 3.3 3.432 3.465 V V 93 97 Maximum Duty Cycle VFB = 2.5V Output Leakage Current VIN = 34V, VSHDN = 5V, VSW = 0V 50 500 µA VIN = 34V, VSHDN = 5V, VSW = –1V 4 20 mA VFB = 4.0V 7 12 mA Quiescent Current % MIC4680-5.0 Output Voltage (±1%) (±3%) 4.950 4.85 5.0 5.05 5.15 V V 8V ≤ VIN ≤ 34V, 0.1A ≤ ILOAD ≤ 1A 4.800 4.750 5.0 5.200 5.250 V V 93 97 Maximum Duty Cycle VFB = 4.0V Output Leakage Current VIN = 34V, VSHDN = 5V, VSW = 0V Quiescent Current % 50 500 µA VIN = 34V, VSHDN = 5V, VSW = –1V 4 20 mA VFB = 6.0V 7 12 mA MIC4680/-3.3/-5.0 Frequency Fold Back 30 50 100 kHz Oscillator Frequency 180 200 220 kHz 1.4 1.8 V 1.8 2.5 A Saturation Voltage IOUT = 1A Short Circuit Current Limit VFB = 0V, see Test Circuit Standby Quiescent Current VSHDN = VIN 1.5 VSHDN = 5V (regulator off) 30 March 2008 1.3 3 µA 100 µA M9999-032808 Micrel, Inc. MIC4680 Parameter Condition Min Typ Shutdown Input Logic Level regulator off 2 1.6 1.0 0.8 V VSHDN = 5V (regulator off) –10 –0.5 10 µA VSHDN = 0V (regulator on) –10 –1.5 10 µA regulator on Shutdown Input Current Thermal Shutdown 160 Max Units V °C Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Absolute maximum rating is intended for voltage transients only, prolonged dc operation is not recommended. 4. VIN(min) = VOUT + 2.5V or 4V whichever is greater. 5. Devices are ESD sensitive. Handling precautions recommended. 6. Measured on 1" square of 1 oz. copper FR4 printed circuit board connected to the device ground leads. 7. Test at TA = +85°C, guaranteed by design, and characterized to TJ = +125°C. Test Circuit +12V SHUTDOWN ENABLE Device Under Test 2 IN 1 SHDN SW 3 FB 4 68µH I GND SOIC-8 5–8 Current Limit Test Circuit Shutdown Input Behavior OFF ON 0.8V 0V 2V 1V 1.6V VIN(max) Shutdown Hysteresis March 2008 4 M9999-032808 Micrel, Inc. MIC4680 Typical Characteristics 4.99 4.98 4.97 4.96 3.5 3.0 5 10 15 20 25 30 INPUT VOLTAGE (V) 2.0 1.5 1.0 210 200 190 180 -50 -25 0 25 50 75 100 125 TEMPERATURE (°C) 80 4 3 2 1 VIN = 12V 1.236 1.234 1.232 VIN = 12V VOUT = 5V IOUT = 1A 1.230 1.228 -50 -25 0 25 50 75 100 125 150 TEMPERATURE (°C) 40 30 20 10 70 60 12V 24V 7V 50 40 30 20 10 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 OUTPUT CURRENT (A) March 2008 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 OUTPUT CURRENT (A) 5 EFFICIENCY (%) 50 24V 6V 35 Frequency vs. Supply Voltage 198 197 0 5 10 15 20 25 30 SUPPLY VOLTAGE (V) 35 Saturation Voltage vs. Temperature 1.4 1.2 1.0 0.8 0.6 0.4 0.2 VIN = 12V VOUT = 5V ILOAD = 1A 0 -50 -25 0 25 50 75 100 125 TEMPERATURE (°C) 5V Output Efficiency 90 EFFICIENCY (%) 12V 10 15 20 25 30 INPUT VOLTAGE (V) 199 1.6 80 60 5 200 196 Feedback Voltage vs. Temperature 1.238 70 0 202 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 OUTPUT CURRENT (A) 1.240 3.3V Output Efficiency 40 201 1.242 FEEDBACK VOLTAGE (V) 220 60 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 OUTPUT CURRENT (A) 5 0 Frequency vs. Temperature 0 Current Limit Characteristic 6 VIN = 12V VSHDN = VIN 80 20 Shutdown Current vs. Temperature 0 -50 -25 0 25 50 75 100 125 TEMPERATURE (°C) FREQUENCY (kHz) 4.98 35 0.5 EFFICIENCY (%) 5.00 4.96 0 2.5 0 5.02 CURRENT (µA) 5.01 5.00 100 VIN = 12V VOUT = 5V FREQUENCY (kHz) OUTPUT VOLTAGE (V) 5.03 5.02 4.0 CURRENT (µA) 5.04 IOUT = 1.0A 5.05 5.04 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 5.06 Shutdown Current vs. Input Voltage Load Regulation SATURATION VOLTAGE (V) Line Regulation 100 90 80 70 60 12V Output Efficiency 15V 24V 50 40 30 20 10 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 OUTPUT CURRENT (A) M9999-032808 Micrel, Inc. MIC4680 Safe Operating Area 1.5 Minimum Current Limit 1.4 1.3 1.2 Note OUTPUT CURRENT (A) 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 VOUT = 5V TA = 60°C Demonstration board layout 0.3 0.2 0.1 0 0 5 10 15 20 25 INPUT VOLTAGE (V) 30 35 Functional Characteristics Frequency Foldback The MIC4680 folds the switching frequency back during a hard short-circuit condition to reduce the energy per cycle and protect the device. March 2008 6 M9999-032808 Micrel, Inc. MIC4680 Bode Plots The following bode plots show that the MIC4680 is stable over all conditions using a 68µF inductor (L) and a 220µF output capacitor (COUT). To assure stability, it is a good practice to maintain a phase margin of greater than 35°. March 2008 7 M9999-032808 Micrel, Inc. MIC4680 Functional Diagrams V IN IN SHDN Internal Regulator 200kHz Oscillator Thermal Shutdown Current Limit Comparator VOUT SW Driver Reset 1A Switch COUT FB Error Amp 1.23V Bandgap Reference MIC4680-x.x GND Fixed Regulator VIN IN SHDN Internal Regulator 200kHz Oscillator Thermal Shutdown ⎛ R1 ⎞ VOUT = VREF ⎜ + 1⎟ ⎝ R2 ⎠ ⎛V ⎞ R1 = R2 ⎜ OUT - 1⎟ ⎝ VREF ⎠ Current Limit VREF = 1.23V Comparator VOUT SW Driver Reset 1A Switch COUT R1 FB Error Amp 1.23V Bandgap Reference R2 MIC4680 [adj.] Adjustable Regulator March 2008 8 M9999-032808 Micrel, Inc. MIC4680 Functional Description A higher feedback voltage increases the error amplifier output voltage. A higher error amplifier voltage (comparator inverting input) causes the comparator to detect only the peaks of the sawtooth, reducing the duty cycle of the comparator output. A lower feedback voltage increases the duty cycle. The MIC4680 uses a voltagemode control architecture. The MIC4680 is a variable duty cycle switch-mode regulator with an internal power switch. Refer to the block diagrams. Supply Voltage The MIC4680 operates from a +4V to +34V unregulated input. Highest efficiency operation is from a supply voltage around +15V. See the efficiency curves. Output Switching When the internal switch is on, an increasing current flows from the supply VIN, through external storage inductor L1, to output capacitor COUT and the load. Energy is stored in the inductor as the current increases with time. When the internal switch is turned off, the collapse of the magnetic field in L1 forces current to flow through fast recovery diode D1, charging COUT. Enable/Shutdown The shutdown (SHDN) input is TTL compatible. Ground the input if unused. A logic-low enables the regulator. A logic-high shuts down the internal regulator which reduces the current to typically 1.5µA when VSHDN = VIN = 12V and 30µA when VSHDN = 5V. See “Shutdown Input Behavior: Shutdown Hysteresis.” Feedback Fixed-voltage versions of the regulator have an internal resistive divider from the feedback (FB) pin. Connect FB directly to the output voltage. Adjustable versions require an external resistive voltage divider from the output voltage to ground, center tapped to the FB pin. See Figure 6b for recommended resistor values Output Capacitor External output capacitor COUT provides stabilization and reduces ripple. See “Bode Plots” for additional information. Return Paths During the on portion of the cycle, the output capacitor and load currents return to the supply ground. During the off portion of the cycle, current is being supplied to the output capacitor and load by storage inductor L1, which means that D1 is part of the high-current return path. Duty Cycle Control A fixed-gain error amplifier compares the feedback signal with a 1.23V bandgap voltage reference. The resulting error amplifier output voltage is compared to a 200kHz sawtooth waveform to produce a voltage controlled variable duty cycle output. March 2008 9 M9999-032808 Micrel, Inc. MIC4680 Applications Information Adjustable Regulators Adjustable regulators require a 1.23V feedback signal. Recommended voltage-divider resistor values for common output voltages are included in Figure 1b. For other voltages, the resistor values can be determined using the following formulas: V IN ⎛ R1 ⎞ VOUT = VREF ⎜ + 1⎟ ⎝ R2 ⎠ 2 MIC4680BM IN SW L1 3 R1 CIN SHUTDOWN ENABLE 1 SHDN FB 4 GND ⎛V ⎞ R1 R1 = R2⎜⎜ OUT − 1⎟⎟ , R2 = V OUT ⎝ VREF ⎠ −1 VREF VOUT D1 R2 COUT 5–8 Figure 1a. Adjustable Regulator Circuit VREF = 1.23V VOUT R1*† R2*† 1.8V 3.01k 6.495k 2.5V 3.01k 2.915k 3.3V 3.01k 1.788k 5.0V 3.01k 982Ω 6.0V 3.01k 776Ω * CIN D1 L1 COUT 68µH 1.5A 2A 60V Schottky 15µF 35V AVX TPSE156035R0200 B260A Vishay-Diode, Inc*** or SS26 General Semiconductor Coiltronics UP2B-680 or Sumida CDRH125-680MC** or Sumida CDRH124-680MC** 220µF 10V AVX TPSE227010R0060 All resistors 1% ** Shielded magnetics for low RFI applications *** Vishay-Diode, Inc. (805) 446-48600 † Nearest available resistor values Figure 1b. Recommended Components for Common Output Voltages March 2008 10 M9999-032808 Micrel, Inc. MIC4680 Thermal Considerations The MIC4680 SuperSwitcher features the power-SOIC8. This package has a standard 8-pin small-outline package profile but with much higher power dissipation than a standard SOIC-8. The MIC4680 SuperSwitcher is the first dc-to-dc converter to take full advantage of this package. The reason that the power SOIC-8 has higher power dissipation (lower thermal resistance) is that pins 5 though 8 and the die-attach paddle are a single piece of metal. The die is attached to the paddle with thermally conductive adhesive. This provides a low thermal resistance path from the junction of the die to the ground pins. This design significantly improves package power dissipation by allowing excellent heat transfer through the ground leads to the printed circuit board. One of the limitation of the maximum output current on any MIC4680 design is the junction-to-ambient thermal resistance (θJA) of the design (package and ground plane).Examining θJA in more detail: θJA = (θJC + θCA) where: θJC = junction-to-case thermal resistance θCA = case-to-ambient thermal resistance θJC is a relatively constant 20°C/W for a power SOIC-8. θCA is dependent on layout and is primarily governed by the connection of pins 5 though 8 to the ground plane. The purpose of the ground plane is to function as a heat sink. θJA is ideally 63°C/W but will vary depending on the size of the ground plane to which the power SOIC-8 is attached. Determining Ground-Plane Heat-Sink Area There are two methods of determining the minimum ground plane area required by the MIC4680. Quick Method Make sure that MIC4680 pins 5 though 8 are connected to a ground plane with a minimum area of 6cm2. This ground plane should be as close to the MIC4680 as possible. The area maybe distributed in any shape around the package or on any pcb layer as long as there is good thermal contact to pins 5 though 8. This ground plane area is more than sufficient for most designs. March 2008 SOIC-8 JA JC CA AM BIE N ground plane heat sink area T printed circuit board Figure 2. Power SOIC-8 Cross Section Minimum Copper/Maximum Current Method Using Figure 3, for a given input voltage range, determine the minimum ground-plane heat-sink area required for the application’s maximum output current. Figure 3 assumes a constant die temperature of 75°C above ambient. 1.5 OUTPUT CURRENT (I) 8V 1.0 12V 24V 34V TA = 50°C 0.5 Minimum Current Limit = 1.3A 0 0 5 10 15 20 25 AREA (cm 2) Figure 3. Output Current vs. Ground Plane Area When designing with the MIC4680, it is a good practice to connect pins 5 through 8 to the largest ground plane that is practical for the specific design. Checking the Maximum Junction Temperature: For this example, with an output power (POUT) of 5W, (5V output at 1A maximum with VIN = 12V) and 65°C maximum ambient temperature, what is the maximum junction temperature? Referring to the “Typical Characteristics: 5V Output Efficiency” graph, read the efficiency (η) for 1A output current at VIN = 12V or perform you own measurement. η = 79% The efficiency is used to determine how much of the output power (POUT) is dissipated in the regulator circuit (PD). 11 M9999-032808 Micrel, Inc. MIC4680 POUT − POUT η PD = 5W − 5W 0.79 Layout Considerations Layout is very important when designing any switching regulator. Rapidly changing switching currents through the printed circuit board traces and stray inductance can generate voltage transients which can cause problems. To minimize stray inductance and ground loops, keep trace lengths, indicated by the heavy lines in Figure 5, as short as possible. For example, keep D1 close to pin 3 and pins 5 through 8, keep L1 away from sensitive node FB, and keep CIN close to pin 2 and pins 5 though 8. See “Applications Information: Thermal Considerations” for ground plane layout. The feedback pin should be kept as far way from the switching elements (usually L1 and D1) as possible. A circuit with sample layouts is provided. See Figure 6a through 6e. PD = 1.33W Calculate the worst-case junction temperature: TJ = PD(IC)θJC + (TC – TA) + TA(max) where: TJ = MIC4680 junction temperature PD(IC) = MIC4680 power dissipation θJC = junction-to-case thermal resistance. The θJC for the MIC4680’s power-SOIC-8 is approximately 20°C/W. (Also see Figure 1.) TC = “pin” temperature measurement taken at the entry point of pins 6 or 7 into the plastic package at the ambient temperature (TA) at which TC is measured. TA = ambient temperature at which TC is measured. TA(max) = maximum ambient operating temp. for the specific design. Calculating the maximum junction temperature given a maximum ambient temperature of 65°C: TJ = 1.064 × 20°C/W + (45°C – 25°C) + 65°C TJ = 106.3°C This value is less than the allowable maximum operating junction temperature of 125°C as listed in “Operating Ratings.” Typical thermal shutdown is 160°C and is listed in “Electrical Characteristics.” Increasing the Maximum Output Current The maximum output current at high input voltages can be increased for a given board layout. The additional three components shown in Figure 4 will reduce the overall loss in the MIC4680 by about 20% at high VIN and high IOUT. Even higher output current can be achieved by using the MIC4680 to switch an external FET. See Figure 9 for a 5A supply with current limiting. J1 VIN 4V to +34V C1 15µF 35V J3 GND MIC4680BM IN SW SHDN 2 OFF ON S1 NKK G12AP 1 IN SW SHDN FB GND SOIC-8 5–8 D1 1N4148 FB 2.2nF GND 5 6 7 8 Figure 4. Increasing Maximum Output Current at High Input Voltages V IN +4V to +34V MIC4680BM 2 CIN 1 IN SHDN SW 3 FB 4 L1 68µH VOUT COUT D1 GND Power SOIC-8 R1 R2 5 6 7 8 GND Figure 5. Critical Traces for Layout U1 MIC4680BM C2 0.1µF 50V 3 Load PD = J2 VOUT 1A L1 3 68µH 4 D1 B260A or SS26 R6 optional R2 6.49k 1 2 * C3 can be used to provide additional stability and improved transient response. C3* optional R1 3.01k JP1a 1.8V R3 2.94k 3 4 JP1b 2.5V R4 1.78k 5 6 JP1c 3.3V R5 7 8 JP1d 5.0V C4 220µF 10V C5 0.1µF 50V J4 GND Figure 6a. Evaluation Board Schematic Diagram March 2008 12 M9999-032808 Micrel, Inc. MIC4680 Printed Circuit Board Layouts Figure 6b. Top-Side Silk Screen Figure 6d. Bottom-Side Silk Screen Figure 6c. Top-Side Copper Figure 6e. Bottom-Side Copper Abbreviated Bill of Materials (Critical Components) Reference Part Number Manufacturer Description C1 TPSD156M035R0300 AVX1 15µF 35V 2 Qty. 1 ECE-A1HFS470 Panasonic C4 TPSD227M010R0150 AVX 220µF 10V 1 D1 B260A Vishay-Diodes, Inc.3 Schottky 1 SS26 General Semiconductor UP2B-680 Coiltronics4 68µH, 1.5A, nonshielded 1 L1 U1 5 CDH115-680MC Sumida CDRH124-680MC Sumida MIC4680BM Micrel (6) 47µF 50V, 8mm × 11.5mm 68µH, 1.5A, nonshielded 68µH, 1.5A, shielded 1A 200kHz power-SO-8 buck regulator 1 Notes: 1. AVX: www.avxcorp.com 2. Panasonic: www.maco.panasonic.co.jp/eccd/index.html 3. Vishay-Diodes, Inc.: www.diodes.com 4. Coiltronics: www.coiltronics.com 5. Sumida: www.sumida.com 6. Micrel, Inc.: www.micrel.com March 2008 13 M9999-032808 Micrel, Inc. MIC4680 Application Circuits For continuously updated circuits using the MIC4680, see Application Hint 37 at www.micrel.com. J1 +34V max. Figure 7. Constant Current and Constant Voltage Battery Charger Figure 8. +12V to –12V/150mA Buck-Boost Converter +4.5V to +17V U1 MIC4680BM MIC4417BM4 2 1 IN SHDN SW 3 FB 4 Si4425DY 3.3V/5A GND SOIC-8 5–8 * I SAT = 8A GND Figure 9. 5V to 3.3V/5A Power Supply March 2008 14 M9999-032808 Micrel, Inc. MIC4680 Package Information 8-Pin SOIC (M) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2000 Micrel, Incorporated. March 2008 15 M9999-032808