MIC4681 Micrel MIC4681 2A-Peak SuperSwitcher™ SOP-8 Buck Regulator General Description Features The MIC4681 SuperSwitcher™ is an easy-to-use step-down (buck) voltage-mode switching regulator. The 200kHz MIC4681 achieves over 1A of continuous output current over a 4V to 30V input range in an 8-lead SOPpackage . The MIC4681 features a high 2.1A minimum current limit, making the device ideal for pulsed current applications such as GSM and TDMA cell phone battery chargers and power supplies. The MIC4681 sustains an output of 4.2V/2A within a typical GSM charging environment. The MIC4681 has an input voltage range of 4V to 30V, 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 6µA of standby current. The MIC4681 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 MIC4681 is available in the 8-lead SOP with a –40°C to +125°C junction temperature range. • • • • • • • • • • • • SO-8 package with over 1A continuous output current Capable of 2A pulse charging for GSM applications All surface mount solution Only 4 external components required Fixed 200kHz operation Output adjustable down to 1.25V Internally compensated with fast transient response Wide 4V to 30V operating input voltage range Less than 6µA typical shutdown-mode current Up to 90% efficiency Thermal shutdown Overcurrent protection Applications • Cellular phone battery charger • Cellular phone power supply • Simple 1A continuous high-efficiency step-down (buck) regulator • Replacement of a TO-220 and TO-263 designs • Positive-to-negative converter (inverting buck-boost) • Negative boost converter • Higher output current regulator using external FET Typical Applications +5V to +30V C1 22µF 35V SHUTDOWN ENABLE Power SOP-8 2 1 MIC4681BM IN SW SHDN FB 3 L1 68µH 4 D1 B340A or SS36 GND 5–8 2.5V/1A R1 3.01k C2 220µF 10V R2 2.94k Adjustable Regulator Circuit SuperSwitcher is a trademark of Micrel, Inc. Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com April 2005 1 MIC4681 MIC4681 Micrel Ordering Information Part Number Standard MIC4681BM Lead-Free Voltage Frequency Junction Temp. Range Package MIC4681YM Adjustable 400kHz –40°C to +125°C 8-lead SOP Pin Configuration SHDN 1 8 GND VIN 2 7 GND SW 3 6 GND FB 4 5 GND SOP-8 (M) Pin Description Pin Number Pin Name 1 SHDN 2 VIN Supply Voltage (Input): Unregulated +4V to +30V 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 1.23V-tap of voltage-divider network 5–8 GND MIC4681 Pin Function Shutdown (Input): Logic low enables regulator. Logic high (>2V) shuts down regulator. Ground 2 April 2005 MIC4681 Micrel Absolute Maximum Ratings (Note 1) Operating Ratings (Note 2) Supply Voltage (VIN), Note 3 ...................................... +34V Shutdown Voltage (VSHDN) .......................... –0.3V to +34V Steady-State Output Switch Voltage (VSW) .................. –1V Feedback Voltage [Adjustable] (VFB) .......................... +12V Storage Temperature (TS) ....................... –65°C to +150°C ESD, Note 5 Supply Voltage (VIN) ....................................... +4V to +30V Junction Temperature (TJ) ...................................... +125°C Package Thermal Resistance (θJA), Note 6 ............ 63°C/W (θJC), Note 6 ........... 20°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 Feedback Voltage (±1%) (±2%) 1.217 1.205 1.230 1.243 1.255 V V 8V ≤ VIN ≤ 30V, 0.1A ≤ ILOAD ≤ 1A, VOUT = 5V 1.193 1.180 1.230 1.267 1.280 V V 93 95 Maximum Duty Cycle VFB = 1.0V Output Leakage Current VIN = 30V, VSHDN = 5V, VSW = 0V 50 500 µA VIN = 30V, VSHDN = 5V, VSW = –1V 4 20 mA VFB = 1.5V 7 12 mA 50 110 kHz 200 220 kHz 1.4 1.8 V 3.4 4.5 A 100 µA Quiescent Current Frequency Fold Back Oscillator Frequency 180 % Saturation Voltage IOUT = 1A Short Circuit Current Limit VFB = 0V, see Test Circuit VIN = 30V (Note 8) Standby Quiescent Current VSHDN = 5V (regulator off) 35 VSHDN = VIN 6 µA 1.4 V Shutdown Input Logic Level regulator off 2.2 2 regulator on Shutdown Input Current 0.8 V VSHDN = 5V (regulator off) –10 –0.5 1 µA VSHDN = 0V (regulator on) –10 –1.5 1 µA Thermal Shutdown @ TJ 160 Note 1. Exceeding the absolute maximum rating may damage the device. Note 2. The device is not guaranteed to function outside its operating rating. Note 3. Absolute maximum rating is intended for voltage transients only, prolonged dc operation is not recommended. Note 4. VIN(min) = VOUT + 2.5V or 4V whichever is greater. Note 5. Devices are ESD sensitive. Handling precautions recommended. Note 6. Measured on 1" square of 1 oz. copper FR4 printed circuit board connected to the device ground leads. Note 7. Test at TA = +85°C, guaranteed by design, and characterized to TJ = +125°C. Note 8. Short circuit protection is guaranteed to 30V max. April 2005 1.25 3 °C MIC4681 MIC4681 Micrel Test Circuit +30V 2 SHUTDOWN ENABLE 1 Device Under Test 3 IN SW SHDN FB 68µH 4 I GND SOP-8 5–8 Current Limit Test Circuit Shutdown Input Behavior OFF ON GUARANTEED ON 0V TYPICAL ON 0.8V 1.25V 2V 1.4V GUARANTEED OFF TYPICAL OFF VIN(max) Shutdown Hysteresis MIC4681 4 April 2005 MIC4681 Micrel Typical Characteristics Line Regulation Load Regulation 5.03 5.01 4.99 4.97 5.01 4.99 4.97 4.95 0 6.6 SHUTDOWN CURRENT (µA) 10 8 6 4 VSHDN = VIN Amb = 25°C 5 10 15 20 25 30 INPUT VOLTAGE (V) 5.8 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 35 FREQUENCY (KHz) FREQUENCY (KHz) 210 201 199 200 195 185 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) EFFICIENCY (%) EFFICIENCY (%) 6Vin 20 April 2005 3 2 1 V = 12V IN Amb = 25°C 0 0 0.5 1 1.5 2 2.5 OUTPUT CURRENT (A) 7Vin 24Vin 40 1.234 1.232 1.230 1.228 1.226 1.224 VIN = 12V 1.222 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 12V Output Efficiency 0 0 15Vin 80 24Vin 60 40 20 20 2.5 3 1.236 12Vin 60 Amb = 25°C 0.5 1 1.5 2 OUTPUT CURRENT (A) 4 100 80 24Vin 35 5 5V Output Efficiency 12Vin 10 15 20 25 30 INPUT VOLTAGE (V) 1.238 100 40 0 0 VIN = 12V 205 MIC4681 3.3V Output Efficiency 5 Feedback Voltage vs. Temperature 190 IOUT = 100mA Amb = 25°C 5 10 15 20 25 30 35 INPUT VOLTAGE (V) VSHDN = 5V Amb = 25°C 10 Frequency vs. Temperature 203 60 30 20 6 VIN = 12V VSHDN = VIN 6 215 80 40 Current Limit Characteristics 6.2 205 195 0 60 50 0 0 6.4 MIC4681BM Frequency vs. Supply Voltage 197 70 2.0 FEEDBACK VOLTAGE (V) SHUTDOWN CURRENT (µA) 12 0 0 80 Shutdown Current vs. Temperature 14 2 0.5 1.0 1.5 OUTPUT CURRENT (A) 100 90 OUTPUT VOLTAGE (V) Shutdown Current vs. Input Voltage Amb = 25°C VIN = 12V EFFICIENCY (%) 4.95 0 Amb = 25°C 5 10 15 20 25 30 INPUT VOLTAGE (V) 5.03 SHUTDOWN CURRENT (µA) 5.05 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE (V) 5.05 Shutdown Current vs. Input Voltage Amb = 25°C 0.5 1.0 1.5 2.0 OUTPUT CURRENT (A) 5 0 0 Amb = 25°C 0.5 1 OUTPUT CURRENT (A) 1.5 MIC4681 Micrel MIC4681 Shutdown Thresholds vs. Temperature Saturation Voltage vs. Output Current 1.5 2 SATURATION VOLTAGE (V) ENABLE THRESHOLD VOLTAGE (V) MIC4681 Regulator Off 1.0 Regulator On 0.5 V IN = 12V 0.0 -40 -20 0 20 40 60 80 100 120 TEMPERATURE (°C) 1.5 1 0.5 V IN 0 0 6 = 12V Amb = 25°C 0.5 1 1.5 2 OUTPUT CURRENT (A) April 2005 MIC4681 Micrel CONTINUOUS OUTPUT CURRENT (A) 4681BMSOA SOA 5Vout 4681BM 5Vout 1.8 TA = 25°C 1.6 1.4 1.2 1.0 0.8 0.6 0.4 VOUT = 5V TA = 60°C 0.2 0 0 5 10 15 20 25 30 INPUT VOLTAGE (V) 35 CONTINUOUS OUTPUT CURRENT (A) 4681BMSOA SOA 3.3Vout 4681BM 3.3Vout April 2005 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 0 TA = 25°C VOUT = 3.3V TA = 60°C 5 10 15 20 25 30 INPUT VOLTAGE (V) 7 35 MIC4681 MIC4681 Micrel Functional Characteristics VSW (NORMAL) 12V IN, 5V/1A OUT Switching Frequency Foldback Load Transient 1.5A IOUT (1A/div) Normal Operation 0A 100mV VOUT (100mV/div) VSW (SHORTED) 12V IN, 0V OUT 200kHz Short Circuit Operation VIN = 12V VOUT = 5V 60kHz TIME TIME (100µs/div) Frequency Foldback The MIC4681 folds the switching frequency back during a hard short-circuit condition to reduce the energy per cycle and protect the device. MIC4681 8 April 2005 MIC4681 Micrel Bode Plots The following bode plots show that the MIC4681 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°. No-Load Stability Phase Margin = 94° Full-Load Stability Phase Margin = 74° L = 68µF COUT = 220µF L = 68µF COUT = 220µF VIN = 7V VOUT = 5.0V IOUT = 0A Amb = 22°C VIN = 7V VOUT = 5.0V IOUT = 1.1A Amb = 22°C No-Load Stability Phase Margin = 102° Full-Load Stability Phase Margin = 53° L = 68µF COUT = 220µF L = 68µF COUT = 220µF VIN = 12V VOUT = 5.0V IOUT = 1.4A Amb = 22°C VIN = 12V VOUT = 5.0V IOUT = 0A Amb = 22°C Full-Load Stability Phase Margin = 59° No-Load Stability Phase Margin = 118° L = 68µF COUT = 220µF L = 68µF COUT = 220µF VIN = 30V VOUT = 5.0V IOUT = 1.1A Amb = 22°C VIN = 30V VOUT = 5.0V IOUT = 0A Amb = 22°C April 2005 9 MIC4681 MIC4681 Micrel Block Diagrams VIN IN SHDN R1 VOUT = VREF + 1 R2 Internal Regulator 200kHz Oscillator Thermal Shutdown V R1 = R2 OUT − 1 VREF Current Limit VREF = 1.23V Comparator VOUT SW Driver Reset 3A Switch COUT R1 FB Error Amp 1.23V Bandgap Reference R2 MIC4681 [adj.] Adjustable Regulator MIC4681 10 April 2005 MIC4681 Micrel 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 MIC4681 uses a voltage-mode control architecture. 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. 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. Functional Description The MIC4681 is a variable duty cycle switch-mode regulator with an internal power switch. Refer to the block diagrams. Supply Voltage The MIC4681 operates from a +4V to +30V unregulated input. Highest efficiency operation is from a supply voltage around +12V. See the efficiency curves on page 6. Enable/Shutdown The shutdown (SHDN) input is TTL compatible. Ground the input if unused. A logic-low enables the regulator. A logichigh shuts down the internal regulator which reduces the current to typically 35µA when VSHDN = VIN = 12V and 6µA when VSHDN = 5V. See “Shutdown Input Behavior: Shutdown Hysteresis.” Feedback Require an external resistive voltage divider from the output voltage to ground, center tapped to the FB pin. See Figure 1b for recommended resistor values. 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. A higher feedback voltage increases the error amplifier output voltage. A higher error amplifier voltage (comparator 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: VIN MIC4681BM 2 IN SW 3 FB 4 L1 R1 CIN SHUTDOWN ENABLE VOUT 1 SHDN GND R1 VOUT = VREF + 1 R2 COUT D1 R2 5–8 V R1 = R2 OUT − 1 VREF Figure 1a. Adjustable Regulator Circuit VREF = 1.23V VOUT R1* R2* CIN D1 L1 3A 40V Schottky 68µH 2.0A COUT 1.8V 3.01k 6.49k 2.5V 3.01k 2.94k 3.3V 3.01k 1.78k 5.0V 3.01k 976Ω 22µF 35V Vishay Dale 593D226X035E2T 6.0V 3.01k 787Ω B340A Vishay-Diode, Inc.*** Coiltronics UP3B-680 or or SS36 General Semiconductor Sumida CDRH127-680MC** 220µF 10V Vishay Dale 594D227X0010D2 * All resistors 1% ** shielded magnetics for low RFI applications *** Vishay-Diode, Inc. (805) 446-4800 Figure 1b. Recommended Components for Common Ouput Voltages April 2005 11 MIC4681 MIC4681 Micrel Minimum Copper/Maximum Current Method Thermal Considerations The MIC4681 SuperSwitcher™ features the power-SOP-8. This package has a standard 8-lead small-outline package profile, but with much higher power dissipation than a standard SOP-8. Micrel's MIC4681 SuperSwitcher™ family are the first dc-to-dc converters to take full advantage of this package. The reason that the power SOP-8 has higher power dissipation (lower thermal resistance) is that pins 5 through 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 limitation of the maximum output current on any MIC4681 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 SOP-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 SOP-8 is attached. CONTINUOUS OUTPUT CURRENT (A) Using Figure 3, for a given input voltage range, determine the minimum ground-plane heat-sink area required for the application’s maximum continuous output current. Figure 3 assumes a constant die temperature of 75°C above ambient. 24V VIN = 30V 0.5 TA = 50°C 0 0 5 10 15 20 25 When designing with the MIC4681, 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). PD = Quick Method Make sure that MIC4681 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 MIC4681 as possible. The area may be 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. POUT η − POUT 5W − 5W 0.79 PD = 1.33W A worst-case rule of thumb is to assume that 80% of the total output power dissipation is in the MIC4681 (PD(IC)) and 20% is in the diode-inductor-capacitor circuit. PD(IC) = 0.8 PD PD(IC) = 0.8 × 1.33W PD(IC) = 1.064W Calculate the worst-case junction temperature: TJ = PD(IC) θJC + (TC – TA) + TA(max) where: TJ = MIC4681 junction temperature PD(IC) = MIC4681 power dissipation PD = SOP-8 θJA AM BIE 1.0 12V Figure 3. Output Current vs. Ground Plane Area There are two methods of determining the minimum ground plane area required by the MIC4681. θCA 8V AREA (cm2) Determining Ground-Plane Heat-Sink Area θJC 1.5 ground plane heat sink area θJC = junction-to-case thermal resistance. The θJC for the MIC4681’s power-SOP-8 is approximately 20°C/W. TC = “pin” temperature measurement taken at the entry point of pins 6 or 7 NT printed circuit board Figure 2. Power SOP-8 Cross Section MIC4681 12 April 2005 MIC4681 Micrel TA = ambient temperature TA(max) = maximum ambient operating temperature 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 within 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.” Layout Considerations Layout is very important when designing any switching regulator. Rapidly changing 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 MIC4681BM 2 IN SW 3 FB 4 L1 VOUT 68µH COUT CIN 1 SHDN Power SOP-8 D1 GND R1 Load VIN +4V to +30V 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 are provided. See Figures 6a though 6e. Gerber files are available upon request. R2 5 6 7 8 GND Figure 5. Critical Traces for Layout J1 VIN 4V to +30V C1 22µF 35V J3 GND 2 C2 0.1µF 50V OFF ON 1 U1 MIC4681BM IN SW SHDN JP1 FB GND SOP-8 5–8 3 J2 VOUT 1A L1 68µH R1 3.01k 4 D1 R6 B340A optional or 1 SS36 2 * C3 can be used to provide additional stability and improved transient response. R2 6.49k 3 JP2a 1.8V 4 C3* 1800pF / 50V optional R3 2.94k 5 JP2b 2.5V R4 1.78k 7 JP2c 3.3V 6 8 R5 976Ω JP2d 5.0V C4 220µF 10V C5 0.1µF 50V J4 GND Figure 6a. Evaluation Board Schematic Diagram April 2005 13 MIC4681 MIC4681 Micrel 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 Material (Critical Components) Reference C1 C4 1 Part Number 593D226X035E2T 594D227X0010D2 Manufacturer Description Qty Vishay Dale1 22µF / 35V 1 Vishay Dale1 220µF / 10V 1 Dale1 0.1 / 50V 1 C2,C5 VJ0805Y104KXXMB Vishay D1 340A Diodes Inc.2 Schottky Diode 3A, 40V 1 L1 CDRH127-680MC Sumida3 68µH, ISAT 2.1A, shielded 1 U1 MIC4681BM Micrel Semiconductor4 200kHz Super Switcher™SOIC 8 pin 1 Vishay Dale, Inc., tel: 1 877-847-4291, http://www.vishay.com 2 Diodes Inc, tel: (805) 446-4800, http://www.diodes.com 3 Sumida, tel: (408) 982-9960, http://www.sumida.com 4 Micrel, tel: (408) 944-0800, http://www.micrel.com MIC4681 14 April 2005 MIC4681 Micrel Applications Circuits* For continuously updated circuits using the MIC4681, see Application Hint 37 at www.micrel.com. 2 U1 MIC4681 IN SW L1 3 100µH C2 100nF OFF ON 1 SHDN S1 NKK G12AP FB 4 R7 4.99k C3 220µF 10V D1 MMBR140LT3 4 GND SOP-8 J2 5V ±2% 800mA ±5% 5–8 R4 16.2k U2 D2 1N4148 5 3 2 R5 221k LM4041DIM3-1.2 C4 10nF To Cellular Telephone C1 22µF 35V J3 GND C5 220nF R1 0.100Ω D3 1N4148 J1 +30V max. R2 3.01k R3 976Ω U3 MIC6211BM5 R6 10k J4 GND Figure 7. Constant Current and Constant Voltage Battery Charger J1 +12V 2 C4 68µF 20V C5 33µF 35V 1 U1 MIC4681 IN SW SHDN FB 33µH C3 0.022µF 50V 4 D1 ES1B 1A 100V GND SOP-8 J2 GND J3 GND L1 3 5–8 R1 8.87k C1 68µF 20V R2 1k C2 0.1µF J4 –12V/150mA Figure 8. +12V to –12V/150mA Buck-Boost Converter +4.5V to +17V 2 C1 100µF 20V C6 0.1µF 50V 1 U2 U1 MIC4681 MIC4417BM4 IN SW 3 SHDN SHUTDOWN ENABLE FB GND SOP-8 5–8 Q1 4 R1 1k 1% * ISAT = 7.5A Si4425DY L1* D1 5A 50µH C2 470µF 6.3V R2 20mΩ C3 470µF 6.3V 3.3V/5A C4 1000pF R3 1k 1% R4 1k 1% R5 16k 1% R6 16k 1% R7 3.01k 1% D2 1N4148 U3 R8 MIC6211BM5 1.78k 1% C5 0.1µF GND Figure 9. 5V to 3.3V/5A Power Supply * See Application Hint 37 at www.micrel.com for bills of material. April 2005 15 MIC4681 MIC4681 Micrel Package Information 0.026 (0.65) MAX) PIN 1 0.157 (3.99) 0.150 (3.81) DIMENSIONS: INCHES (MM) 0.020 (0.51) 0.013 (0.33) 0.050 (1.27) TYP 0.064 (1.63) 0.045 (1.14) 45° 0.0098 (0.249) 0.0040 (0.102) 0.197 (5.0) 0.189 (4.8) 0°–8° SEATING PLANE 0.010 (0.25) 0.007 (0.18) 0.050 (1.27) 0.016 (0.40) 0.244 (6.20) 0.228 (5.79) 8-Lead SOP (M) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB USA 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 at Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. © 2005 Micrel, Incorporated. MIC4681 16 April 2005