MIC4681 Micrel Semiconductor, MIC4681 Datasheet
MIC4681
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MIC4681 Summary of contents
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... 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 30V, with excellent line, load, and transient response. The regulator performs cycle-by-cycle current limiting and thermal shut- down for protection under fault conditions ...
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... MIC4681 Ordering Information Part Number MIC4681BM Pin Configuration Pin Description Pin Number Pin Name 1 SHDN 2 VIN 5–8 GND MIC4681 Voltage Junction Temp. Range Adjustable – +125 C SHDN 1 8 GND VIN 2 7 GND GND GND SOP-8 (M) Pin Function Shutdown (Input): Logic low enables regulator. Logic high (> ...
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... Note 6 ........... 20 C/W JC Min Typ Max 1.217 1.230 1.243 1.205 1.255 1.193 1.230 1.267 1.180 1.280 500 110 180 200 220 1.4 1.8 2.2 3.4 4.5 35 100 6 2 1.4 1.25 0.8 –10 –0.5 1 –10 –1.5 1 160 MIC4681 Micrel Units kHz kHz ...
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... MIC4681 Test Circuit SHUTDOWN Shutdown Input Behavior MIC4681 Device Under Test +30V SHDN FB ENABLE GND SOP-8 5–8 Current Limit Test Circuit ON GUARANTEED ON 0.8V 2V TYPICAL ON 0V 1.25V 1.4V Shutdown Hysteresis OFF GUARANTEED OFF TYPICAL OFF V IN(max) Micrel February 2001 ...
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... INPUT VOLTAGE (V) MIC4681BM Frequency vs. Supply Voltage 205 203 201 199 197 I = 100mA OUT Amb = 25 C 195 INPUT VOLTAGE (V) MIC4681 3.3V Output Efficiency 80 12Vin 60 24Vin 6Vin 40 20 Amb = 0.5 1 1.5 2 2.5 OUTPUT CURRENT (A) February 2001 Load Regulation 5 ...
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... MIC4681 Shutdown Thresholds vs. Temperature 1.5 Regulator Off Regulator On 1.0 0.5 0.0 -40 - 100 120 TEMPERATURE ( C) MIC4681 V = 12V IN 6 Saturation Voltage vs. Output Current 2 1 12V IN Amb = 0.5 1 1.5 2 OUTPUT CURRENT (A) February 2001 Micrel ...
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... MIC4681 February 2001 4681BM SOA 5Vout 4681BM SOA 5Vout 1 1.6 1.4 1.2 1.0 0.8 0.6 0 OUT 0 INPUT VOLTAGE (V) 4681BM SOA 3.3Vout 4681BM SOA 3.3Vout 2 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0 3.3V OUT 0 INPUT VOLTAGE ( Micrel MIC4681 ...
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... MIC4681 Functional Characteristics Switching Frequency Foldback 200kHz 60kHz TIME 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 Normal Operation Short Circuit Operation 8 Micrel Load Transient 1.5A 0A 100mV ...
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... MIC4681 Bode Plots The following bode plots show that the MIC4681 is stable over all conditions using inductor (L) and a 220 F output capacitor ( assure stability good practice to maintain a phase margin of greater than 35 . OUT No-Load Stability Phase Margin = 5.0V OUT ...
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... MIC4681 Block Diagrams MIC4681 SHDN Internal Regulator 200kHz Thermal Current Oscillator Shutdown Limit Com- parator Driver Reset Error 1.23V Amp Bandgap Reference MIC4681 [adj.] Adjustable Regulator OUT REF R2 V OUT REF V 1.23V REF V SW OUT ...
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... MIC4681 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. ...
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... There are two methods of determining the minimum ground plane area required by the MIC4681. Quick Method Make sure that MIC4681 pins 5 though 8 are connected to a ground plane with a minimum area of 6cm 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 ...
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... A circuit with sample layouts are provided. See Figures 6a though 6e. Gerber files are available upon request. V MIC4681BM SHDN FB D1 GND Figure 5. Critical Traces for Layout U1 MIC4681BM SHDN GND B340A optional SOP-8 5– SS36 2 Figure 6a ...
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... 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 Figure 6d. Bottom-Side Silk Screen Figure 6e. Bottom-Side Copper Manufacturer Description 1 Vishay Dale 35V 1 Vishay Dale 220 F / 10V ...
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... MIC4681 Applications Circuits* For continuously updated circuits using the MIC4681, see Application Hint 37 at www.micrel.com. J1 +30V max 100nF C1 OFF SHDN ON 35V S1 J3 NKK G12AP GND SOP-8 Figure 7. Constant Current and Constant Voltage Battery Charger J1 +12V 20V ...
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... MIC4681 Package Information 0.026 (0.65) 0.157 (3.99) 0.150 (3.81) 0.064 (1.63) 0.045 (1.14) MIC4681 MAX) PIN 1 DIMENSIONS: INCHES (MM) 0.020 (0.51) 0.013 (0.33) 0.050 (1.27) TYP 0.0098 (0.249) 0.0040 (0.102) 0 –8 0.197 (5.0) 0.189 (4.8) SEATING PLANE 8-Lead SOP ( 0.010 (0.25) 0.007 (0.18) 0.050 (1.27) 0.016 (0.40) 0.244 (6.20) 0.228 (5.79) Micrel February 2001 ...
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... MIC4681 February 2001 17 Micrel MIC4681 ...
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... MIC4681 MIC4681 18 Micrel February 2001 ...
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... This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. February 2001 + 1 (408) 944-0970 http://www.micrel.com FAX WEB © 2000 Micrel Incorporated 19 Micrel MIC4681 ...