MIC2186 MICREL [Micrel Semiconductor], MIC2186 Datasheet
MIC2186
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MIC2186 Summary of contents
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... MIC2186 General Description Micrel’s MIC2186 is a high efficiency boost PWM control IC. With its wide input voltage range of 2.9V to 14V, the MIC2186 can be used to efficiently boost voltages 2-cell Li Ion battery powered applications, as well as to boost voltages in fixed 3.3V, 5V, or 12V systems. Its powerful 1.6 driver allows the MIC2186 to supply large output currents with the selection of proper external MOSFETs ...
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... VINA 2 SKIP COMP 5 SGND EN/UVLO 8 VREF 9 CSH 10 VDD 11 SYNC 12 PGND 13 HIDC 14 OUTN 15 FREQ/2 16 VINP MIC2186 VINA 1 16 VINP SKIP 2 15 FREQ OUTN COMP 4 13 HIDC SGND 5 12 PGND SYNC EN/UVLO 7 10 VDD VREF 8 9 CSH 16-pin Narrow Body SOP (M) ...
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... P) ........................ +2.9V to +14V unless otherwise specified. Bold values J Min Typ Max 1.233 1.245 1.258 1.220 1.270 1.208 1.245 1.282 50 +0.08 –1.2 0.7 2.8 0.6 0.5 5 2.82 3.0 3.18 0.03 2.9 2.75 2.65 1.226 1.245 1.264 1.213 1.276 2 1 Micrel T + +125 C J Units MIC2186 ...
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... The maximum allowable power dissipation is a function of the maximum junction temperature the junction-to-ambient thermal resistance, J(max) Note 2. The device is not guaranteed to function outside its operating rating. Note 3. Devices are ESD sensitive. Handling precautions recommended. Note 4. See application information for limitations on maximum operating frequency. MIC2186 = 1.0V HIDC = 1.0V HIDC = 1.5V, V ...
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... INPUT VOLTAGE (V ) INA VDD vs. Input Voltage 3.10 3.05 3.00 2.95 2.90 2. 12V INPUT VOLTAGE (V ) INA Ienable vs. Venable 300 12V – 250 200 150 20 C 100 VENABLE (V) MIC2186 ...
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... 12V IN DC 404 402 400 398 396 394 392 INPUT VOLTAGE (V ) INA MIC2186 Oscillator Frequency vs. Temperature 405 400 395 390 385 380 375 12V IN DC 370 365 -50 -30 - TEMPERATURE ( C) Overcurrent Threshold vs ...
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... An internal correc- tive ramp provides slope compensation for stable operation above a 50% duty cycle. The controller is optimized for high efficiency, high performance DC-DC converter applications. Figure 1 shows a block diagram of the MIC2186 configured as a PWM boost converter. July 2002 C ...
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... Figure 2. MIC2186 SKIP Mode Block Diagram Control Loop PWM and SKIP modes of operation The MIC2186 can operate in either PWM (pulse width modu- lated) or SKIP mode. The efficiency of the boost converter can be improved at lower output loads by manually selecting the skip mode of operation. The potential disadvantage of skip mode is the variable switching frequency that accompa- nies this mode of operation ...
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... The switching converter then turns the gate drive back on. While the gate drive is disabled, the MIC2186 draws less IC supply current then while it is switch- ing, thereby improving efficiency at low output loads. Figure 4 shows the efficiency improvement at low output loads when SKIP mode is selected ...
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... ON T PER Figure 6: PWM Control Loop A block diagram of the MIC2186 PWM current mode control loop is shown in Figure 1. The inductor current is sensed by measuring the voltage across a resistor, Rsense. The current sense amplifier buffers and amplifies this signal. A ramp is added to this signal to provide slope compensation, which is required in current mode control to prevent unstable opera- tion at duty cycles greater than 50% ...
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... Vgs threshold voltage of the N-channel MOSFET must be low enough to operate at the minimum VinP voltage to guarantee the boost converter will start up. The maximum amout of MOSFET gate charge that can be driven is limited by the power dissipation in the MIC2186. The power dissipated by the gate drive circuitry is calculated below: P_gate_drive=Q_gate * VinP * fs ...
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... Vdd voltage for the internal supply bus. The reference voltage in the MIC2186 is buffered and brought out to pin 8. The Vref pin must be bypassed to GND (pin 4) with a 0.1uf capacitor. The Vdd pin must be decoupled to ground with a 1uf ceramic capacitor ...
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... As the soft start voltage increases, the output voltage rises in a controlled fashion until the output voltage reaches the regulated value. HiDC=H F/2=L HiDC=L F/2=L Voltage Setting Components The MIC2186 requires two resistors to set the output voltage as shown in figure 11 13 Micrel Soft Start 0V Figure 10. MIC2186 ...
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... Use a low gate charge MOSFET or use the smallest MOSFET, which is still adequate for the MIC2186 maximum output current. * Allow the MIC2186 to run in skip mode at lower currents. If running in PWM mode, set the R1 MIC2186 to switch at a lower frequency ferrite material for the inductor core, which ...
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... SEATING PLANE 16-Pin SOIC (M) PIN 1 0.012 (0.30) 0.025 (0.635) BSC 0.008 (0.20) 0.0098 (0.249) 0.0075 (0.190) 0.196 (4.98) 0.189 (4.80) 16-Pin QSOP (QS –8 0.050 (1.27) 0.016 (0.40) 0.244 (6.20) 0.228 (5.79) DIMENSIONS: INCHES (MM 0.050 (1.27) 0.016 (0.40) 0.2284 (5.801) 0.2240 (5.690) Micrel MIC2186 ...
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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. MIC2186 + 1 (408) 944-0970 http://www ...