MIC2169 Micrel Semiconductor, MIC2169 Datasheet
MIC2169
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MIC2169 Summary of contents
Page 1
... PWM synchronous buck control IC housed in a small MSOP- 10 package. The MIC2169 allows compact DC/DC solutions with a minimal external component count and cost. The MIC2169 operates from 14.5V input, without the need of any additional bias voltage. The output voltage can be precisely regulated down to 0.8V. The adaptive all N-Channel MOSFET drive scheme allows efficiencies over 95% across a wide load range ...
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... MIC2169 Ordering Information Part Number Frequency MIC2169BMM 500kHz Pin Configuration Pin Description Pin Number Pin Name 1 VIN 2 VDD COMP/ GND 7 LSD 8 VSW 9 HSD 10 BST M9999-111803 Junction Temp. Range – +125 C 10-lead MSOP 10-Pin MSOP (MM) Pin Function Supply Voltage (Input 14.5V. ...
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... MIC2169 Absolute Maximum Ratings Supply Voltage (V ) .................................................. 15.5V IN Booststrapped Voltage (V ) ............................... V BST Junction Temperature (T ) ................ – Storage Temperature (T ) ....................... – +150 C S Electrical Characteristics 5V; bold values indicate –40 C < Parameter Condition Feedback Voltage Reference ( 1%) Feedback Voltage Reference ( 2% over temp) ...
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... MIC2169 Electrical Characteristics Parameter Condition Error Amplifier DC Gain Transconductance Soft-Start Soft-Start Current After timeout of internal timer. See Current Sense CS Over Current Trip Point V CS Temperature Coefficient Output Fault Correction Thresholds Upper Threshold, V (relative to V FB_OVT Lower Threshold, V (relative to V FB_UVT Gate Drivers ...
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... MIC2169 Typical Characteristics PWM Mode Supply Current vs. Temperature 2.9 2.7 2.5 2.3 2.1 1.9 1.7 1.5 1.3 1.1 0.9 0.7 0.5 -40 - 100120140 TEMPERATURE ( C) V vs. Temperature FB 0.806 0.804 0.802 0.800 0.798 0.796 0.794 0.792 -60 - 120 150 TEMPERATURE ( C) V Line Regulation DD vs. Temperature 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 -60 - 120 150 TEMPERATURE ( C) ...
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... This will cause the PWM comparator to increase t the top side MOSFET, causing the output voltage and bringing V Soft-Start The COMP/EN pin on the MIC2169 is used for the following three functions: 1. Disables the part by grounding this pin 2. External compensation to stabilize the voltage control loop 3 ...
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... Inductor Ripple Current = V F SWITCHING 200 A is the internal sink current to program the MIC2169 current limit. The MOSFET R therefore recommended to add a 50% margin to the load current (I LOAD limiting due to increased MOSFET junction temperature rise also recommended to connect R ...
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... For the low-side MOSFET G[low-side](avg) ISS GS Since the current from the gate drive comes from the input voltage, the power dissipated in the MIC2169 due to gate drive is GATEDRIVE IN G[high-side](avg) A convenient figure of merit for switching MOSFETs is the on resistance times the total gate charge R numbers translate into higher efficiency ...
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... Maximizing efficiency requires the proper selection of core material and minimizing the winding resistance. The high frequency operation of the MIC2169 requires the use of ferrite materials for all but the most cost sensitive applications. Lower cost iron powder cores may be used but the increase in core loss will reduce the efficiency of the power supply ...
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... MIC2169 Voltage Setting Components The MIC2169 requires two resistors to set the output voltage as shown in Figure 2. Error Amp V REF 0.8V MIC2169 [adj.] Figure 2. Voltage-Divider Configuration Where: V for the MIC2169 is typically 0.8V REF The output voltage is determined by the equation REF R2 A typical value of R1 can be between 3k and 10k . too large, it may allow noise to be introduced into the voltage feedback loop ...
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... Figure 4, versus 105 for Figure 6. The simple RC and C2 compensation scheme allows a maximum error amplifier phase boost of about 90 . Therefore easier to stabilize the MIC2169 voltage control loop by using high ESR value output capacitors. g Error Amplifier ...
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... Figure 7. Error Amplifier Gain Curve Figure 8. Error Amplifier Phase Curve Total Open-Loop Response The open-loop response for the MIC2169 controller is easily obtained by adding the power path and the error amplifier gains together, since they already are in Log scale desirable to have the gain curve intersect zero dB at tens of kilohertz, this is commonly called crossover frequency ...
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... The compensation resistor and capacitors should be placed right next to the COMP/EN pin and the other side should connect directly to the GND pin on the MIC2169 rather than going to the plane. 5. The input bulk capacitors should be placed close to the drain of the top MOSFET. ...
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... MIC2169 Package Information MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA + 1 (408) 944-0800 TEL The information furnished by Micrel in this datasheet 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. ...