MIC2177-5.0BWM Micrel Inc, MIC2177-5.0BWM Datasheet
MIC2177-5.0BWM
Specifications of MIC2177-5.0BWM
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MIC2177-5.0BWM Summary of contents
Page 1
... The Micrel MIC2177 is a 200kHz synchronous buck (step- down) switching regulator designed for high-efficiency, battery-powered applications. The MIC2177 operates from a 4.5V to 16.5V input and features internal power MOSFETs that can supply up to 2.5A output current. It can operate with a maximum duty cycle of 100% for use in low-dropout conditions ...
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... Micrel, Inc. Ordering Information Part Number Output Voltage MIC2177-3.3BWM 3.3V MIC2177-5.0BWM 5.0V MIC2177BWM Adj. MIC2177-3.3YWM 3.3V Pin Configuration April 2008 Switching Temperature Range Frequency 200kHz –40°C to +85°C 200kHz –40°C to +85°C 200kHz –40°C to +85°C 200kHz –40°C to +85°C ...
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... Connect to SGND if not used. Bias Supply: Internal 3.3V bias supply output. Decouple with 0.01µF bypass capacitor and 10kΩ to SGND. Do not apply any external load. Enable (Input): Logic high enables operation. Logic low shuts down regulator. Do not allow pin to float. 3 MIC2177 M9999-042108 ...
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... PWM mode, output not switching, 4.5V ≤ V ≤ 16.5V IN skip mode, output not switching, 4.5V ≤ V ≤ 16. 0V, 4.5V ≤ V ≤ 16. 16.5V IN MIC2177 [adj.]: V = 3.3V, I OUT MIC2177 [adj.]: V = 3.3V, OUT 5V ≤ V ≤ 16V, 10mA ≤ MIC2177-5. LOAD MIC2177-5.0: 6V ≤ V ≤ 16V, 10mA ≤ MIC2177-3 ...
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... Minimum Switch Current for PWM Operation General Note: Devices are ESD sensitive. Handling precautions recommended. April 2008 Condition V = 16. 5. 1.5V, VAUTO < 0. – OUT V – OUT 5 MIC2177 Min Typ Max Units 1 µA 10 0.8 1.6 V 2.2 0.01 µA –1 1 1.6 V 0.8 11 µ 220 mA ...
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... TEMPERATURE (°C) PWM-Mode Supply Current 12 OUTPUT 10 SWITCHING INPUT VOLTAGE (V) April 2008 Reference Voltage vs. Temperature 1.252 MIC2177 [adj.] 1.250 1.248 1.246 1.244 1.242 1.240 1.238 -60 - 120 150 TEMPERATURE (°C) Error-Amplifier Gain vs. Temperature 19.0 18.5 18.0 17.5 17.0 16.5 16.0 -60 -30 ...
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... Shutdown 20 BIAS 19 10k 0.01µF internal supply voltage SYNC 200kHz Oscillator 18 AUTO Auto-Mode PWM 11 2.2nF COMP MIC2177 [Adjustable] April 2008 Output I SENSE Control Amp. Logic I LIMIT Comp. PWM/ I MIN Skip-Mode Comp. Select Logic I MIN Thrshld. CORRECTIVE RAMP 3.3V Low Output Comp. ...
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... April 2008 Shutdown Mode The MIC2177 has a low-current shutdown mode that is controlled by the enable input (EN). When a logic 0 is applied to EN, the MIC2177 is in shutdown mode and its quiescent current drops to less than 5µA. Internal Bias Regulator An internal 3.3V regulator provides power to the MIC2177 control circuits. This internal supply is brought out to the BIAS pin for bypassing by an external 0.01µ ...
Page 9
... Changing from PWM to Skip Mode Refer to “Block Diagram” for circuits described in the following sections. The MIC2177 automatically changes from PWM to skip mode operation when I value. I peak inductor current (I done by the minimum current comparator which detects if the output P-Channel current equals 420mA during each switching cycle ...
Page 10
... L1 PWM mode result, AUTO stays below 1.6V for several switching cycles after PWM operation begins, forcing the MIC2177 to remain in PWM mode during this transition. External PWM-Mode Selection The MIC2177 can be forced to operate in only PWM mode by connecting AUTO to ground. This prevents skip-mode operation in applications that are sensitive to switching noise ...
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... Micrel, Inc. PWM-Mode Functional Diagram 200kHz Stop Oscillator MIC2177 [Adjustable] PWM-Mode Signal Path Reset Pulse Error Amp. Output April 2008 Corrective Ram p Reset Pulse R Q PWM S Comp. Error Amp. V 1.245V LOAD 4.5V to 16. VIN 100m V = 1.245 OUT P-channel Amp 100m P GND ...
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... Micrel, Inc. Skip-Mode Functional Diagram Output Control Logic MIC2177 [Adjustable] Skip-Mode Signal Pat V One-Shot Pulse April 2008 One Shot Amp. I LIMIT Comp. I LIMIT Thresh. Voltage Skip-Mode Comp. V 1.245V LIM 5mV – 5mV 4.5V to 16. VIN 1.245 + 1 100m OUT R2 P-channel GND MIC2177 ...
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... V Inductor Selection The inductor must be at least a minimum value in order for the MIC2177 to change from PWM to skip mode at the correct value of output current. This minimum value ensures the inductor ripple current never exceeds 600mA, and is calculated using the following formula: ⎛ ...
Page 14
... Micrel, Inc. the MIC2177. A good design takes into consideration component placement and routing of power traces. The first thing to consider is the locations of the input capacitor, inductor, output diode, and output capacitor. The input capacitor must be placed very close to the V pin, the inductor and output diode very close to the SW pin, and the output capacitor near the inductor ...
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... 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 April 2008 20-Pin Wide SOIC (WM) indemnify Micrel for any damages resulting from such use or sale. © 1999 Micrel, Incorporated. 15 MIC2177 M9999-042108 ...