MIC2183 General Description
Micrel's MIC2183 is a high efficiency PWM synchronous buck control IC. With its wide input voltage range of 2.9V to
14V, the MIC2183 can be used to efficiently step voltages down in 1- or 2-cell Li Ion battery powered applications, as well as in fixed 3.3V, 5V, or 12V systems.
Efficiencies over 90% are achievable over a wide range of load conditions with the MIC2183's PWM control scheme.
The operating frequency can be divided by two by raising the FREQ/2 pin to VDD. This allows the user to optimize efficiency versus board space. It also allows the MIC2183 to be externally synchronized to frequencies below its nominal 400KHz.
The MIC2183 features an oscillator output, FreqOut, which can be used to implement a simple charge pump in low
voltage applications. The output of the charge pump can be fed into the gate drive power circuitry via the VINP pin. This feature allows enhanced gate drive, hence higher efficiencies at low input voltages.
MIC2183 also features a 1A shutdown mode, and a programmable undervoltage lockout, making it well-suited for
portable applications.
The MIC2183 is available in 16-pin SOP and QSOP packaging options with a junction temperature range from -40°C to +125°C.
MIC2183 Maximum Ratings
Supply Voltage (VINA, VINP) .......................................15V
Digital Supply Voltage (VDD) ........................................7V
Comp Pin Voltage (VCOMP) ....................... 0.3V to +3V
Feedback Pin Voltage (VFB) ...................... 0.3V to +3V
Enable Pin Voltage (VEN/UVLO) .................. 0.3V to 15V
Current Sense Voltage (VCSHVCSL) .......... 0.3V to 1V
Sync Pin Voltage (VSYNC) ............................ 0.3V to 7V
Freq/2 Pin Voltage (VFREQ/2) ........................ -0.3V to 7V
Power Dissipation (PD)
16 lead SOIC ........................... 400mW @ TA = 85°C
16 lead QSOP .................................. 245mW @ 85°C
Ambient Storage Temp ................... 65°C to +150°C
MIC2183 Features
• Input voltage range: 2.9V to 14V
• >90% efficiency
• Oscillator frequency of 400kHz
• Frequency divide-by-two pin
• Frequency sync to 600kHz
• FreqOut oscillator output allows simple charge pump implementation in low voltage systems
• Front edge blanking
• 5 output drivers (typical)
• Soft start
• PWM current mode control
• 1A shutdown current
• Cycle-by-cycle current limiting
• Frequency foldback short circuit protection
• Adjustable under-voltage lockout
• 16-pin narrow-body SOP and QSOP package options
MIC2183 Typical Application
• 3.3V to 2.5V/1.8V/1.5V conversion
• DC power distribution systems
• Wireless modems
• ADSL line cards
• 1-and 2-cell Li Ion battery operated equipment
• Satellite Phones
MIC2183 Connection Diagram
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