MIC2183 Micrel, Inc. MIC2183 Low Voltage Synchronous Buck PWM Control IC General Description Features Micrels MIC2183 is a high efficiency PWM synchronous Input voltage range: 2.9V to 14V buck control IC. With its wide input voltage range of 2.9V to >90% efficiency 14V, the MIC2183 can be used to efficiently step voltages Oscillator frequency of 400kHz down in 1- or 2-cell Li Ion battery powered applications, as Frequency divide-by-two pin well as in fixed 3.3V, 5V, or 12V systems. Frequency sync to 600kHz FreqOut oscillator output allows simple charge pump Efficiencies over 90% are achievable over a wide range of implementation in low voltage systems load conditions with the MIC2183s PWM control scheme. Front edge blanking The operating frequency can be divided by two by raising the 5 output drivers (typical) FREQ/2 pin to V . This allows the user to optimize efficiency DD Soft start versus board space. It also allows the MIC2183 to be exter- PWM current mode control nally synchronized to frequencies below its nominal 400KHz. 1A shutdown current The MIC2183 features an oscillator output, FreqOut, which Cycle-by-cycle current limiting can be used to implement a simple charge pump in low Frequency foldback short circuit protection voltage applications. The output of the charge pump can be Adjustable under-voltage lockout fed into the gate drive power circuitry via the V P pin. This IN 16-pin narrow-body SOP and QSOP package options feature allows enhanced gate drive, hence higher efficiencies Applications at low input voltages. MIC2183 also features a 1A shutdown mode, and a pro- 3.3V to 2.5V/1.8V/1.5V conversion grammable undervoltage lockout, making it well-suited for DC power distribution systems portable applications. Wireless modems ADSL line cards The MIC2183 is available in 16-pin SOP and QSOP packag- 1-and 2-cell Li Ion battery operated equipment ing options with a junction temperature range from -40C to Satellite Phones +125C. Typical Application % *+ , - MIC2183 EFFICIENCY 100 ( 95 . ) 90 85 & /() *+ , 80 75 /()%& % 70 & *+ , V = 3.3V IN 65 & % V = 2.5V 60 OUT % *+ , f = 200kHz 55 S 50 012345 OUTPUT CURRENT (A) Adjustable Output Synchronous Buck Converter Micrel, Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 474-1000 MIC2183 Micrel, Inc. Ordering Information Part Number Output Junction Standard Pb-Free Voltage Frequency Temp. Range Package MIC2183BM MIC2183YM Adj. 200/400KHz 40C to +125C 16-lead SOP MIC2183BQS MIC2183YQS Adj. 200/400KHz 40C to +125C 16-lead QSOP Pin Configuration VINA 1 16 VINP FreqOut 2 15 FREQ/2 SS 3 14 OUTP COMP 4 13 OUTN SGND 5 12 PGND FB 6 11 SYNC EN/UVLO 7 10 VDD CSL 8 9 CSH 16 Lead SOIC (M) 16 Lead QSOP (QS) M9999-042205 2 April 2005