link to page 22 link to page 22 Data SheetADP1851TYPICAL PERFORMANCE CHARACTERISTICS100100PULSE SKIPPULSE SKIP90FORCED PWM90FORCED PWM80807070)) %(%60(60YYCCN50N50IEIE C40FFIC40FFIEE30302020101000 7 0.1110100 004 0.1110100 00 LOAD (A) 595- 10595- LOAD (A) 10 Figure 4. Efficiency Plot Figure 7. Efficiency Plot 12 VIN to 1.8 VOUT, 600 kHz (see Figure 34 for Circuit) 12 VIN to 3.3 VOUT, 300 kHz (see Figure 35 for Circuit) LOADLOAD CURRENTCURRENT44VOUT_ACVOUT_AC22 5 CH2 100mV 008 BM 100µs 50MS/sA CH4 13.4A 00 CH2 200mVBWM 100µs 5.0MS/sA CH4 14.2AWCH4 10A 595- B20ns/ptΩ 595- CH4 10AΩ BW200ns/ptW 10 10 Figure 5. 10 A to 20 A Load Step, Figure 8. 10 A to 20 A Load Step, 12 VIN to 1.8 VOUT, 600 kHz, Current Mode 12 VIN to 3.3 VOUT, 300 kHz, Voltage Mode VINVIN11VOUT_ACVOUT_AC22DL 9 006 00 CH1 5V BBCH1 5VBCH2 200mVBM 100µs 250MS/s A CH111.3VW CH2 100mVW M 100µs 125MS/s A CH111.3V 95- WW 595- 8.0ns/pt4ns/pt 105 10 Figure 6. 9 V to 15 V Line Step, Figure 9. 9 V to 15 V Line Step, 1.8 VOUT, 20 A Load, Current Mode 3.3 VOUT, 15 A Load, Voltage Mode Rev. B | Page 9 of 24 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION TYPICAL OPERATION CIRCUIT REVISION HISTORY SIMPLIFIED BLOCK DIAGRAM SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS THEORY OF OPERATION CONTROL ARCHITECTURE OSCILLATOR FREQUENCY SYNCHRONIZATION PWM AND PULSE SKIP MODES OF OPERATION SYNCHRONOUS RECTIFIER AND DEAD TIME INPUT UNDERVOLTAGE LOCKOUT INTERNAL LINEAR REGULATOR OVERVOLTAGE PROTECTION POWER GOOD SHORT-CIRCUIT AND CURRENT-LIMIT PROTECTION ENABLE/DISABLE CONTROL THERMAL OVERLOAD PROTECTION APPLICATIONS INFORMATION ADIsimPower DESIGN TOOL SETTING THE OUTPUT VOLTAGE SOFT START SETTING THE CURRENT LIMIT ACCURATE CURRENT-LIMIT SENSING INPUT CAPACITOR SELECTION VIN PIN FILTER BOOST CAPACITOR SELECTION INDUCTOR SELECTION OUTPUT CAPACITOR SELECTION MOSFET SELECTION LOOP COMPENSATION—VOLTAGE MODE Type III Compensation LOOP COMPENSATION—CURRENT MODE Setting the Slope Compensation Setting the Current Sense Gain Type II Compensation SWITCHING NOISE AND OVERSHOOT REDUCTION VOLTAGE TRACKING Coincident Tracking Ratiometric Tracking PCB LAYOUT GUIDELINES TYPICAL OPERATING CIRCUITS OUTLINE DIMENSIONS ORDERING GUIDE