link to page 1 link to page 1 link to page 1 link to page 1 link to page 2 link to page 4 link to page 5 link to page 6 link to page 7 link to page 9 link to page 10 link to page 10 link to page 11 link to page 11 link to page 12 link to page 15 link to page 15 link to page 16 link to page 17 link to page 18 link to page 19 link to page 20 link to page 21 link to page 24 link to page 24 link to page 24 link to page 25 link to page 25 link to page 26 link to page 27 link to page 27 link to page 28 link to page 29 link to page 29 link to page 30 link to page 30 link to page 31 link to page 31 link to page 32 link to page 33 link to page 33 link to page 33 link to page 33 link to page 34 IR 888 OptiMOS™ IPOL25 A single-voltage synchronous Buck regulatorTable of contentsTable of contents Features .. 1Potential applications ... 1Product validation .. 1Description .. 1Table of contents .. 21Ordering information ... 42Functional block diagram .. 53Typical application diagram .. 64Pin descriptions ... 75Absolute maximum ratings ... 96Thermal Characteristics ... 10 6.1 Thermal Characteristics .. 10 7Electrical specifications ... 11 7.1 Recommended operating conditions ... 11 7.2 Electrical characteristics ... 12 8Typical efficiency and power loss curves .. 15 8.1 PVin = Vin = 12 V, Fsw = 600 kHz .. 15 8.2 PVin = Vin = 12 V, Fsw = 800 kHz .. 16 8.3 PVin = Vin = 12 V, Fsw = 1000 kHz... 17 8.4 PVin = Vin = VCC = 5 V, Fsw = 600 kHz .. 18 9Thermal De-rating curves ... 1910RDS(ON) of MOSFET Over Temperature .. 2011Typical operating characteristics (-40 °C ≤ Tj ≤ +125 °C) .. 2112Theory of operation ... 24 12.1 Fast Constant On-Time Control .. 24 12.2 Enable .. 24 12.3 FCCM and DEM Operation ... 25 12.4 Pseudo Constant Switching Frequency .. 25 12.5 Soft-start .. 26 12.6 Pre-bias Start-up ... 27 12.7 Internal Low - Dropout (LDO) Regulator ... 27 12.8 Over Current Protection (OCP) ... 28 12.9 Under Voltage Protection (UVP) ... 29 12.10 Over Voltage Protection (OVP) .. 29 12.11 Over Temperature Protection (OTP) .. 30 12.12 Power Good (PGood) Output .. 30 12.13 Minimum On - Time and Minimum Off - Time .. 31 12.14 Selection of Feedforward Capacitor and Feedback Resistors ... 31 12.15 Resistors for Configuration Pins ... 32 13Design example ... 33 13.1 Enabling the IR3888 ... 33 13.2 Programming the Switching Frequency and Operation Mode .. 33 13.3 Selecting Input Capacitors .. 33 13.4 Inductor Selection ... 34 Final Datasheet 2 of 49 V2.1 2019-12-11 Document Outline Revision History Trademarks Disclaimer