IR3888 IR3888 OptiMOS IPOL 25 A single-voltage synchronous Buck regulator Features Single 4.3 V to 17 V application or Wide Input Voltage Range from 2.0 V to 17 V with an External VCC Precision Reference Voltage (0.6 V +/- 0.5%) Enhanced Fast COT engine stable with Ceramic Output Capacitors and No External Compensation Optional Forced Continuous Conduction Mode and Diode Emulation for Enhanced Light Load Efficiency Programmable Switching Frequency from 600 kHz to 2 MHz Monotonic Start-Up with Four Selectable Soft-Start Time & Enhanced Pre-Bias Start-Up Thermally Compensated Internal Over Current Protection with Four Selectable Settings Enable input with Voltage Monitoring Capability & Power Good Output Thermal Shut Down Operating Temp: -40 C < T < 125 C j Small Size: 6 mm x 5 mm PQFN Halogen-free and RoHS2 Compliant with Exemption 7a Potential applications Server Applications Storage Applications Telecom & Datacom Applications Distributed Point of Load Power Architectures Product validation Qualified for industrial applications according to the relevant tests of JEDEC47/20/22 Description The IR3888 is an easy-to-use, fully integrated dc - dc Buck regulator. The onboard PWM controller and OptiMOS FETs with integrated bootstrap diode make IR3888 a small footprint solution, providing high-efficient power delivery. Furthermore, it uses a fast Constant On-Time (COT) control scheme, which simplifies the design efforts and achieves fast control response. The IR3888 has an internal low dropout voltage regulator, allowing operations with a single supply. It can also operate with an external bias supply, extending the operating input voltage (PVin) range. The IR3888 is a versatile regulator, offering programmable switching frequency from 600 kHz to 2 MHz, four selectable current limits, four selectable soft-start time, Forced Continuous Conduction Mode (FCCM) and Diode Emulation Mode (DEM) operation. It also features important protection functions, such as pre-bias start-up, thermally compensated current limits, over voltage and under voltage protection, and thermal shutdown to give required system level security in the event of fault conditions. Final Datasheet Please read the Important Notice and Warnings at the end of this document V2.3 www.infineon.com page 1 of 49 2021-7-20 IR888 OptiMOS IPOL 25 A single-voltage synchronous Buck regulator Table of contents Table of contents Features ........................................................................................................................................ 1 Potential applications ..................................................................................................................... 1 Product validation .......................................................................................................................... 1 Description .................................................................................................................................... 1 Table of contents ............................................................................................................................ 2 1 Ordering information ............................................................................................................. 4 2 Functional block diagram ........................................................................................................ 5 3 Typical application diagram .................................................................................................... 6 4 Pin descriptions ..................................................................................................................... 7 5 Absolute maximum ratings ..................................................................................................... 9 6 Thermal Characteristics ......................................................................................................... 10 6.1 Thermal Characteristics ........................................................................................................................ 10 7 Electrical specifications ......................................................................................................... 11 7.1 Recommended operating conditions ................................................................................................... 11 7.2 Electrical characteristics ....................................................................................................................... 12 8 Typical efficiency and power loss curves .................................................................................. 15 8.1 PV = V = 12 V, F = 600 kHz ................................................................................................................ 15 in in sw 8.2 PV = V = 12 V, F = 800 kHz ................................................................................................................ 16 in in sw 8.3 PV = V = 12 V, F = 1000 kHz............................................................................................................... 17 in in sw 8.4 PV = V = VCC = 5 V, F = 600 kHz ........................................................................................................ 18 in in sw 9 Thermal De-rating curves ....................................................................................................... 19 10 R of MOSFET Over Temperature ........................................................................................ 20 DS(ON) 11 Typical operating characteristics (-40 C T +125 C) .............................................................. 21 j 12 Theory 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 13 Design 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 V2.3 2021-7-20