Final Datasheet 2 of 51 V2.2
2022-4-4
TDA88 OptiMOS™ IPOL
40 A single-voltage synchronous Buck regulator
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 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
9 Thermal De-rating curves ....................................................................................................... 19
10 R
DS(ON)
of MOSFET Over Temperature ........................................................................................ 20
11 Typical operating characteristics (- °C ≤ T
j
≤ +125 °C) .............................................................. 21
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 TDA38840 ......................................................................................................................... 33
13.2 Programming the Switching Frequency and Operation Mode ............................................................ 33
13.3 Selecting Input Capacitors .................................................................................................................... 33
13.4 Inductor Selection ................................................................................................................................. 34
