TLE7233G_15 Datasheet, PDF (16/33 Pages) Infineon Technologies AG – 4 channel low-side driver with limp home

SPI Driver for Enhanced Relay Control
SPIDER - TLE7233G
Power Stages
Maximum Load Inductance
During demagnetization of inductive loads, energy has to be dissipated in the TLE7233G.
This energy can be calculated with following equation:
E = V_DS(CL) ⋅
V_{-----B---A---T----}–_-----V_{----D----S---(-C----L--)}
⋅
⎛
ln⎜1
–
-----------^R-----^L----^â‹---^I--^D-------------
⎞
⎟
R_L
⎝ ^V_BAT ^{– V}_DS(CL) ⎠
+ I_D
⋅ --^L----
R_L
Following equation simplifies under the assumption of R_L = 0:
E
=
1_--
2
LI_D²
⋅
⎛
⎜1
–
-------------^V-----^B---^A---^T--------------
⎞
⎟
⎝ ^V_BAT ^{– V}_DS(CL) ⎠
The maximum energy, which is converted into heat, is limited by the thermal design of the component.
6.3
Timing Diagrams
The power transistors are switched on and off with a dedicated slope via the IN bits of the serial peripheral
interface SPI. The switching times t_ON and t_OFF are designed equally.
CS
VDS
80%
SPI: ON
tON
SPI: OFF
tOFF
t
20%
Figure 7 Switching a Resistive Load
SwitchOn.emf
t
In input direct drive mode, a high signal at the input pin is equivalent to a SPI ON command and a low signal to
SPI OFF command respectively. Please refer to Chapter 9.3 for details on operation modes.
The listed switching times are not valid, when switching to or from stand-by mode.
Datasheet
16
Rev. 1.2, 2014-05-09