TLE75008-EMD_15 Datasheet, PDF (36/64 Pages) Infineon Technologies AG – SPI Driver for Enhanced Relay Control

TLE75008-EMD
Power Stages
7
Power Stages
The TLE75008-EMD is an eight channels low-side relay switch. The power stages are built by N-channel lateral
power MOSFET transistors.
7.1
Output ON-state resistance
The ON-state resistance R_DS(ON) depends on the supply voltage as well as the junction temperature T_J.
7.1.1 Switching Resistive Loads
When switching resistive loads the following switching times and slew rates can be considered.
INn /
OUT.OUTn
V_DS
90% of V_S
70% of V_S
t_{DELAY (ON)}
30% of V_S
10% of V_S
t_ON
dV /
d t_ON
Figure 15 Switching a Resistive Load
t_{DELAY (OFF)}
t_OFF t
70%
dV /
d t_OFF
30%
t
SwitchON .emf
7.1.2 Inductive Output Clamp
When switching off inductive loads, the voltage across the power switch rises to V_DS(CL) potential, because the
inductance intends to continue driving the current. The voltage clamping is necessary to prevent device
destruction.
Figure 16 shows a concept drawing of the implementation. Nevertheless, the maximum allowed load inductance
is limited. The clamping structure protects the device in all operative modes (Sleep, Idle, Active, Limp Home).
Data Sheet
36
Rev. 1.1, 2015-09-25