TLE7235E Datasheet, PDF (5/37 Pages) Infineon Technologies AG – 8 Channel High-Side and Low-Side Relay Switch with Limp Home Mode

TLE7235E
Overview
Detailed Description
The TLE7235E is an eight channel high-side and low-side relay switch providing embedded protective functions.
The output stages incorporate two low-side switches (0.9 Ω per channel), four high-side switches (two channels
with 0.9 Ω and two channels with 1.6 Ω) and two auto-configuring high-side or low-side switches (0.9 Ω per
channel). The auto-configuring switches can be utilized in high-side or low-side configuration just by connecting
the load accordingly. They are also suitable to switch a 5 V supply line in high-side configuration. Protective and
diagnostic functions adjust automatically to the chosen configuration.
The 8 bit serial peripheral interface (SPI) is utilized for control and diagnosis of the device and the loads. The SPI
interface provides daisy chain capability in order to assemble multiple devices in one SPI chain by using the same
number of micro-controller pins.
Furthermore, the TLE7235E is equipped with two input pins that can be individually routed to the output control of
each channel thus offering complete flexibility in design and PCB-layout. The input multiplexer is controlled via
SPI.
In limp home mode (fail-safe mode), the input pins are directly routed to the configurable output channels 4 and
5. The limp home mode operates independently of digital power supply and is activated via pin LHI.
The device provides full diagnosis of the load via open load, over load and short circuit detection. SPI diagnosis
flags indicate latched fault conditions that may have occurred.
Each output stage is protected against short circuit. In case of over load, the affected channel switches off. There
are temperature sensors available for each channel to protect the device against over temperature.
The device protects itself with a build in reverse polarity protection which prohibits intrinsic current flow through
the logic during reverse polarity. However the output stages still incorporate a reverse diode where current can
flow through during reverse polarity.
The power transistors are built by N-channel power MOSFETs. The inputs are ground referenced CMOS
compatible. The device is monolithically integrated in Smart Power Technology.
Data Sheet
5
Rev. 1.0, 2008-10-30