TLE9221SX Datasheet, PDF (32/91 Pages) Infineon Technologies AG – FlexRay Transceiver

TLE9221SX
Power Supply Interface
8.1
INH Output
The INH output signal is intended to control an external voltage regulator. When the FlexRay transceiver
TLE9221SX is in BD_Sleep mode, the INH output is open and floating. In every other operation mode the INH
output voltage is uINH1_Not-Sleep. The voltage uINH1_Not-Sleep is derived from the power supply uV_BAT by an internal
open drain transistor (see Figure 22).
According to the FlexRay Electrical Physical Layer Specification, version 3.0.1, the transceiver TLE9221SX
signals “Sleep” at the INH pin, while the device is in BD_Sleep mode and “Not_Sleep” in any other mode of
operation (BD_Standby, BD_Normal, BD_ReceiveOnly and the BD_GoToSleep command).
V_BAT (11)
INH (1)
State
Machine
U
“Not_Sleep”
“Sleep” ¹⁾
uV_BAT
uINH1_{Not_Sleep}
(BD_Normal)
(BD_ReceiveOnly)
(BD_Standby)
(BD_GoToSleep)
(BD_Sleep)
t
1) _{The INH output is usually floating.}
To achive a “low” signal on the INH output an external load is required.
Figure 22 Circuit diagram of the INH output
8.2
BD_Off and Undervoltage
The FlexRay transceiver TLE9221SX monitors the two power supplies uV_CC and uV_Bat and also the reference
voltage uV_IO. In case one of the three voltages falls below its dedicated undervoltage detection threshold, the
TLE9221SX changes its mode of operation to low power mode (see Figure 23). For undervoltage condition, the
Central State Machine is still functional.
Data Sheet
32
Rev. 1.10, 2013-07-15