TLE75008-EMD_15 Datasheet, PDF (22/64 Pages) Infineon Technologies AG – SPI Driver for Enhanced Relay Control

TLE75008-EMD
Power Supply
6
Power Supply
The TLE75008-EMD is supplied by two supply voltages:
• V_S (analog supply voltage used also for the logic)
• V_DD (digital supply voltage)
The V_S supply line is connected to a battery feed and used, in combination with V_DD supply, for the driving circuitry
of the power stages. In situations where V_S voltage drops below V_DD voltage (for instance during cranking events
down to 3.0 V), an increased current consumption may be observed at VDD pin.
V_S and V_DD supply voltages have an undervoltage detection circuit, which prevents the activation of the associated
function in case the measured voltage is below the undervoltage threshold. More in detail:
• An undervoltage on both V_S and V_DD supply voltages prevents the activation of the power stages and any SPI
communication (the SPI registers are reset)
• An undervoltage on V_DD supply prevents any SPI communication. SPI read/write registers are reset to default
values.
• An undervoltage on V_S supply forces the TLE75008-EMD to drain all needed current for the low-side switches
and for the logic from V_DD supply.
Figure 10 shows a basic concept drawing of the interaction between supply pins VS and VDD, the output stage
drivers and SO supply line.
VS
IVS
VDD
IVDD
SO
VREG
GD
UVR
VDD
UVR
VS
SPI
LS
GND
SupplyConcept_xLS.emf
Figure 10 TLE75008-EMD Internal Power Supply concept
When 3.0 V ≤ V_S ≤ V_DD - V_SDIFF TLE75008-EMD operates in “Cranking Operative Range” (COR). In this condition
the current consumption from VDD pin increases while it decreases from VS pin where the total current
consumption remains within the specified limits. Figure 11 shows the voltage levels at VS pin where the device
goes in and out of COR. During the transition to and from COR operative region, I_VS and I_VDD change between
values defined for normal operation and for COR operation. The sum of both current remains within limits specified
in “Overall current consumption” section (see Table 8).
Data Sheet
22
Rev. 1.1, 2015-09-25