TLE9261-3QX Datasheet, PDF (68/186 Pages) Infineon Technologies AG – Dedicated Data Sheets are available for the different product variants

TLE9261-3QX
External Voltage Regulator 3
VS
C₁
R_SHUNT
T1
VS
VCC3SH
VCC3B
VCC3
I_CC3
R_Lim
C₂
100 Ω
VCC3REF
R_BE
V_S - V_CC3shunt
> V_{shunt_threshold}
State Machine
I_CC3base
+
- _VREF
Figure 24 Protecting the VCC3 against inductive short circuits when configured as an independent
voltage regulator for off-board supply
8.2.2 External Voltage Regulator in Load Sharing Mode
The purpose of the load sharing mode is to increase the total current capability of VCC1 without increase of the
power dissipation within the SBC. The load current is shared between the VCC1 internal regulator and the external
PNP transistor of VCC3. Figure 25 shows the setup for Load Sharing. Load Sharing is active in SBC Normal
Mode. It can also be configured via SPI to stay active in SBC Stop Mode.
An input voltage up to V_Sx,MAX is regulated to V_CC3,nom = 5.0 V with a precision of ±2% when used in the load sharing
configuration in SBC Normal Mode.
This configuration is set and locked by enabling VCC3_LS for the first time while VCC3_ON has no function, i.e.
keep VCC3_ON = 0. Trying to change the VCC3 configuration after VCC3_LS has been set will result in the
SPI_FAIL bit being set and keeping the VCC3 configurations unchanged. Load sharing will be automatically
disabled (only if VCC3_LS_ STP_ON = 0) during SBC Stop Mode due to power saving reasons but the bit will
remain set to automatically switch back on after returning to SBC Normal Mode. It must be ensured that the same
VCC3 output voltage level is selected as for VCC1.
In this configuration VCC3 has no undervoltage signalization. VCC3 shuts down if Fail-Safe Mode is reached,
e.g. due to undervoltage shutdown (V_S,UV monitoring).
VCC3 has no over current limitation in this configuration and the shunt resistor is defining the load sharing ratio
between the VCC1 and VCC3 load currents (see Equation (2) in Chapter 8.4). Thus, no over current condition
VCC3_OC will be signaled in this configuration.
Data Sheet
68
Rev. 1.1, 2014-09-26