TLE9263QX datasheet(51/164 Pages) INFINEON

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Data Sheet

Rev. 1.1, 2014-09-26

TLE9263QX

External Voltage Regulator 3

Figure 19

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 20 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

Sx,MAX is regulated to VCC3,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 (VS,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.

RBE

VS -VCC3shunt

> Vshunt_threshold

VREF

State Machine

ICC3base

VCC3REF

VCC3B

VCC3SH

RSHUNT

VCC3

ICC3

RLim

100

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