TLD5541-1QV Datasheet, PDF (43/82 Pages) Infineon Technologies AG – H-Bridge DC/DC Controller with SPI Interface

H-Bridge DC/DC Controller with SPI Interface
TLD5541-1QV
Linear Regulator
9
Linear Regulator
The TLD5541-1QV features an integrated voltage regulator for the supply of the internal gate driver stages.
Furthermore an external voltage regulator can be connected to the IVCC_EXT pin to achieve an alternative gate
driver supply if required.
9.1
IVCC Description
When the IVCC pin is connected to the IVCC_EXT pin, the internal linear voltage regulator supplies the internal
gate drivers with a typical voltage of 5V and current up to I_LIM (P_9.2.2). An external output capacitor with low ESR
is required on pin IVCC for stability and buffering transient load currents. During normal operation the external
MOSFET switches will draw transient currents from the linear regulator and its output capacitor (Figure 25,
drawing A). Proper sizing of the output capacitor must be considered to supply sufficient peak current to the gate
of the external MOSFET switches. A minimum capacitance value is given in parameter C_IVCC (P_9.2.4).
Alternative IVCC_EXT Supply Concept:
The IVCC_EXT pin can be used for an external voltage supply to alternatively supply the MOSFET Gate drivers.
This concept is beneficial in the high input voltage range to avoid power losses in the IC (Figure 25, drawing B).
Integrated undervoltage protection for the external switching MOSFET:
An integrated undervoltage reset threshold circuit monitors the linear regulator output voltage. This undervoltage
reset threshold circuit will turn OFF the gate drivers in case the IVCC or IVCC_EXT voltage falls below their
undervoltage Reset switch OFF Thresholds V_{IVCC_RTH,d} (P_9.2.9) and V_{IVCC_EXT_RTH,d} (P_9.2.5).
In Limp Home state the Undervoltage Reset switch OFF threshold for the IVCC has no impact on the switching
activity.
The Undervoltage Reset threshold for the IVCC and the IVCC_EXT pins help to protect the external switches from
excessive power dissipation by ensuring the gate drive voltage is sufficient to enhance the gate of the external
logic level N-channel MOSFETs.
A
B
V_IN
Internal
VREG
IVCC
V_IN
Power
On Reset
IVCC_EXT
Gate Drivers
Figure 25 Voltage Regulator Configurations
Internal
VREG
IVCC
Power
On Reset
IVCC_EXT
Gate Drivers
External
VREG
Data Sheet
43
Rev. 1.0, 2016-05-20