TLD5190QV Datasheet, PDF (19/58 Pages) Infineon Technologies AG – H-Bridge DC/DC Controller for High Power LED Lighting

H-Bridge DC/DC Controller
TLD5190QV
Regulator Description
6
Regulator Description
The TLD5190QV includes all of the functions necessary to provide constant current to the output as usually
required to drive LEDs. A voltage mode regulation can also be implemented (Refer to Chapter 6.6).
It is designed to control 4 gate driver outputs in a H-Bridge topology by using only one inductor and 4 external
MOSFETs. This topology is able to operate in high power BOOST, BUCK-BOOST and BUCK mode applications
with maximum efficiency.
The transition between the different regulation modes is done automatically by the device itself, with respect to the
application boundary conditions.
The transition phase between modes is seamless.
6.1
Regulator Diagram Description
The TLD5190QV includes two analog current control inputs (IIN1, IIN2) to limit the maximum Input current (Block
A1 and A7 in Figure 6).
A second analog current control loop (A5, A6) connected to the sensing pins FBL, FBH regulates the output
current.
The regulator function is implemented by a pulse width modulated (PWM) current mode controller. The error in the
output current loop is used to determine the appropriate duty cycle to get a constant output current.
An external compensation network (R_COMP, C_COMP) is used to adjust the control loop to various application
boundary conditions.
The inductor current for the current mode loop is sensed by the R_SWCS resistor.
R_SWCS is used also to limit the maximum external switches / inductor current.
If the Voltage across R_SWCS exceeds its overcurrent threshold (V_{SWCS_buck} or V_{SWCS_boost} for buck or boost operation
respectively) the device reduces the duty cycle in order to bring the switches current below the imposed limit.
The current mode controller has a built-in slope compensation as well to prevent sub-harmonic oscillations.
The control loop logic block (LOGIC) provides a PWM signal to four internal gate drivers. The gate drivers
(HSGD1,2 and LSGD1,2) are used to drive external MOSFETs in an H-Bridge setup .
The control loop block diagram displayed in Figure 6 shows a typical constant current application. The voltage
across R_FB sets the output current. R_IN is used to fix the maximum input current.
Data Sheet
19
Rev. 1.0, 2016-05-20