TLD5095EL_15 Datasheet, PDF (10/35 Pages) Infineon Technologies AG – Multitopology LITIX Power DC/DC Controller IC

Infineon® LITIX™ Power
TLD5095EL
Regulator
5
Regulator
5.1
Description
The TLD5095 regulator is suitable for Boost, Buck, Buck-Boost, SEPIC and Flyback configurations. The
constant output current is especially useful for light emitting diode (LED) applications. The regulator function
is implemented by a pulse width modulated (PWM) current mode controller.
The PWM current mode controller uses the peak current through the external power switch and error in the
output current to determine the appropriate pulse width duty cycle (on time) for constant output current. The
current mode controller it provides a PWM signal to an internal gate driver which then outputs the same PWM
signal to external n-channel enhancement mode metal oxide field effect transistor (MOSFET) power switch.
The current mode controller also has built-in slope compensation to prevent sub-harmonic oscillations which
is a characteristic of current mode controllers operating at high duty cycles (>50% duty).
An additional built-in feature is an integrated soft start that limits the current through the inductor and
external power switch during initialization. The soft start function gradually increases the inductor and switch
current over 1 ms (typical) to minimize potential overvoltage at the output.
OVFB
COMP
FBH
FBL
FREQ/
SYNC
OV FB
VRef =
1.25V
H when
OVFB >1.25V
x1
EA
VRef ₌
0.3 V
Soft start
gmEA
IEA
Current
Comp
High when
lEA - ISLOPE - ICS > 0
OFF
when H
Low when
T_j > 175 °C
R
&^Q
Oscillator
I ^{Slope Comp}
t
Clock
S^& _Q
Error -FF
TLD5095
High when
IVCC < 4.0V
UV IVCC
NOR
> Output Stage
OFF when
1 ^Low
R
&
= VRef
4 .0V
INV
Q
1
Gate Driver
Supply
Gate
Driver
NAND 2
&
S^& _Q
PWM-FF
Current
Sense
ICS
IVCC
SWO
SWCS
SGND
Figure 5-1 Block Diagram Buck Regulator
Data Sheet
10
Revision 1.4
2015-03-11