TLD5085EJ_1 Datasheet, PDF (12/16 Pages) Infineon Technologies AG – 1.8A DC/DC Step-Down Converter

TLD5085EJ
Application Information
8.4
Constant Output Voltage Mode for LED applications
V_Batt
D_RV
L₁
C_S
C₁ C₂
Ignition Key
Terminal 15
PWM Dimming
Optional
Parts
CCOMP
R_COMP
8 _VS
TLD5085
BDS 5
C_bootstrap
7 _EN
1 _PWMI
BUO ⁶
3 _COMP
GND
2
FB ⁴
L_BU
D_BU
R₁
V R2
FB
C_BU1 C_BU2
R_balance1
V_CC
R_balance2
SPIDER-LS TLE7240 SL
Figure 5 Application Diagram (constant voltage mode)
Note: This is a very simplified example of an application circuit. The function must be verified in the real application
The output voltage of the TLD5085EJ can be programmed by a voltage divider connected to the feedback pin FB.
The divider cross current should be 300 µA at minimum, therefore the maximum R₂ calculates:
R₂ ≤ V_FB / I_R2 --> R₂ ≤ 0.6V / 300 µA = 2 kΩ
For the desired output voltage level V_CC, R₁ calculates then (neglecting the small FB input current):
R₁
=
R_{2}
V_----C----C--
V_FB
–
1_
.
Datasheet
12
Rev. 1.1, 2009-12-16