TCA62735AFLG Datasheet, PDF (9/12 Pages) Marktech Corporate – Charge Pump type DC/DC Converter for White LED Driver

TENTATIVE
3) Input Logic signal
User can adjust ILED with Logic signal input as indicated in recommended circuit.
The Resistor connected the ON-State Nch MOS Drain and R_SET determines ILED.
ILED can be set according to the next expression.

ILED[mA] =
400 × 0.61[V]
R[kΩ]
TCA62735AFLG
About combined resistance R[kΩ]
M1
M2
R[kΩ]
R_SET[kΩ] × R₁[kΩ] × R₂[kΩ]
ON
ON
R₁[kΩ]×R_SET[kΩ] + R₂[kΩ]×R_SET[kΩ] + R₁[kΩ]×R₂[kΩ]
ON
OFF
R_SET[kΩ] × R₁[kΩ]
R_SET[kΩ] + R₁[kΩ]
OFF
ON
R_SET[kΩ] × R₂[kΩ]
R_SET[kΩ] + R₂[kΩ]
OFF
OFF
R_SET[kΩ]
M₂
M₁
C₁=1.0µF
C₂=1.0µF
R₂
R₁
C1-
C2-
C2+
GND
C_OUT=1.0µF
CTL2
CTL1
CTL0
EN
R_SET
V_IN=2.8V to 4.2V
C_IN=2.2µF
This method is without repeating IC ON/OFF, and no need to consider holding rash current.

This datasheet is tentative, the values and contents are subject to change without any notice. 2005-04-26 (Page 9 of 12)