TCA62735AFLG Datasheet, PDF (14/18 Pages) Marktech Corporate – Charge Pump type DC/DC Converter for White LED Driver

TCA62735AFLG
3) Input Logic signal
User can adjust I_LED with Logic signal input as indicated in recommended circuit.
The Resistor connected the ON-State Nch MOS Drain and R_SET determines I_LED.
I_LED can be set according to the next expression.

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

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2007-06-21