TCA62735AFLG Datasheet, PDF (8/12 Pages) Marktech Corporate – Charge Pump type DC/DC Converter for White LED Driver

TENTATIVE
2) Input analog voltage to ISET terminal
1. Precondition

• Please set the range of the analog voltage input by 0 to 0.61V.
2. The maximum current is defined as αmA.
R₁[kΩ] + R₂[kΩ]




α[mA] = 0.61[V] ×









× 400
R₁[kΩ] × R₂[kΩ]
3. A minimum current is defined as βmA.
1

β[mA] = 0.61[V] ×




× 400
R₂[kΩ]
4. ILED can be set according to the next expression.
β[mA] - α[mA]

ILED[mA] = V_ADJ[V] ×






+ α[mA]
0.61[V]
ILED vs. VADJ
25
20
15
10
5
0
0
0.2
0.4
0.6
VADJ (V)
V_ADJ=0V to 0.61V
R₂=47kΩ
R₁=16kΩ
C₁=1.0µF
C₂=1.0µF
C1-
C2-
C2+
GND
C_OUT=1.0µF
CTL2
CTL1
CTL0
EN
TCA62735AFLG
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 8 of 12)