CAT3644_0710 Datasheet, PDF (3/14 Pages) Catalyst Semiconductor – 4-Channel Ultra High Efficiency Quad-Mode™ LED Driver

RECOMMENDED EN/DIM TIMING
For 2.4V ≤ V_IN ≤ 5.5V, over full ambient temperature range -40ºC to +85ºC.
Symbol Name
Conditions
Min
T_SETUP EN/DIM setup from shutdown
10
T_LO
EN/DIM program low time
0.2
T_HI
EN/DIM program high time
0.2
T_PWRDWN EN/DIM low time to shutdown
1.5
T_LED
LED current settling time
CAT3644
Typ Max Units
μs
100
μs
μs
ms
40
μs
T_SETUP
T_HI
T_PWRDWN
EN/DIM
T_LED
LED
Current
Shutdown
100%
T_LO
100%
50%
25% _{12.5% 6.25% 3.12%}
Figure 1. EN/DIM Digital Dimming Timing Diagram
Shutdown
LED Current Setting
The nominal LED current is set by the external
resistor connected between the RSET pin and
ground. Table 1 lists standard resistor values for
several LED current settings.
LED current (mA)
2
5
10
15
20
25
30
RSET (kΩ)
40.0
15.8
7.87
5.23
4.02
3.16
2.67
Table 1. Resistor RSET and LED current
© Catalyst Semiconductor, Inc.
3
Characteristics subject to change without notice
Doc. No. MD-5023, Rev. E