CAT3648 Datasheet, PDF (3/14 Pages) Catalyst Semiconductor – 4-Channel Ultra High Efficiency Quad-Mode™ LED Driver with 32 Dimming Levels

RECOMMENDED EN/DIM TIMING
For 2.4V ≤ V_IN ≤ 5.5V, over full ambient temperature range -40ºC to +85ºC.
Symbol Name
Conditions
Min
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
CAT3648
Typ Max Units
100
μs
μs
ms
40
μs
EN/DIM
T_LED
LED
Current
Shutdown
T_HI
T_LO
100%
97% _94%
32 Levels
3% _0%
100%
T_PWRDWN
Shutdown
Figure 1. EN/DIM Digital Dimming Timing Diagram
LED Current Setting
The full scale 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.
Table 1. Resistor RSET and LED Current
Full Scale
LED Current [mA]
2
5
RSET [kΩ]
37.4
14.7
10
7.50
15
4.99
20
3.74
25
3.00
30
2.49
© Catalyst Semiconductor, Inc.
3
Characteristics subject to change without notice
Doc. No. MD-5031, Rev. A