cat4002a ON Semiconductor, cat4002a Datasheet - Page 3

• Manufacturer Part Number: cat4002a
• Description: Constant Current Led Driver With 32 Dimming Levels And Rset
• Manufacturer: ON Semiconductor

NOTE:
LED Current Setting
external resistor connected between the RSET pin and
ground. Table 5 lists standard resistor values for several
LED current settings.
becomes enabled and the LED channel current is set to the
full scale current according to the resistor RSET.
LED current ≅ 125 x V
Table 3. RECOMMENDED OPERATING CONDITIONS
Table 4. RECOMMENDED EN/DIM TIMING
V
Ambient Temperature Range
I
On the CAT400XA, the full scale LED current is set by the
When the EN/DIM is initially taken high, the CAT400XA
LED
T
IN
Symbol
PWRDWN
T
T
T
per LED pin
LED
LO
HI
Typical application circuit with external components is shown on page 1.
EN/DIM
Current
LED
EN/DIM program low time
EN/DIM program high time
LED current settling time
EN/DIM low time to shutdown
Shutdown
T
LED
RSET
/ RSET
Name
Figure 2. CAT400XA EN/DIM Dimming Timing Diagram
Parameter
T
100%
LO
(For 2.4 V ≤ V
97% 94%
http://onsemi.com
T
HI
IN
32 Levels
≤ 5.5 V, over full ambient temperature range −40°C to +85°C.)
3
Conditions
Table 5. RSET RESISTOR AND LED CURRENT
3%
LED Current [mA]
0%
Full Scale
10
15
20
25
30
40
2
5
100%
Min
0.2
0.2
T
PWRDWN
−40 to +85
Typ
2.4 to 5.5
10
3
Rating
0 to 40
Shutdown
RSET [kW]
Max
100
5
40.2
15.4
7.68
4.99
3.74
3.00
2.49
1.87
Units
Unit
mA
°C
ms
V
ms
ms
ms