MBI5171 Datasheet, PDF (28/31 Pages) List of Unclassifed Manufacturers – 8-Bit Constant Current LED Driver with LED Error Detection and Run-Time Current Adjustment

MBI5171
8-Bit Constant Current LED Sink Driver with
LED Error Detection and Run-Time Current Adjustment
Application Information
Package Power Dissipation (P_D)
The maximum allowable package power dissipation is determined as P_D(max) = (Tj – Ta) / R_th(j-a). When 8 output
channels are turned on simultaneously, the actual package power dissipation is
P_D(act) = (I_DD x V_DD) + (I_OUT x Duty x V_DS x 8)
Therefore, to keep P_D(act) ≤ P_D(max), the allowable maximum output current as a function of duty cycle is
I_OUT = { [ (Tj – Ta) / R_th(j-a) ] – (I_DD x V_DD) } / V_DS / Duty / 8
where Tj = 150°C.
Iout vs. Duty Cycle at Rth = 61.65 (°C/W)
120
110
100
90
80
70
60
50
40
30
20
10
0
Duty Cycle
CN Device Type
Iout vs. Duty Cycle at Rth = 61.63 ( °C/W)
120
110
100
90
80
70
60
50
40
30
20
10
0
Duty Cycle
CDW Device Type
120
110
100
90
80
70
60
50
40
30
20
10
0
120
110
100
90
80
70
60
50
40
30
20
10
0
Iout vs. Duty Cycle at Rth = 85.82 ( °C/W)
Duty Cycle
CD Device Type
Iout vs. Duty Cycle at Rth = 94.91 ( °C/W)
Duty Cycle
CP Device Type
Condition：V_DS = 1.0V, V_DD= 5.0V, 8 output channels active, Ta is listed in the
legend below.
Device Type R_th(j-a)(°C/W)
Note
CN
61.65
CD
85.82
25℃
55℃
85℃
CDW
61.63
CP
94.91
- 28 -
August 2004, VA.00