V
SUPPLY
is the supply voltage used to drive the LED (V).
V
LED
is the forward voltage of the LED (V).
V
OL
is the output low voltage of the MAX6964 when
sinking I
LED
(V).
I
LED
is the desired operating current of the LED (A).
For example, to operate a 2.2V red LED at 14mA from a
5V supply, R
LED
= (5 - 2.2 - 0.25) / 0.014 = 182Ω.
Driving Load Currents Higher than 50mA
The MAX6965 can be used to drive loads drawing more
than 50mA, like relays and high-current white LEDs, by
paralleling outputs. Use at least one output per 50mA of
load current; for example, a 6V 330mW relay draws
55mA and needs two paralleled outputs to drive it.
Ensure that the paralleled outputs chosen are controlled
by the same blink phase register, i.e., select outputs from
the O0 through O7 range. This way, the paralleled out-
puts are turned on and off together. Do not use output
O8 as part of a load-sharing design. O8 cannot be
switched at the same time as any of the other outputs
because it is controlled by a different register.
MAX6965
9-Output LED Driver with Intensity Control
and Hot-Insertion Protection
16 ______________________________________________________________________________________
Table 9. PWM Intensity Settings (Blink Disabled)
LED BEHAVIOR WHEN
OUTPUT BLINK PHASE 0
REGISTER BIT = 1
(LED IS ON WHEN
OUTPUT IS LOW)
0x0 1/16 15/16 Lowest PWM intensity 15/16 1/16 Highest PWM intensity
0x1 2/16 14/16 14/16 2/16
0x2 3/16 13/16 13/16 3/16
0x3 4/16 12/16 12/16 4/16
0x4 5/16 11/16 11/16 5/16
0x5 6/16 10/16 10/16 6/16
0x6 7/16 9/16 9/16 7/16
0x7 8/16 8/16 8/16 8/16
0x8 9/16 7/16 7/16 9/16
0x9 10/16 6/16 6/16 10/16
0xA 11/16 5/16 5/16 11/16
0xB 12/16 4/16 4/16 12/16
0xC 13/16 3/16 3/16 13/16
0xD 14/16 2/16
Increasing PWM intensity
2/16 14/16
Increasing PWM intensity
0xE 15/16 1/16 Highest PWM intensity 1/16 15/16 Lowest PWM intensity
0xF
