MAX16810 Maxim Integrated Products, MAX16810 Datasheet - Page 19

• Manufacturer Part Number: MAX16810
• Description: (MAX16809 / MAX16810) Integrated 16-Channel LED Drivers
• Manufacturer: Maxim Integrated Products

All the output channels can be dimmed simultaneously
by applying a PWM signal (50Hz to 30kHz) to OE. This
allows for a wide range of dimming up to a 5000:1 ratio.
Each channel can be independently turned on and off
using a 4-wire serial interface. The dimming is propor-
tional to the PWM duty cycle.
Using an analog or digital potentiometer as R
for LED current amplitude adjustment and linear dimming.
Use the following equation to estimate the upper limit
power dissipation (PD) for the MAX16809/MAX16810:
where:
V+ = supply voltage
I+ = V+ operating supply current
DUTY = PWM duty cycle applied to OE
V
when driving load LED(s)
I
PD = power dissipation
OUTi
OUTi
PD
= LED drive current programmed by R
=
= MAX16809/MAX16810 port output voltage
+
DUTY
(
LED Current Amplitude Adjustment
V
CC
×
x I
Switch-Mode Boost and SEPIC Controller
Computing Power Dissipation
______________________________________________________________________________________
⎡
⎢
⎢
⎣
CC
(
Integrated 16-Channel LED Drivers with
V
)
+
x I
+ +
)
i
i
LED Dimming
=
=
∑
15
V
0
PWM Dimming
OUTi
x I
SET
SET
OUTi
allows
⎤
⎥
⎥
⎦
Careful PCB layout is critical to achieve low switching
losses and clean, stable operation. Use a multilayer
board whenever possible for better noise immunity.
Protect sensitive analog grounds by using a star
ground configuration. Minimize ground noise by con-
necting AGND, PGND, the input bypass-capacitor
ground lead, and the output-filter ground lead to a sin-
gle point (star ground configuration). Also, minimize
trace lengths to reduce stray capacitance, trace resis-
tance, and radiated noise. The trace between the out-
put voltage-divider and the FB pin must be kept short,
as well as the trace between AGND and PGND.
PCB Layout Guidelines
19