MAX16824/MAX16825
High-Voltage, Three-Channel Linear
High-Brightness LED Drivers
10
Maxim Integrated
data. Holding OE low allows the output channels to fol-
low the state of the output latches. The duty cycle
depends on LE’s frequency. All output channels are
affected at the same time.
Another method of pulse dimming the outputs is to hold
LE high and drive OE with a PWM signal. Because the
input bits are always latched, the serial input constantly
refreshes the register. The control bits must be carefully
selected to dim the outputs properly.
LE
CLK
DO
D1
D2
DO
t
R
t
F
t
OEL
t
OEH
t
OEW
20%
80%
t
DO
t
DS
t
DH
t
CL
t
CH
t
CP
t
LW
t
LS
DIN
DOUT
OE
OUT_
50%
50%
50%
50%
50%
50%
50%
50%
50%
50%
50%
Figure 3. 4-Wire Serial-Interface Timing Diagram
MAX16824/MAX16825
High-Voltage, Three-Channel Linear
High-Brightness LED Drivers
11
Maxim Integrated
50%
50%
50%
50%
LE
OUT_
t
LRR
OUT_
CLK
t
CRR
OUT_
CLK
t
CRF
LE
OUT_
t
LRF
50%
50%
50%
50%
Figure 4. LE and CLK to OUT_ Timing
MAX16824/MAX16825
High-Voltage, Three-Channel Linear
High-Brightness LED Drivers
12
Maxim Integrated
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
OUT1
OUT2
CS2
N.C.
CS3
OUT3
GND
DOUT
OE
TOP VIEW
TSSOP-EP
CS1
IN
CLK
REG
N.C.
DIN
LE
MAX16825
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
OUT1
OUT2
CS2
N.C.
CS3
OUT3
GND
N.C.
PWM3
TOP VIEW
TSSOP-EP
CS1
IN
REG
N.C.
PWM1
PWM2
MAX16824
N.C.
+
+
Pin Configurations
A third method is to hold both LE and OE in the
enabled state. This allows the data bits to directly con-
trol the output channels, and hence, pulse dim the out-
put current. Make sure that the clock frequency does
not exceed the maximum rate at which the device can
change the state of the output channels.
Power Dissipation
The power dissipation (P
D
) of the MAX16824/
MAX16825 is determined from the following equation:
where:
V
IN
= supply voltage
V
INL
= supply voltage to the LED strings
I
IN
= supply current
V
LED_
= total forward voltage for one LED string
I
LED_
= LED current
V
CS_
= 200mV drop across R
CS_
DUTY_ = PWM_ duty cycle
The worst-case power dissipation occurs when the
drop across each internal MOSFET is at its maximum
with all three channels delivering the maximum allow-
able output current. The maximum drop across the
internal MOSFETs is determined by:
V
INL
- V
LED_
- V
CS_
when V
LED_
is at its minimum.
Higher ambient temperature increases the thermal stress
even further due to the reduction in voltage drop across
the LEDs. The MAX16824/MAX16825 thermal specifica-
tions are given according to the JEDEC-51 guidelines.
Good mechanical/thermal design practices must be
applied to help maintain the device junction temperature
below the absolute maximum ratings at all times.
P V I V V V I DUT
DININ INLLEDCSLED
+ × ×()( )(
11 1
YY
V V V I DUTY
V
INL LED CS LED
INL
1
2
22 2
)
()()
(
+− × ×
+−VV V I DUTY
LED CS LED33 3
3−××)( )
Chip Information
PROCESS: BiCMOS-DMOS
Package Information
For the latest package outline information and land patterns (foot-
prints), go to www.maximintegrated.com/packages
. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but the
drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE NO.
LAND
PATTERN NO.
16 TSSOP-EP U16E+3
21-0108
90-0120

MAX16824AUE+

Mfr. #:
Manufacturer:
Maxim Integrated
Description:
LED Lighting Drivers 3Ch Linear HB
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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