MAX16839EVKIT+ Maxim Integrated Products, MAX16839EVKIT+ Datasheet - Page 3

• Manufacturer Part Number: MAX16839EVKIT+
• Description: KIT EVAL FOR MAX16839
• Manufacturer: Maxim Integrated Products

Specifications of MAX16839EVKIT+

• Core Chip: MAX16839
• No. Of Outputs: 3
• Output Current: 100mA
• Dimming Control Type: PWM
• Development Tool Type: Hardware / Software - Eval/Demo Board
• Mcu Supported Families: MAX16839 Family
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

*Default position.
The EV kit can drive three separate HB LED loads. Each
load can consist of multiple HB LEDs in series with a
total forward voltage up to 39V. If the HB LED forward
voltage is > 6.5V, the input voltage must rise within 14Fs
to avoid a fault, or the fault feature must be disabled by
connecting the FLTS output to ground. The EV kit circuit
drives HB LEDs rated for a minimum of 100mA and can
be reconfigured to drive up to 50mA. Proper heat-sinking
of the LEDs is important for optimum LED performance
and durability.
The EV kit features jumpers to reconfigure each
MAX16839 linear current-sink circuit on each channel.
When inserted on pins 1-2, jumpers JU1, JU2, and JU3
configure the current sink’s limit to 100mA, respectively.
Installing the jumpers on pins 2-3 configures the current
sink’s limit to 50mA. See Table 1 for channel 1, Table 2
for channel 2, and Table 3 for channel 3 jumper settings.
To reconfigure the circuit for another current limit,
replace resistor R2, R4, or R6 for channels 1, 2, and 3,
respectively, and use the following equation to calculate
a new value for the desired current:
where I
((I
R4, or R6 resistor value in ohms for obtaining the desired
HB LED current. Install the respective jumper (JU1, JU2,
or JU3) on pins 1-2 when configuring the channel for
another current.
Table 1. Channel 1
Table 2.
*Default position.
LED1
POSITION
POSITION
SHUNT
SHUNT
1-2*
1-2*
2-3
2-3
, I
LED_
LED2
Channel 2 HB LED Current (JU2)
is the desired HB LED current in amps
, and I
_______________________________________________________________________________________
Connected to R2
Connected to R1
Connected to R4
Connected to R3
R
SENSE
LED3
CS PIN
CS PIN
HB LED Current Settings
HB LED Current (JU1)
) and R
LED Load Configuration
=
203mV
I
LED _
SENSE
HB LED CURRENT
HB LED CURRENT
is the new R2,
(mA)
(mA)
100
100
50
50
MAX16839 Evaluation Kit
If designing for a higher LED current, verify that the
desired current setting does not exceed the power rating
of the corresponding resistor (R1–R6) or the LED load.
Do not set the LED current above 100mA.
The EV kit features PCB pads for accessing the fault sig-
nal (FLTS_) at each IC (U1, U2, and U3). Storage capaci-
tors C5, C6, and C7 are provided at each IC’s FLTS pin,
respectively, for fault retention/memorization. When the
voltage across the capacitor exceeds 1.65V during a
fault event, the respective HB LED driver turns off, unless
this feature is disabled by connecting the FLTS output
of the respective IC to ground. Jumpers JU6 and JU7
are provided to connect all FLTS signals together, which
shuts down all channels if a fault is detected at one of
them. See Table 4 for configuring the FLTS jumpers.
Refer to the Open-LED Detection and Fault Event Status
Memory section in the MAX16839 IC data sheet for fur-
ther information on the FLTS signal.
The MAX16839 integrated open HB LED detection fea-
ture is enabled when VIN > 7.38V (typ) and the voltage
at the DIM pin is high and the IC thermal shutdown is
low. When any of these conditions are violated, the fault-
detection function is disabled.
The EV kit features three independent PWM PCB pads
and jumpers for accessing/configuring the current-dim-
ming input (DIM) signal at each IC (U1, U2, and U3).
Jumpers JU4 and JU5 are provided to connect all the DIM
signals together or to operate independently. Each chan-
nel can have a different dimming-signal pattern.
Table 3.
*Default position.
Table 4. Fault FLTS1, FLTS2, FLTS3
(JU6, JU7)
*Default position.
POSITION
Not installed*
POSITION
SHUNT
Installed
SHUNT
1-2*
2-3
Channel 3 HB LED Current (JU3)
Faults (FLTS1, FLTS2, FLTS3) and
Connected to R6
Connected to R5
Connected together
U1, U2, AND U3
Independent
FLTS PINS
CS PIN
Open HB LED Detection
Dimming Operation
HB LED CURRENT
OPERATION
Simultaneous
Independent
FAULT
(mA)
100
50
3