MAX16839EVKIT+ Maxim Integrated Products, MAX16839EVKIT+ Datasheet - Page 4

• 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

MAX16839 Evaluation Kit
Use a digital PWM signal with a 5V logic level and
a switching frequency between 100Hz and 10kHz.
Frequencies lower than 100Hz can introduce flickering
in the light output. Vary the duty cycle of the signal to
adjust the LED brightness. LED brightness increases as
the duty cycle increases and vice versa. When the PWM
signal’s duty cycle is 100%, the LEDs are continuously
on. At 0% duty cycle, the outputs are disabled.
See Table 5 for configuring the DIM_ jumpers. Refer to
the PWM Dimming section in the MAX16839 IC data
sheet for further information on the DIM signal.
The EV kit includes several other features to facilitate
evaluating the MAX16839 IC. A power-supply chopper-
circuit feature, and the ability to cascade multiple kits for
operation, are detailed in the following sections.
The EV kit features a power-supply chopper
the VIN input supply. The input supply chopper circuit
is comprised of p-channel MOSFET P1, biasing resistor/
diode pair R7/D2, and switching transistor Q1. When
Table 5. DIM1,
*Default position.
4
Not installed*
POSITION
______________________________________________________________________________________
Installed
SHUNT
Additional Configurations and Features
Connected together
DIM2, DIM3 (JU4, JU5)
U1, U2, AND U3
Independent
Chopper-Circuit Operation
DIM PINS
OPERATION
Synchronous
Independent
DIM
circuit for
installed, jumper JU11 is provided to bypass the chop-
per circuit.
To use the chopper circuit, connect a function generator
with a digital signal to the CHOP and GND PCB pads.
Use a 3V to 5V low-frequency pulse-width-modulated
(PWM) signal to switch the chopper circuit on/off.
The EV kit features PCB pads and jumpers for cascading
multiple kits. To cascade another EV kit, use the follow-
ing guidelines:
1) Install all DIM_ shunts on jumpers JU4 and JU5.
2) Install all FLTS_ shunts on jumpers JU6 and JU7.
3) Connect the DIM3 PCB pad on kit #1 to the DIM1 PCB
4) Connect the FLTS3 pad on kit #1 to the FLTS1 pad on
5) Connect the GND PCB pad nearest DIM3 on kit #1 to
6) Connect a common power supply to both kits’ VIN
Table 6.
(JU11)
*Default position.
Not installed*
POSITION
pad on kit #2.
kit #2.
the GND PCB pad nearest the DIM3 pad on kit #2.
and PGND PCB pads.
Installed
SHUNT
Chopper-Circuit Operation
MOSFET P1/ BIASING
Connected to ground
Connected to Q1
RESISTOR R8
Cascading Multiple Kits
OPERATION
CHOPPER-
Bypassed
CIRCUIT
Running