Maxim Integrated MAX17129 Evaluation Kit MAX17129EVKIT+ MAX17129EVKIT+ 데이터 시트
제품 코드
MAX17129EVKIT+
JUMPER
SHUNT
POSITION
DESCRIPTION
JU14
1-2
Removes WLEDs D19, D20, and D21 from the string of WLEDs going to the FB2 pin of the device.
When installing the MAX17149, the shunt is only allowed in this position.
When installing the MAX17149, the shunt is only allowed in this position.
Open*
Connects WLEDs D19, D20, and D21 to the string of WLEDs going to the FB2 pin of the device.
JU15
1-2
Removes WLEDs D9, D10, and D11 from the string of WLEDs going to the FB1 pin of the device.
When installing the MAX17149, the shunt is only allowed in this position.
When installing the MAX17149, the shunt is only allowed in this position.
Open*
Connects WLEDs D9, D10, and D11 to the string of WLEDs going to the FB1 pin of the device.
JU17
1-2
Connects the IN pin and VCC pin of the device together. The voltage applied at the VIN PCB pad
of the EV kit must be between 3V to 5.5V.
of the EV kit must be between 3V to 5.5V.
Open*
Disconnects the IN pin and VCC pin of the device together. The voltage applied at the VIN PCB
pad of the EV kit must be between 6V to 26V.
pad of the EV kit must be between 6V to 26V.
_________________________________________________________________ Maxim Integrated Products 3
MAX17129 Evaluation Kit
Evaluates: MAX17129/MAX17149
Detailed Description of Hardware
The MAX17129 EV kit operates on a 3V to 26V wide-
input voltage range and provides an adjustable 10mA to
45mA full-scale LED current. The EV kit utilizes a step-up
DC-DC converter to generate the voltage required to
drive up to six strings of 10 surface-mount WLEDs.
Input Supply
When jumper JU17 doesn’t have a shunt installed, the
input supply range is 6V to 26V at the VIN PCB pad on
the EV kit. If JU17 is installed, the input supply range
changes to 3V to 5.5V.
White LED String Configuration
As configured, the EV kit is assembled with six strings of
10 WLEDs. Each string has an associated 3-pin header
(JU1–JU6) and feedback pin (FB1–FB6). The function of
the 3-pin jumpers is summarized in Table 1. To evaluate
the EV kit with off-board WLED strings, see the Off-Board
White LED String Configuration section.
Off-Board White LED String Configuration
The EV kit can also be used to drive off-board WLED
strings. To evaluate external WLED strings, reconfigure
shunts from jumpers JU1–JU6 (see Table 1). Removing
the shunt completely disconnects the on-board WLED
strings between the output and feedback pins, allowing
for the connection of external WLED strings. For each
external WLED string, connect the cathode terminal
of the string to the corresponding feedback PCB pad
(FB1–FB6) on the EV kit and connect the anode terminal
of the string to the VOUT PCB pad on the EV kit. Once the
external WLED strings are connected between the VOUT
PCB pad and the FB_ pins, the EV kit can be evalu-
ated in the same manner as the on-board WLED strings.
Evaluating more than 10 WLEDs per string could require
component changes. Refer to the MAX17129/MAX17149
IC data sheet for component selections.
Enable (EN)
The device is in normal operation when a shunt is
installed on jumper JU8, which drives the EN pin high.
To place the device into shutdown, remove the shunt
from JU8.
installed on jumper JU8, which drives the EN pin high.
To place the device into shutdown, remove the shunt
from JU8.
Brightness Control (BRT)
To control the brightness of the WLEDs, apply a PWM
signal between 0.1kHz and 25kHz on the BRT PCB pad
on the EV kit.
signal between 0.1kHz and 25kHz on the BRT PCB pad
on the EV kit.
LED String Capacitance
In some LCD panel applications, a 0.1FF (typ) capacitor
(C
(C
LED
) is placed in parallel with each WLED string to
improve ESD immunity. As such, the EV kit provides a
capacitor footprint across each WLED string for optional
C
capacitor footprint across each WLED string for optional
C
LED
.
Full-Scale LED Current-Adjustment (ISET)
The EV kit uses resistors R1 and R2 to set the full-scale
LED current (I
LED current (I
LED_FS
). The resistance from the ISET pin
of the device to GND controls the full-scale current in
each WLED string according to the following equation:
each WLED string according to the following equation:
LED_FS
20mA 100k
I
R1 R2
×
Ω
=
+
where R1 is a 500kI potentiometer and R2 is a 39kI
resistor.
resistor.
Switching-Frequency Selection (FSEL)
The EV kit can operate from 1MHz or 500kHz using
jumper JU7. Place a shunt on JU7 in the 1-2 position and
the switching frequency set to 500kHz. When JU7 is the
2-3 position, 1MHz switching frequency is achieved.
jumper JU7. Place a shunt on JU7 in the 1-2 position and
the switching frequency set to 500kHz. When JU7 is the
2-3 position, 1MHz switching frequency is achieved.
Table 1. Jumper Descriptions (JU1–JU15, JU17) (continued)
*Default position.