Техническая Спецификация для Maxim Integrated MAX16814 Evaluation Kit MAX16814EVKIT+ MAX16814EVKIT+
Модели
MAX16814EVKIT+
MAX16814 Evaluation Kit
Evaluates:
MAX
16814
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Quick Start
Required Equipment
• MAX16814 EV kit
• 6.5V to 40V, 4A DC power supply
• One digital voltmeter
• Four series-connected HB LED strings rated no less
• 6.5V to 40V, 4A DC power supply
• One digital voltmeter
• Four series-connected HB LED strings rated no less
than 150mA
• A current probe to measure the HB LED current
Output Testing
The EV kit is fully assembled and tested. Follow the
steps below to verify board operation. Caution: Do_not_
turn_ on_ the_ power_ supply_ until_ all_ connections_ are_
completed.
1) Verify that a shunt is installed on jumper JU1 and on
steps below to verify board operation. Caution: Do_not_
turn_ on_ the_ power_ supply_ until_ all_ connections_ are_
completed.
1) Verify that a shunt is installed on jumper JU1 and on
pins 1-2 of jumper JU2 (enabled).
2) Verify that a shunt is installed on jumper JU3
(150mA).
3) Verify that shunts are not installed on jumpers
JU4–JU7 (all channels powered).
4) Connect the power supply to the VIN pad and the
power supply’s ground to the PGND PCB pad.
5) Connect the digital voltmeter across the OUT1 and
PGND PCB pads.
6) Connect each HB LED string as follows:
Channel 1: Connect an HB LED string anode to the
VOUT PCB pad and the cathode to the OUT1 PCB
pad.
VOUT PCB pad and the cathode to the OUT1 PCB
pad.
Channel 2: Connect an HB LED string anode to the
VOUT PCB pad and the cathode to the OUT2 PCB
pad.
VOUT PCB pad and the cathode to the OUT2 PCB
pad.
Channel 3: Connect an HB LED string anode to the
VOUT PCB pad and the cathode to the OUT3 PCB
pad.
VOUT PCB pad and the cathode to the OUT3 PCB
pad.
Channel 4: Connect an HB LED string anode to the
VOUT PCB pad and the cathode to the OUT4 PCB
pad.
VOUT PCB pad and the cathode to the OUT4 PCB
pad.
7) Clip the current probe across the channel 1 HB LED
wire to measure the HB LED current.
8) Turn on the power supply and set it to 10V.
9) Measure the voltage from the OUT1–OUT4 PCB
9) Measure the voltage from the OUT1–OUT4 PCB
pads to PGND and verify that the lowest voltage is
approximately 1V.
approximately 1V.
10) Measure the HB LED current using the current
probe and verify all channels.
Detailed Description of Hardware
The MAX16814 EV kit demonstrates the MAX16814 HB
LED driver with an integrated step-up DC-DC preregula-
tor followed by 4 channels of linear current sinks. The
preregulator switches at 350kHz and operates as a
current-mode-controlled regulator providing up to 600mA
for the linear circuit while providing OVP. Cycle-by-cycle
current limit is set by resistor R4 and resistors R6 and
R7 set the OVP voltage to 33V. The preregulator power
section consists of inductor L2, MOSFET N1, power-
sense resistor R4, and switching diode D1.
The EV kit circuit operates from a DC supply voltage
of 6.5V up to the HB LED forward string voltage. The
circuit handles load-dump conditions up to 40V. Bulk
capacitors C1, C2 and inductor L1 provide EMI filtering
on the VIN power line. The IN power UVLO is set to 5.5V
by resistors R1 and R2. The IC, in a 20-pin TSSOP pack-
age with an exposed pad, provides enhanced thermal
power dissipation on a proven 1oz copper PCB design.
Each of the 4 linear channels (OUT1–OUT4) can oper-
ate up to 40V and sink up to 150mA per channel. Each
of the 4 channel’s linear current sinks are configurable
for 150mA or 100mA, or can be disabled indepen-
dently. Jumpers JU4–JU7 provide the disable feature
when the HB LED string is not connected. See the
Channel 1–Channel 4 Current-Sink Disabling section.
Resistors R15, R16 and jumper JU3 configure the linear
current setting for the IC SETI pin, which sets the HB LED
string current.
The EV kit features PCB pads to facilitate connect-
ing HB LED strings for evaluation. The VOUT PCB
pads provide connections for connecting each HB
LED string’s anode to the DC-DC preregulator output.
The OUT1–OUT4 PCB pads provide connections for
connecting each HB LED string’s cathode to the
respective linear channel’s current sink. Additionally,
2-pin headers JU8–JU11 provide convenient access
to the VOUT and respective OUT_ connections when
using a twisted-pair wiring-connection scheme. On each
header, pin 1 provides access to the respective OUT_
connection and pin 2 provides access to the VOUT
connection. Capacitors C18–C21 are included on the
design to prevent oscillations and provide stability when
using long, untwisted HB LED connecting cables during
lab evaluation. These capacitors are not required on a
typical HB LED design.
A DIM PCB pad is provided for using a digital PWM
signal to control the brightness of the HB LEDs. The EV
kit can also demonstrate the IC’s synchronizing feature
LED driver with an integrated step-up DC-DC preregula-
tor followed by 4 channels of linear current sinks. The
preregulator switches at 350kHz and operates as a
current-mode-controlled regulator providing up to 600mA
for the linear circuit while providing OVP. Cycle-by-cycle
current limit is set by resistor R4 and resistors R6 and
R7 set the OVP voltage to 33V. The preregulator power
section consists of inductor L2, MOSFET N1, power-
sense resistor R4, and switching diode D1.
The EV kit circuit operates from a DC supply voltage
of 6.5V up to the HB LED forward string voltage. The
circuit handles load-dump conditions up to 40V. Bulk
capacitors C1, C2 and inductor L1 provide EMI filtering
on the VIN power line. The IN power UVLO is set to 5.5V
by resistors R1 and R2. The IC, in a 20-pin TSSOP pack-
age with an exposed pad, provides enhanced thermal
power dissipation on a proven 1oz copper PCB design.
Each of the 4 linear channels (OUT1–OUT4) can oper-
ate up to 40V and sink up to 150mA per channel. Each
of the 4 channel’s linear current sinks are configurable
for 150mA or 100mA, or can be disabled indepen-
dently. Jumpers JU4–JU7 provide the disable feature
when the HB LED string is not connected. See the
Channel 1–Channel 4 Current-Sink Disabling section.
Resistors R15, R16 and jumper JU3 configure the linear
current setting for the IC SETI pin, which sets the HB LED
string current.
The EV kit features PCB pads to facilitate connect-
ing HB LED strings for evaluation. The VOUT PCB
pads provide connections for connecting each HB
LED string’s anode to the DC-DC preregulator output.
The OUT1–OUT4 PCB pads provide connections for
connecting each HB LED string’s cathode to the
respective linear channel’s current sink. Additionally,
2-pin headers JU8–JU11 provide convenient access
to the VOUT and respective OUT_ connections when
using a twisted-pair wiring-connection scheme. On each
header, pin 1 provides access to the respective OUT_
connection and pin 2 provides access to the VOUT
connection. Capacitors C18–C21 are included on the
design to prevent oscillations and provide stability when
using long, untwisted HB LED connecting cables during
lab evaluation. These capacitors are not required on a
typical HB LED design.
A DIM PCB pad is provided for using a digital PWM
signal to control the brightness of the HB LEDs. The EV
kit can also demonstrate the IC’s synchronizing feature