MAX8664EVKIT+ Maxim Integrated Products, MAX8664EVKIT+ Datasheet - Page 3

• Manufacturer Part Number: MAX8664EVKIT+
• Description: KIT EVAL FOR MAX8664
• Manufacturer: Maxim Integrated Products

Specifications of MAX8664EVKIT+

• Main Purpose: DC/DC, Step Down
• Outputs And Type: 2, Non-Isolated
• Voltage - Input: 4.5 ~ 28V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: MAX8664
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Voltage - Output: -
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

• Power supply capable of delivering at least 12V at
• Voltmeter
• Two loads
1) Preset the power supply to 12V and turn the power
2) Connect the positive power-supply terminal to one of
3) Connect the power-supply ground to one of the EV
4) Connect the first load from the EV kit pads labeled
5) Connect the second load from the EV kit pads
6) Verify that the jumpers are in their default positions
7) Turn on the power supply.
8) With the voltmeter, verify OUT1 is 2.5V and OUT2
Table 1. Jumper Functions
Bold indicates the default jumper positions.
JUMPER
4A
supply off. Do not turn the power supply on until
all connections are completed.
the EV kit pads labeled IN.
kit pads labeled PGND.
OUT1 to PGND1.
labeled OUT2 to PGND2.
(JU1 open, JU2 pins 2-3, and JU3 pins 1-2).
is 1.8V.
JU1
JU2
JU3
REFIN2 to set the feedback regulation
regulator 2 for fixed output voltage
voltage for OUT2. Leave JU3 open.
Connect an external reference to
Use the internal reference for
operation. Leave JU1 open.
Shut down both regulators
_______________________________________________________________________________________
Recommended Equipment
1-2
Quick Start
Procedure
REFIN2 is connected to OUT1 so the
OUT2 voltage tracks OUT1. Leave
Enable both regulators
MAX8664 Evaluation Kit
JU3 open.
Power good (PWRGD) is an open-drain output of the
MAX8664A that pulls low when OUT1 is in regulation.
The EV kit includes a 10kΩ pullup resistor from PWRGD
to VCC. Refer to the MAX8664 IC data sheet for more
information on the power-good output.
In the default configuration, OUT2 is fixed to 1.8V, using
the internal reference. To use the internal reference,
place a shunt across the pins of JU3, and remove the
shunt from JU1.
To use an external reference to set the OUT2 regulation
voltage, remove the shunt from JU3 and place a shunt
across pins 1-2 of JU1. Connect the external 0 to 1.3V
reference to the REFIN2 pad on the EV kit. Connect the
reference ground to the GND pad.
To use OUT1 as the reference for tracking applications,
remove the shunt from JU3 and connect pins 2-3 of JU1.
In this configuration, R33 and R11 form a voltage-divider
from OUT1 to REFIN2. The ratio of these resistors deter-
mines the V
REFIN2 does not exceed 1.3V when OUT1 is in regula-
tion. Refer to the MAX8664 IC data sheet for changes to
the feedback network. Typically, R8 is not installed so
that V
sheet shows an example tracking circuit.
Detailed Description of Hardware
2-3
—
OUT2
OUT2
= V
FB2
/V
OUT1
. Figure 3 in the MAX8664 IC data
pins 1-2) or OUT1 tracking (jumper on
OUT2 External Reference
internal reference (jumper on JU3
OUT2 Internal Reference
Connect an external enable control
Leave JU1 open when using the
external reference (jumper on JU1
ratio. Ensure that the voltage at
Leave JU3 open when using an
signal to the EN pad
Power-Good Output
JU1 pins 2-3)
pins 1-2)
OPEN
Tracking
3