MAX1556 Datasheet, PDF (2/6 Pages) Maxim Integrated Products – MAX1556 Evaluation Kit

MAX1556 Evaluation Kit
Procedure (MAX1556ETB)
The MAX1556 EV kit is fully assembled and tested.
Follow the steps below to verify board operation:
1) Select the desired output voltage with JU1, JU2,
and JU3 (see Table 1). The EV kit is preset to a
1.8V output.
2) Connect the positive terminal of the voltmeter to the
pad labeled OUT. Connect the ground terminal of
the voltmeter to the pad labeled GND nearest the
OUT pad. Connect a load from OUT to the GND
pad closest to OUT.
3) Preset the power supply to between 2.6V and 5.5V,
and turn the power supply off. Do not turn on the
power supply until all connections are completed.
4) Connect the positive power-supply terminal to the
pad labeled IN. Connect the power-supply ground
to the pad labeled GND nearest the IN pad.
5) Turn on the power supply and verify the output volt-
age is the desired voltage from setting JU1, JU2,
and JU3 (default is 1.8V).
Procedure (MAX1557ETB)
The MAX1556 EV kit is fully assembled and tested.
Follow the steps below to verify board operation:
1) Select the desired output voltage with JU4, JU5,
and JU6 (see Table 2). The EV kit is preset to a
1.0V output.
2) Connect the positive terminal of the voltmeter to the
pad labeled OUT2. Connect the ground terminal of
the voltmeter to the pad labeled GND2 nearest the
OUT2 pad. Connect a load from OUT2 to the GND2
pad closest to OUT2.
3) Preset the power supply to between 2.6V and 5.5V,
and turn the power supply off. Do not turn on the
power supply until all connections are completed.
4) Connect the positive power-supply terminal to the
pad labeled IN2. Connect the power-supply ground
to the pad labeled GND2 nearest the IN2 pad.
5) Turn on the power supply and verify the output volt-
age is the desired voltage from setting JU4, JU5,
and JU6 (default is 1.0V).
Detailed Description
The MAX1556 EV kit contains two separate PWM step-
down DC-DC converter circuits. Either circuit can be
powered from a DC power supply with a 2.6V to 5.5V
input range. The top and bottom circuit are separate from
each other and do not share a common ground plane.
The top circuit (MAX1556) provides pin-selectable out-
put voltages of 3.3V, 2.5V, 1.8V, and adjustable at 1.2A.
The bottom circuit (MAX1557) provides pin-selectable
output voltages of 1.5V, 1.3V, 1.0V, and adjustable at
600mA.
Pin-Selectable Output Voltages
The MAX1556 output voltage is selected with JU1 and
JU2, as shown in Table 1.
The MAX1557 output voltage is selected with JU4 and
JU5, as shown in Table 2.
Evaluating Other Output Voltages
The MAX1556 EV kit comes with the MAX1556 preset to
a 1.8V output and the MAX1557 preset to a 1V output.
To evaluate other voltages besides the preset values,
set the MAX1556 (or MAX1557) to adjustable mode.
The footprints for the feedback resistors are available
on the backside of the evaluation kit. Refer to the
Adjusting the Output Voltage section in the MAX1556
data sheet for a detailed description on calculating
these feedback resistor values for the desired output
voltage. Resistor R1 for the MAX1556 circuit (R3 on
MAX1557) is shorted on the evaluation kit. This short
must be cut prior to the placement of a resistor on the
footprint. Resistor R2 for the MAX1556 circuit (R4 for
MAX1557) is open and requires no modification before
placing a resistor on the footprint.
Table 1. Output Voltage Selection (MAX1556ETB)
JU1
JU2
1 and 2
1 and 2
1 and 2
2 and 3
2 and 3
1 and 2
2 and 3
2 and 3
—
—
Note: Default configuration is JU1, JU2, and JU3 (1 and 2).
JU3
1 and 2
1 and 2
1 and 2
1 and 2
2 and 3
MAX1556 V_OUT
1.8V
2.5V
3.3V
ADJ
Shutdown
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