Quick Start
Recommended Equipment
• MAX17112 EV kit
• 4.5V to 5.5V, 5A DC power supply (VIN)
• One voltmeter
Procedure
The MAX17112 EV kit is fully assembled and tested.
Follow the steps below to verify board operation.
Caution: Do not turn on power supply or the elec-
tronic load until all connections are completed.
1) Verify that a shunt is placed across pins 1-2 of JU1.
2) Connect the positive terminal of the DC power sup-
ply to the VIN pad. Connect the negative terminal of
the DC power supply to the GND pad.
3) Turn on the 4.5V to 5.5V DC power supply and veri-
fy that the step-up switching regulator output
(VOUT) is 15V.
Detailed Description of Hardware
The MAX17112 evaluation kit (EV kit) provides a proven
design to evaluate the MAX17112 high-performance
step-up DC-DC converter, which provides a regulated
supply voltage for active-matrix thin-film transistor (TFT)
liquid-crystal displays (LCDs).
The EV kit operates from a 4.5V to 5.5V DC power sup-
ply. As configured, the step-up switching regulator
generates a 15V output (VOUT) and provides 600mA
with a 4.5V input. The step-up switching regulator out-
put voltage can be adjusted from VIN to 20V by chang-
ing the values of the feedback resistors (see the
Evaluating Other Output Voltages
section).
The MAX17112 EV kit can operate from a 2.6V to 5.5V
input supply. When input voltage is less than 4.5V, out-
put current needs to be reduced from 600mA to avoid
reaching inductor current limit. Operation at a differ-
ent input voltage, output voltage, or switching fre-
quency may require a different inductor, output
capacitor, and compensation components. Refer to
the MAX17112 IC data sheet for detailed information on
loop compensation and component selection.
Shutdown Mode (
SHDN
)
The EV kit features a shutdown mode that reduces the
MAX17112 quiescent current. JU1 selects the shut-
down mode. See Table 1 for jumper JU1 functions.
When the shunt of JU1 is placed in the 1-2 position, the
SHDN pin is connected to the on-board capacitor
(C10). The internal 5µA current source of the
MAX17112 charges this capacitor. When the voltage
on the SHDN pin rises above 1.24V, the MAX17112 is
enabled.
To shut down the MAX17112, place the shunt of JU1 in
the 2-3 position.
When JU1 is open, the SHDN pin is controlled by the
external signal on the SHDN pad.
Evaluating Other Output Voltages
The MAX17112 EV kit’s step-up switching-regulator
output (VOUT) is set to 15V by feedback resistors R3
and R4. To generate output voltages other than 15V,
select different external voltage-divider resistors, R3
and R4. Select R3 in the 10kΩ to 50kΩ range. R4 is
then given by the following equation:
R4 = R3 x [(VOUT/VFB) - 1]
where VFB = 1.24V. For significantly different operation
points, the EV kit might require a different inductor and
component changes. Refer to the MAX17112 IC data
sheet for proper component selection.
Evaluates: MAX17112
MAX17112 Evaluation Kit
2 _______________________________________________________________________________________
Table 1. Jumper JU1 Functions.
*
Default position.
