Datasheet

Evaluates: MAX17062
MAX17062 Evaluation Kit
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Detailed Description
The MAX17062 EV kit contains a high-efficiency, pulse-
width-modulated (PWM), step-up switching regulator, a
positive single-stage unregulated charge pump, and a
negative single-stage unregulated charge pump. The
MAX17062 features a programmable soft-start, loop-
compensation pin, and an internal MOSFET switch.
The EV kit operates from a +4.5V to +5.5V DC power
supply.
As configured, the step-up switching regulator gener-
ates a +15V output (VOUT) and can provide 600mA
with a 4.5V input. The step-up switching regulator out-
put voltage can be adjusted from VIN to +20V by
changing the values of the feedback resistors (see the
Evaluating Other Output Voltages section).
The VGON supply consists of a single positive charge-
pump stage to generate approximately twice the VOUT
voltage (or approximately +29V) and provide 30mA.
The VGOFF supply consists of a single negative
charge-pump stage to generate approximately -VOUT
(or approximately -15V) and provide 30mA.
The EV kit is configured for a +4.5V input and a 1.2MHz
switching frequency. Operation at a different input
voltage, output voltage (VOUT), or switching fre-
quency may require a different inductor, output
capacitors, and compensation components. Refer to
the MAX17062 IC data sheet for detailed information on
loop compensation and component selection.
Jumper Selection
Shutdown Mode ( SHDN )
The EV kit features a shutdown mode that reduces the
MAX17062 quiescent current. JU1 selects the shut-
down mode. See Table 1 for jumper JU1 functions.
Switching-Frequency
Selection (FREQ)
The MAX17062 EV kit provides the option to configure
the switching frequency of the step-up DC-DC convert-
er. Table 2 lists jumper JU2 settings for configuring the
switching frequency. The EV kit is configured and
shipped to operate at 1.2MHz. For operation at
640kHz, cut the trace between pins 1 and 2 of jumper
JU2 and short pins 2 and 3. Refer to the MAX17062
data sheet for selecting the proper components.
Evaluating Other
Output Voltages
The MAX17062 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
(VIN to +20V), select different external voltage-divider
resistors, R3 and R4. Select R3 in the 10kΩ to 50kΩ
range. R4 is then given by:
where V
FB
= 1.24V. Note that changing the VOUT volt-
age also changes the VGON and VGOFF charge-pump
output voltages. For significantly different operation
points, the EV kit may require a different inductor and
component changes. Refer to the MAX17062 data
sheet for proper component selection.
RRx
VOUT
V
FB
43 1=
⎛
⎝
⎜
⎞
⎠
⎟
−
⎡
⎣
⎢
⎢
⎤
⎦
⎥
⎥
Table 1. Jumper JU1 Functions
SHUNT
POSITION
SHDN PIN MAX17062 OUTPUT
Installed Connected to GND
Shutdown mode,
VOUT = VIN - V
DIODE
Not installed*
Connected to VIN
through R1
MAX17062 enabled,
VOUT = +15V
* Default position.
Table 2. Jumper JU2 Functions
SHUNT
POSITION
FREQ PIN
SWITCHING
FREQUENCY
1-2*
Connected to VIN with a
PC trace
1.2MHz
2-3
Connected to GND (cut the
trace between pins 1-2
before shorting pins 2-3)
640kHz
* Default position.