Datasheet

Maxim Integrated │ 2
www.maximintegrated.com
Evaluates: MAX16936
MAX16936 Evaluation Kit
Detailed Description of Hardware
The EV kit demonstrates the MAX16936 high-voltage,
high-frequency, step-down converter with low operating
current. The EV kit operates over a wide 3.5V to 36V input
range and the output is set for 5V at 2.5A.
Enable (EN)
Place a shunt in the 1-2 position on jumper JU1 for normal
operation. To place the device into shutdown mode, move
the shunt on JU1 to the 2-3 position.
Synchronization Input (FSYNC)
The EV kit features jumper JU2 to control the synchro-
nization input (FSYNC). The device synchronizes to an
external signal applied to FSYNC. Connect FSYNC to
AGNDtoenableskip-modeoperation.ConnecttoBIAS
or to an external clock to enable fixed-frequency forced-
PWM mode operation.
To use an external clock, uninstall the shunt on JU2 and
apply the signal at the FSYNC test point. The external
clock frequency at FSYNC can be higher or lower than the
internal clock by 20%. Ensure that the duty cycle of the
external clock used has a minimum 100ns pulse width.
Synchronizing Output (SYNCOUT)
The EV kit provides jumper JU3 to pull up the open-drain
SYNCOUT to the OUT voltage. SYNCOUT is a 180° out-
of-phase clock output relative to the internal oscillator
at SYNCOUT to create cascaded power supplies with
multiple MAX16936s.
Setting the Switching Frequency (FOSC)
The EV kit switching frequency is set by a resistor, R
FOSC
(R2),connectedfromFOSCtoAGND.RefertoFigure3.
in the MAX16936 IC data sheet for a graphical approach
of selecting the correct R
FOSC
(R2) value.
Power-Good Output (PGOOD)
The EV kit provides a PGOOD test point to monitor the
status of the device output. PGOOD asserts when VOUT
rises above 95% of its regulation voltage. PGOOD
deasserts when VOUT drops below 92% of its regulation
voltage.
Output
Connect FB to BIAS for a fixed +5V (EV kit default
output) or a fixed +3.3V output voltage. To set the output
to other voltages between 1V and 10V, connect a resis-
tivedividerfromoutput(OUT)toFBtoAGND.Usethe
followingformulatodeterminetheR4andR6 of the resis-
tive divider network:
OUT
FB
V
R4 R6 1
V

=×−


where V
FB
= 1V.