Analog Devices
│
2
MAX25262/MAX25263
Evaluation Kit
Evaluates: MAX25262/MAX25263
Detailed Description of Hardware
The MAX25262 and MAX25263 EV kits provide a
proven layout for the MAX25262 and MAX25263 synchro-
nous buck regulator ICs, respectively. The input voltages
range from 3.5V to 65V and deliver up to 3A. The EV kits
can handle an input supply transient up to 70V. Various
test points are included for evaluation.
External Synchronization
The IC can operate in two modes: forced-PWM (FPWM)
mode or skip mode. Skip mode has better efficiency for
light-load conditions. When SYNC is pulled low, the IC
operates in skip mode for light loads and PWM mode for
larger loads. When SYNC is pulled high, the IC is forced
to operate in PWM mode across all load conditions.
SYNC can be used to synchronize with other supplies if
a clock source is present. The IC is forced to operate in
FPWM mode when SYNC is connected to a clock source.
Buck Output Monitoring (PGOOD)
The EV kit provides a power-good output test point
(PGOOD) to monitor the status of the buck output (OUT).
PGOOD is high impedance when the output is in regula-
tion. PGOOD goes low when the corresponding regulator
output voltage drops below 93.5% (typ) of its nominal
regulation voltage or goes above 108% (typ) of its nomi-
nal regulation voltage.
Programming Buck Output Voltage
The IC can provide a fixed 3.3V/5V output voltage or an
adjustable 1V to 20V output voltage. To program V
OUT
voltage, place appropriate resistors in positions R5 and
R6 according to the following equation:
R5 = R6 (V
OUT
/V
FB
- 1)
where typically V
FB
= 1V (typ) and R6 = 100kΩ.
Spread Spectrum Option
The spread spectrum is pin selectable using the SPS pin.
Pull the pin high to enable spread spectrum. When spread
spectrum is enabled, the operating frequency is varied
±6%, centered at switching frequency.
The internal spread spectrum is disabled if the devices
are synchronized to an external clock. However, the
devices do not filter the input clock on the FSYNC pin and
pass any modulation (including spread spectrum) present
on the driving external clock.
EXTVCC Switchover
The internal linear regulator can be bypassed by connect-
ing an external supply, or the MAX25262/MAX25263 out
-
put to EXTVCC. With valid supply applied to EXTVCC, it
will be the supply for the internal gate driver. The R
DSON
of the FET will increase if the EXTVCC drops below 5V,
which will reduce the efficiency, therefore approximately
5V for EXTVCC is recommended for higher efficiency.
Table 1. Default Jumper Settings
#Denotes RoHS compliant.
Note
: If the output voltage is configured above 5V, please
ensure the EXTVCC jumper is at position 2-3 to avoid damage
to the part.
JUMPER
DEFAULT SHUNT
POSITION
FUNCTIONS
ENABLE
1-2
Buck enabled
PGOOD
Installed
PGOOD TP
pulled up to bias
SPS
1-2
Spread Spectrum ON
SYNC
1-2
FPWM mode
EXTVCC
1-2
EXTVCC connect
to OUT
PART
TYPE
MAX25262EVKIT#
EV Kit
MAX25263EVKIT#
EV Kit
Ordering Information
