MAX6397EVKIT Maxim Integrated, MAX6397EVKIT Datasheet - Page 3

• Manufacturer Part Number: MAX6397EVKIT
• Description: Supervisory Circuits Evaluation Kit for the MAX6397
• Manufacturer: Maxim Integrated
• Series: MAX6397, MAX6398r

Specifications of MAX6397EVKIT

• Number Of Voltages Monitored: 1
• Undervoltage Threshold: 1.181 V
• Overvoltage Threshold: 1.248 V
• Supply Voltage - Max: 72 V
• Supply Current (typ): 118 uA
• Supply Voltage - Min: 5.5 V

formed by R1 and R2, so the equation given for over-
voltage mode also applies to the threshold voltage in
overvoltage limiter mode. During an input overvoltage
transient in this mode, the MOSFET switches off until
the output voltage falls to 95% of the threshold voltage,
and then the MOSFET switches back on. This cycle
repeats, generating a sawtooth waveform on the output.
The minimum output voltage in overvoltage limiter
mode depends on load current, output capacitance,
and the MOSFET’s switching period. The MAX6397 EV
kit comes with one 22µF capacitor at the output to sup-
ply the load during the time when the MOSFET is off.
Connect the optional electrolytic capacitor C13 (150µF,
100V) to support load currents higher than 0.5A when
the EV kit operates in overvoltage limiter mode.
Add capacitor C3 on the gate of MOSFET M1 to
decrease the frequency of the sawtooth waveform. This
process helps limit the device’s power dissipation.
Connections are also included for the linear regulator
output and the power-good (POK) signal. The linear
regulator supplies up to 100mA at 5V, limited by the
ambient temperature, the input/output voltages, and the
package power dissipation. The POK signal has a
100kΩ resistor (R3) to the regulator output. The linear
regulator is always on regardless of the state of
_______________________________________________________________________________________
Linear Regulator Output and
Power-Good Signal
SHDN.
MAX6397 Evaluation Kit
To filter fast transients that may be present at the input
from reaching the MAX6397, place a small resistor, R4,
(10Ω, for example) on the board, and cut jumper J1.
Three-pin jumper J2 selects between overvoltage mode
and overvoltage limiter mode; do not leave this jumper
unconnected. Three-pin jumper J3 controls the gate
drive of p-channel MOSFET M3 used as a reverse- bat-
tery protection. Use J3 to disconnect resistor R5 when
M3 is not used to avoid supply leakage through R5.
Three-pin jumper J4 controls the SHDN pin of the
MAX6397 and can enable or disable the MOSFET M1
enhancement. Table 1 lists the jumper options.
Table 1. Jumper Function
*Default configuration.
JUMPER
J1
J2
J3
J4
Overvoltage mode*
M2 gate drive is
U1 is enabled*
SHUNT POSITION AND FUNCTION
disabled*
1 and 2
Shorted: RC input filter disabled*
Jumper Selection
Overvoltage limiter
M2 gate drive is
U1 is disabled
enabled
2 and 3
mode
3