MAX4971EVKIT+ Maxim Integrated, MAX4971EVKIT+ Datasheet - Page 8

• Manufacturer Part Number: MAX4971EVKIT+
• Description: Power Switch ICs - Power Distribution Overvoltage-Protection Controllers with a Low RON Internal FET
• Manufacturer: Maxim Integrated

Specifications of MAX4971EVKIT+

• On Resistance (max): 90 mOhms
• On Time (max): 13 ms
• Off Time (max): 8 us
• Operating Supply Voltage: 2.2 V to 28 V
• Maximum Power Dissipation: 678 mW

Overvoltage-Protection Controllers
with a Low R
ACOK is an active-low, open-drain output that asserts
low when V
MAX4972. ACOK asserts low when V
15ms (typ) for the MAX4970 and MAX4971. Connect a
pullup resistor from ACOK to the logic I/O voltage of
the host system. During a short-circuit fault, ACOK
may deassert due to V
high current.
The MAX4970/MAX4971/MAX4972 feature thermal-
shutdown circuitry. The internal nFET turns off when the
junction temperature exceeds +150°C (typ). The device
exits thermal shutdown after the junction temperature
cools by 40°C (typ).
The optional external p-channel MOSFET can provide
reverse polarity protection down to the voltage rating of
the pFET.
For most applications, bypass IN to GND with a 1µF
ceramic capacitor as close as possible to the device to
enable ±15kV (HBM) ESD protection on the pin. If the
external pFET is used, the 1uF capacitor must be con-
nected between the drain and ground. If ±15kV (HBM)
ESD is not required, there is no capacitor required at
IN. If the power source has significant inductance due
to long lead length, take care to prevent overshoots
due to the LC tank circuit and provide protection if nec-
essary to prevent exceeding the +30V absolute maxi-
mum rating on IN.
The slow turn-on time provides a soft-start function that
allows the MAX4970/MAX4971/MAX4972 to charge an
output capacitor up to 1000µF without turning off due to
an overcurrent condition.
8
_______________________________________________________________________________________
UVLO
Applications Information
Thermal-Shutdown Protection
< V
Reverse Polarity Protection
IN
IN
< V
dropping below V
OUT Output Capacitor
OVLO
IN Bypass Capacitor
ON
for 15ms (typ) for the
Internal FET
IN
> V
UVLO
UVLO
ACOK
from
for
ESD performance depends on a number of conditions.
The MAX4970/MAX4971/MAX4972 are specified for
±15kV (HBM) typical ESD resistance on IN when IN is
bypassed to ground with a 1µF ceramic capacitor.
Figure 3 shows the Human Body Model, and Figure 4
shows the current waveform it generates when dis-
charged into a low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the device through a
1.5kΩ resistor.
Figure 3. Human Body ESD Test Model
Figure 4. Human Body Current Waveform
AMPERES
VOLTAGE
SOURCE
HIGH-
DC
I
P
36.8%
100%
90%
10%
CHARGE-CURRENT-
0
LIMIT RESISTOR
0
1MΩ
t
R
RL
C
100pF
C s
CURRENT WAVEFORM
STORAGE
CAPACITOR
TIME
RESISTANCE
DISCHARGE
1.5kΩ
R
D
t
DL
ESD Test Conditions
HBM ESD Protection
I r
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
DEVICE
UNDER
TEST