MAX14588 Datasheet, PDF (13/15 Pages) Maxim Integrated Products – 1A Adjustable Overcurrent and Overvoltage Protector with High Accuracy

MAX14588
1A Adjustable Overcurrent and Overvoltage
Protector with High Accuracy
OUT Bypass Capacitor
For stable operation over the full temperature range and
over the entire programmable current-limit range, con-
nect a 4.7µF ceramic capacitor from OUT to ground.
Excessive output capacitance can cause a false overcur-
rent condition due to decreased dv/dt across the capaci-
tor. Calculate the maximum capacitive load (C_MAX) value
that can be connected to OUT by using the following
formula:
C_MAX(µF)
=
I _LIM
(mA)
x t _{BLANK (TYP)}
VIN (V)
(ms)
For example, for V_IN = 24V, t_BLANK(TYP) = 20ms, and
I_LIM = 1A, C_MAX equals 833µF.
Output Freewheeling Diode for
Inductive Hard Short to Ground
In applications that require protection form a sudden short
to ground with an inductive load or a long cable, a schottky
diode between the OUT terminal and ground is recom-
mended. This is to prevent a negative spike on the OUT
due to the inductive kickback during a short-circuit event.
Layout and Thermal Dissipation
To optimize the switch response time to output short-
circuit conditions, it is very important to keep all traces
as short as possible to reduce the effect of undesirable
parasitic inductance. Place input and output capacitors as
close as possible to the device (no more than 5mm). IN
and OUT must be connected with wide short traces to the
power bus. During normal operation, the power dissipa-
tion is small and the package temperature change is mini-
mal. If the output is continuously shorted to ground at the
maximum supply voltage, the switches with the autoretry
option do not cause thermal shutdown detection to trip:
P(MAX)
=
V_IN(MAX) × I_OUT(MAX) × t _BLANK
t _RETRY + t _BLANK
Attention must be given to continuous current-limit mode
when the power dissipation during a fault condition can
cause the device to reach the thermal shutdown threshold.
Thermal vias from the exposed pad to ground plane are
highly recommended to increase the system thermal capac-
itance while reducing the thermal resistance to the ambient.
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