Rainbow Electronics MAX4995 - Manual (Page 8)

MAX4995A/AF/AL/MAX4995B/MAX4995C
50mA to 600mA Programmable
Current-Limit Switches
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continues beyond the blanking time. Reset the switch
by either toggling the control logic (ON) or cycling the
input voltage. If the thermal power rating of the pack-
age is exceeded during t
BLANK , the MAX4995B goes
into thermal shutdown.
Continuous Current Limit (MAX4995C)
When the forward current reaches the forward current-
limit threshold, the MAX4995C limits the output current
to the programmed current limit.
FLAG asserts if the
current limit is present for t BLANK and deasserts when
the overload condition is removed. In this mode, if the
thermal power rating of the package is exceeded, the
MAX4995C goes into thermal shutdown.
Switch-On/Off Control
The ON input for the MAX4995_/MAX4995AF and ON
input for the MAX4995AL control the switch; see Table
1. Toggle ON for the MAX4995B to reset the fault condi-
tion once the short current is detected and the device
shuts down.
Reverse-Current Protection
The MAX4995 features a reverse-current protection cir-
cuit that limits the backflow current to 10µA when the
output voltage exceeds the input voltage by 110mV
(typ). The switch turns off and
FLAG asserts without
waiting for t BLANK to elapse. The switch turns back on
and FLAG deasserts when the output voltage drops
below the detecting threshold by 10mV (typ).
OUT
SETI
IN
MAX4995A/MAX4995AF/
MAX4995AL/MAX4995B/
MAX4995C
CONTROL
LOGIC
REVERSE-
CURRENT
PROTECTION
THERMAL
SHUTDOWN
CURRENT
LIMIT
BANDGAP
REFERENCE
BUFFER
TIMING
CIRCUITRY
BUFFER
N.C.
FLAG
SOFT-START
ON (ON)*
UVLO
*( ) FOR THE MAX4995AL ONLY.
GND
Functional Diagram
MAX4995_/
MAX4995AF
MAX4995AL
ON
ON
SWITCH
STATUS
0 1 Off
1 0 On
Table 1. Switch Truth Table