MAX14523AATA+T Maxim Integrated Products, MAX14523AATA+T Datasheet - Page 9

• Manufacturer Part Number: MAX14523AATA+T
• Description: IC CURRENT LIMIT SWITCH 8-DFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX14523AATA+T

• Function: Current Switch
• Accuracy: ±10%
• Voltage - Input: 1.7 ~ 5.5 V
• Current - Output: Adjustable
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-TDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensing Method: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: MAX14523AATA+T

The autoretry feature saves system power in case of an
overcurrent or short-circuit condition. During t
time, when the switch is on, the supply current is held
at the current limit. During time t
is off, the current through the switch is zero. Thus, the
average output current is much less than the pro-
grammed current limit. Calculate the average output
current using the following equation:
With a typical t
560ms, the duty cycle is 3%, resulting in a 97% power
savings over the switch being on the entire time.
When the forward current reaches the current thresh-
old, the t
asserts if an overcurrent condition is present for greater
than t
condition disappears before t
The switch turns off if the overcurrent condition contin-
ues beyond the blanking time. Reset the switch by
either toggling the control logic (ON or ON) or cycling
the input voltage. If the die temperature exceeds
+170°C (typ) due to self heating, the MAX14523B goes
into thermal shutdown until the die temperature
drops by approximately 15°C (see the Thermal
Shutdown section).
When the forward current reaches the forward-current
threshold, the MAX14523C limits the output current to
the programmed current limit. FLAG asserts if the cur-
rent limit is present for t
overload condition is removed. In this mode, if die tem-
perature exceeds +170°C (typ) due to self heating, the
MAX14523C goes into thermal shutdown until the die
temperature drops by approximately 15°C (see the
Thermal Shutdown section).
Table 1. Switch Truth Table
MAX14523A
MAX14523B
MAX14523C
Continuous Current Limit (MAX14523C)
BLANK
I
LOAD
ON
0
1
BLANK
= I
time. The timer resets if the overcurrent
BLANK
LIM
timer begins counting (Figure 3). FLAG
_______________________________________________________________________________________
[(t
MAX14523AL
BLANK
= 17.5ms and typical t
BLANK
Latchoff (MAX14523B)
1
0
)/(t
and deasserts when the
BLANK
RETRY
BLANK
SWITCH STATUS
, when the switch
+ t
RETRY
has elapsed.
Off
On
RETRY
)]
BLANK
250mA to 1.5A, Adjustable
=
Current-Limit Switches
The ON input for the MAX14523A/MAX14523B/
MAX14523C and ON input for the MAX14523AL control
the switch, see Table 1. Toggle ON for the MAX14523B
to reset the fault condition once the short-circuit current
is detected and the device shuts down.
The MAX14523A/MAX14523AL/MAX14523B/MAX14523C
feature a reverse-current protection circuit that limits
the backflow current to 2µA when the reverse-current
protection circuitry has tripped. The switch turns off and
FLAG asserts without waiting for t
switch turns back on and FLAG deasserts when V
V
95mV (typ).
FLAG is an open-drain fault indicator output and
requires an external pullup resistor to a DC supply.
FLAG goes low when any of the following conditions
occur:
•
•
•
•
Thermal-shutdown circuitry protects the devices from
overheating. The switch turns off and FLAG goes low
immediately when the junction temperature exceeds
+170°C (typ). The switch turns on again after the
device temperature drops by approximately 15°C (typ).
A resistor from SETI to ground programs the current
limit/threshold value for the MAX14523A/MAX14523AL/
MAX14523B/MAX14523C. Table 2 lists various current
limit/thresholds set by different resistor values at SETI.
Leaving SETI unconnected selects a 0 current
limit/threshold. Connecting SETI to ground asserts
FLAG.
Use the following formula to calculate the current limit:
OUT
The blanking time has elapsed
The reverse-current protection has tripped
The die temperature exceeds +170°C
SETI is connected to ground.
drops below the reverse-current threshold by
Setting the Current Limit/Threshold
R
SETI
Applications Information
(
k
Ω
)
Reverse-Current Protection
=
141400
I
LIM
(
Switch-On/Off Control
mA
( )
V
)
Thermal Shutdown
−
BLANK
2 48
FLAG Indicator
.
(
k
Ω
to elapse. The
)
IN
9
-