MAX14523A_11 Datasheet, PDF (10/11 Pages) Maxim Integrated Products – 250mA to 1.5A, Adjustable Current-Limit Switches

250mA to 1.5A, Adjustable
Current-Limit Switches
Table 2. Current Limit/Threshold vs.
Resistor Values
R_SETI (k) TYPICAL CURRENT LIMIT/THRESHOLD (mA)
91.78
1500
121
1145
221
632
301
466
422
333
563.12
250

(Open)
0
Do not use an R_SETI value smaller than 91.78kΩ.
Note: Connecting any capacitance larger than 20pF to
SETI can cause instability.
IN Bypass Capacitor
Connect a minimum of 1µF capacitor from IN to GND to
limit the input voltage drop during momentary output
short-circuit conditions. Larger capacitor values further
reduce the voltage undershoot at the input.
OUT Bypass Capacitor
For stable operation over the full temperature range
and over the full-programmable current-limit range, use
a 1µF ceramic capacitor from OUT to ground.
Excessive output capacitance can cause a false over-
current condition due to decreased dv/dt across the
capacitor. Calculate the maximum capacitive load
(C_MAX) value that can be connected to OUT using the
following formula:
C_MAX
(µF)
=
I_LIM (mA)
×
t_BLANK(MIN)
V_IN (V)
(ms)
For example, for V_IN = 3.3V, t_BLANK = 10ms, and I_LIM =
300mA, C_MAX equals 909µF.
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
dissipation is small and the package temperature
change is minimal. If the output is continuously shorted
to ground at the maximum supply voltage, the opera-
tion of the switches with the autoretry option does not
cause problems because the total power dissipated
during the short is scaled by the duty cycle:
P_(MAX)
=
V_IN(MAX) × I_OUT(MAX) × t_BLANK
t_RETRY + t_BLANK
Attention must be given to the MAX14523C continuous
current-limit version when the power dissipation during
a fault condition can cause the device to reach the ther-
mal shutdown threshold.
PROCESS: BiCMOS
Chip Information
Pin Configuration
N.C. 1 +
8 GND
FLAG 2
SETI 3
OUT 4
MAX14523A
MAX14523AL
MAX14523B
MAX14523C
*EP
7 ON(ON)**
6 N.C.
5 IN
TDFN
3mm x 3mm
*CONNECT EXPOSED PAD TO GND.
**( ) FOR THE MAX14523AL ONLY.
Package Information
For the latest package outline information and land patterns,
go to www.maxim-ic.com/packages. Note that a “+”, “#”, or
“-” in the package code indicates RoHS status only. Package
drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
PACKAGE
TYPE
8 TDFN-EP
PACKAGE
CODE
T833+2
OUTLINE
LAND
NO. PATTERN NO.
21-0137
90-0059
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