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Chip information, Package information, Pin configuration – Rainbow Electronics MAX14523C User Manual

Page 10

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MAX14523A/MAX14523AL/MAX14523B/MAX14523C

250mA to 1.5A, Adjustable
Current-Limit Switches

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implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

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© 2009 Maxim Integrated Products

Maxim is a registered trademark of Maxim Integrated Products, Inc.

Do not use an R

SETI

value smaller than 91.78k

Ω.

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:

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:

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.

Chip Information

PROCESS: BiCMOS

P

V

I

t

t

t

MAX

IN MAX

OUT MAX

BLANK

RETRY

BLA

(

)

(

)

(

)

=

Ч

Ч

+

N

NK

C

µF

I

mA

t

ms

V

V

MAX

LIM

BLANK MIN

IN

(

)

(

)

(

)

( )

(

)

=

×

R

SETI

(k

)

TYPICAL CURRENT LIMIT/THRESHOLD (mA)

91.78 1500

121 1145

221 632

301 466

422 333

563.12 250

(Open)

0

Table 2. Current Limit/Threshold vs.
Resistor Values

PACKAGE TYPE

PACKAGE CODE

DOCUMENT NO.

8 TDFN-EP

T833+2

21-0137

Package Information

For the latest package outline information and land patterns, go to

www.maxim-ic.com/packages

.

Pin Configuration

MAX14523A

MAX14523AL

MAX14523B
MAX14523C

1

+

TDFN

3mm x 3mm

N.C.

2

FLAG

3

SETI

4

OUT

8

GND

7

ON(ON)**

6

N.C.

5

IN

*CONNECT EXPOSED PAD TO GND.
**( ) FOR THE MAX14523AL ONLY.

*EP