Rainbow Electronics MAX14523C User Manual

General Description

The MAX14523A/MAX14523AL/MAX14523B/MAX14523C
programmable current-limit switches feature internal
current limiting to prevent damage to host devices due
to faulty load conditions. These current-limit switches
feature a low 70mΩ on-resistance and operate from a
+1.7V to +5.5V input voltage range. The current limit is
adjustable from 250mA to 1.5A, making these devices
ideal for SDIO (secure digital input/output) and other
load-switching applications.

Each device in the family handles an overcurrent event
differently depending on the option selected. The
MAX14523A/MAX14523AL go into an autoretry mode,
the MAX14523B latches off the switch, and the
MAX14523C features a continuous current-limit mode.
Additional safety features include thermal shutdown to
prevent overheating and reverse-current blocking to
prevent current from being driven back into the source.

The MAX14523A/MAX14523AL/MAX14523B/MAX14523C
are available in a tiny 8-pin, 3mm x 3mm, TDFN pack­age and operate over the -40°C to +125°C automotive
temperature range.

Applications

SDIO Ports

USB Ports

Notebook VGA Ports

GPS

Cell Phones

MP3 Players

UTCA/ATCA Platforms

Features

♦ Accurate (±10%) Overload Current Limit

♦ Adjustable Current-Limit Threshold

♦ Low-Dropout Voltage (70mV at 1A Load Current)

♦ Short-Circuit Protection

♦ Thermal-Shutdown Protection

♦ Reverse-Current Protection

♦ 170µA (typ) Supply Current

♦ Shutdown Reverse Current, 0.6µA (max)

♦ +1.7V to +5.5V Supply Voltage Range

♦ Tiny 8-Pin, 3mm x 3mm, TDFN Package

MAX14523A/MAX14523AL/MAX14523B/MAX14523C

250mA to 1.5A, Adjustable

Current-Limit Switches

________________________________________________________________

Maxim Integrated Products

1

Ordering Information/Selector Guide

Typical Operating Circuit

19-4814; Rev 0; 7/09

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

PART PIN-PACKAGE TOP MARK ON POLARTIY

OVERCURRENT RESPONSE

MAX14523AATA+ 8 TDFN-EP* BLO Active-High Autoretry

MAX14523ALATA+**

8 TDFN-EP* BLP Active-Low Autoretry

MAX14523BATA+ 8 TDFN-EP* BLQ Active-High Latch-Off

MAX14523CATA+ 8 TDFN-EP* BLS Active-High Continuous

Pin Configuration appears at end of data sheet.

Note: All devices are specified over the -40°C to +125°C operating temperature range.

+

Denotes a lead(Pb)-free package/RoHs-compliant package.

*

EP = Exposed pad.

**

Future product—contact factory for availability.

BIAS

VOLTAGE

POWER
SUPPLY

μP

10kΩ

V

PULLUP

OUTIN

1μF

CHARGE

PUMP

R

SETI

FLAG

ON(ON)*

CURRENT

REFERENCE

CONTROL

LOGIC

N.C.

MAX14523A

MAX14523AL

MAX14523B
MAX14523C

GND

LOAD

1μF

*ON FOR THE MAX14523AL ONLY.

MAX14523A/MAX14523AL/MAX14523B/MAX14523C

250mA to 1.5A, Adjustable
Current-Limit Switches

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= +1.7V to +5.5V, R

SETI

= 94.2kΩ, CIN= C

OUT

= 1µF, and TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values

are at V

IN

= +3.3V, TA= +25°C.) (Note 2)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-

layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-turorial

.

(All voltages referenced to GND.)

IN, ON, ON, FLAG, OUT, and SETI to GND .............-0.3V to +6V

Current into Any Pin (Except IN, OUT)................................20mA

Out Short Circuit to GND...................................Internally Limited

Continuous Power Dissipation (T

A

= +70°C) for multilayer board:

8-Pin TDFN (derate 24.4mW/°C above +70°C) .........1952mW

Junction-to-Case Thermal Resistance (θ

JC

)

(Note 1) ...................................................................8.0°C/W

Junction-to-Ambient Thermal Resistance (θ

JA

)

(Note 1) .................................................................41.0°C/W

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

SUPPLY OPERATION

Operating Voltage VIN 1.7 5.5 V

Quiescent Current IQ I

Latchoff Current I

Shutdown Forward Current I

Shutdown Re verse Current I

INTERNAL FET

Switch-On Resistance R

Forward-Current Limit I

(R

+2.48k) × I

SETI

Reverse Bloc king Current

Reverse Blocking Threshold V

FLAG Assertion Drop Voltage
Threshold

ON, ON INPUT
ON, ON Input Leakage I
ON, ON Input Logic-High Voltage V
ON, ON Input Logic-Low Voltage V

Product

LIM

LATCH

SHDN

RSHDN

ON

LIM

- VIN

OUT

V

FA

VON, VON = V

LEAK

IH

IL

= 0A, switch on, V

OUT

V

= 3.3V, I

IN

= 0A , after an overcurrent

OUT

fault (MAX14523B)

VON = 0V, VON = VIN, V

V

= 0V, VON = VIN, V

ON

5.5V (current into OUT)

VIN = 3.3V, I

R

= 91.78k, VIN - V

SETI

R

= 563.12k , VIN - V

SETI

I

= 250mA to 1500mA,

LIM

- V

V

IN

OUT

V

> VIN + 140mV, after reverse-current-

OUT

OUT

= 1V

lower than I

limit shutdown

V

- VIN = 300mV, OUT falling until

OUT

switch turns on

Increase (V
asserts, I

- V

IN

OUT

limiting, VIN = 3.3V

OUT

or V

IN

= 3.3V 170 300 μA

IN

10 20 μA

= 5.5V, V

IN

= 1.7V, V

IN

LIM

= 1V 1350 1500 1650

OUT

= 1V 225 250 275

OUT

= 0V 0.5 7 μA

OUT

=

OUT

0.01 0.6 μA

70 130 m

127.2 141.4 155.5 kV

2 μA

40 95 140 mV

) drop until FLAG

-1 +1 μA

GND

350 mV

1.6 V

0.4 V

mA

MAX14523A/MAX14523AL/MAX14523B/MAX14523C

250mA to 1.5A, Adjustable

Current-Limit Switches

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VIN= +1.7V to +5.5V, R

SETI

= 94.2kΩ, CIN= C

OUT

= 1µF, and TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values

are at V

IN

= +3.3V, TA= +25°C.) (Note 2)

Note 2: All devices are 100% tested at 125°C. Electrical limits across the full temperature range are guaranteed by design and correlation.

Note 3: Blanking time and retry time are generated by the same oscillator. Therefore, the ratio of is a constant value of 32.

See Figures 2 and 3.

t

t

RETRY

BLANK

Figure 1. Timing Diagram for Measuring Turn-On Time (tSS) and Turn-Off Time (t

OFF

)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

FLAG OUTPUT

FLAG Output Logic-Low Voltage I
FLAG Output Lea kage Current VIN = V

DYNAMIC

Turn-On Time t

Turn-Off Time t

Current-Limit Reaction Time t

Blanking Time t

Retry Time t

THERMAL PROTECTION

Thermal Shutdown Low-to-high +170 °C

Thermal Shutdown Hysteresi s 15 °C

SS

OFF

LIM

BLANK

RETRY

= 1mA 0.4 V

SINK

= 5.5V, FLAG deas serted 1 μA

FLAG

Time from ENABLE signal to V
of V

= 3.3V, Figure 1

IN

Time from DISABLE signal to V
of V

= 3.3V, RL = 20, Figure 1

IN

V

= 3.3V, R

IN

output high and then short-circuit applied

= 91.78k to 563.12 k,

SETI

OUT

OUT

= 90%

= 10%

1 ms

250 μs

3 μs

(Note 3) 10 14.5 25 m s

MAX14523A/MAX14523AL (Note 3) 320 875 ms

ON(ON)*

t

SS

V

OUT

*( ) THE POLARITY OF THE SIGNAL IS REVERSED FOR THE MAX14523AL ONLY.

90% V

IN

10% V

t

OFF

IN