General Description
The MAX4795MAX4798 family of switches feature inter-
nal current limiting to prevent damage to host devices
due to faulty load conditions. These analog switches
have a low 0.2
on-resistance and operate from a 2.0V
to 4.5V input voltage range. They are available with guar-
anteed 450mA and 500mA current limits, making them
ideal for SDIO and other load-switching applications.
When the switch is on and a load is connected to the
port, a guaranteed blanking time of 14ms ensures the
transient voltages settle down. If after this blanking time,
the load current is greater than the current limit, the
MAX4795 and MAX4797 switches are turned off and
FLAG is issued to the microprocessor. The switch can be
turned on again by cycling the power or the ON input.
The MAX4796 and MAX4798 have an autoretry feature
where the switch turns off and issues a FLAG to the
microprocessor after the blanking time and then contin-
uously checks to see if the overload condition is pre-
sent. The switch remains on after the overload condition
disappears and FLAG deasserts.
The MAX4795MAX4798 are available in tiny, space-
saving, 5-pin SOT23 and 6-pin TDFN (3mm x 3mm)
packages.
Applications
SDIO
PDAs and Palmtop Devices
Cell Phones
GPS Systems
Hand-Held Devices
Features
o Guaranteed Current Limit: 450mA and 500mA
o Thermal-Shutdown Protection
o Reverse-Current Protection
o 0.2 On-Resistance
o 14ms Guaranteed Blanking Time
o FLAG Function
o Autoretry (MAX4796/MAX4798)
o 80A Supply Current
o 6A Latchoff Current
(MAX4795/MAX4797)
o 0.01A Shutdown Current
o +2V to +4.5V Supply Range
o Fast Current-Limit Response Time
o Tiny SOT23 and TDFN Packages
o UL Certification Pending
MAX4795MAX4798
450mA/500mA Current-Limit Switches
________________________________________________________________ Maxim Integrated Products
1
Ordering Information
+2.0V TO +4.5V
IN
OUT
FLAG
GND
ON
P
TO SDIO PORT
MAX4795
MAX4796
MAX4797
MAX4798
Typical Operating Circuit
19-2944; Rev 0; 8/03
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
PART
TEMP RANGE
PIN-
PACKAGE
TOP
MARK
MAX4795EUK-T
-40C to +85C
5 SOT23-5
AEDI
MAX4795ETT*
40C to +85C
6 TDFN-EP**
--
MAX4796EUK-T
-40C to +85C
5 SOT23-5
AEDJ
MAX4796ETT*
-40C to +85C
6 TDFN-EP**
--
MAX4797EUK-T
-40C to +85C
5 SOT23-5
AEDK
MAX4797ETT*
-40C to +85C
6 TDFN-EP**
--
MAX4798EUK-T
-40C to +85C
5 SOT23-5
AEDL
MAX4798ETT*
-40C to +85C
6 TDFN-EP**
--
GND
FLAG
1
5 OUT
IN
MAX4795
MAX4796
MAX4797
MAX4798
SOT23
TOP VIEW
2
3
4
ON
OUT
FLAG
1
6 ON
5 GND
IN
MAX4795
MAX4796
MAX4797
MAX4798
TDFN
2
3
4
N.C.
Pin Configurations
*Future product--contact factory for availability.
**EP = Exposed pad.
Selector Guide appears at end of data sheet.
MAX4795MAX4798
450mA/500mA Current-Limit Switches
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= +2.0V to +4.5V, T
A
= -40C to +85C, unless otherwise noted. Typical values are at V
IN
= 3.3V, T
A
= +25C.) (Note 1)
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: All parts are 100% tested at +25C. Electrical limits across the full temperature range are guaranteed by design and correlation.
Note 2: Latch-off current does not include the current flowing into FLAG.
Note 3: TDFN packages are guaranteed by design.
Note 4: The on-time is defined as the time taken for the current through the switch to go from 0mA to full load. The off-time is defined as
the time taken for the current through the switch to go from full load to 0mA.
Note 5: Retry time is typically 15 times the blanking time.
IN, ON, FLAG, OUT to GND .....................................-0.3V to +6V
OUT Short Circuit to GND .................................Internally Limited
Continuous Power Dissipation (T
A
= +70C)
5-Pin SOT23 (derate 7.1mW/C above +70C)............571mW
6-Pin TDFN (derate 24.4mW/C above +70C) .........1951mW
Operating Temperature Range ...........................-40C to +85C
Junction Temperature ......................................................+150C
Storage Temperature Range .............................-65C to +150C
Lead Temperature (soldering, 10s) .................................+300C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Operating Voltage
V
IN
2.0
4.5
V
Quiescent Current
I
Q
V
ON
= V
IN
, I
OUT
= 0, switch on
V
IN
= +3.3V
80
125
A
Latch-Off Current
I
LATCH
V
ON
= V
IN
, after an overcurrent
fault (MAX4795/MAX4797) (Note 2)
V
IN
= +3.3V
6
10
A
Shutdown Current
I
SHDN
V
ON
= 0V
0.03
1
A
MAX4795/MAX4796, V
IN
= 3.3V, V
OUT
= GND
450
720
Forward Current Limit
MAX4797/MAX4798, V
IN
= 3.3V, V
OUT
= GND
500
800
mA
MAX4795/MAX4796
720
Reverse Current Limit
MAX4797/MAX4798
800
mA
ON Input Leakage
-1
+1
A
Shutdown Forward Leakage
V
ON
= 0V, V
OUT
= 0V
0.01
1
A
Shutdown Reverse Leakage
V
ON
= 0V, V
IN
= 2V, V
OUT
= 4.5V
1
A
MAX4795/MAX4796, I
LOAD
= 100mA
0.2
0.4
On-Resistance (Note 3)
R
ON
MAX4797/MAX4798, I
L OA D
= 100m A
0.18
0.36
V
IN
= +2V to +3.6V
1.4
ON Input Logic High Voltage
V
IH
V
IN
> 3.6V
2
V
ON Input Logic Low Voltage
V
IL
0.5
V
FLAG Output Logic Low Voltage
I
S IN K
= 1m A
0.4
V
FLAG Output High Leakage
Current
V
IN
= V
F LAG
= V
ON
= 4.5V
1
A
Thermal Shutdown
150
C
Thermal-Shutdown Hysteresis
15
C
DYNAMIC
Turn-On Time
V
ON
fr om l ow to hi g h; I
OU T
= 10m A, C
L
= 0.1F ( N ote 4)
120
s
Turn-Off Time
V
ON
fr om hi g h to l ow ; I
OU T
= 10m A, C
L
= 0.1F ( N ote 4)
100
ns
Blanking Time
t
BLANK
Overcurrent fault; Figures 2, 3
14
60
ms
Short-Circuit Current-Limit
Response Time
V
ON
= V
IN
, short circuit applied to OUT
5
s
Retry Time
t
RETRY
MAX4796/MAX4798, Figure 2 (Note 5)
210
900
ms
MAX4795MAX4798
450mA/500mA Current-Limit Switches
_______________________________________________________________________________________
3
0
20
40
60
80
100
120
140
160
2.0
2.5
3.0
3.5
4.0
4.5
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX4795 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (
A)
V
ON
= V
IN
50
60
80
70
90
100
-40
10
-15
35
60
85
SUPPLY CURRENT vs. TEMPERATURE
MAX4795 toc02
TEMPERATURE (
C)
SUPPLY CURRENT (
A)
V
ON
= V
IN
0
3
2
1
4
5
6
7
8
9
10
LATCH-OFF CURRENT
vs. TEMPERATURE
TEMPERATURE (
C)
LATCH-OFF CURRENT (
A)
-40
10
-15
35
60
85
MAX4795 toc03
V
ON
= V
IN
100
-40
-15
10
35
60
85
10
1
0.1
0.01
0.001
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX4795 toc04
TEMPERATURE (
C)
SHUTDOWN SUPPLY CURRENT (nA)
SHUTDOWN LEAKAGE CURRENT
vs. TEMPERATURE
MAX4795 toc05
-40
-15
10
35
60
85
10
1
0.1
0.01
0.001
TEMPERATURE (
C)
SHUTDOWN SUPPLY CURRENT (nA)
V
ON
= 0V, V
OUT
= 0V
LATCH-OFF LEAKAGE CURRENT
vs. TEMPERATURE
MAX4795 toc06
-40
-15
10
35
60
85
10
100
1
0.1
0.01
0.001
0.0001
TEMPERATURE (
C)
LATCH-OFF LEAKAGE CURRENT (nA)
10
-40
-15
10
35
60
85
1
0.1
0.01
0.001
0.0001
SHUTDOWN REVERSE LEAKAGE CURRENT
vs. TEMPERATURE
MAX4795 toc07
TEMPERATURE (
C)
SHUTDOWN LEAKAGE CURRENT (nA)
V
ON
= 0V, V
OUT
= 4.5V
0
0.4
0.2
0.8
0.6
1.2
1.0
1.4
-40
10
-15
35
60
85
NORMALIZED ON-RESISTANCE
vs. TEMPERATURE
MAX4795 toc08
TEMPERATURE (
C)
NORMALIZED R
ON
(
)
0
200
100
500
400
300
600
700
900
800
1000
0
0.6 0.9
0.3
1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
OUTPUT CURRENT
vs. OUTPUT VOLTAGE
MAX4795 toc09
V
IN
- V
OUT
(V)
OUTPUT CURRENT (mA)
MAX4797/MAX4798
MAX4795/MAX4796
Typical Operating Characteristics
(V
IN
= 3.3V, T
A
= +25C, unless otherwise noted.)
MAX4795MAX4798
450mA/500mA Current-Limit Switches
4
_______________________________________________________________________________________
FORWARD CURRENT LIMIT
vs. SUPPLY VOLTAGE
MAX4795 toc10
SUPPLY VOLTAGE (V)
FORWARD CURRENT LIMIT (mA)
4.0
3.5
3.0
2.5
525
550
575
600
625
650
500
2.0
4.5
OUT = GND
MAX4797/MAX4798
MAX4795/MAX4796
SWITCH TURN-ON/OFF TIMES
vs. TEMPERATURE
MAX4795 toc11
-40
-15
10
35
60
85
1000
100
10
1
0.1
0.01
0.001
TEMPERATURE (
C)
TURN-ON/OFF TIMES (
s)
OFF
ON
I
LOAD
= 10mA
20
25
35
30
40
45
50
-40
10
-15
35
60
85
FLAG-BLANKING TIMEOUT
vs. TEMPERATURE
MAX4795 toc12
TEMPERATURE (
C)
FLAG-BLANKING TIMEOUT (ms)
0V
0V
3.3V
0V
3.3V
V
IN
= 3.3V C
OUT
= 1
F
C
IN
= 1
F V
SEL
= 3.3V
40
s/div
V
IN
2V/div
V
ON
2V/div
I
OUT
200mA/div
MAX4797/MAX4798
CURRENT-LIMIT RESPONSE
MAX4795 toc13
0V
3V
0V
V
IN
= V
ON
C
OUT
= 1
F
C
IN
= 1
F
40
s/div
V
IN
= V
ON
1V/div
I
OUT
200mA/div
MAX4797/MAX4798
CURRENT-LIMIT RESPONSE
MAX4795 toc14
0V
3.3V
3.3V
0V
0V
4
s/div
V
IN
2V/div
V
OUT
2V/div
I
OUT
5A/div
CURRENT-LIMIT RESPONSE
(OUT SHORTED TO GND)
MAX4795 toc15
C
IN
= 1
F
C
OUT
= 1
F
0V
0V
3V
3V
0V
200
s/div
V
IN
2V/div
V
OUT
2V/div
I
OUT
1A/div
MAX4797/MAX4798
REVERSE CURRENT LIMIT
MAX4795 toc16
C
IN
= 1
F
C
OUT
= 1
F
0V
3V
0V
20
s/div
V
ON
1V/div
I
OUT
10mA/div
SWITCH TURN-ON TIME RESPONSE
MAX4795 toc17
V
IN
= 3.3V
Typical Operating Characteristics (continued)
(V
IN
= 3.3V, T
A
= +25C, unless otherwise noted.)
MAX4795MAX4798
450mA/500mA Current-Limit Switches
_______________________________________________________________________________________
5
Pin Description
PIN
SOT23
TDFN
NAME
FUNCTION
1
1
IN
Input. Bypass with a 0.1F ceramic
capacitor to ground.
2
5
GND
Ground
3
6
ON
Acti ve-H i g h S w itch On Inp ut. A log i c
hi gh tur ns the sw i tch on.
4
4
FLAG
Faul t Outp ut. Thi s op en- d r ai n outp ut
g oes l ow w hen the devi ce stays i n
forw ar d or r ever se cur rent l i m it for
m ore than the bl anki ng ti m e p eri od .
FLAG i s hi gh i mp ed ance w hen a faul t
i s not p r esent or when ON is l ow .
5
2
OUT
S w itch Output. Byp ass wi th a 0.1F
ceram i c capaci tor to g round.
--
3
N.C.
No Connection. Not internally
connected.
N
REVERSE-CURRENT
DETECTOR
FORWARD-CURRENT
DETECTOR
OUT
FLAG
IN
ON
GND
LOGIC
AUTORETRY
MAX4795MAX4798
BLANKING TIME
CIRCUITRY
Figure 1. Functional Diagram
0V
0V
3.3V
40ns/div
V
ON
1V/div
I
OUT
10mA/div
SWITCH TURN-OFF TIME RESPONSE
MAX4795 toc18
Typical Operating Characteristics (continued)
(V
IN
= 3.3V, T
A
= +25C, unless otherwise noted.)
0V
0V
0V
0V
3.3V
3.3V
3.3V
10ms/div
V
IN
2V/div
V
OUT
2V/div
V
FLAG
2V/div
I
OUT
500mA/div
MAX4797/MAX4798
FLAG-BLANKING RESPONSE
(OVERLOAD CONDITION)
MAX4795 toc19
V
IN
= 3.3V
C
IN
= 1
F
C
OUT
= 1
F
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