19-3458; Rev 0; 10/04
0.075A to 1.5A, Programmable
Current-Limit Switch
General Description
The MAX4766 is a programmable current-limit switch
that uses a proprietary control topology to provide a
±10% accurate current limit. It operates from 2.25V to
4.5V input voltage.
The current limit is resistor settable from 0.075A to 1.5A
and features an adjustable soft-start function to control
the output-voltage ramp rate, thereby limiting the inrush
current. It also has an adjustable blanking time to
accommodate various capacitive loads.
If the load current is greater than the current-limit
threshold, the current limiter handles the overcurrent
situation in one of three ways depending on the option
selected. It enters an autoretry mode (MAX4766A),
latches off the switch (MAX4766B), or places the
device in a continuous current-limit mode (MAX4766C).
Additional safety features include thermal shutdown to
prevent overheating and reverse-current blocking to
prevent current from being driven back into the source.
The MAX4766 is available in a tiny 8-pin 3mm x 3mm
TDFN package and operates over the extended tem-
perature range of -40°C to +85°C.
♦
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♦
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♦
♦
Features
±10% Accurate Current Limit
0.075A to 1.5A Programmable Current Limit
Inrush Current Protection
Thermal Shutdown Protection
Reverse-Current Protection
Low Dropout Voltage
Programmable Blanking Time
Programmable Soft-Start Time
FLAG
Function (MAX4766B/MAX4766C)
Tiny 8-Pin TDFN Package (3mm x 3mm)
2.25V to 4.5V Supply Range
MAX4766
Typical Operating Circuit
2.25V TO 4.5V
Applications
SDIO Ports
Notebook Computers
PDAs and Palmtop Devices
Cell Phones
µP
IN
ON
FLAG*
SETI
SETS
GND
8 GND
7 ON
MAX4766
6 SETS
5 IN
OUT
MAX4766
SETB
Pin Configuration
TOP VIEW
SETB 1
FLAG 2
SETI 3
OUT 4
*MAX4766B/C
TDFN
Ordering Information/Selector Guide
PART
MAX4766AETA
MAX4766BETA
MAX4766CETA
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 TDFN
8 TDFN
8 TDFN
TOP MARK
AKV
AKW
AKX
PKG CODE
T833-1
T833-1
T833-1
SOFT-START/
BLANKING
Programmable
Programmable
Programmable
OVERCURRENT
RESPONSE
Autoretry
Latch-Off
Continuous
________________________________________________________________
Maxim Integrated Products
1
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.
0.075A to 1.5A, Programmable
Current-Limit Switch
MAX4766
ABSOLUTE MAXIMUM RATINGS
IN, OUT, ON,
FLAG
to GND .....................................-0.3V to +5V
SETB, SETS, SETI to GND ...........................-0.3V to (V
IN
+ 0.3V)
IN to OUT ...............................................................................±5V
OUT Short-Circuit Duration ........................................Continuous
Continuous Switch Current .................................................1.75A
Current into any Pin (Except IN, OUT)..............................±20mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin TDFN (derate 18.2mW/°C above +70°C)...455mW (T833-1)
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Human Body Model ESD Protection ....................................±2kV
Lead Temperature (soldering, 10s) .................................+300°C
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.
ELECTRICAL CHARACTERISTICS
(V
IN
= 2.25V to 4.5V, C
OUT
= 2.2µF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C, unless other-
wise noted.) (Note 1)
PARAMETER
Operating Voltage Range
Undervoltage Lockout
Undervoltage Lockout Hysteresis
I
OUT
= 0, switch on, R
SETI
= 0Ω (I
LIMIT
= 1.5A)
Quiescent Current
I
Q
I
OUT
= 0, switch on, R
SETI
= 200.9kΩ
(I
LIMIT
= 0.56A)
I
OUT
= 0, switch on, R
SETI
= 1500kΩ
(I
LIMIT
= 0.075A)
V
IN
= 3.6V, V
ON
= 0, V
OUT
= 0V,
T
A
= +25°C
V
IN
= 3.6V, V
ON
= 0, V
OUT
= 0V,
T
A
= +85°C
V
IN
= 4.0V, V
ON
= 0, V
OUT
= 0V,
T
A
= +25°C
V
IN
= 4.0V, V
ON
= 0, V
OUT
= 0V,
T
A
= +85°C
V
OUT
= 0V, R
SETI
= 0Ω (V
IN
= 2.25 to 4.0V)
V
OUT
= 0V, R
SETI
= 200.9kΩ
(V
IN
= 2.25 to 4.0V)
Current Limit
I
LIM
V
OUT
= 0V, R
SETI
= 1500kΩ
(V
IN
= 2.25 to 3.6V)
V
OUT
= 0V, R
SETI
= 1500kΩ
(V
IN
= 2.25 to 4.0V)
1.35
537
73
73
1.50
590
79.5
80
SYMBOL
V
IN
V
UVLO
V
IN
rising
CONDITIONS
MIN
2.25
1.6
125
35
95
75
85
135
120
0.1
13.5
µA
0.12
18
1.67
640
85.5
mA
87
A
µA
TYP
MAX
4.5
2.0
UNITS
V
V
mV
Shutdown Current
I
SHDN
2
_______________________________________________________________________________________
0.075A to 1.5A, Programmable
Current-Limit Switch
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 2.25V to 4.5V, C
OUT
= 2.2µF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C, unless other-
wise noted.) (Note 1)
PARAMETER
R
SETI
I
LIM
Product
SYMBOL
CONDITIONS
0.075A
≤
I
LIMIT
≤
1.5A, V
OUT
= 0V
V
ON
= V
IN
= 3V, I
OUT
= 0.9 x I
LIMIT(min)
,
R
SETI
= 0Ω (typical I
LIMIT
= 1.5A)
Switch Dropout Voltage (Note 2)
V
ON
= V
IN
= 3V, I
OUT
= 0.33 x I
LIMIT(min)
,
R
SETI
= 0Ω (typical I
LIMIT
= 1.5A)
V
ON
= V
IN
= 3V, I
OUT
= 0.9 x I
LIMIT(min)
,
R
SETI
= 200.9kΩ (typical I
LIMIT
= 0.56A)
V
IN
= 3.6V, V
ON
= 0V, V
OUT
= 0V,
T
A
= +25°C
Forward-Off Switch Leakage
Current
V
IN
= 3.6V, V
ON
= 0V, V
OUT
= 0V,
T
A
= +85°C
V
IN
= 4.0V, V
ON
= 0V, V
OUT
= 0V,
T
A
= +25°C
V
IN
= 4.0V, V
ON
= 0V, V
OUT
= 0V,
T
A
= +85°C
V
IN
= 0V, V
OUT
= 3.6V, V
ON
= 0V,
T
A
= +25°C
Reverse Leakage Current
(Device Disabled)
V
IN
= 0V, V
OUT
= 3.6V, V
ON
= 0V,
T
A
= +85°C
V
IN
= 0V, V
OUT
= 4.0V, V
ON
= 0V,
T
A
= +25°C
V
IN
= 0V, V
OUT
= 4.0V, V
ON
= 0V,
T
A
= +85°C
V
IN
= 0V, V
OUT
= 3.6V, V
ON
= V
OUT
,
T
A
= +25°C
Reverse Leakage Current
(Device Enabled)
V
IN
= 0V, V
OUT
= 3.6V, V
ON
= V
OUT
,
T
A
= +85°C
V
IN
= 0V, V
OUT
= 4.0V, V
ON
= V
OUT
,
T
A
= +25°C
V
IN
= 0V, V
OUT
= 4.0V, V
ON
= V
OUT
,
T
A
= +85°C
ON LOGIC
ON Logic-High Voltage
ON Logic-Low Voltage
V
IH
V
IL
1.4
0.6
V
V
MIN
101
TYP
112.5
MAX
124
290
105
245
0.1
13.5
µA
0.12
18
0.1
13.8
µA
0.125
18
0.17
30
µA
0.22
40
mV
UNITS
kV
MAX4766
I
OUT(OFF)
I
INR(OFF)
I
INR(OFF)
_______________________________________________________________________________________
3
0.075A to 1.5A, Programmable
Current-Limit Switch
MAX4766
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 2.25V to 4.5V, C
OUT
= 2.2µF, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C, unless other-
wise noted.) (Note 1)
PARAMETER
FLAG
OUTPUT LOGIC
FLAG
Output Logic-Low Voltage
FLAG
Output High Leakage Current
THERMAL PROTECTION
Thermal Shutdown
Thermal Shutdown Hysteresis
DYNAMIC
Turn-On Time (Note 3)
Turn-Off Time
Current-Limit Reaction Time
Blanking Time
Retry Time
t
BLANK
T
SS
T
OFF
C
SETS
= 0.01µF
V
ON
from high to low; R
L
= 10Ω, R
SET
= 0,
V
IN
= 3.3V
V
IN
= 4V, R
SET
= 0Ω, output high and then
short-circuit applied
C
SETB
= 0.01µF
3.5
225
5
9
75
1
6.75
420
11.5
700
17.5
150
ms
µs
µs
ms
ms
V
IN
= 3.3V, junction temperature rising
V
IN
= 3.3V
150
15
°C
°C
V
OL
I
SINK
= 1mA
V
IN
= V
FLAG
= 5.5V
0.4
1
V
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Note 1:
All parameters tested at T
A
= +25°C. Limits through the temperature range are guaranteed by design.
Note 2:
Not production tested. Guaranteed by design.
Note 3:
Turn-on time (also called soft-start time) is defined as the difference in the time between when the output crosses 10%, and
90% of the final output voltage.
Typical Operating Characteristics
(V
IN
= 3.3V, C
OUT
= 2.2µF, R
SETI
= 0kΩ, T
A
= +25°C, unless otherwise noted.)
CURRENT LIMIT
vs. SUPPLY VOLTAGE
MAX4766 toc01
CURRENT LIMIT
vs. TEMPERATURE
MAX4766 toc02
BLANKING TIME
vs. TEMPERATURE
MAX4766 toc03
1.60
V
CC
= 3V
1.55
CURRENT LIMIT (A)
1.60
V
CC
= 3V
1.55
CURRENT LIMIT (A)
10
9
BLANKING TIME (ms)
8
1.50
1.50
7
1.45
1.45
6
1.40
2.25
3.00
3.75
4.50
SUPPLY VOLTAGE (V)
1.40
-40
-15
10
35
60
85
TEMPERATURE (°C)
5
-40
-15
10
35
60
85
TEMPERATURE (°C)
4
_______________________________________________________________________________________
0.075A to 1.5A, Programmable
Current-Limit Switch
Typical Operating Characteristics (continued)
(V
IN
= 3.3V, C
OUT
= 2.2µF, R
SETI
= 0kΩ, T
A
= +25°C, unless otherwise noted.)
MAX4766
CURRENT-LIMIT RESPONSE
MAX4766 toc04a
CURRENT-LIMIT RESPONSE
MAX4766 toc04b
SUDDEN SHORT
APPLIED AT THE
OUTPUT
OUTPUT
2V/div
2A OF LOAD APPLIED
AT THE OUTPUT
OUTPUT
2V/div
OUTPUT LOAD
2A/div
OUTPUT LOAD
1A/div
10µs/div
10µs/div
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX4766 toc05
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX4766 toc06
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
SHUTDOWN SUPPLY CURRENT (
µA)
MAX4766 toc07
140
130
120
110
100
90
80
70
60
50
40
30
20
2.25
R
ISET
OPEN
R
ISET
= 0Ω
140
130
SUPPLY CURRENT (
µA)
120
110
100
90
80
70
60
50
40
30
20
-40
R
ISET
= 0Ω
5
4
SUPPLY CURRENT (
µA)
3
2
R
ISET
OPEN
1
0
-15
10
35
60
85
-40
-15
10
35
60
85
VOLTAGE (V)
TEMPERATURE (°C)
3.00
3.75
4.50
VOLTAGE (V)
SHUTDOWN LEAKAGE CURRENT
vs. TEMPERATURE
REVERSE SHUTDOWN LEAKAGE CURRENT (µA)
MAX4766 toc08
REVERSE SHUTDOWN LEAKAGE CURRENT
vs. TEMPERATURE
MAX4766 toc09
REVERSE SHUTDOWN LEAKAGE CURRENT
vs. TEMPERATURE
REVERSE SHUTDOWN LEAKAGE CURRENT (µA)
7
6
5
4
3
2
1
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
V
ON
= V
CC
MAX4766 toc10
5
SHUTDOWN LEAKAGE CURRENT (µA)
5
V
ON
= 0V
4
8
4
3
3
2
2
1
1
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
0
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
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