19-3672; Rev 1; 8/09
50mA/100mA Current-Limit Switches with
NO-LOAD Flag in µDFN
General Description
The MAX4826–MAX4831 family of switches has internal
current limiting to prevent host devices from being
damaged due to faulty load conditions. These analog
switches have a low 0.7Ω on-resistance and operate
from a +2.3V to +5.5V input voltage range. These
devices are available with guaranteed 50mA and
100mA current limits, making them ideal for load-
switching applications. In addition to the current-limit
fault flag (FFLG), an open-drain no-load flag indicator
(NOLD) notifies the system when the current through
the switch is less than 10mA (MAX4826–MAX4829), or
5mA (MAX4830/MAX4831).
When the switch is on and a load is connected to the
port, a guaranteed blanking time of 14ms ensures that
the transient voltages settle down. If, after this blanking
time, the load current is greater than the current limit,
the MAX4826/MAX4828/MAX4830 enter a latchoff state
where the switch is turned off, and
FFLG
is issued to
the microprocessor. The switch can be turned on again
by cycling the power or ON.
The MAX4827/MAX4829/MAX4831 have an autoretry
feature where the switch turns off after the blanking
time, and then continuously checks to see if the over-
load condition is present. The current-limit fault flag
(FFLG) is issued and remains low until after the fault
condition is removed. The switch remains on after the
overload condition disappears.
The MAX4826–MAX4831 operate over the extended
-40°C to +85°C temperature range, and are available in a
tiny space-saving, 1mm x 1.5mm, 6-pin µDFN package.
♦
Thermal Shutdown Protection
♦
Reverse-Current Protection
♦
0.7Ω On-Resistance (MAX4826–MAX4831)
♦
14ms Guaranteed Blanking Time
♦
Fault Flag (FFLG)
♦
No-Load Flag (NOLD)
♦
65µA Supply Current
♦
8µA Latchoff Current
♦
0.01µA Shutdown Current
♦
+2.3V to +5.5V Supply Range
♦
Undervoltage Lockout
♦
Fast Current-Limit Response Time
♦
6-Pin
µDFN
Package (1mm x 1.5mm)
Features
♦
Guaranteed Current Limit: 50mA, 100mA
MAX4826–MAX4831
Applications
GPS Systems
Cell Phones
Digital Still Cameras
PDAs and Palmtop Devices
MP3 Players
Ordering Information/Selector Guide
PART
MAX4826ELT+T
MAX4827ELT+T*
MAX4828ELT+T*
MAX4829ELT+T
MAX4830ELT+T
MAX4830ELT/V+T
MAX4831ELT+T*
PIN-PACKAGE
6 μDFN
6 μDFN
6 μDFN
6 μDFN
6 μDFN
6 μDFN
6 μDFN
MIN FULL-LOAD
LIMIT
(mA)
50
50
100
100
50
50
50
MAX NO-LOAD
LIMIT
(mA)
10
10
10
10
5
5
5
ON-RESISTANCE
( )
T
A
= +25°C
1
1
1
1
2
2
2
MODE
Latchoff
Autoretry
Latchoff
Autoretry
Latchoff
Latchoff
Autoretry
TOP
MARK
AK
AL
AM
AN
AO
OX
AP
Note:
All devices operate over the -40°C to +85°C operating range.
T = Tape and reel.
*Future product—contact factory for availability.
/V denotes an automotive qualified part.
Pin Configuration appears at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
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.
50mA/100mA Current-Limit Switches with
NO-LOAD Flag in µDFN
MAX4826–MAX4831
ABSOLUTE MAXIMUM RATINGS
IN, ON,
FFLG, NOLD,
OUT to GND .........................-0.3V to +6V
OUT Short Circuit to GND .................................Internally Limited
Continuous Power Dissipation (T
A
= +70°C)
6-Pin µDFN (derate 2.1mW/°C above +70°C) .............168mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
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
= +2.3V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
IN
= +3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Operating Voltage
Quiescent Current
Latchoff Current (Note 2)
Shutdown Current
Shutdown Reverse Leakage
Forward-Current Limit
SYMBOL
V
IN
I
Q
I
LATCH
I
SHDN
I
SHDNRV
I
FWD
V
ON
= V
IN
, I
OUT
= V
IN
= +2.3V to +5.0V
0, switch on
V
IN
= +5.0V to +5.5V
V
ON
= V
IN
= 3.3V, after an overcurrent fault
(MAX4826/MAX4828/MAX4830)
V
ON
= 0, I
OUT
= 0mA
V
ON
= 0, V
IN
= +2.3V, V
OUT
= +5.5V
(MAX4826/MAX4827/MAX4830/MAX4831)
R
L
= 10Ω
(MAX4828/MAX4829) R
L
= 5Ω
Reverse-Current Limit
I
REV
V
OUT
- V
IN
< 0.5V
(MAX4826/MAX4827/MAX4830/MAX4831)
V
OUT
- V
IN
< 0.5V (MAX4828/MAX4829)
No-Load Threshold
ON Input Leakage
Off-Switch Leakage
Undervoltage Lockout
Undervoltage Lockout Hysteresis
I
NLTH
I
ONLK
I
SWLK
UVLO
UVLO
HYS
T
A
= +25°C, I
OUT
= 20mA
On-Resistance
R
ON
T
A
= -40°C to
+85°C,
I
OUT
= 20mA
(MAX4826–MAX4829)
(MAX4830/MAX4831)
(MAX4826–MAX4829)
(MAX4830/MAX4831)
2.0
0.8
I
SINK
= 1mA
0.4
MAX4826–MAX4829
MAX4830/MAX4831
V
ON
= V
IN
or GND
V
IN
= +5.5V, V
ON
= 0, V
OUT
= 0
Rising edge
1.8
100
0.7
1.4
1.0
2.0
1.3
2.6
V
V
V
Ω
1.0
0.5
-1
0.01
50
100
CONDITIONS
MIN
2.3
65
TYP
MAX
5.5
100
120
8
0.01
0.01
15
1
1
120
240
120
240
10.0
5.0
+1
1
2.2
mA
µA
µA
V
mV
mA
UNITS
V
µA
µA
µA
µA
mA
ON Input-Logic-High Voltage
ON Input-Logic-Low Voltage
FFLG, NOLD
Output-Logic-Low
Voltage
V
IH
V
IL
2
_______________________________________________________________________________________
50mA/100mA Current-Limit Switches with
NO-LOAD Flag in µDFN
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +2.3V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
IN
= +3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
FFLG, NOLD
Output-High
Leakage Current
Thermal Shutdown
Thermal-Shutdown Hysterisis
DYNAMIC
Turn-On Time
Turn-Off Time
Blanking Time
Short-Circuit Current-Limit
Response Time
No-Load-Detection Response
Time
Retry Time
t
RETRY
t
BLANK
ON from low to high; I
OUT
= 10mA,
C
L
= 0.1µF (Note 3)
ON from high to low; I
OUT
=10mA,
C
L
= 0.1µF (Note 3)
Overcurrent fault
V
ON
= V
IN
= +3.3V, short circuit applied to
OUT
I
OUT
falling step signal from 15mA to 0mA,
C
L
= 0.1µF
Overcurrent fault (Figure 2) (Note 4)
196
14
5
60
840
50
30
60
µs
ns
ms
µs
µs
ms
SYMBOL
CONDITIONS
V
IN
= V
FFLG
= V
NOLD
= +5.5V
+150
15
MIN
TYP
MAX
1
UNITS
µA
°C
°C
MAX4826–MAX4831
Note 1:
All parts are 100% tested at T
A
= +25°C. Limits at T
A
= -40°C to +85°C are guaranteed by design.
Note 2:
Latchoff current does not include the current flowing into
FFLG
and
NOLD.
Note 3:
Turn-on time is defined as the time taken for the current through the switch to go from 0mA to full load. Turn-off time is
defined as the time taken for the current through the switch to go from full load to 0mA.
Note 4:
Retry time is typically 14x the blanking time.
Typical Operating Characteristics
(V
IN
= +3.3V, T
A
= +25°C, unless otherwise noted.)
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX4826 toc01
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE
V
ON
= V
IN
MAX4826 toc02
LATCHOFF CURRENT
vs. TEMPERATURE
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
V
ON
= V
IN
MAX4826 toc03
90
80
SUPPLY CURRENT (μA)
70
60
50
40
30
20
10
0
V
ON
= V
IN
V
IN
= +2.3V TO +5.5V
90
80
SUPPLY CURRENT (μA)
70
60
50
40
30
20
10
0
V
IN
= 5V
V
IN
= 3.3V
LATCHOFF CURRENT (μA)
V
IN
= 5V
V
IN
= 3.3V
2.3
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
-40
-15
10
35
60
85
-40
-15
10
35
60
85
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
3
50mA/100mA Current-Limit Switches with
NO-LOAD Flag in µDFN
MAX4826–MAX4831
Typical Operating Characteristics (continued)
(V
IN
= +3.3V, T
A
= +25°C, unless otherwise noted.)
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX4826 toc04
SHUTDOWN LEAKAGE CURRENT
vs. TEMPERATURE
MAX4826 toc05
SHUTDOWN REVERSE LEAKAGE CURRENT
vs. TEMPERATURE
V
ON
= V
IN
= OV
V
OUT
= 5V
1
MAX4826 toc06
10
SHUTDOWN SUPPLY CURRENT (nA)
10
SHUTDOWN LEAKAGE CURRENT (nA)
10
REVERSE LEAKAGE CURRENT (nA)
1
1
0.1
V
IN
= 5V
0.01
V
IN
= 3.3V
0.001
0.1
V
IN
= 5V
0.01
V
IN
= 3.3V
0.001
0.1
0.01
0.001
0.0001
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.0001
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.0001
-40
-15
10
35
60
85
TEMPERATURE (°C)
LATCHOFF-LEAKAGE CURRENT
vs. TEMPERATURE
MAX4826 toc07
NORMALIZED ON-RESISTANCE
vs. TEMPERATURE
MAX4826 toc08
OUTPUT CURRENT vs. OUTPUT VOLTAGE
MAX4826 toc09
10
LATCHOFF-LEAKAGE CURRENT (nA)
1.4
V
ON
= V
IN
= 3.3V
1.2
1.0
0.8
0.6
0.4
0.2
0
300
250
OUTPUT CURRENT (mA)
200
MAX4828/MAX4829
150
100
50
0
MAX4826/MAX4827/MAX4830/MAX4831
1
0.1
V
IN
= 5V
0.01
V
IN
= 3.3V
0.001
0.0001
-40
-15
10
35
60
85
TEMPERATURE (°C)
NORMALIZED R
ON
-40
-15
10
35
60
85
0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
V
IN
- V
OUT
(V)
TEMPERATURE (°C)
SWITCH TURN-ON/OFF TIMES
vs. TEMPERATURE
MAX4826 toc10
FFLG-BLANKING TIMEOUT
vs. TEMPERATURE
MAX4826 toc11
100
ON
10
TURN-ON/OFF TIMES (μs)
V
IN
= 3.3V
V
IN
= 5V
40
35
FFLG-BLANKING TIME (ms)
30
25
20
15
1
0.1
OFF
0.01
I
LOAD
= -10mA
0.001
-40
10
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
50mA/100mA Current-Limit Switches with
NO-LOAD Flag in µDFN
Typical Operating Characteristics (continued)
(V
IN
= +3.3V, T
A
= +25°C, unless otherwise noted.)
MAX4826–MAX4831
CURRENT-LIMIT RESPONSE
MAX4826 toc12
CURRENT-LIMIT RESPONSE
MAX4826 toc13
V
ON
= 3.3V
V
OUT
= GND
C
IN
= 1μF
C
OUT
= 1μF
V
IN
2V/div
V
ON
2V/div
V
ON
= 3.3V
V
OUT
= GND
C
IN
= 1μF
C
OUT
= 1μF
V
IN
= V
ON
1V/div
I
OUT
100mA/div
I
OUT
100mA/div
40μs/div
20μs/div
CURRENT-LIMIT RESPONSE
(OUT SHORTED TO GND)
MAX4826 toc14
SWITCH TURN-ON-TIME RESPONSE
MAX4826 toc15
V
IN
2V/div
V
OUT
2V/div
V
IN
= 3.3V
I
LOAD
= 10mA
V
ON
2V/div
I
OUT
100mA/div
I
OUT
2A/div
40μs/div
100μs/div
SWITCH TURN-OFF-TIME RESPONSE
MAX4826 toc16
FFLG-BLANKING RESPONSE
MAX4826 toc17
V
IN
= 3.3V
I
LOAD
= 10mA
V
ON
2V/div
V
IN
2V/div
V
ON
2V/div
I
OUT
10mA/div
FFLG
2V/div
I
OUT
100mA/div
100ns/div
4ms/div
_______________________________________________________________________________________
5
PCB设计
