19-6257; Rev 0; 3/12
EVALUATION KIT AVAILABLE
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
General Description
The MAX14626 current loop protector features a current-
limit switch to prevent damage to the sensor devices due
to faulty current loop conditions. The current-limit switch
features a 25I (typ) on-resistance and operates from a
+2.3V to +36V input voltage range. The accurate current
limit is set to 30mA, making the part ideal for protecting
the sensor reading devices.
The MAX14626 handles an overcurrent event in a con-
tinuous current-limit mode. Additional safety features
include thermal shutdown to prevent overheating and
reverse-input blocking to protect from being reverse con-
nected into the sensor.
The device is available in a tiny 6-pin (3mm x 3mm),
TDFN exposed pad package and is
specified
over the
-40NC to +85NC extended temperature range.
Benefits and Features
S
High Performance
Low On-Resistance 25I (typ)
Accurate
Q10%
Current Limit
+2.3V to +40V Wide Supply Voltage Range
Low Operating Current
Ultra-Low Temperature Coefficient
S
Robust Protection for Sensors
Avoids Power Dissipation Issues Compared to
Discrete Solutions
Thermal Shutdown
Reverse Input Protection
S
Saves Space in Compact Systems
Eliminates Need for Discrete PTC Poly Switch,
Zener Diodes, and Resistors
3mm x 3mm, 6-Pin TDFN Package
Ordering Information
appears at end of data sheet.
For related parts and recommended products to use with this part,
refer to
www.maxim-ic.com/MAX14626.related.
Applications
Industrial Current Loop Control
Typical Operating Circuit
4–20mA CURRENT
SENSOR
(4–20mA)
CURRENT
IN
MAX14626
OUT
R
LOAD
CURRENT LIMIT
GATE CONTROL
IA
ADC
REF
SUPPLY
CONTROL AND
PROTECTION
GND
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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.
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
IN to GND ..............................................................-40V to +40V
OUT to GND ........................................................ -0.3V to +40V
Current into IN ................................................ Internally Limited
Current into OUT ..............................................................100mA
Continuous Power Dissipation (T
A
= +70NC)
TDFN (derate 23.8mW/NC above +70NC) ...............1904.8mW
Operating Temperature Range ........................ -40NC to +125NC
Maximum Junction Temperature.....................................+150NC
Storage Temperature Range............................ -65NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional opera-
tion 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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
TDFN
Junction-to-Ambient Thermal Resistance (B
JA
) ............. 42NC/W
Junction-to-Case Thermal Resistance (B
JC
) .................... 9NC/W
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-tutorial.
DC ELECTRICAL CHARACTERISTICS
(I
IN
= 50FA to 24mA, T
A
= -40NC to +85NC, R
LOAD
= 25I to 1kI, unless otherwise noted. Typical values are at I
IN
= 10mA, R
LOAD
= 250I, and T
A
= +25NC.) (Note 2)
PARAMETER
SUPPLY VOLTAGE
Operating Start Voltage
Operating IN Voltage
Operating IN to OUT Drop
Voltage
Quiescent Current (Normal
Mode: 4–20mA)
Quiescent Current (Current-
Limit Mode: Current > 25mA)
Reverse Current
IN to OUT Switch
On-Resistance
Forward Current Limit
DYNAMIC
Turn-On Time
Turn-Off Time
Current-Limit Reaction Time
Current-Limit Overshoot Voltage
Input Small Signal Bandwidth
BW
t
SS
t
OFF
t
LIM
V
IN
= 3V, time from V
IN
applied to
V
OUT
= 90% of V
IN
(Note 3)
Time from thermal shutdown (Note 3)
Input current source from 20mA to 50mA
(Note 4)
Input current source from 0mA to 50mA
2mA
P
DC I
IN
P
24mA,
DI
IN
= 1mA
P-P
at
1kI
10
20
50
50
> 10
Fs
Fs
Fs
%
kHz
I
Q
I
Q
I
REV
R
ON
I
LIM
V
IN_ST
V
IN
I
IN
= 24mA
R
LOAD
P
250I
I
OUT
= 30mA, V
IN
= 5V, R
LOAD
= 25I
V
IN
= -36V, V
OUT
= 0V, current into OUT
V
IN
= 4V, I
OUT
= 16mA
V
IN
= 36V
27
0.01
25
30
40
I
IN
= 20FA
2.3
36
2.8
56
65
0.3
45
33
V
V
V
FA
FA
FA
I
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
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Maxim Integrated Products
2
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
DC ELECTRICAL CHARACTERISTICS (continued)
(I
IN
= 50FA to 24mA, T
A
= -40NC to +85NC, R
LOAD
= 25I to 1kI, unless otherwise noted. Typical values are at I
IN
= 10mA, R
LOAD
= 250I, and T
A
= +25NC.) (Note 2)
PARAMETER
THERMAL PROTECTION
Thermal Shutdown
Thermal-Shutdown Hysteresis
+150
20
NC
NC
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Note 2:
All devices are 100% production tested at T
A
= +25NC, unless otherwise noted. Limits over the -40NC to +85NC operating
temperature range are guaranteed by design.
Note 3:
Turn-on time and turn-off time are defined as the difference in the time between when the output voltage crosses 10% and
90% of the final output voltage.
Note 4:
Input current source can support voltage up to +40V (absolute maximum). Current reaction time is defined as the settling
time of the output current after a fault event.
Typical Operating Characteristics
(V
IN
= 24V, I
IN
= 10mA, R
LOAD
= 250I, unless otherwise noted. Typical values are at T
A
= +25NC.)
QUIESCENT I
Q
vs. V
IN
MAX14626 toc01
QUIESCENT I
Q
vs. I
IN
MAX14626 toc02
90
80
QUIESCENT I
Q
(µA)
70
60
50
40
30
20
10
0
0
NO LOAD
90
80
QUIESCENT I
Q
(µA)
70
60
50
40
30
20
10
0
90
80
QUIESCENT I
Q
(µA)
70
60
50
40
30
20
R
L
= 250I
I
IN
= 10mA
I
IN
= 20mA
I
IN
= 4mA
I
IN
= 0mA
R
L
= 100I
0
5
10
I
IN
(mA)
15
20
10
0
-40 -25 -10 5
20 35 50 65 80 95 110
TEMPERATURE (°C)
4
8
12
16
20
24
28
32
36
V
IN
(V)
½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½½
Maxim Integrated Products
3
MAX14626 toc03
100
100
QUIESCENT I
Q
vs. TEMPERATURE
100
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Typical Operating Characteristics (continued)
(V
IN
= 24V, I
IN
= 10mA, R
LOAD
= 250I, unless otherwise noted. Typical values are at T
A
= +25NC.)
ON-RESISTANCE vs. TEMPERATURE
MAX14626 toc04
REVERSE CURRENT vs. V
OUT
MAX14626 toc05
I
IN
0mA TO 20mA
50
50
40
REVERSE CURRENT (nA)
30
20
10
0
MAX14626 toc06
I
OUT
= 10mA
40
ON-RESISTANCE (
I
)
30
20
10
0
-40 -25 -10 5
V
OUT
2V/div
1)
V
IN
= +2.36V
V
IN
= +5V
V
IN
= +24V
V
IN
= +12V
I
IN
10mA /div
2)
1) CH1 V
OUT
2V 100µs
2) CH4 L
IN
100mV 100µs
20 35 50 65 80 95 110
0
10
20
V
OUT
(V)
30
40
100µs/div
TEMPERATURE (°C)
SOFT CURRENT LIMIT:
I
IN
15mA TO 35mA
MAX14626 toc07
FAULT RESPONSE (SHORT TO WIRE):
I
IN
10mA TO 100mA
MAX14626 toc08
V
OUT
1)
5V/div
1)
V
OUT
5V/div
I
IN
2)
10mA /div
1) CH1 V
OUT
5V 100µs
2) CH4 L
IN
100mV 100µs
2)
1) CH1 V
OUT
5V 50µs
2) CH4 L
IN
100mV 50µs
I
IN
20mA /div
100µs/div
50µs/div
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Maxim Integrated Products
4
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Pin Configuration
GND
OUT
6
5
MAX14626
+
1
IN
2
I.C.
*EP
3
I.C.
TQFN
*CONNECT EP TO GND
I.C.
4
TOP VIEW
Pin Description
PIN
1
2, 3, 4
5
6
—
NAME
IN
I.C.
GND
OUT
EP
Power Input
Internally Connected. Connect I.C. to GND.
Ground
Switch Output
Exposed Pad. Connect EP to GND. Connect to a large ground plane to maximize thermal
performance. Not intended as an electrical connection point.
FUNCTION
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Maxim Integrated Products
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