MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
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Typical Operating Circuit
19-6257; Rev 0; 3/12
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.
EVALUATION KIT AVAILABLE
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.
Applications
Industrial Current Loop Control
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
REF SUPPLY
OUT
GND
ADC
RLOAD
IN
4–20mA CURRENT
IA
SENSOR
(4–20mA)
CURRENT
CONTROL AND
PROTECTION CURRENT LIMIT
GATE CONTROL
MAX14626
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.
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MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
(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 (TA = +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
TDFN
Junction-to-Ambient Thermal Resistance (BJA) ............. 42NC/W Junction-to-Case Thermal Resistance (BJC) .................... 9NC/W
ABSOLUTE MAXIMUM RATINGS
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.
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)
DC ELECTRICAL CHARACTERISTICS
(IIN = 50FA to 24mA, TA = -40NC to +85NC, RLOAD = 25I to 1kI, unless otherwise noted. Typical values are at IIN = 10mA, RLOAD
= 250I, and TA = +25NC.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SUPPLY VOLTAGE
Operating Start Voltage VIN_ST IIN = 20FA2.3 V
Operating IN Voltage VIN 36 V
Operating IN to OUT Drop
Voltage IIN = 24mA 2.8 V
Quiescent Current (Normal
Mode: 4–20mA) IQRLOAD P 250I40 56 FA
Quiescent Current (Current-
Limit Mode: Current > 25mA) IQIOUT = 30mA, VIN = 5V, RLOAD = 25I65 FA
Reverse Current IREV VIN = -36V, VOUT = 0V, current into OUT 0.01 0.3 FA
IN to OUT Switch
On-Resistance RON VIN = 4V, IOUT = 16mA 25 45 I
Forward Current Limit ILIM VIN = 36V 27 30 33 mA
DYNAMIC
Turn-On Time tSS VIN = 3V, time from VIN applied to
VOUT = 90% of VIN (Note 3) 10 Fs
Turn-Off Time tOFF Time from thermal shutdown (Note 3) 20 Fs
Current-Limit Reaction Time tLIM Input current source from 20mA to 50mA
(Note 4) 50 Fs
Current-Limit Overshoot Voltage Input current source from 0mA to 50mA 50 %
Input Small Signal Bandwidth BW 2mA P DC IIN P 24mA, DIIN = 1mAP-P at
1kI> 10 kHz
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MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Note 2: All devices are 100% production tested at TA = +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.
DC ELECTRICAL CHARACTERISTICS (continued)
(IIN = 50FA to 24mA, TA = -40NC to +85NC, RLOAD = 25I to 1kI, unless otherwise noted. Typical values are at IIN = 10mA, RLOAD
= 250I, and TA = +25NC.) (Note 2)
Typical Operating Characteristics
(VIN = 24V, IIN = 10mA, RLOAD = 250I, unless otherwise noted. Typical values are at TA = +25NC.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
THERMAL PROTECTION
Thermal Shutdown +150 NC
Thermal-Shutdown Hysteresis 20 NC
QUIESCENT IQ vs. VIN
MAX14626 toc01
VIN (V)
32
2820 248 12 164
10
20
30
40
50
60
70
80
90
100
0
03
6
NO LOAD
QUIESCENT IQ (µA)
QUIESCENT IQ vs. IIN
MAX14626 toc02
IIN (mA)
QUIESCENT IQ (µA)
10
20
30
40
50
60
70
80
90
100
0
02
015105
RL = 250I
RL = 100I
958050 65-10 5 20 35-25
QUIESCENT IQ vs. TEMPERATURE
MAX14626 toc03
TEMPERATURE (°C)
QUIESCENT IQ (µA)
10
20
30
40
50
60
70
80
90
100
0
-40 110
IIN = 20mA
IIN = 10mA
IIN = 0mA
IIN = 4mA
����������������������������������������������������������������� Maxim Integrated Products 4
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Typical Operating Characteristics (continued)
(VIN = 24V, IIN = 10mA, RLOAD = 250I, unless otherwise noted. Typical values are at TA = +25NC.)
50
95
8050 65-10 5 20 35-25
ON-RESISTANCE vs. TEMPERATURE
MAX14626 toc04
TEMPERATURE (°C)
ON-RESISTANCE (I)
0
-40 110
VIN = +2.36V
VIN = +5V
VIN = +12V
VIN = +24V
IOUT = 10mA
10
20
30
40
50
REVERSE CURRENT vs. VOUT
MAX14626 toc05
VOUT (V)
REVERSE CURRENT (nA)
0
04
0
10
20
30
40
302010
IIN 0mA TO 20mA
MAX14626 toc06
2V/div
10mA/div
1) CH1 VOUT 2V 100µs
2) CH4 LIN 100mV 100µs
100µs/div
VOUT
IIN
1)
2)
SOFT CURRENT LIMIT:
IIN 15mA TO 35mA
MAX14626 toc07
5V/div
10mA/div
1) CH1 VOUT 5V 100µs
2) CH4 LIN 100mV 100µs
100µs/div
VOUT
IIN
1)
2)
FAULT RESPONSE (SHORT TO WIRE):
IIN 10mA TO 100mA
MAX14626 toc08
5V/div
20mA/div
1) CH1 VOUT 5V 50µs
2) CH4 LIN 100mV 50µs
50µs/div
VOUT
IIN
2)
1)
����������������������������������������������������������������� Maxim Integrated Products 5
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Pin Description
Pin Configuration
PIN NAME FUNCTION
1 IN Power Input
2, 3, 4 I.C. Internally Connected. Connect I.C. to GND.
5 GND Ground
6 OUT Switch Output
— EP Exposed Pad. Connect EP to GND. Connect to a large ground plane to maximize thermal
performance. Not intended as an electrical connection point.
I.C.
I.C.
IN
GND
I.C.
OUT
123
654
*EP
TQFN
MAX14626
TOP VIEW
+
*CONNECT EP TO GND
����������������������������������������������������������������� Maxim Integrated Products 6
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Detailed 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.
Reverse Input Protection
The device features reverse input protection to protect
the downstream sensor. When a reverse input voltage is
detected, control circuitry turns off the internal FET and
isolates the output from the input.
Thermal Shutdown
The device enters thermal shutdown when the die tem-
perature exceeds +150NC (typ). In thermal shutdown, the
internal FETs are turned off. When the die temperature
drops by 20NC, the device turns back on automatically.
Applications Information
Figure 1 shows the device in a 4–20mA current loop sensor
application.
Exposed Pad and Layout Concerns
Connect the exposed pad to a large ground plane to
maximize thermal performance. The exposed pad is not
intended as an electrical connection point.
To optimize the switch response time to output short-
circuit conditions, it is very important to keep all traces
as short as possible to reduce the effect of undesirable
parasitic inductance.
Functional Diagram
REF SUPPLY
OUT
GND
IN
CONTROL AND
PROTECTION CURRENT LIMIT
GATE CONTROL
MAX14626
����������������������������������������������������������������� Maxim Integrated Products 7
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Figure 1. 4–20mA Current Loop Sensor Application
Ordering Information
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed pad.
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
Chip Information
PROCESS: BiCMOS
PART TEMP
RANGE
PIN-
PACKAGE
TOP
MARK
MAX14626ETT+T -40NC to
+85NC6 TDFN-EP* AVF
PACKAGE
TYPE
PACKAGE
CODE
DOCUMENT
NO.
LAND
PATTERN
6 TDFN T633+2 21-0137 90-0058
ADC
IA
IA
MAX14626
VOLTAGE SPIKE AND RF SUPRESSION
ANALOG INPUT MODULE
+INPUT
+
-
CURRENT
LOOP
SENSOR
(4–20mA)
CURRENT
DC SUPPLY
19.2V TO 32V
-INPUT
RLOAD = 250I
ADC
MAX14626
VOLTAGE SPIKE AND RF SUPRESSION
ANALOG INPUT MODULE
+INPUT
-INPUT
RLOAD = 250I
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 8
© 2012 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 3/12 Initial release —
