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MAX14626
EVALUATION KIT AVAILABLE
High-Voltage Reverse-Input-Capable 4–20mA Current Loop Protector
General Description
The MAX14626 current loop protector features a currentlimit switch to prevent damage to the sensor devices due to faulty current loop conditions. The current-limit switch features a 25Ω (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 continuous current-limit mode. Additional safety features include thermal shutdown to prevent overheating and reverse-input blocking to protect from being reverse connected into the sensor.
The device is available in a tiny 6-pin (3mm x 3mm), TDFN exposed pad package and is specified over the -40°C to +85°C extended temperature range.
Applications
●● Industrial Current Loop Control
Benefits and Features
●● High Performance • Low On-Resistance 25Ω (typ) • Accurate ±10% Current Limit • +2.3V to +40V Wide Supply Voltage Range • Low Operating Current • Ultra-Low Temperature Coefficient
●● Robust Protection for Sensors • Avoids Power Dissipation Issues Compared to Discrete Solutions • Thermal Shutdown • Reverse Input Protection
●● 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.
Typical Operating Circuit
SENSOR (4–20mA) CURRENT
IN
4–20mA CURRENT
MAX14626
REF SUPPLY
CONTROL AND PROTECTION
OUT
CURRENT LIMIT GATE CONTROL
RLOAD
IA ADC
GND
19-6257; Rev 1; 9/17
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 (TA = +70°C)
TDFN (derate 23.8mW/°C above +70°C)................1904.8mW
Operating Temperature Range.......................... -40°C to +125°C Maximum Junction Temperature......................................+150°C Storage Temperature Range............................. -65°C to +150°C Lead Temperature (soldering, 10s).................................. +300°C Soldering Temperature (reflow)........................................ +260°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.
Package Thermal Characteristics (Note 1)
TDFN Junction-to-Ambient Thermal Resistance (θJA)...........42°C/W
Junction-to-Case Thermal Resistance (θJC)..................9°C/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.maximintegrated.com/thermal-tutorial.
DC Electrical Characteristics
(IIN = 50µA to 24mA, TA = -40°C to +85°C, RLOAD = 25Ω to 1kΩ, unless otherwise noted. Typical values are at IIN = 10mA, RLOAD = 250Ω, and TA = +25°C.) (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
SYMBOL VIN_ST VIN
IQ IQ IREV
CONDITIONS IIN = 20µA
IIN = 24mA RLOAD ≤ 250Ω IOUT = 30mA, VIN = 5V, RLOAD = 25Ω VIN = -36V, VOUT = 0V, current into OUT
MIN TYP MAX UNITS
2.3 V 36 V
2.8 V
40 56 µA
0.01
65 0.3
µA µA
IN to OUT Switch On-Resistance
RON
VIN = 4V, IOUT = 16mA
25 45
Ω
Forward Current Limit DYNAMIC Turn-On Time Turn-Off Time Current-Limit Reaction Time Current-Limit Overshoot Voltage Input Small Signal Bandwidth
ILIM
tSS tOFF tLIM
BW
VIN = 36V
VIN = 3V, time from VIN applied to VOUT = 90% of VIN (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 ≤ DC IIN ≤ 24mA, DIIN = 1mAP-P at 1kΩ
27 30 33 mA
10 20 50 50 > 10
µs µs µs % kHz
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MAX14626
High-Voltage Reverse-Input-Capable 4–20mA Current Loop Protector
DC Electrical Characteristics (continued)
(IIN = 50µA to 24mA, TA = -40°C to +85°C, RLOAD = 25Ω to 1kΩ, unless otherwise noted. Typical values are at IIN = 10mA, RLOAD = 250Ω, and TA = .