MAX14626 Datasheet, PDF (6/8 Pages) Maxim Integrated Products – High-Voltage Reverse-Input-Capable 4–20mA Current Loop Protector

MAX14626
High-Voltage Reverse-Input-Capable 4–20mA
Current Loop Protector
Functional Diagram
MAX14626
IN
OUT
REF
SUPPLY
CONTROL AND
PROTECTION
CURRENT LIMIT
GATE CONTROL
GND
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.
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