19-1514; Rev 0; 7/99
Fault-Protected, High-Voltage,
Signal-Line Protector
General Description
The MAX4505 is a single signal-line protector featuring a
fault-protected input and Rail-to-Rail
®
signal handling
capability. The input is protected from overvoltage faults
up to ±36V with power on or ±40V with power off. During
a fault condition, the input terminal becomes an open cir-
cuit and only nanoamperes of leakage current flow from
the source, while the switch output (AOUT) furnishes typ-
ically 19mA from the appropriate polarity supply to the
load. This ensures an unambiguous rail-to-rail output
when a fault begins and ends.
The MAX4505 protects both unipolar and bipolar analog
signals using either unipolar (+9V to +36V) or bipolar
(±8V to ±18V) power supplies. The device has no logic
control inputs; the protector is always on when the sup-
plies are on. On-resistance is 100Ω max, and on-leakage
is less than 0.5nA at T
A
= +25°C. The MAX4505 is avail-
able in 5-pin SOT23 and 8-pin µMAX packages.
Features
o
Overvoltage Protection
±40V with Power Off
±36V with Power On
o
Open Signal Paths with Power Off
o
Output Clamps to Either Rail with an Input
Overvoltage
o
100Ω max On-Resistance
o
10ns Overvoltage Turn-On Delay
o
No Latchup During Power Sequencing
o
Rail-to-Rail Signal Handling
o
500Ω Output Clamp Resistance During
Overvoltage
o
Tiny 5-Pin SOT23 Package
MAX4505
Applications
Process Control Systems
Hot-Insertion Boards/Systems
Data-Acquisition Systems
Redundant/Backup Systems
ATE Equipment
Sensitive Instruments
PART
MAX4505EUK-T
MAX4505EUA
Ordering Information
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
5 SOT23-5
8 µMAX
TOP
MARK
ADLW
—
Typical Operating Circuit
TOP VIEW
V-
V-
Pin Configurations
MAX4505
V-
V+
V+
V+
AIN
1
5
V-
V+
2
RAIL
SENSOR
AOUT
3
IN
AIN
AOUT
OUT
R
OUT
MAX4505
4
N.C.
SOT23-5
Pin Configurations continued at end of data sheet.
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
