Datasheet

OPTEK Technology Inc.— 1645 Wallace Drive, Carrollton, Texas 75006
Phone: [phone] FAX: [phone] [e-mail] www.optekinc.com
Issue A 02/ 05
Page 1
Hallogic Hall Effect Sensor Assembly
OHB900
Features:
• Non-contact motion sensing
• Operates over a broad range of supply voltages
• Excellent temperature stability
• Hall element, linear amplifier, and Schmitt trigger on a single Hallogic silicon
chip
• Performs in high dust and dirt environments over a wide temperature range
• 0.125” (3.18mm) wide gap
Description:
The OHB900 consists of a Hall Effect sensor similar to the OH180U and a rare earth magnet mounted in a
low cost plastic housing. The magnet produces optimum magnetic flux at the Hall Effect sensor location. The
sensor has an open collector transistor output which is activated when the slot is open. When the slot is
blocked by a ferrous material, reducing the magnetic flux density at the Hall Effect sensor location, the open
collector output transistor switches off. The device provides up to 25 mA of sink current. Output
characteristics are constant at switching frequencies from DC to over 200 kHz.
The Uni-Polar turns on with a (logic level “O”) with after a sufficient magnetic field from the south pole of a
magnet approached the symbolized face of the device (Operating Point) and turns off (logic level “1”) after the
magnetic field reached a minimum value. This feature makes these sensors ideal for applications in non-
contact switching operations.
Hall
Element
Voltage
Regulator
2
3
1Vcc
Output
Ground
Magnet
Supply Voltage, Vcc 25 V
Storage Temperature Range, T
S
-50°C to +160°C
Operating Temperature Range, T
A
-50°C to +150°C
Lead Soldering Temperature (1/8 in. (3.2 mm) from case for 5 sec. with soldering iron) 260°C
Output ON Current, I
SINK
25 mA
Output OFF Voltage, V
OUT
25 V
Magnetic Flux Density, B Unlimited
Absolute Maximum Ratings (TA=25°C unless otherwise noted)