3250 AND
3251
PROGRAMMABLE, CHOPPER-
STABILIZED, HALL-EFFECT SWITCHES
PRELIMINARY INFORMATION
(subject to change without notice)
April 23, 2002
The A3250 and A3251 are programmable switches that provide
tooth/valley recognition in large gear-tooth sensing, high-temperature
applications. Each sensor consists of a single element, chopper-
stabilized Hall-effect IC that can be programmed to the desired mag-
netic operate switch point (drastically reducing the effects of variations
found in a production environment), while the hysteresis remains fixed.
The small package can be easily assembled and used in conjunction
with a wide variety of gear/target shapes and sizes. The A3250 output
turns on in the presence of the programmed south-pole magnetic field
while the A3251 turns off with the programmed south-pole magnetic
field.
PTCT
V
CC
1
2
3
These sensor systems are ideal for use in gathering speed, position,
and timing information using gear-tooth-based configurations. They are
particularly suited to those applications that require accurate duty cycle
control or accurate edge detection. The lower vibration sensitivity also
makes these devices extremely useful for transmission speed sensing.
The first character of the part number suffix determines the device
operating temperature range. Suffix ‘J–’ is for the automotive and
industrial temperature range of -40°C to +115°C. Suffix ‘L–’ is for the
automotive and military temperature range of -40°C to +150°C. The
Dwg. PH-003-2
ABSOLUTE MAXIMUM RATINGS
package is a three-lead ultra-mini-SIP for through-hole mounting
(suffix ‘–UA’). It is also available with lead forming for surface-
mount applications (suffix ‘–UA-TL’).
Supply Voltage, VCC ........................ 26.5 V*
Reverse Supply Voltage, VRCC ............ -18 V
Overvoltage Supply Current, ICC ..... 100 mA
Output Off Voltage, VOUT ................... 26.5 V
Continuous Output Current, IOUT ..... 20 mA†
Magnetic Flux Density, B ............ Unlimited
Package Power Dissipation, PD ... See Graph
Operating Temperature Range, TA
Suffix ‘J–’ .................. -40°C to +115°C
Suffix ‘L–’.................. -40°C to +150°C
Junction Temperature, TJ .................. +165°C
Storage Temperature Range,
FEATURES AND BENEFITS
■ Chopper Stabilized for Extremely Low Switch-Point Drift and
Immunity to Mechanical Stress
■ Externally Programmed Switch Point
■ On-Chip Supply-Transient Protection
■ Output Short-Circuit Protection
■ Reverse Battery Protection
■ Wide Operating Voltage Range
■ Defined Power-On State
TS ................................ -65°C to +170°C
* Fault conditions that produce supply voltage
transients will be clamped by an internal Zener
diode. These conditions can be tolerated but
should be avoided.
† Internal current limiting is intended to protect
the device from output short circuits.
Always order by complete part number: the prefix 'A' + the basic four-digit
part number + a suffix to indicate operating temperature range (‘J’ or ‘L’) +
a suffix to indicate package style (‘UA’), e.g., A3250LUA .