Product Brief
HIGH VOLTAGE HALL EFFECT LATCH
Description
The AH278 is an integrated Hall sensor with output driver
designed for electronic commutation of brushless DC
motor applications. The device includes an on-chip Hall
sensor for magnetic sensing, an amplifier that amplifies
the Hall voltage, a Schmitt trigger to provide switching
hysteresis for noise rejection and two complementary
open-collector drivers for sinking large load current. It
also includes an internal band-gap regulator which is used
to provide bias voltage for internal circuits and allows a
wide operating supply voltage ranges.
Placing the device in a variable magnetic field, if the mag-
netic flux density is larger than threshold B
OP
, the pin DO
will be turned low (on) and pin DOB will be turned high
(off). This output state is held until the magnetic flux den-
sity reverses and falls below B
RP,
then causes DO to be
turned high (off) and DOB turned low (on).
AH278
Parametric Table
Supply Current (mA)
Output Saturation Voltage
(24V, 300mA) (V)
Hysteresis (Gauss)
Output Leakage Current (
µA
)
Package
12.5
0.25
80
0.1
TO-94
Features
·
·
·
·
·
·
·
·
On-Chip Hall Sensor
4V to 30V Supply Voltage
500mA (avg) Output Sink Current
Build in Protection Diode for Reverse Power
Connecting
-20
o
C to 85
o
C Operating Temperature
Low Profile TO-94 (SIP-4L) Package
Build in Over Temperature Protection Function
ESD Rating: 300V(Machine Model)
Benefits
·
·
·
·
·
Good High Temperature Performance
With Over Temperature Protection (OTP) function
Very Low Saturation Voltage
Complementary Output
Optimization Solution: Higher Current at High
Voltage(24V) and Temperature (85
o
C)
Applications
·
·
·
·
12V/24V Dual-Coil Brushless DC Motor/Fan
Power Supply and Switchboard
Communications Facilities
Industrial Equipment
Additional Available Materials
·
·
·
·
Samples
Data Sheet
Reliability Report
ESD Report
Feb. 2007
BCD Semiconductor Manufacturing Limited
BCDSEMI [ BCD SEMICONDUCTOR MANUFACTURING LIMITED ]
