APX9131 Datasheet, PDF (6/14 Pages) Anpec Electronics Coropration – Hall Effect Micro Switch IC

APX9131
Function Description
Operation
Pole-independent
The output of APX9131 switches low (turns on) when
in presence of strong flux density facing the marked
side of package exceeds the operate point B (or is
OPS
less than B_OPN). After turn-on, the output is capable of
sinking up to 1 mA and the output voltage is low (turns
on). In absence of flux density below the release point
B_RPS (or increased above B_RPN), the APX9131 output
switches high (turns off). The difference in the magnetic
operated and released point is the hysteresis (B_hys) of
the device. This built-in hysteresis allows clean
switching of the output even in the presence of external
mechanical bouncing vibration and electrical noise.
5V
MAX
OUTPUT OFF
B_OPN
B_OPS
B_RPN
B_{RPS OUTPUT ON}
0
-B
0
+B
MAGNETIC FLUX
The pole-independent sensing technique allows for
operation with either a north or south pole magnet
orientation, enhancing the manufacturability of the
device. The state-of-the-art technology provides the
same output polarity for either pole in presence.
Awake & Sleep
Internal awake & sleep timing block circuit activates the
sensor for 180 us and deactivates it for the remainder of
the period (60 ms). A short “awake” time allows for
stabilization prior to the sensor sampling and data
latching on the falling edge of the timing pulse. While
in sleep cycle the output is latched in its previous
state.
Chopper Stabilized Technique
The chopper stabilized technique cancels the
mismatching of the hall element, the amplifier offset
voltage and temperature sensitive drift by the dynamic
offset cancellation and switched capacitor technique.
This technique produces devices have an extremely
stable Hall output voltage, therefore the magnetic
switch points are stable.
Application Information
It is strongly recommended that an external bypass
capacitor be connected (in close to the Hall sensor)
between the supply and ground of the device to reduce
both external noise and noise generated by the
chopper-stabilization technique. This is especially
true due to the relatively high impedance of battery
supplies.The output is an open drain output, it must be
connected a pull-up resistor to a supply voltage which
is lower than 5V, connect a 50kΩ resistor to VDD in
common use.
Copyright © ANPEC Electronics Corp.
6
Rev. A.7 - Sep., 2005
www.anpec.com.tw