Diodes AH276Q User Manual
Ah276q, Description, Features
AH276Q
Document number: DS31066 Rev. 6 - 2
1 of 6
September 2013
© Diodes Incorporated
AH276Q
COMPLEMENTARY OUTPUT HALL EFFECT LATCH
Description
AH276 are integrated Hall sensors with output drivers, mainly
designed for electronic commutation of brush-less DC Fan. This IC
internally includes the regulator, protecting diode, Hall plate, amplifier,
comparator, and a pair of complementary open-collector outputs (DO,
DOB).
While the magnetic flux density (B) is larger than operate point (Bop),
DO will turn on (low), and meanwhile DOB will turn off (high). Each
output is latched until B is lower than release point (Brp), and then
DO, DOB transfer each state.
For DC fan application, sometimes need to test power reverse
connection condition. Internal diode only protects chip-side but not for
coil-side. If necessary, add one external diode to block the reverse
current from coil-side.
Features
On-chip Hall sensor with two different sensitivity and hysteresis
settings for AH276
Built-in protecting diode only for chip reverse power connecting
-20°C to +85°C operating temperature
Lead Free Package: SIP-4L
SIP-4L: Available in “Green” Molding Compound (No Br, Sb)
Lead-Free Finish; RoHS Compliant (Notes 1 & 2)
Halogen and Antimony Free. “Green” Device (Note 3)
Pin Assignments
276
1 2
4
3
1 : Vcc
2 : DO
3 : DOB
4 : GND
( Top View )
Applications
Dual-coil Brush-less DC Motor
Dual-coil Brush-less DC Fan
Revolution
Counting
Speed
Measurement
Notes:
1. EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant. All applicable RoHS exemptions applied.
2. S more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green"
and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
Typical Applications Circuit
Brush-less DC Fan
Green