ATS278
Two Phase Hall Effect Latch With FG Output
Features
- On-chip Hall plate
- Operating voltage: 3.5V~20V
- Internal bandgap regulator allows temperature
compensated operations and a wide operating
voltage range
- High output sinking capability up to 400mA for
driving large load
- Built-in protection diode only for chip reverse
power connecting
- Frequency Generation (FG) output
- Package: SIP-5L
General Description
ATS278 is an integrated Hall sensor with two output
drivers and rotor speed output, typically designed
for electronic commutation of two-phase brush-less
DC fan applications.
On-chip Hall sensor will generate Hall voltage due
to magnetics sensing. The amplifier will amplify the
Hall voltage. The Schmitt trigger determines
switching hysteresis and then control internal
driver’s on/off to sink load current. Meanwhile, An
internal bandgap regulator is used to provide stable
bais due to temperature-compensation. FG pin will
provide switching frequency of driver. Major feature
is to minimize the external components by
building-in FG output transistor.
If a magnetic flux density larger than threshold Bop,
DO is turned on (low) and DOB is turned off (high).
The output state is held until a magnetic flux density
reversal falls below Brp causing DO to be turned off
and DOB turned on.
Applications
-
Dual-coil Brush-less DC Motor
-
Dual-coil Brush-less DC Fan
-
Revolution Counting
-
Speed Measurement
Ordering Information
ATS278 X - X X - X
Wafer Body
Blank or
A~Z : if necessary
to specify
Package
P: SIP-5L
Lead
L : Lead Free
Magnetic
Characteristics
A or B
*Packing: Bulk
Typical Application Circuit
5V/12V
+
C1
R
pu
1
2
3
4
5
278
Coil1
Coil2
Speed
R1 = R2 = 47Ω
C1 = C2 = 2.2
μ
F
The R, C value need to be fine tuned
base on coils design.
R1
C1
R2
C2
5V/12V DC Brush-less Fan with FG output function
This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of
this product. No rights under any patent accompany the sale of the product.
Rev. 1.0
1/6
Oct 4, 2005
ATS278
Two Phase Hall Effect Latch With FG Output
Absolute Maximum Ratings
Characteristics
Supply voltage
Reverse V
CC
Polarity Voltage
Magnetic flux density
Continuous
Output “on” current
Hold
Peak (Start Up)
Sink current of FG
Operating temperature range
Storage temperature range
Package Power Dissipation
Symbol
V
CC
V
RCC
B
Ic
I
FG
Ta
Ts
PD
Values
20
-20
Unlimited
0.4
0.5
0.7
40
-20~+85
-65~+150
550
A
mA
°C
°C
mW
Unit
V
V
Electrical Characteristics
( Ta=+25°C )
Characteristic
Supply Voltage
Output Saturation Voltage
Output Zener Breakdown
Output Leakage Current
Supply Current
Output Rise Time
Output Falling Time
Switch Time Differential
FG saturation voltage
Symbol
VCC
Vce(sat)
Vz*
Icex
Icc
tr
tf
∆t
Conditions
Vcc=14V, IL=300mA
Vce=14V, Vcc=14V
Vcc=20V, Output Open
Vcc=14V, RL=820Ω,
CL=20pF (Test Circuit)
Vcc=14V, RL=820Ω,
CL=20pF (Test Circuit)
Vcc=14V, RL=820Ω,
CL=20pF (Test Circuit)
Vcc=14V, IL=20 mA
Min
3.5
----
----
----
----
----
----
----
Typ
----
300
46
<0.1
16
3.0
0.3
3.0
200
Max
20
800
10
25
10
1.5
10
700
Unit
V
mV
V
µA
mA
µs
µs
µs
mV
V
FG
*Note:
The Vz may vary with the inductance/resistance of DC Fan. In order to reduce the risk of dynamic operation, the capacitor/
resistor is recommended to add below the DO/DOB as Application Circuit (on page 1).
278
1
2
3
4
5
R
L1
=
R
L2
=
820
Ω
C
L1
=
C
L2
=
20 pf
14V
R
L1
R
L2
C
L1
C
L2
DO
DOB
( Test circuit )
Anachip Corp.
www.anachip.com.tw
3/6
Rev. 1.0 Oct 4, 2005
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