US2881/2882
CMOS High Sensitivity Latch
•
•
•
•
•
•
•
•
•
•
•
•
Features and Benefits
Chopper stabilized amplifier stage
Optimized for BDC motor applications
New miniature package / thin, high reliability package
Operation down to 3.5V
CMOS for optimum stability, quality, and cost
Ultra low I
DD
current
Solid state switch
Brushless DC motor commutation
Speed sensing
Linear position sensing
Angular position sensing
Current sensing
Applications
Ordering Information
Part No.
US2881 / US2882
US2881 / US2882
Temperature Suffix
Package
Temperature Range
E
SO or UA
-40
o
C to 85
o
C Extended
L
SO or UA
-40
o
C to 150
o
C Full Temp.
*Contact Factory or Sales Representative for Legacy Temperature Versions
Functional Diagram
Description
The design specifications and performance of the
Melexis US2881 have been optimized for commu-
tation applications in brushless DC motors and
automotive speed sensing.
The output transistor will be latched on (B
OP
) in the
presence of a sufficiently strong South pole mag-
netic field facing the marked side of the package.
Similarly, the output will be latched off (B
RP
) in the
presence of a North field. The SOT-23 device is
reversed from the UA package. The SOT-23 output
transistor will be latched on (B
OP
) in the presence
of a sufficiently strong North pole magnetic field
subjected to the marked face.
SO Package
Pin 1 - V
D D
Pin 2 - Output
Pin 3 - GND
V
DD
Output
Voltage
Regulator
Chopper
GND
UA Package
Pin 1 - V
D D
Pin 2 - GND
Pin 3 - Output
Note:
Static sensitive device; please observe ESD precautions. Re -
verse V
DD
protection is not included. For reverse voltage protection,
a 100Ω resistor in series with V
DD
is recommended.
US2881 CMOS High Sensitivity Latch
3901002881 Rev 5.6
23/July/00
Page 1
US2881/2882
CMOS High Sensitivity Latch
US2881 and US2882 Electrical Specifications
DC operating parameters: T
A
= 25
o
C, V
DD
= 12V
DC
(unless otherwise specified).
Parameter
Supply Voltage
Supply Current
Saturation Voltage
Output Leakage
Output Rise Time
Output Fall Time
Symbol Test Conditions
V
DD
I
DD
V
DS(on)
I
OFF
t
r
t
f
Operating
B<B
OP
I
OUT
= 20 mA, B>B
OP
B<B
RP
, V
OUT
= 27V
V
DD
= 12V, R
L
= 1.1KÙ, C
L
= 20pf
V
DD
= 12V, R
L
= 1.1KÙ, C
L
= 20pf
Min
3.5
1.5
Typ
2.0
0.4
0.01
0.04
0.18
Max
27
4.0
0.5
5.0
Units
V
mA
V
ìA
ìs
ìs
US2881 Magnetic Specifications
Parameter
Operating Point
Release Point
Hysteresis
Symbol Test Conditions
B
OP
B
RP
B
hys
Min
0.5
-4.5
3.0
Typ
2.0
-2.0
4.0
Max
4.5
-0.5
5.0
Units
mT
mT
mT
US2882 Magnetic Specifications
Parameter
Operating Point
Release Point
Hysteresis
Note:
1 mT = 10 Gauss.
Symbol Test Conditions
B
OP
B
RP
B
hys
Min
-2.0
-6.0
3.0
Typ
2.0
-2.0
4.0
Max
6.0
2.0
5.0
Units
mT
mT
mT
Absolute Maximum Ratings
Supply Voltage (Operating), V
DD
Supply Current (Fault), I
DD
Output Voltage, V
OUT
Output Current (Fault), I
OUT
Power Dissipation, P
D
Operating Temperature Range, T
A
Storage Temperature Range, T
S
Melexis Inc. reserves the right to make changes without further no-
tice to any products herein to improve reliability, function or design.
Melexis does not assume any liability arising from the use of any
product or application of any product or circuit described herein.
24V
50mA
24V
50mA
100mW
-40 to 150°C
-65 to 150°C
175°C
+/- 4KV
Page 2
Maximum Junction Temp, T
J
ESD Sensitivity (All Pins)
23/July/00
US2881 CMOS High Sensitivity Latch
3901002881 Rev 5.6
US2881/2882
CMOS High Sensitivity Latch
Performance Graphs
Typical Magnetic Switch Points
versus
Supply Voltage
12.5
Typical Magnetic Switch Points
versus
Temperature
12
B
HYS
2881
2881
7.5
B
OP
7.5
Flux Density (mT)
Flux Density (mT)
B
OP
2.5
2.5
-2.5
-2.5
B
RP
-7.5
-7.5
B
RP
-12.5
0
5
10
15
20
25
30
-12.5
-40
0
40
80
120
160
200
Supply Voltage (V)
Temperature (
o
C)
Min/Max Magnetic Switch
Range
versus
Temperature
12.5
Output Voltage
versus
Flux Density
30
2881
2881
B
OP
Max
7.5
24
V
DD
Flux Density (mT)
B
OP
Output Voltage (V)
2.5
B
OP
Min
18
-2.5
B
RP
Max
12
-7.5
B
RP
Min
6
B
RP
V
out
-12.5
-40
0
0
40
80
120
160
200
-30
-20
-10
0
10
20
30
Temperature (
o
C)
Flux Density (mT)
US2881 CMOS High Sensitivity Latch
3901002881 Rev 5.6
23/July/00
Page 3
US2881/2882
CMOS High Sensitivity Latch
Performance Graphs
Typical Supply Current
versus
Supply Voltage
5
Typical Saturation Voltage
versus
Temperature
V
DD
= 12 V, I
OUT
= 20mA
2881
500
2881
4
400
Supply Current (mA)
T
A
= -40
o
C
3
T
A
= 25
o
C
2
T
A
= 125
o
C
V
DS(ON)
(mV)
300
V
DS(ON)
200
1
100
0
0
5
10
15
20
25
30
0
-40
0
40
80
120
160
200
Supply Voltage (V)
Temperature (
o
C)
Power Dissipation
versus
Temperature
500
Wave Soldering Parameters
All Devices
All Devices
280
Package Power Dissipation (mW)
400
260
300
Solder Temperature (
o
C)
200
UA Package
R
θ
JA
=206
o
C/W
240
200
220
100
SO Package
R
θJA
=575
o
C/W
0
-40
0
40
80
120
160
200
0
5
10
15
20
25
30
Temperature (
o
C)
Time in Wave Solder (Seconds)
US2881 CMOS High Sensitivity Latch
3901002881 Rev 5.6
23/July/00
Page 4
US2881/2882
CMOS High Sensitivity Latch
Unique Features
CMOS Hall IC Technology
The Chopper Stabilized Amplifier, using
switched capacitor techniques, eliminates the
amplifier offset voltage, which in bipolar devices
is a major source of temperature sensitive drift.
CMOS makes this advanced technique possi-
ble.
The CMOS chip is also much smaller than the
Bipolar chip, allowing very sophisticated cir-
cuitry to be placed in less space. The small chip
size also contributes to lower physical stress
and less power consumption.
Application Comments
If reverse supply protection is desired, use a re-
sistor in series with the V
DD
pin. The resistor will
limit the Supply Current (Fault), I
DD
, to 50mA.
For severe EMC conditions, use the application
circuit below.
Installation
Consider temperature coefficients of Hall IC and
magnetics, as well as air gap and life time varia-
tions. Observe temperature limits during wave
soldering.
Applications Examples
Automotive and Severe
Environment Protection Circuit
R
1
100Ω
V
DD
D1
Z1
C1
4.7n
F
Two Wire Optional Current
Biasing Circuit
R
L
I
DD
V
R
L
1.2
K
OUT
C2
4.7n
F
DD
I
IN
Iout
Supply
Voltage
Hall IC
V
SS
R
b
Hall
IC
The resistors R
b
and R
L
can be used to bias the input current, Iin. Refer
to the part specification for limiting values. This circuit will help in getting
the precise ON and OFF currents desired.
B
RP
= Ioff = (V
DD
/ Rb +
DD
)
I
B
OP
= Ion = (Ioff + V / R
L
)
DD
US2881 CMOS High Sensitivity Latch
3901002881 Rev 5.6
23/July/00
Page 5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
