Ultrasensitive Two-Wire Chopper-Stabilized
Unipolar Hall Effect Switches
A1145 and
A1146
3
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
ELECTRICAL CHARACTERISTICS over the operating voltage and temperature ranges, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Supply Voltage
1
V
CC
3.5 – 24 V
Supply Current
2
I
CCL
B > B
OP
for A1145; B < B
RP
for A1146 5 – 6.9 mA
I
CCH
B > B
OP
for A1146; B < B
RP
for A1145 12 – 17 mA
Reverse Supply Current I
RCC
V
RCC
= –18 V – – –1.6 mA
Supply Zener Clamp Voltage V
ZSUPPLY
I
CC
= I
CCL(max)
+ 3 mA; T
A
= 25°C 28 – 40 V
Supply Zener Clamp Current
3
I
ZSUPPLY
V
ZSUPPLY
= 28 V – – 9.9 mA
Output Slew Rate
4
di/dt
Capacitance of the oscilloscope performing
the measurement = 20 pF
– 36 – mA/s
Chopping Frequency f
C
– 200 – kHz
Power-On Time
5
t
on
C
BYPASS
= 0.01 F
––25s
Power-On State
6,7
POS t < t
on
; V
CC
slew rate > 25 mV/s – HIGH – –
1
V
CC
represents the generated voltage between the VCC pin and the GND pin.
2
Relative values of B use the algebraic convention, where positive values indicate south magnetic polarity, and negative values indicate north magnetic
polarity; therefore greater B values indicate a stronger south polarity field (or a weaker north polarity field, if present).
3
I
ZSUPPLY(max)
= I
CCL(max)
+ 3 mA.
4
Measured without bypass capacitor between VCC and GND. Use of a bypass capacitor results in slower current change.
5
Measured with and without bypass capacitor of 0.01 F. Adding a larger bypass capacitor causes longer Power-On Time.
6
POS is defined as true only with a V
CC
slew rate of 25 mV / s or greater. Operation with a V
CC
slew rate less than 25 mV / s can permanently harm
device performance.
7
POS is undefined for t > t
on
or B
RP
< B < B
OP
.
MAGNETIC CHARACTERISTICS over the operating voltage and temperature ranges, unless otherwise specified
Characteristic Symbol Test Conditions Min. Typ.* Max. Units
Operate Point B
OP
A1145 I
CC
= I
CCL
20 37 60 G
A1146 I
CC
= I
CCH
Release Point B
RP
A1145 I
CC
= I
CCH
10 22 55 G
A1146 I
CC
= I
CCL
Hysteresis B
HYS
B
HYS
= B
OP
– B
RP
51530G
*Typical data are for initial design estimations only, and assume optimum manufacturing and application conditions, such as T
A
= 25°C and V
CC
= 12 V.
Performance may vary for individual units, within the specified maximum and minimum limits.
