Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
5
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Characteristic Symbol Test Conditions Min. Typ.
[1]
Max. Unit
NARROW PULSE WIDTH OPTION (-xSNxx VARIANTS)
Forward Pulse Width
[6]
t
w(FWD)
38 45 52 μs
Reverse Pulse Width
[6]
t
w(REV)
76 90 104 μs
Nondirection Pulse Width
[6]
t
w(ND)
153 180 207 μs
Operating Frequency,
Forward Rotation
[7]
f
FWD
0 – 12 kHz
Operating Frequency,
Reverse Rotation
[7]
f
REV
0 – 7 kHz
Operating Frequency,
Nondirection Pulses
[7]
f
ND
0 – 4 kHz
WIDE PULSE WIDTH OPTION (-xSWxx VARIANTS)
Forward Pulse Width
[6]
t
w(FWD)
38 45 52 μs
Reverse Pulse Width
[6]
t
w(REV)
153 180 207 μs
Nondirection Pulse Width
[6]
t
w(ND)
306 360 414 μs
Operating Frequency,
Forward Rotation
[7]
f
FWD
0 – 12 kHz
Operating Frequency,
Reverse Rotation
[7]
f
REV
0 – 4 kHz
Operating Frequency,
Nondirection Pulses
[7]
f
ND
0 – 2.2 kHz
INPUT CHARACTERISTICS AND PERFORMANCE
Operating Differential Magnetic Input
[8]
B
DIFF(pk-pk)
Differential peak-to-peak magnetic input
signal; see Figure 7
5 – – G
Operating Differential Magnetic Range
[8]
B
DIFF
Differential magnetic input range; see Figure 7 –300 – 300 G
Operating Differential Magnetic Offset B
DIFFEXT
Differential magnetic offset; see Figure 7 –40 – 40 G
Operating Single-Ended Bx Field
Magnitude
Bx Refer to Figure 8 for field orientations –50 – 50 G
Operating Magnetic Input Signal
Variation
ΔB
DIFF(pk-pk)
Bounded amplitude ratio within T
WINDOW
[9]
; no
missed output transitions or flat line condition;
possible incorrect direction information;
see Figure 4 and Figure 5
0.6 – – –
Operating Magnetic Input Signal
Window
T
WINDOW
Rolling window where ΔB
DIFF(pk-pk)
cannot
exceed bounded ratio; see Figure 4 and Figure 5
3 – – T
CYCLE
Operate Point B
OP
% of peak-to-peak IC-processed signal – 70 – %
Release Point B
RP
% of peak-to-peak IC-processed signal – 30 – %
Switch Point Separation B
DIFF(SP-SEP)
Required amount of amplitude separated
between channels at each B
OP
and B
RP
occurrence; see Figure 6
20 – – %B
DIFF(pk-pk)
OPERATING CHARACTERISTICS (continued): Valid over operating voltage and temperature ranges,
unless otherwise specied
[7]
Maximum Operating Frequency is determined by satisfactory separation of output pulses: I
CC(LOW)
of t
w(FWD)(MIN)
.
[8]
Differential magnetic field measured for Channel A (E1-E3) and Channel B (E2-E4) independently; see Figure 11. Magnetic field is measured in the By direction; refer to Figure 8
through Figure 10.
[9]
Symmetrical signal variation is defined as the largest amplitude ratio from B
n
to B
n
+ T
WINDOW
. Signal variation may occur continuously while B
DIFF
remains in the operating magnetic
range.
Continued on the next page…
