A1425 Allegro MicroSystems, A1425 Datasheet - Page 4

• Manufacturer Part Number: A1425
• Description: High Accuracy Analog Speed Sensor with Integrated Filter Capacitor and Dual Zero-Crossing Output Signal
• Manufacturer: Allegro MicroSystems

Defi nitions of Terms
The following provide additional information about some of
the parameters cited in the Operating Characteristics table.
For additional information, visit the Allegro Web site at
www.allegromicro.com.
density which is calculated as the arithmetic difference of the
fl ux densities observed by each of the two Hall elements.
Output Off Switchpoint (Operate Point), B
increasing differential magnetic fl ux density at which the device
output switches from low to high. This value may be greater than
or less than 0 G.
Output On Switchpoint (Release Point), B
decreasing differential magnetic fl ux density at which the device
THERMAL CHARACTERISTICS
A1425-DS Rev. 0b
Applied Magnetic Field, B
Package Thermal Resistance
Preliminary - Subject to Change
Without Notice November 10, 2004
High Accuracy Analog Speed Sensor with Integrated Filter Capacitor and Dual Zero-Crossing Output Signal
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
0
20
Characteristic
40
T
J(max)
60
Minimum-K PCB
Power Derating Curve
(R
θJA
= 165ºC; I
80
= 177 ºC/W)
diff
100
– The differential magnetic fl ux
CC
= I
120
may require derating at maximum conditions, see application information
CC(max)
Symbol
140
RP
R
OP
θJA
– The value of
– The value of
160
Minimum-K PCB (single-sided with copper limited to
solder pads)
180
V
V
CC(max)
CC(min)
A1425
output switches from high to low. This value may be greater
than or less than 0 G.
Power-On Time, t
power is applied, to initialize all circuitry necessary for proper
operation.
Settling Time, t
and after a valid magnetic signal has been applied, to provide
proper output transitions. Settling time is a function of magnetic
offset, offset polarity, signal phase, signal frequency, and signal
amplitude.
Response Time – The total time required for generating zero-
crossing output transitions after power-up (the sum of power-on
time and settling time).
Test Conditions
900
850
800
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
20
T
40
S
J(max)
– The time required by the device, after t
Maximum Power Dissipation, P
PO
= 165ºC; V
– The time needed by the device, after
60
Temperature (°C)
80
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
CC
= V
100
CC(max)
Min.
177
120
; I
CC
Typ.
140
= I
–
D(max)
CC(max)
Max Units
160
–
PO
ºC/W
180
,
4