A1190 ALLEGRO [Allegro MicroSystems], A1190 Datasheet - Page 9

• Manufacturer Part Number: A1190
• Description: Programmable, Chopper-Stabilized, Two Wire Hall-Effect Switches
• Manufacturer: ALLEGRO [Allegro MicroSystems]

A1190, A1192,
and A1193
Overview
Programming is accomplished by sending a series of input volt-
age pulses serially through the VCC (supply) pin of the device.
A unique combination of different voltage level pulses controls
the internal programming logic of the device to select a desired
programmable parameter and change its value. There are three
voltage levels that must be taken into account when program-
ming. These levels are referred to as high (V
low (V
The A119x family features two programmable modes, Try mode
and Blow mode.
• In Try mode, programmable parameter values are set and mea-
• In Blow mode, the value of a programmable parameter may
The programming sequence is designed to help prevent the
device from being programmed accidentally; for example, as a
result of noise on the supply line. Although any programmable
variable power supply can be used to generate the pulse wave-
forms, Allegro highly recommends using the Allegro Sensor IC
Evaluation Kit, available on the Allegro website On-line Store.
The manual for that kit is available for download free of charge,
and provides additional information on programming these
devices.
Table 1. Programming Pulse Requirements, Protocol at T
Programming Voltage
Programming Current
Pulse Width
Pulse Rise Time
Pulse Fall Time
Blow Pulse Slew Rate
sured. A parameter value is stored temporarily, and reset after
cycling the supply voltage.
be permanently set by blowing solid-state fuses internal to the
device. Device locking is also accomplished in this mode.
Characteristic
PL
) (see figure 1 and table 1).
Symbol
SR
t
ACTIVE
t
t
BLOW
V
V
V
LOW
I
t
t
BLOW
PP
PM
Pr
PH
Pf
PL
Measured at the VCC pin.
t
required to ensure proper fuse blowing. C
VCC and GND pins during programming to provide the current necessary for fuse
blowing.
Duration at V
Duration of pulses at V
Duration of pulse at V
V
V
Pr
PL
PH
= 11 μs, V
to V
to V
PM
PL
PH
, or V
, or V
CC
PL
), mid (V
separating pulses at V
= 5 → 26 V, C
PM
PL
Programming Guidelines
to V
to V
PH
PM
PH
PL
PM
for fuse blowing.
.
.
or V
), and
BLOW
PH
for key/code selection.
Programmable, Chopper-Stabilized,
A
= 0.1 μF (min). Minimum supply current
= 25°C (refer also to figure 4)
Notes
PM
Definition of Terms
Register. The section of the programming logic that controls the
choice of programmable modes and parameters.
Bit Field. The internal fuses unique to each register, represented
as a binary number. Changing the bit field selection in a particu-
lar register causes its programmable parameter to change, based
on the internal programming logic.
Key. A series of V
or V
BLOW
Two Wire Hall-Effect Switches
PH
Figure 4. Programming pulse definition (see table 1)
must be connected between the
.
V
V
V
PM
PH
PL
0
PM
(Supply
cycled)
voltage pulses used to select a register or mode.
t
ACTIVE
t
Pr
Programming
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
pulses
t
LOW
t
Pf
Min. Typ. Max. Unit
12.5
pulse
175
375
Blow
4.5
21
20
20
90
5
5
t
100
BLOW
5
–
–
–
–
–
–
–
–
t
LOW
100
100
5.5
14
27
–
–
–
–
–
mV/ μs
mA
μs
μs
μs
μs
μs
V
V
V
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