A3250LLT-T Allegro Microsystems Inc, A3250LLT-T Datasheet - Page 10

• Manufacturer Part Number: A3250LLT-T
• Description: IC SW HALL EFFECT UNI SOT-89
• Manufacturer: Allegro Microsystems Inc
• Type: Unipolar Switchr

Specifications of A3250LLT-T

• Sensing Range: 50G
• Voltage - Supply: 4.2 V ~ 24 V
• Current - Supply: 10mA
• Current - Output (max): 20mA
• Output Type: Digital, Open Collector
• Features: Regulated Voltage
• Operating Temperature: -40°C ~ 150°C
• Package / Case: SOT-89-3
• Magnetic Type: Unipolar
• Operating Supply Voltage (min): 4.2V
• Operating Supply Voltage (typ): 5/9/12/15/18V
• Operating Supply Voltage (max): 24V
• Output Current: 20mA
• Mag Sensor Operate Point (g): 50Gs
• Mag Sensor Hysteresis(g): 13Gs
• Package Type: SOT-89
• Pin Count: 3 +Tab
• Mounting: Surface Mount
• Operating Temp Range: -40C to 150C
• Operating Temperature Classification: Automotive
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

A3250
A3251
Programming Protocol
The operate switchpoint, B
so, a coded series of voltage pulses through the VCC pin is used
to set bitfields in onboard registers. The effect on the device
output can be monitored, and the registers can be cleared and
set repeatedly until the required B
setting permanent, bitfield-level solid state fuses are blown, and
finally, a device-level fuse is blown, blocking any further cod-
ing. It is not necessary to program the release switchpoint, B
because the difference between B
hysteresis, B
The range of values between B
64 increments. The actual change in magnetic flux (G) repre-
sented by each increment is indicated by B
Characteristics table; however, testing is the only method for
verifying the resulting B
ments are individually identified using 6 data bits, which are
physically represented by 6 bitfields in the onboard registers.
By setting these bitfields, the corresponding calibration value is
programmed into the device.
Three voltage levels are used in programming the device: a low
voltage, V
mid-level voltage, V
in the device; and a high voltage, V
V
long in duration). A fourth voltage level, essentially 0 V, is used
to clear the registers between pulse sequences. The pulse values
are shown in the Programming Protocol Characteristics table and
in figure 1.
PROGRAMMING PROTOCOL CHARACTERISTICS, T
Programming Voltage
Programming Current
Pulse Width
Pulse Rise Time
Pulse Fall Time
1
2
the current necessary to blow the fuse.
Programming voltages are measured at the VCC pin.
A bypass capacitor with a minimum capacitance of 0.1 μF must be connected from VCC to the GND pin of the device in order to provide
PM
pulses (when short in duration) and to blow fuses (when
Characteristic
PL
HYS
, a minimum required to sustain register settings; a
and
, is fixed.
PM
1
2
, used to increment the address counter
OP
). For programming, the 64 incre-
OP
, can be field-programmed. To do
OP(min)
Symbol
OP
OP
V
PH
V
t
t
t
V
I
d(P)
d(0)
d(1)
and B
PP
PM
t
t
is achieved. To make the
PH
PL
r
f
and B
, used to separate sets of
RP
RES
Minimum voltage range during programming
Maximum supply current during programming
OFF time between programming bits
Pulse duration (ON time) for enable, address, fuse
blowing or lock bits
Pulse duration (ON time) for fuse blowing
V
V
OP(max)
PL
PM
, referred to as the
(see the Operating
to V
to V
Field-Programmable, Chopper-Stabilized,
PM
is scaled to
PL
; V
; V
A
PL
PH
= 25ºC, unless otherwise noted
to V
Test Conditions
to V
RP
PH
,
PL
Additional information on device programming and program-
ming products is available on www. allegromicro.com. Program-
ming hardware is available for purchase, and programming
software is available free of charge.
Code Programming.
do so, a pulse sequence must be transmitted for each bitfield that
is being set to 1. If more than one bitfield is being set to 1, all
pulse sequences must be sent, one after the other, without allow-
ing V
The same pulse sequence is used to provisionally set bitfields as
is used to permanently set bitfield-level fuses. The only differ-
ence is that when provisionally setting bitfields, no fuse-blowing
pulse is sent at the end of the pulse sequence.
Unipolar Hall-Effect Switches
CC
to fall to zero (which clears the registers).
V
V
V
PH
PM
PL
0
V+
Figure 1. Pulse amplitudes and durations
T
d(1)
Each bitfield must be individually set. To
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
Min.
100
4.5
10
23
20
20
11
–
5
T
d(P)
T
d(0)
Typ.
500
300
5.0
11
25
–
–
–
–
Max.
5.5
t
12
26
–
–
–
–
–
–
Units
mA
μs
μs
μs
μs
μs
V
V
V
9