A19571LUBBTN-RSWPLA [ALLEGRO]
GMR Transmission Speed and Direction Sensor IC;型号: | A19571LUBBTN-RSWPLA |
厂家: | ALLEGRO MICROSYSTEMS |
描述: | GMR Transmission Speed and Direction Sensor IC |
文件: | 总17页 (文件大小:2130K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
A19571
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
FEATURES AND BENEFITS
DESCRIPTION
• GMR technology delivers high magnetic sensitivity for
large air gaps and minimal jitter
The A19571 is a magnetic sensor integrated circuit (IC) that
usesgiantmagnetoresistance(GMR)technologytoencodethe
speed and direction of rotating ring magnets. Using a state-of-
the-art GMR stack design integrated with a BiCMOS process,
the IC differentially measures magnetic fields and applies
advanced digital processing to robustly measure ring magnets
commonly used in automotive transmissions.
• SolidSpeed Digital Architecture provides robust,
adaptive performance with advanced algorithms that
provide vibration immunity over the full target pitch
• Flexible orientation allows parallel or perpendicular
placement to the magnet
• ISO 26262 ASIL B with integrated diagnostics and
certified safety design process (pending assessment)
• EEPROM enables traceability throughout product life
cycle
The A19571 features Allegro’s SolidSpeed Digital Archi-
tecture for robust and reliable target tracking that adapts to
changes in the air gap and the environment. Its advanced
algorithms distinguish vibration from rotation to provide
reliable speed and direction information to a controller.
The IC has been designed to a certified ISO 26262 design
processtoalloweasyintegrationintohighsafetylevelsystems.
Integrated diagnostics are used to detect an IC failure that
impacts the output protocol’s accuracy, providing coverage
compatible with ASIL B compliance (pending assessment).
2
-
PACKAGE:
The A19571 is provided in a 2-pin miniature SIP package
(suffix UB) that is lead (Pb) free, with tin leadframe plating.
The UB package includes an IC and capacitor integrated into
a single overmolded package, with an additional molded
lead-stabilizing bar for robust shipping and ease of assembly.
2-Pin SIP
(suffix UB)
Not to scale
Voltage
Regulators
VCC
Bias
Control
+
ADC
–
ESD,
EMC
GMR
Elements
Front End
Amplifiers
Digital
Controller
+
ADC
–
Current
Source
GND
Diagnostics
EEPROM
Figure 1: Functional Block Diagram
A19571-DS
September 4, 2020
MCO-0000941
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
SELECTION GUIDE
SELECTION GUIDE*
Part Number
Packing
A19571LUBBTN-FSNPH
A19571LUBBTN-RSNPH
Tape and Reel, 4000 pieces per reel
* Not all combinations are available. Contact Allegro sales for availability and pricing
of custom programming options.
2
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Characteristic
Symbol
VCC
Notes
Refer to Power Derating section
Rating
28
Unit
V
Supply Voltage
Reverse Supply Voltage
VRCC
TA
–18
V
Operating Ambient Temperature
Maximum Junction Temperature
Storage Temperature
–40 to 150
165
°C
°C
°C
G
TJ(max)
Tstg
–65 to 170
500
Applied Magnetic Flux Density
B
In any direction
INTERNAL DISCRETE CAPACITOR RATINGS
Characteristic
Symbol
Test Conditions
Value
Unit
Nominal Capacitance
CSUPPLY
Connected between pin 1 and pin 2; see Figure 2
10
nF
PINOUT DIAGRAM AND TERMINAL LIST
Package
Silicon
1
2
CSUPPLY
1
2
VCC
VOUT = ICC × RL
CL
RL
Package UB, 2-Pin SIP Pinout Diagram
Terminal List Table
Pin Name
Pin Number
Function
Supply Voltage
Ground
Figure 2: Application Circuit
VCC
GND
1
2
3
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
OPERATING CHARACTERISTICS: Valid over operating voltage and temperature ranges, unless otherwise specified
Characteristic
Symbol
Test Conditions
Min.
Typ. [1]
Max.
Unit
ELECTRICAL CHARACTERISTICS
Voltage across pin 1 and pin 2;
does not include voltage across RL
Supply Voltage[2]
VCC
4
–
24
V
Undervoltage Lockout
VCC(UV)
IRCC
–
–
–
3.95
–
V
Reverse Supply Current[3]
Supply Zener Clamp Voltage
VCC = –18 V
–10
28
mA
V
VZsupply
ICC(LOW)
ICC(HIGH)
ICC = 19 mA
–
–
Low-current state
High-current state
5.9
12
7
8.4
16
mA
mA
Supply Current
14
ICC(HIGH)
ICC(LOW)
/
Supply Current Ratio [4]
Ratio of high current to low current (isothermal)
1.9
1.5
–
3
–
–
ASIL Safety Current
IFAULT
3.9
mA
POWER-ON CHARACTERISTICS
Power-On State
POS
tPO
VCC > VCC(min)
ICC(LOW)
–
mA
ms
Time from VCC > VCC(min), to when IC enters
Calibration mode
Power-On Time [5]
–
–
1
4
OUTPUT CHARACTERISTICS
Voltage measured at device GND, see Typical
Application Circuit; RL = 100 Ω, CL = 10 pF,
measured between 10% and 90% of the signal
Output Rise, Fall Time
tr, tf
2
µs
Warning Fault Pulse Width [6]
Critical Fault Pulse Width [6]
tw(FAULT,W) Refer to Figure 13
tw(FAULT,C) Refer to Figure 13
–
3
90
–
–
6
μs
ms
[1] Typical values are at TA = 25°C and VCC = 12 V. Performance may vary for individual units, within the specified maximum and minimum limits.
[2] Maximum voltage must be adjusted for power dissipation and junction temperature; see representative Power Derating section.
[3] Negative current is defined as conventional current coming out of (sourced from) the specified device terminal.
[4] Supply current ratio is taken as a mean value of ICC(HIGH) / ICC(LOW)
[5] Output transients prior to tPO should be ignored.
.
[6] Pulse width measured at threshold of (ICC(HIGH) + ICC(LOW)) / 2. ASIL Safe State Current Time is measured at the threshold of (IFAULT + ICC(LOW)) / 2.
Continued on the next page…
4
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
OPERATING CHARACTERISTICS (continued): Valid over operating voltage and temperature ranges,
unless otherwise specified
Characteristic
Symbol
Test Conditions
Min.
Typ. [1]
Max.
Unit
NARROW PULSE WIDTH OPTION (-xSNxx VARIANTS)
Forward Pulse Width [6]
Reverse Pulse Width[6]
Nondirection Pulse Width [6]
tw(FWD)
tw(REV)
tw(ND)
38
76
45
90
52
μs
μs
μs
104
207
153
180
Operating Frequency,
Forward Rotation [7]
fFWD
fREV
fND
0
0
0
–
–
–
12
7
kHz
kHz
kHz
Operating Frequency,
Reverse Rotation [7]
Operating Frequency,
Nondirection Pulses [7]
4
WIDE PULSE WIDTH OPTION (-xSWxx VARIANTS)
Forward Pulse Width [6]
Reverse Pulse Width[6]
Nondirection Pulse Width [6]
tw(FWD)
tw(REV)
tw(ND)
38
45
52
μs
μs
μs
153
306
180
360
207
414
Operating Frequency,
Forward Rotation [7]
fFWD
fREV
fND
0
0
0
–
–
–
12
4
kHz
kHz
kHz
Operating Frequency,
Reverse Rotation [7]
Operating Frequency,
Nondirection Pulses [7]
2.2
INPUT CHARACTERISTICS AND PERFORMANCE
Differential peak-to-peak magnetic input
signal; see Figure 7
Operating Differential Magnetic Input [8] BDIFF(pk-pk)
5
–
–
G
Operating Differential Magnetic Range [8]
Operating Differential Magnetic Offset
BDIFF
Differential magnetic input range; see Figure 7
Differential magnetic offset; see Figure 7
–300
–40
–
–
300
40
G
G
BDIFFEXT
Operating Single-Ended Bx Field
Magnitude
Bx
Refer to Figure 8 for field orientations
–50
0.6
3
–
–
–
50
G
Bounded amplitude ratio within TWINDOW[9]; no
missed output transitions or flat line condition;
possible incorrect direction information;
see Figure 4 and Figure 5
Operating Magnetic Input Signal
Variation
ΔBDIFF(pk-pk)
–
–
Operating Magnetic Input Signal
Window
Rolling window where ΔBDIFF(pk-pk) cannot
exceed bounded ratio; see Figure 4 and Figure 5
TWINDOW
–
TCYCLE
Operate Point
Release Point
BOP
BRP
% of peak-to-peak IC-processed signal
% of peak-to-peak IC-processed signal
Required amount of amplitude separated
–
–
70
30
–
–
%
%
Switch Point Separation
BDIFF(SP-SEP) between channels at each BOP and BRP
occurrence; see Figure 6
20
–
–
%BDIFF(pk-pk)
[7] Maximum Operating Frequency is determined by satisfactory separation of output pulses: ICC(LOW) of tw(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 Bn to Bn + TWINDOW. Signal variation may occur continuously while BDIFF remains in the operating magnetic
range.
Continued on the next page…
5
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
OPERATING CHARACTERISTICS (continued): Valid throughout full operating voltage and ambient temperature ranges,
unless otherwise specified
Characteristic
Symbol
Test Conditions
Min.
Typ. [1]
Max.
Unit
THERMAL CHARACTERISTICS
Magnetic Temperature Coefficient[10]
Package Thermal Resistance
TC
Valid for full temperature range based on ferrite
Single-layer PCB with copper limited to solder pads
–
–
0.2
–
–
%/°C
°C/W
RθJA
213
PERFORMANCE CHARACTERISTICS (-xSxxH VARIANTS)
Vibration Immunity Startup
Vibration Immunity Running Mode
Initial Calibration [11]
ErrVIB(SU)
ErrVIB
2
2
–
–
–
–
–
–
4
TCYCLE
TCYCLE
TCYCLE
TCAL
First Direction-Pulse Output Following
Direction Change [11]
–
–
–
–
–
–
4
TCYCLE
TCYCLE
TCYCLE
First Direction-Pulse Output Following
Startup Mode Vibration [11]
4.25
4.25
First Direction-Pulse Output Following
Running Mode Vibration [11]
PERFORMANCE CHARACTERISTICS (-xSxxL VARIANTS)
Vibration Immunity Startup
Vibration Immunity Running Mode
Initial Calibration [11]
ErrVIB(SU)
ErrVIB
0.06
0.03
–
–
–
–
–
–
4
TCYCLE
TCYCLE
TCYCLE
TCAL
First Direction-Pulse Output Following
Direction Change [11][12]
–
–
–
–
–
–
1.75
3.75
3.75
TCYCLE
TCYCLE
TCYCLE
First Direction-Pulse Output Following
Startup Mode Vibration [11] [12]
First Direction-Pulse Output Following
Running Mode Vibration [11] [12]
[10] Magnets decrease in strength with increasing temperature. The temperature coefficient compensates to help maintain a consistent maximum air gap over temperature.
[11] Rotational frequencies ≤ 1 kHz. Rotational frequencies above 1 kHz may require more input magnetic cycles until output edges are achieved.
[12] It is possible with the -xxxxL variant to get incorrect direction pulses during direction change and vibration. See Direction Changes, Vibrations, and Anomalous Events
section for further details.
6
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
Target
S
N
S
N
TCYCLE
BDIFF
TCYCLE = Target Cycle; the amount of rotation that
moves one north pole and one south pole
across the sensor
BDIFF = Differential Input Signal; the differential magnetic
flux density sensed by the sensor
Figure 3: Definition of TCYCLE
Figure 4: Single Period-to-Period Variation
Figure 5: Repeated Period-to-Period Variation
7
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
S
N
S
N
TCYCLE
BDIFF(SP)
BDIFF(BOP)
(BOP
)
Channel B
BDIFF(pk-pk)
(BRP
)
BDIFF(BRP)
BDIFF(SP)
Channel A
BDIFF(SP)
BDIFF(pk-pk)
BDIFF(SP-SEP)
=
Figure 6: Definition of Switch Point Separation
ꢀDIꢁꢁ
ꢁꢂꢃꢄꢄꢅmaꢆꢇ
Aꢈꢈlied ꢁꢂꢃꢄꢄ
ꢁꢂꢃꢄꢄꢅꢈꢉ-ꢈꢉꢇ
0 ꢀ
ꢁꢂꢃꢄꢄꢊꢋꢌ
ꢁꢂꢃꢄꢄꢅminꢇ
Time
Figure 7: Input Signal Definition
8
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
FUNCTIONAL DESCRIPTION
The A19571 sensor IC contains a single-chip GMR circuit that
uses spaced elements. These elements are used in differential
pairs to provide electrical signals containing information regard-
ing edge position and direction of rotation. The A19571 is
intended for use with ring magnet targets.
Installation Orientation Flexibility
The A19571 can be installed in a parallel, perpendicular, or any
orientation in between with respect to the ring magnet. Refer to
Figure 8, Figure 9, and Figure 10 for parallel and perpendicular
orientations of the sensor.
The IC detects the peaks of the magnetic signals and sets
dynamic thresholds based on these detected signals.
ꢀꢁ
ꢀy
ꢀꢂ
Pin 1
Figure 8: UB Package Orientation
Pin 1
Rotation
Rotation
Pin 1
Figure 10: UB Package Perpendicular Orientation
Figure 9: UB Package Parallel Orientation
9
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
Forward Rotation. For the -Fxxxx variant, when the target is
rotating such that a target feature passes from pin 1 to pin 2, this
Data Protocol Description
When a target passes in front of the device (opposite the branded
face of the package case), the A19571 generates an output pulse
for each magnetic pole-pair (-xSxxx variant) of the target. Speed
information is provided by the output pulse rate, while direction
of target rotation is provided by the duration of the output pulses.
The sensor IC can sense target movement in both the forward and
reverse directions.
is referred to as forward rotation. This direction of rotation is
indicated on the output by a tW(FWD) pulse width. For the -Rxxxx
variant, forward direction is indicated for target rotation from pin
2 to 1.
Reverse Rotation. For the -Fxxxx variant, when the target
is rotating such that a target feature passes from pin 2 to pin 1,
this is referred to as reverse rotation. This direction of rotation is
indicated on the output by a tW(REV) pulse width. For the -Rxxxx
variant, reverse direction is indicated for target rotation from pin
1 to 2.
Output edges are triggered by BDIFF transitions through the
switch points. On a crossing, the output pulse of ICC(HIGH) is pres-
S
N
N
Pacꢇage ꢈase ꢀranded ꢉace
Device Orientation to Target
ent for tw(FWD) or tw(REV)
.
IC
ꢅPin ꢄ Sideꢆ
ꢈhannel ꢀ
ꢂꢃ ꢂ3 ꢂꢄ ꢂ1
ꢅPin 1 Sideꢆ
The IC is always capable of properly detecting input signals up
to the defined operating frequency. At frequencies beyond the
operational frequency specifications (refer to Operational Fre-
quency specifications), the ICC(HIGH) pulse duration will collide
with subsequent pulses.
ꢅꢌoꢍ ꢎiew oꢏ
Pacꢇage ꢈaseꢆ ꢂlement Pitch
ꢈhannel A
ꢂlement Pitch
Mechanical Position (Target moves past device pin 1 to pin 2)
ꢌarget
ꢌhis ꢍole
sensed later
ꢌhis ꢍole
sensed earlier
ꢅRadial Ring Magnetꢆ
S
ꢀ
ꢀ
Target Magnetic Profile
ꢈhannel
ꢂlement Pitch
ꢊꢀ
N
S
N
S
ꢋꢀ
ICC(HIGH)
tW(FWD)
tW(FWD)
IC Internal Differential Analog Signals, BDIFF
ꢀꢁP
ꢀꢁP
ICC(LOW)
ꢈhannel A
ꢀRP
ꢀꢁP
ꢈhannel ꢀ
Figure 12: Output Timing Example (-xSxxx variant)
ꢀRP
Detected Channel Switching
ꢈhannel A
ꢈhannel ꢀ
Device Output Signal
ꢐꢈꢈꢅHꢐꢑHꢆ
ꢐꢈꢈꢅꢒꢁꢓꢆ
Figure 11: Basic Operation
10
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
ASIL Safe State Output Protocol
The xxxxx-A variant contains diagnostic circuitry that will
continuously monitor occurrences of failure defects within the
IC. Refer to Figure 13 for the output protocol of the ASIL safe
state after an internal defect has been detected. Warning faults
will result from faults due to overfrequency conditions from the
input signal. Critical faults will result from hard failures detected
within the A19571 such as a regulator and front end fault.
Note: If a fault exists continuously, the device will stay in perma-
nent safe state. Refer to the A19571 Safety Manual for additional
details on the ASIL Safe State Output Protocol.
Magnetic
ꢀncoder
ꢀ
S
ꢀ
S
ꢀ
ꢁꢂꢂꢃHꢁꢄHꢅ
Normal
ꢇꢍeration
ꢁꢂꢂꢃꢆꢇꢈꢅ
ꢁꢂꢂꢃHꢁꢄHꢅ
ꢀrror
ꢈarning
ꢉaꢌlt
ꢁꢂꢂꢃꢆꢇꢈꢅ
ꢁꢉAUꢆꢊ
ꢉirst ꢋirection ꢇꢌtꢍꢌt Pꢌlse
twꢃꢉAUꢆꢊ,ꢈꢅ
ꢁꢂꢂꢃHꢁꢄHꢅ
ꢀrror
ꢂritical
ꢉaꢌlt
ꢁꢂꢂꢃꢆꢇꢈꢅ
ꢉirst ꢋirection Pꢌlse ꢇꢌtꢍꢌt
ꢁꢉAUꢆꢊ
twꢃꢉAUꢆꢊ,ꢂꢅ
Figure 13: Output Protocol of the -xxxBx-A Variant (ASIL Safe State)
11
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
Calibration and Direction Validation
When power is applied to the A19571, the built-in algorithm per-
forms an initialization routine. For a short period after power-on,
the device calibrates itself and determines the direction of target
rotation. For the -xxxPx variant, the output transmits nondirection
pulses during calibration (Figure 14). For the -xxxBx variant, the
output does not transmit any pulses during calibration.
Once the calibration routine is complete, the A19571 will trans-
mit accurate speed and direction information.
Target Rotation
N
S
N
S
N
S
N
S
N
Target
Differential
Magnetic
Profile
tW(FWD) or
tW(REV)
tW(FWD) or
tW(REV)
tW(FWD) or
tW(REV)
tW(FWD) or
tW(REV)
tW(FWD) or
tW(REV)
tW(FWD) or
tW(REV)
tW(FWD) or
tW(REV)
tW(FWD) or
tW(REV)
tW(ND)
tW(ND)
tW(ND)
tW(ND)
Opposite
north pole
tW(ND)
tW(ND)
Opposite
N→S boundary
I
CC
Opposite
south pole
tW(ND)
Opposite
t
S→N boundary
Device Location at Power-On
Figure 14: Calibration Behavior of the -xSxPH Variant
12
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
Direction Changes, Vibrations, and
Anomalous Events
During normal operation, the A19571 will be exposed to changes The -xxxxL variant may output an incorrect direction pulse
in the direction of target rotation (Figure 15), vibrations of the
target (Figure 16), and anomalous events such as sudden air
gap changes. These events cause temporary uncertainty in the
A19571’s internal direction detection algorithm.
during direction change and vibration, the -xxxPH variant may
transmit nondirection pulses during direction change and vibra-
tion, and the -xxxBH variant will not transmit any pulses during
direction change and vibration.
Direc�on
Change
Forward
Reverse
Rota�on
Rota�on
N
S
N
S
N
S
N
S
N
Target Differen�al
Magne�c Profile
tW(FWD)
tW(FWD)
tW(FWD)
tW(FWD)
tW(REV)
tW(REV)
tW(REV)
ICC
-xSxBH variant
-xSxPH variant
tW(FWD)
tW(ND)
tW(ND)
W(FWD) or tW(REV)
tW(FWD)
-xSxxL variant
tW(REV)
t
Figure 15: Direction Change Behavior
Vibra�on
Target Rota�on
Target Rota�on
N
S
N
S
N
S
N
S
N
Target Differen�al
Magne�c Profile
tW(FWD)
tW(FWD)
tW(FWD)
tW(FWD)
tW(FWD)
tW(FWD)
tW(FWD)
tW(FWD)
tW(FWD)
-xSxPH variant
-xSxBH variant
-xSxxL variant
ICC
tW(ND)
tW(FWD) or tW(REV)
Figure 16: Vibration Behavior
13
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
POWER DERATING
The device must be operated below the maximum junction
temperature of the device, TJ(max). Under certain combinations of
peak conditions, reliable operation may require derating supplied
power or improving the heat dissipation properties of the appli-
cation. This section presents a procedure for correlating factors
affecting operating TJ. (Thermal data is also available on the
Allegro MicroSystems website.)
A worst-case estimate, PD(max), represents the maximum allow-
able power level (VCC(max), ICC(max)), without exceeding TJ(max)
at a selected RθJA and TA.
,
Example: Reliability for VCC at TA = 150°C.
Observe the worst-case ratings for the device, specifically:
RθJA = 213°C/W (subject to change), TJ(max) = 165°C, VCC(max)
= 24 V, and ICC(AVG) = 15.4 mA. ICC(AVG) is computed using
ICC(HIGH)(max) and ICC(LOW)(max), with a duty cycle of 92%
computed from tw(ND)(max) on-time and tw(FWD)(min) off-time
(pulse-width protocol). This condition happens at a select limited
frequency.
The Package Thermal Resistance, RθJA, is a figure of merit sum-
marizing the ability of the application and the device to dissipate
heat from the junction (die), through all paths to the ambient air.
Its primary component is the Effective Thermal Conductivity,
K, of the printed circuit board, including adjacent devices and
traces. Radiation from the die through the device case, RθJC, is
a relatively small component of RθJA. Ambient air temperature,
TA, and air motion are significant external factors, damped by
overmolding.
Calculate the maximum allowable power level, PD(max). First,
invert equation 3:
ΔTmaxꢀ=ꢀTJ(max)ꢀ–ꢀTAꢀ=ꢀ165°Cꢀ–ꢀ150°Cꢀ=ꢀ15°C
This provides the allowable increase to TJ resulting from internal
power dissipation. Then, invert equation 2:
The effect of varying power levels (Power Dissipation, PD) can
be estimated. The following formulas represent the fundamental
relationships used to estimate TJ, at PD.
PD(max)ꢀ=ꢀΔTmax ÷ RθJAꢀ=ꢀ15°Cꢀ÷ꢀ213°C/Wꢀ=ꢀ70.4ꢀmWꢀ
Finally, invert equation 1 with respect to voltage:
PD = VIN × IIN
ΔTꢀ=ꢀPD × RθJA
TJꢀ=ꢀTAꢀ+ꢀΔTꢀꢀ
(1)
(2)
(3)
VCC(est) = PD(max) ÷ ICC(max)ꢀ=ꢀ70.4ꢀmWꢀ÷ꢀ15.4ꢀmAꢀ=ꢀ4.6ꢀVꢀ
The result indicates that, at TA , the application and device can
ꢀ
ꢀ
dissipate adequate amounts of heat at voltages ≤ VCC(est)
.
For example, given common conditions such as:
Compare VCC(est) to VCC(max). If VCC(est) ≤ VCC(max), then reli-
able operation between VCC(est) and VCC(max) requires enhanced
RθJA. If VCC(est) ≥ VCC(max), then operation between VCC(est) and
VCC(max) is reliable under these conditions.
TA= 25°C, VCC = 12 V, RθJA = 213°C/W, and ICC = 7.15 mA,
then:
PD = VCC × ICC = 12 V × 7.15 mA = 85.8 mW
ΔTꢀ=ꢀPD × RθJAꢀ=ꢀ85.8ꢀmWꢀ×ꢀ213°C/Wꢀ=ꢀ18.3°C
TJꢀ=ꢀTAꢀ+ꢀΔTꢀ=ꢀ25°Cꢀ+ꢀ18.3°Cꢀ=ꢀ43.3°C
14
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
Power Derating Curve
ꢃ5
ꢃꢄ
ꢃ3
ꢎ
ꢊꢊꢈmaꢌꢋ
ꢃꢃ
ꢃ1
ꢃ0
19
1ꢂ
1ꢁ
1ꢀ
15
1ꢄ
13
1ꢃ
11
10
9
1-layer Pꢊꢓ, Pacꢔage Uꢓ
ꢈRθꢏA ꢐ ꢃ13ꢉꢊꢑꢒꢋ
ꢂ
ꢁ
ꢀ
5
ꢄ
3
ꢎ
ꢊꢊꢈminꢋ
ꢃ
ꢃ0
ꢄ0
ꢀ0
ꢂ0
100
1ꢃ0
1ꢄ0
1ꢀ0
1ꢂ0
ꢅemꢆeratꢇre ꢈꢉꢊꢋ
Power Dissipation versus Ambient Temperature
1900
1ꢄ00
1ꢃ00
1ꢂ00
1500
1ꢁ00
1300
1ꢀ00
1100
1000
900
1-layer Pꢊꢒ, Pacꢓage Uꢒ
ꢈRθꢎA ꢏ ꢀ13ꢐꢊꢑꢍꢋ
ꢄ00
ꢃ00
ꢂ00
500
ꢁ00
300
ꢀ00
100
0
ꢀ0
ꢁ0
ꢂ0
ꢄ0
100
1ꢀ0
1ꢁ0
1ꢂ0
1ꢄ0
ꢅemꢆeratꢇre ꢈꢉꢊꢋ
15
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
PACKAGE OUTLINE DRAWING
For Reference Only – Not for Tooling Use
(ꢀꢁꢂꢁꢃꢁꢄꢅꢁ Dꢆꢇ-ꢈꢈꢈꢈꢉꢈꢊꢋ ꢀꢁꢌꢍ ꢎ)
Dꢏꢐꢁꢄꢑꢏꢒꢄꢑ ꢏꢄ ꢐꢏꢓꢓꢏꢐꢁꢔꢁꢃꢑ ꢕ ꢖꢗꢘ ꢘꢗ ꢙꢚꢛꢜꢝ
Dꢏꢐꢁꢄꢑꢏꢒꢄꢑ ꢁꢞꢅꢓꢟꢑꢏꢌꢁ ꢒꢂ ꢐꢒꢓd flꢠꢑꢡꢋ ꢢꢠꢔꢁ ꢣꢟꢃꢑꢋ ꢠꢄꢤ ꢤꢠꢐꢣꢠꢃ pꢃꢒꢔꢃꢟꢑꢏꢒꢄꢑ
Exact case and lead configuration at supplier discretion within limits shown
ꢰꢈꢍꢈꢴ
ꢕꢈꢍꢈꢭ
ꢉꢍꢈꢈ
B
ꢉꢨꢩꢈꢯ
ꢩꢍꢭꢈ ꢬꢈꢍꢈꢭ
ꢈꢍꢴꢴ
ꢀ
ꢈꢍꢱꢉ
ꢈꢍꢱꢉ
ꢈꢍꢮꢪꢱ
ꢈꢍꢱꢭꢭ
ꢥꢒꢓꢤ ꢝꢦꢁꢅꢔꢒꢃ
ꢧꢏꢄ Iꢄꢤꢁꢄꢔ
ꢳꢳꢳꢳꢳ
Dꢠꢔꢁ ꢚꢒꢤꢁ
ꢜꢒꢔ ꢖꢟꢐꢣꢁꢃ
ꢰꢈꢍꢈꢴ
ꢉꢍꢈꢈ
ꢝꢉ
ꢝ
ꢝ
ꢝꢩ
ꢕꢈꢍꢈꢮ
ꢝ
ꢝꢎ
ꢝꢪ
ꢝ
ꢉꢭꢯ
Bꢃꢠꢄꢤꢁꢤ
Fꢠꢅꢁ
D
ꢙꢔꢠꢄꢤꢠꢃꢤ Bꢃꢠꢄꢤꢏꢄꢢ ꢀꢁꢂꢁꢃꢁꢄꢅꢁ ꢲꢏew
ꢛ
ꢈꢍꢊꢭ ꢬꢈꢍꢈꢭ
ꢁine 1ꢂ 5 characters
ꢁines ꢃ, 3ꢂ 5 characters
ꢈꢍꢉꢪ ꢬꢈꢍꢈꢭ
ꢉ ꢨ ꢪꢍꢭꢈ ꢬꢈꢍꢩꢈ
ꢈꢍꢪꢭ ꢀꢝF
ꢈꢍꢎꢈ ꢀꢝF
ꢪꢍꢭꢉ ꢀꢝF
ꢁine 1ꢂ Part Nꢄmꢅer
ꢁine ꢃꢂ ꢆ-digit date code
ꢁine 3ꢂ ꢀharacters 5, ꢇ, ꢈ, ꢉ oꢊ
Assemꢅly ꢁot Nꢄmꢅer
ꢋꢌceꢍtion allowed ꢊor ꢍarts with
mꢄltiꢍle ꢍacꢎage ꢏariantsꢂ
ꢁine 1ꢂ ꢁast ꢆ digits oꢊ ꢍart nꢄmꢅer ꢍlꢄs
Pacꢎage ꢐariant
ꢩ
ꢪ
ꢩꢊꢍꢈꢈ ꢬꢈꢍꢩꢈ
ꢩꢪꢍꢪꢈ ꢬꢈꢍꢩꢈ
ꢉ ꢨ ꢮꢍꢎꢮ ꢀꢝF
ꢩꢍꢈꢈ ꢬꢈꢍꢈꢭ
ꢰꢈꢍꢈꢮ
ꢕꢈꢍꢈꢎ
ꢈꢍꢪꢭ
ꢩꢍꢊꢈ ꢬꢈꢍꢩꢈ
ꢛ
B
ꢚ
D
ꢝ
F
Dꢠꢐꢣꢠꢃ ꢃꢁꢐꢒꢌꢠꢓ pꢃꢒꢔꢃꢟꢑꢏꢒꢄ (ꢊꢨ)
ꢇꢠꢔꢁ ꢠꢄꢤ ꢔꢏꢁ ꢣꢟꢃꢃ ꢠꢃꢁꢠ
ꢛꢅꢔꢏꢌꢁ ꢛꢃꢁꢠ Dꢁpꢔꢡꢋ ꢈꢍꢎꢊ ꢬꢈꢍꢈꢎ ꢐꢐ
ꢈꢍꢎꢊ ꢀꢝF
ꢈꢍꢪꢭ ꢀꢝF
Bꢃꢠꢄꢤꢏꢄꢢ ꢑꢅꢠꢓꢁ ꢠꢄꢤ ꢠppꢁꢠꢃꢠꢄꢅꢁ ꢠꢔ ꢑꢟppꢓꢏꢁꢃ ꢤꢏꢑꢅꢃꢁꢔꢏꢒꢄ
ꢇꢥꢀ ꢁꢓꢁꢐꢁꢄꢔꢑ (ꢝꢩꢋ ꢝꢪꢋ ꢝꢎꢋ ꢠꢄꢤ ꢝꢉ)ꢫ ꢄꢒꢔ ꢔꢒ ꢑꢅꢠꢓꢁ
ꢥꢒꢓꢤꢁꢤ ꢜꢁꢠꢤ Bꢠꢃ ꢂꢒꢃ pꢃꢁꢌꢁꢄꢔꢏꢄꢢ ꢤꢠꢐꢠꢢꢁ ꢔꢒ ꢓꢁꢠꢤꢑ ꢤꢟꢃꢏꢄꢢ ꢑꢡꢏpꢐꢁꢄꢔ
ꢉ ꢨ ꢈꢍꢊꢭ ꢀꢝF
ꢈꢍꢊꢭ ꢬꢈꢍꢈꢭ
ꢰꢈꢍꢈꢴ
ꢕꢈꢍꢈꢮ
ꢩꢍꢊꢈ
F
ꢰꢈꢍꢈꢴ
ꢉꢍꢈꢈ
ꢩꢍꢭꢈ ꢬꢈꢍꢈꢭ
ꢕꢈꢍꢈꢭ
Figure 17: Package UB, 2-Pin SIP
16
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Large Air Gap, Vibration-Tolerant,
GMR Transmission Speed and Direction Sensor IC
A19571
Revision History
Number
Date
Description
–
September 4, 2020
Initial release
Copyright 2020, Allegro MicroSystems.
Allegro MicroSystems reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit
improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the
information being relied upon is current.
Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of
Allegro’s product can reasonably be expected to cause bodily harm.
The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems assumes no responsibility for its use; nor
for any infringement of patents or other rights of third parties which may result from its use.
Copies of this document are considered uncontrolled documents.
For the latest version of this document, visit our website:
www.allegromicro.com
17
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
相关型号:
©2020 ICPDF网 联系我们和版权申明