ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
FEATURES AND BENEFITS
DESCRIPTION
•
Two independent digital outputs representing the sensed
target’s mechanical profile
•
Optional output with high-resolution position and direction detection information
•
Air gap independent switch points
The ATS605LSG provides a single IC solution to rotational
position sensing applications with a ferrous gear target.
The SG package incorporates a rare-earth pellet for ease of
manufacturing, consistent performance over temperature, and
enhanced reliability.
•
Integrated back-biasing magnetic circuit
•
Immunity to external magnetic interference
•
Wide operating voltage range
•
Single chip IC for high reliability
•
Robust test coverage and reliability using Scan and
IDDQ test methodologies
•
Optional Double-Bandwidth configuration
Three Hall elements are incorporated to create two independent
differential channels. These channels are processed by the
IC which contains a sophisticated digital circuit designed
to eliminate the detrimental effects of magnet and system
offsets. Hall differential signals are used to produce a highly
accurate speed output and, if desired, provide information on
the direction of rotation.
Advanced calibration techniques are used to optimize signal
offset and amplitude. This calibration, combined with the
digital tracking of the signal, results in accurate switch points
over air gap, speed, and temperature. The open-drain outputs
provide voltage output signals which mirror the sensed target’s
shape, with a phase separation between the two channels
proportionate to the size of the target teeth versus the Hall
element spacing. This sensor IC system is optimized for a
variety of applications requiring dual phase gear speed and
position signal information or simultaneous high-resolution
gear speed and direction information.
PACKAGE: 4-PIN SIP (SUFFIX SG)
The ATS605 is offered in a lead (Pb) free 4-pin SIP package
with an integrated back-biasing magnet with a 100% mattetin-plated leadframe.
Not to scale
Functional Block Diagram
VCC
REGULATOR
(Analog)
REGULATOR
(Digital)
SPEED A
DIRECTION
Hall Amp
OFFSET
ADJUST
AGC
FILTER
OFFSET
ADJUST
AGC
FILTER
Current
Limit
MULTIPLEXED
SIGNALS
Current
Limit
OUT A
ADC
SYNCHRONOUS
DIGITAL
CONTROLLER
Hall Amp
MULTIPLEXED
SIGNALS
SPEED B
XOR SPEED
OUT B
ADC
GND
ATS605LSG-DS, Rev. 5
MCO-0000216
July 9, 2021
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
SELECTION GUIDE
Part Number
Output Configuration
Operational
Frequency
(kHz)
ATS605LSGTN-S-T
Speed (OUTA); Speed (OUTB)
20
ATS605LSGTN-S-H-T
Speed (OUTA); Speed (OUTB)
40
ATS605LSGTN-F-T
Direction (OUTA); XOR Speed (OUTB)
20
ATS605LSGTN-F-H-T
Direction (OUTA); XOR Speed (OUTB)
40
ATS605LSGTN-R-T
Inverse Direction (OUTA);
XOR Speed (OUTB)
20
ATS605LSGTN-R-H-T
Inverse Direction (OUTA);
XOR Speed (OUTB)
40
Operating Ambient
Temperature Range
TA, (°C)
Packing*
–40 to 150
800 pieces per 13-in. reel
* Contact Allegro™ for additional packing options.
ABSOLUTE MAXIMUM RATINGS
Characteristic
Symbol
Supply Voltage
VCC
Reverse Supply Voltage
VRCC
Notes
Rating
Unit
28
V
–18
V
Refer to Power Derating section
Reverse Supply Current
IRCC
–50
mA
Reverse Output Voltage
VROUT
–0.5
V
Forward Output Voltage
VOUT
28
V
25
mA
Output Sink Current
IOUTSINK
Internal current limiting is intended to protect the device from
output short circuits, but is not intended for continuous operation.
Operating Ambient Temperature
TA
–40 to 150
°C
Maximum Junction Temperature
TJ(max)
165
°C
Tstg
–65 to 170
°C
Storage Temperature
Pinout Diagram
Branded
Face
1
2
3
4
L temperature range
Terminal List Table
Number
Name
Descritpion
1
VCC
2
OUTB
Option [-S]: Speed (OUTB)
Option [-F]: XOR Speed
Option [-R]: XOR Speed
3
OUTA
Option [-S]: Speed (OUTA)
Option [-F]: Default Direction
Option [-R]: Inverse Direction
4
GND
Ground
Supply voltage
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
2
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
OPERATING CHARACTERISTICS: Over operating voltage and temperature range, unless otherwise noted
Characteristic
Symbol
Test Conditions
Min.
Typ. [1]
Max.
Unit
4.0
–
24
V
–18
–
–
V
–
–
3.95
V
VCC = –18 V
–
–
–10
mA
ICC = ICC(max) + 3 mA, TA = 25°C
28
–
–
V
Output OFF (VOUT = High)
–
8.5
13
mA
Output ON (VOUT = Low)
–
8.5
13
mA
VOUTA, VOUTB, as connected in Figure 7
–
High
–
fOP < 200 Hz
–
–
2
ms
IOUT = 10 mA, Output = ON
–
165
350
mV
VZoutput
IOUT = 3 mA, TA = 25 °C
28
–
–
V
Output Current Limit
IOUT(LIM)
Output = ON (VOUT = Low), measured with
RPULLUP = 0 Ω, TJ < TJ(MAX)
30
55
85
mA
Output Leakage Current
IOUT(OFF)
Output = OFF, VOUT = 24 V
–
–
10
μA
–
10
–
μs
–
0.6
–
μs
–60
–
60
G
ELECTRICAL CHARACTERISTICS
Supply Voltage
VCC
Reverse Supply Voltage
VRCC
Under Voltage Lockout
VCC(UV)
Reverse Supply Current
Supply Zener Clamp Voltage
IRCC
VZsupply
ICC
Supply Current
Operating, TJ < TJ(max)
VCC from 0 → 5 V or 5 → 0 V
POWER-ON STATE CHARACTERISTCS
Power-On State
Power On Time [2][3]
POS
tPO
OUTPUT STAGE FOR EACH OUTPUT PIN
Low Output Voltage
Output Zener Clamp Voltage
VOUT(SAT)
Output Rise Time
tr
10% - 90%, VPU = 12V, RPULLUP = 1 kΩ,
CL = 4.7 nF
Output Fall Time
tf
90% - 10%, VPU = 12V, RPULLUP = 1 kΩ,
CL = 4.7 nF
DAC CHARACTERISTICS
Allowable User-Induced Magnetic
Offset [4][5]
BDIFFEXT
User induced differential offset
SWITCHPOINT CHARACTERISTICS
Minimum Operational Frequency
Maximum Operational Frequency
fOPmin
fOPmax
Allegro reference target
0
–
–
kHz
Allegro reference target
–
20
–
kHz
Allegro reference target, double-bandwidth
option, suffix “-H”
–
40
–
kHz
Cutoff frequency for low-pass filter
–
20
–
kHz
Analog Signal Bandwidth
f-3dB
Cutoff frequency for low-pass filter, doublebandwidth option
–
40
–
kHz
Operate Point
BOP
% of VPROC(PKPK), Output OFF to ON
–
70
–
%
Release Point
BRP
% of VPROC(PKPK), Output ON to OFF
–
30
–
%
Lockout Enable
VLOE
VPROC(PKPK) < VLOE = Output Switching Disabled
–
250
–
mV
Lockout Release
VLOR
VPROC(PKPK) > VLOE = Output Switching Enabled
–
350
–
mV
Continued on the next page…
[1] Typical
data is at VCC = 12 V and TA = +25°C. Performance may vary for individual units, within the specified maximum and minimum limits.
Time is the time required to complete the internal automatic offset adjust; the registers are then ready for peak acquisition.
speed power-on compliant, however several missing output transitions are possible.
[4] 1 G (gauss) = 0.1 mT (millitesla).
[5] The device compensates for magnetic and installation offsets. Offsets greater than specification in gauss may cause inaccuracies in the output.
[2] Power-On
[3] High
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
3
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
OPERATING CHARACTERISTICS (continued): Valid throughout full operating and temperature ranges; using Reference Target
60-0; unless otherwise specified
Characteristic
Symbol
Test Conditions
Min.
Typ. [7]
Max.
Unit
–
1
–
tooth
–
3
8
edge
CALIBRATION
First Output Edge
Initial
Calibration [8]
–
fOP < 600 Hz, VCC > VCC(MIN)
CALI
OPERATING CHARACTERISTICS (with Allegro 60-0 reference target)
Operational Air Gap Range [9]
Direction Output Delay
Maximum Sudden Air Gap Change /
Signal Reduction [10]
Duty Cycle Variation
Minimum Operating Signal [11]
0.75
–
3
mm
Delay between first XOR SPEED output
transition and reported direction change
–
400
–
ns
Differential magnetic signal reduction due to
instantaneous air gap change; symmetrical
signal reduction,
fOP < 500 Hz, VPROC(PKPK) > VLOE after sudden
air gap change
–
40
–
% pk-pk
Valid for SPEED(OUTA) and SPEED(OUTB)
40
50
60
%
fOP < 10 kHz
–
30
–
G
10 kHz ≤ fOP ≤ 20 kHz
–
60
–
G
fOP < 10 kHz
Double-bandwidth option, suffix “-H”
–
30
–
G
10 kHz ≤ fOP ≤ 20 kHz
Double-bandwidth option, suffix “-H”
–
45
–
G
20 kHz < fOP
Double-bandwidth option, suffix “-H”
–
60
–
G
AG
td
ΔBIN
ΔD
BIN
[7] Typical
data is at VCC = 12 V and TA = +25°C. Performance may vary for individual units, within the specified maximum and minimum limits.
reduced edge accuracy, ΔD not guaranteed. Edges are sensed target mechanical edges (see Definitions of Terms for Switch Points).
[9] Operating air gap is dependent on the available magnetic field. The available field is target geometry and material dependent and should be independently characterized.
[10] Maximum single outward sudden allowable air gap change is in outward direction (increase in air gap).
[11] Output switching (no missed edges). Minimum operating signal, for either operating frequency range, is the differential magnetic field.
[8] Possible
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
4
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
DEFINITIONS OF TERMS FOR SWITCH POINTS
Definitions of Terms for Switchpoints
Sensed Edgea
Differential Processed
Signal, VProc (V)
Differential Magnetic
Flux Density, BDIFF (G)
Reverse
Tooth
Forward
Valley
+B
BOP(REV)b
BOP(FWD)b
BRP(REV)
BRP(FWD)
–B
+V
VPROC(BOP)
100 %
VPROC(BRP)
BOP %
BRP %
–V
t
aSensed Edge: leading (rising) mechanical edge in forward rotation, trailing (falling) mechanical edge in reverse rotation
bB
triggers
the output
transition
during forward
rotation,
and BOP(REV)
triggers the
output(falling)
transition during
reverse rotation
OP(FWD)
Figure 1: (a) Sensed
Edge:
leading
(rising)
mechanical
edge
in forward
rotation,
trailing
mechanical
edge in reverse rotation;
(b) BOP(FWD) triggers the output transition during forward rotation, and BOP(REV) triggers the output transition during reverse rotation.
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
5
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
REFERENCE TARGET CHARACTERISTICS 60-0 (60 Tooth Target)
Symbol
Test Conditions
Typ.
Unit
Outside Diameter of
Target
120
mm
Face Width
F
Breadth of tooth, with
respect to sensor IC
6
mm
Circular Tooth Length
t
Length of tooth, with
respect to sensor IC;
measured at DO
3
deg
Circular Valley Width
tv
Length of valley, with
respect to sensor IC;
measured at DO
3
deg
Tooth Whole Depth
ht
3
mm
–
–
Material
Low Carbon Steel
Do
ht
F
tv
DO
Outside Diameter
Symbol Key
Branded Face
of Package
t
Characteristics
Air Gap
Figure 2: Example of Allegro Reference Gear
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
6
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
FUNCTIONAL DESCRIPTION
Sensing Technology
Target Profiling During Operation
The ATS605 module contains a single-chip, dual differential
Hall-effect sensor IC, a rare earth pellet, and a flat ferrous pole
piece (concentrator). As shown in Figure 4, the Hall IC supports
three Hall elements, which sense the magnetic profile of the
ferrous gear target simultaneously, but at different points (each
channel spaced at a 1.75 mm pitch), generating two differential
internal analog voltages, VPROC, that is processed for precise
switching of the digital output signals.
An operating device is capable of providing digital information
that is representative of the mechanical features of a rotating gear.
The waveform diagram in Figure 4 presents the automatic translation of the mechanical profile, through the magnetic profile that
it induces, to the digital output signal of the ATS605. No additional optimization is needed and minimal processing circuitry is
required. This ease of use reduces design time and incremental
assembly costs for most applications.
The Hall IC is self-calibrating and also possesses a temperature compensated amplifier and offset cancellation circuitry. Its
voltage regulator provides supply noise rejection throughout the
operating voltage range. Changes in temperature do not greatly
affect this device due to the stable amplifier design and the offset
rejection circuitry. The Hall transducers and signal processing
electronics are integrated on the same silicon substrate, using a
proprietary BiCMOS process.
Operating Modes:
Calibration
Once the power-on time has elapsed, the sensor IC internally
detects the magnetic profile of the target. The output becomes
active at the first detected switchpoint.
The gain of the sensor IC is adjusted during the Calibration
period, normalizing the internal signal amplitude for the air gap
range of the device. This Automatic Gain Control (AGC) feature
ensures that operational characteristics are isolated from the
effects of installation air gap variation.
Automatic Offset Adjustment (AOA) is circuitry that compensates for the effects of chip, magnet, and installation offsets. (For
capability, see Allowable User-Induced Magnetic Offset, in the
Operating Characteristics table.) This circuitry works with the
AGC during calibration to help center VPROC in the dynamic
range to allow for DAC acquisition of signal peaks.
Calibration also allows for the peak detecting DACs to properly
acquire the magnetic signal, so that Running Mode switch points
can be accurately computed.
Running Mode
After calibration is complete, direction information is available.
This information is communicated through the available output
option.
Peak-tracking DAC algorithms allow tracking of signal drift over
temperature changes, as well as tracking of target variations, such
as tooth-to-tooth variation and effective runout. The sensor’s
dynamic monitoring of these signal peaks is updated on each
tooth and valley edge.
Figure 3: Target Rotation for Default Sensing Configuration.
(A) Pin 4 to pin 1 is forward, and (B) pin 1 to pin 4 is reverse.
Automatic Offset Adjust remains active, allowing the IC to compensate for offsets induced by temperature variations over time.
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
7
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
Output
The device provides three outputs (DIRECTION, XOR SPEED,
and SPEED), available in two combinations: Option #1 (-S) is
SPEED (Ch. A) and SPEED (Ch. B), and Option #2 (-F) is XOR
SPEED and DIRECTION. DIRECTION provides the target
rotation direction relative to the device. XOR SPEED provides
an XOR’d output of the two speed channels (Ch. A and Ch. B),
which results in double the speed data rate without requiring
changes to be made to the controller. SPEED will be updated
before DIRECTION and is updated at every transition of both
Channel A and Channel B allowing the use of up-down counters
without the loss of pulses.
Output Polarity
In Figure 4, the top panel, labeled Mechanical Position, represents the mechanical features of the target gear and orientation
to the device. The bottom panel, labeled Output Option # 1, the
–S variant, displays the square waveforms corresponding to the
digital SPEED output signals for channels A and B for a rotating
gear in the forward rotation direction (gear tooth passing from the
pin 4 side to the pin 1 side, Figure 3). The end result is the sensor
output switching from high state to low state as the leading edge
of a tooth (a rising mechanical edge, as detected by the sensor)
passes the sensor face. If the direction of rotation is reversed so
that the gear rotates from the pin 1 side to the pin 4 side (Figure
3), then the output polarity inverts (i.e., the output signal goes
high when a rising edge is detected, and a tooth is the nearest
feature to the sensor).
The Output Option #2 panel refers to the –F variant, for which
DIRECTION polarity is defined as ON (low) when the target
crosses the sensor face in the forward direction (from the pin
4 side to the pin 1 side), and OFF (high) for the reverse direction (from the pin 1 side to the pin 4 side). There is an option,
ATS605LSGTN-R-T, that inverts this DIRECTION output signal
polarity (SPEED output polarity is unaffected and remains as
defined above). XOR SPEED polarity is defined as SPEED A
XOR SPEED B.
Table 1: Output Pin Descriptions
Figure 4: The magnetic profile reflects the geometry of the
target, allowing the ATS605 to present an accurate digital output
response. Please see Figure 5 for more detailed output switching.
Option
Pin 2 / OUTB
Pin 3 / OUTA
Option 1 (“-S”)
SPEED B
SPEED A
Option 2 (“-F”)
XOR SPEED
DIRECTION
Option 2 (“-R”)
XOR SPEED
Inverted DIRECTION
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
8
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
BCHA
BCHB
Channel A
Channel B
OUTA:
OUTB:
Figure 5: Direction change, first showing the default forward rotation output polarity and then for the same output configuration, the
reverse direction polarity is shown (Pin 4 to Pin 1 is FWD).
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
9
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
Undervoltage Lockout
DEVICE FEATURES
Automatic Offset Adjust (AOA)
When the supply voltage falls below the undervoltage lockout
voltage, UVLO, the device enters Reset, where the output state
returns to the Power-On State (POS) until sufficient VCC is
supplied. ICC levels may not meet datasheet limits when VCC <
VCC(min). This lockout feature prevents false signals, caused by
undervoltage conditions, from propagating to the output of the
sensor.
The AOA circuitry automatically compensates for the effects of
chip, magnet, and installation offsets. (For capability, see Allowable User-Induced Magnetic Offset, in the Operating Characteristics table.) This circuitry is continuously active, including both
during power-on mode and running mode, compensating for any
offset drift (within Allowable User-Induced Magnetic Offset).
Continuous operation also allows it to compensate for offsets
induced by temperature variations over time.
Power Supply Protection
Lockout
The device contains an on-chip regulator and can operate over a
wide VCC range. For devices that need to operate from an unregulated power supply, transient protection must be added externally.
For applications using a regulated line, EMI/RFI protection may
still be required. Contact Allegro MicroSystems for information
on the circuitry needed for compliance with various EMC specifications. Refer to Figure 7 for an example of a basic application
circuit.
Automatic Gain Control (AGC)
This feature allows the device to operate with an optimal internal
electrical signal, regardless of the air gap (within the AG specification). At power-on, the device determines the peak-to-peak
amplitude of the signal generated by the target. The gain of the
sensor is then automatically adjusted. Figure 6 illustrates the
effect of this feature.
The ATS605 has a lockout feature to prevent switching on small
signals that are characteristic of vibration signals. The internal
logic of the chip will consider small signal amplitudes below a
certain level to be vibration. The output will then be held to the
state prior to lockout until the amplitude of the signal returns to
normal operational levels. Lockout is independent between speed
channels for the SPEED and SPEED output configuration, allowing one channel to continue switching without the other. The
alternative XOR SPEED and DIRECTION configuration requires
both channels to exceed the lockout release value before enabling
these output signals.
Assembly Description
The ATS605 is integrally molded into a plastic body that has
been optimized for size, ease of assembly, and manufacturability.
High operating temperature materials are used in all aspects of
construction.
VCC
RS
R PULLUP(B)
R PULLUP(A)
1
C BYP
0.1 µF
ATS605
VOUTB
2
C LOAD(B)
VOUTA
3
4
C LOAD(A)
GND
Figure 7: Typical Application Circuit
Figure 6: Automatic Gain Control (AGC). The AGC function corrects for
variances in the air gap. Differences in the air gap cause differences in
the magnetic field at the device, but AGC prevents that from affecting
device performance, as shown in the lower panel.
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
10
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
Start Mode Hysteresis
This feature helps to ensure optimal self-calibration by rejecting electrical noise and low-amplitude target vibration during
initialization. This prevents AGC from calibrating the IC on such
spurious signals. Calibration can be performed using the actual
target features.
A typical scenario is shown in Figure 8. The Start Mode Hysteresis, POHYS, is a minimum level of the peak-to-peak amplitude
of the internal analog electrical signal, VPROC, that must be
exceeded before the ATS605 starts to compute switch points.
Figure 8: Operation of Start Mode Hysteresis
• At power-on (position 1), the ATS605 begins sampling VPROC.
• At the point where the Start Mode Hysteresis, POHYS, is exceeded, the device establishes an initial switching threshold, by using the
Continuous Update algorithm. If VPROC is falling through the limit on the low side (position 2), the switchpoint is BRP, and if VPROC
is rising through the limit on the high side (position 4), it is BOP. After this point, Start Mode Hysteresis is no longer a consideration. Note that a valid VPROC value exceeding the Start Mode Hysteresis can be generated either by a legitimate target feature or by
excessive vibration.
• In either case, because the switchpoint is immediately passed as soon as it is established, the ATS605 enables switching:
--If on the low side, at BRP (position 2) the output would switch from low to high. However, because output is already high, no
output switching occurs.
At the next switchpoint, where BOP is passed (position 3), the output switches from high to low.
--If on the high side, at BOP (position 4) the output switches from high to low.
As this example demonstrates, initial output switching occurs with the same polarity, regardless of whether the Start Mode Hysteresis
is exceeded on the high side or on the low side
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
11
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
CHARACTERISTIC PERFORMANCE
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
12
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
CHARACTERISTIC PERFORMANCE (continued)
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
13
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
THERMAL CHARACTERISTICS
Characteristic
Package Thermal Resistance
Symbol
RqJA
Test Conditions
Value
Unit
Minimum-K PCB, single-layer, single-sided, with copper limited to
solder pads)
126
°C/W
Low-K PCB, single-layer, single-sided with copper limited to solder
pads and 3.57 in.2 (23.03 cm2) of copper area each side
84
°C/W
VCC(max)
VCC(min)
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
14
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
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 application. 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 allowable power level (VCC(max), ICC(max)), without exceeding TJ(max),
at a selected RθJA and TA.
The Package Thermal Resistance, RθJA, is a figure of merit summarizing 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 relatively
small component of RθJA. Ambient air temperature, TA, and air
motion are significant external factors, damped by overmolding.
RθJA = 126°C/W, TJ(max) = 165°C, VCC(max) = 24 V, and
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.
Example: Reliability for VCC at TA = 150°C, package SG, using
single-layer PCB.
Observe the worst-case ratings for the device, specifically:
ICC = 13 mA.
Calculate the maximum allowable power level, PD(max). First,
invert equation 3:
∆Tmax = TJ(max) – TA = 165°C – 150°C = 15°C
This provides the allowable increase to TJ resulting from internal
power dissipation. Then, invert equation 2:
PD(max) = ∆Tmax ÷ RθJA = 15°C ÷ 126°C/W = 119 mW
Finally, invert equation 1 with respect to voltage:
PD = VIN × IIN (1)
VCC(est) = PD(max) ÷ ICC(max) = 119 mW ÷ 13 mA = 9.2 V
∆T = PD × RθJA (2)
The result indicates that, at TA, the application and device can
dissipate adequate amounts of heat at voltages ≤ VCC(est).
TJ = TA + ∆T (3)
For example, given common conditions such as:
TA= 25°C, VCC = 12 V, RθJA = 126°C/W, and
ICC = 8.5 mA, then:
PD = VCC × ICC = 12 V × 8.5 mA = 102 mW
∆T = PD × RθJA = 102 mW × 126°C/W = 12.9°C
TJ = TA + ∆T = 25°C + 12.9°C = 37.9°C
Compare VCC(est) to VCC(max). If VCC(est) ≤ VCC(max), then reliable 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.
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
15
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
Package SG, 4-Pin SIP
For Reference Only – Not for Tooling Use
(Reference DWG-0000392)
Dimensions in millimeters. NOT TO SCALE.
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
Top View
Gate Location
Ø3.0
Ejector pin
5.50 ±0.05
30° REF
0.71 ±0.05
1.75 1.75
Ø8.00 ±0.05
Magnet Side
Tiebar
1.50 ±0.10 (4×)
1.50 REF (2×)
R0.3 REF (8×)
E2
E1
A
0.50 +0.15
–0.05
5.80 ±0.05
E3
2.90 ±0.05
1.70 ±0.10
0.43 ±0.025
Nominal Active Area Depth Ref
0.10 MAX (16×)
Dambar protrusion
4.41 ±0.10
0.60 ±0.10 (4×)
Sensor Elements
Ø0.3 B A S
Angular Die Placement: ±3°
0.40 ±0.10 (4×)
4.70 ±0.10
B
24.65 ±0.10
Hall Elements
E1, E2, E3
not to scale
15.30 ±0.10
0.38 +0.06
–0.04
Plating included
5.50 ±0.10
0.71 ±0.10
1.60 ±0.10
0.80 REF
1.0 REF
10° REF
2.75 REF
0.71 ±0.10
0.635 REF
Ø1.5 Ejector pin (2×)
Tiebar
1.27 ±0.10 (×3)
1.80 ±0.10
0.60 (4×)
End view of molded lead bar
Lot Number
XXX
Date Code
Standard Branding Reference View
Lines 2, 3, 4 = 7 characters.
Line 1: Logo A molded in
Line 2: 7-digit alpha numeric Lot Number
Line 3: Last 3 digit of Part Number.
Additional suffixes may be
added to Part number as required.
Line 4: 4-digit Date Code
Center align
Branding scale and appearance at supplier discretion
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
16
ATS605LSG
Dual Output Differential Speed and Direction Sensor IC
Revision History
Number
Date
Description
–
March 28, 2014
1
December 5, 2016
Initial release
2
June 15, 2017
Corrected typo in symbol for Output Fall Time (page 3)
3
June 20, 2018
Minor editorial updates
4
July 3, 2019
Minor editorial updates
5
July 9, 2021
Updated package drawing (page 16)
Updated Functional Block Diagram (page 1) and Minimum Operating Signal (page 4)
Copyright 2021, 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
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
17
