A1645LK-I2 Allegro Microsystems Inc, A1645LK-I2 Datasheet - Page 12

• Manufacturer Part Number: A1645LK-I2
• Description: IC SENSOR HALL EFFECT AC 4-SIP
• Manufacturer: Allegro Microsystems Inc
• Type: Special Purposer

Specifications of A1645LK-I2

• Sensing Range: 120mV Trip, 120mV Release
• Voltage - Supply: 4 V ~ 24 V
• Current - Supply: 8.4mA
• Output Type: Digital, Open Collector
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 4-SIP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output (max): -
• Features: -

A1642
The device must be operated below the maximum junction
temperature of the device, T
peak conditions, reliable operation may require derating sup-
plied power or improving the heat dissipation properties of the
application. This section presents a procedure for correlating
factors affecting operating T
the Allegro MicroSystems Web site.)
The Package Thermal Resistance, R
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, R
relatively small component of R
T
overmolding.
The effect of varying power levels (Power Dissipation, P
be estimated. The following formulas represent the fundamental
relationships used to estimate T

For example, given common conditions such as: T
V

A worst-case estimate, P
able power level (V
T
A
J
CC
(max), at a selected R
, and air motion are signifi cant external factors, damped by
T = P
T = P
= 12 V, I
P
T
D
J
= T
= V
A
D
CC
+ T = 25°C + 12.2°C = 37.2°C
×
CC
×
R
= 6 mA, and R
I
JA
CC
P
T
CC
D
J
= 12 V
= 72 mW
= T
(max), I
= V
JA
D
A
D
(max), represents the maximum allow-
IN
+ ΔT
and T
×
J(max)
J
×
×
. (Thermal data is also available on
CC
R
×
6 mA = 72 mW
I
JA
J
JA
JA
, at P
IN
(max)), without exceeding
A
. Under certain combinations of
170 °C/W = 12.2°C
.
Peak-Detecting Sensor IC with Continuous Calibration
= 170 °C/W, then:
. Ambient air temperature,
JA
D
.
, is a fi gure of merit sum-
Two-Wire True Zero-Speed Miniature Differential
A
= 25°C,
Power Derating
JC
D
), can
, is
(1)
(2)
(3)
Example: Reliability for V
(I1 trim), using 1-layer PCB
Observe the worst-case ratings for the device, specifi cally:
R
I
Calculate the maximum allowable power level, P
invert equation 3:
This provides the allowable increase to T
power dissipation. Then, invert equation 2:
P
Finally, invert equation 1 with respect to voltage:
The result indicates that, at T
dissipate adequate amounts of heat at voltages ≤V
Compare V
able operation between V
R
and V
CC
JA
JA
V
T
(max) = 16 mA.
D
CC(est)
. If V
= 170 °C/W, T
(max) = T
CC
max
(max) is reliable under these conditions.
= T
= P
CC(est)
CC(est)
J
D
(max) – T
(max) ÷ I
max
≥ V
to V
J
(max) = 165°C, V
÷ R
CC
CC
(max), then operation between V
JA
A
CC
(max). If V
CC(est)
= 165 °C – 150 °C = 15 °C
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
CC
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
(max) = 88.2 mW ÷ 16 mA = 5.5 V
= 15°C ÷ 170 °C/W = 88.2 mW
A
at T
, the application and device can
and V
A
= 150°C, package KN
CC(est)
CC
CC
(max) = 24 V, and
(max) requires enhanced
J
resulting from internal
≤ V
CC
(max), then reli-
D
CC(est)
(max). First,
.
CC(est)
12