A6850KLTR-T Allegro Microsystems Inc, A6850KLTR-T Datasheet - Page 7

• Manufacturer Part Number: A6850KLTR-T
• Description: IC SWITCH INTERFACE 2CHAN 8-SOIC
• Manufacturer: Allegro Microsystems Inc
• Type: Hall Effect Switchr

Specifications of A6850KLTR-T

• Input Type: Voltage
• Output Type: Voltage
• Interface: 2-Wire Serial
• Current - Supply: 5mA
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Interface Applications: Microprocessors, 2 Wire Hall Effect Sensor IC
• Supply Voltage Range: 4.75V To 26.5V
• Power Dissipation Pd: 52mW
• Operating Temperature Range: -40°C To +125°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 620-1185-2

A6850
T
the A6850. To calculate P
When I
When I
and V
The temperature rise of the A6850 can be calculated by multiply-
ing P
The formula for temperature rise, ΔT, is:

The R
board with minimum copper area is 140 °C/W. (More thermal
data is available on the Allegro MicroSystems website.)
The total junction temperature can be calculated by:
where T
J
can be estimated by calculating the power dissipation (P
D
P
P
ΔT = P
OUTPUTx
θJA
T
D
D
and the thermal resistance from junction to ambient, R
OUTPUTx
OUTPUTx
J
A
= V
– V
– V
= V
+ (V
+ (V
+ (V
+ (V
(V
I
= T
for an 8-pin SOIC (Allegro L package) on a one-layer
OUTPUTx
is the ambient air temperature.
IN
OUTPUT1
SENSE1
A
IN
IN
D
IN
IN
IN
IN
– V
+ ΔT ,
× R
is set by the loading on the OUTPUTx pin.
I
I
INQ
INQ
– V
– V
– V
– V
× R
× R
OUTPUTx
θJA
= I
OUTPUT1
OUTPUT2
SENSE1
SENSE2
I
DS(on)
DS(on)
SENSE1
I
OUTPUT
.
OUTPUT1
D
) I
) I
< approximately 700 mV, then:
> approximately 700 mV, then:
) = I
:
– V
) I
) I
SENSE1
SENSE2
(max) ,
OUTPUT1
OUTPUT2
OUTPUTx
– V
SENSE2
OUTPUT2
.
I
SENSE2
× R
I
DS(on)
OUTPUT2
.
.
D
(6)
(7)
(8)
(9)
) of
θJA
.
Dual Channel Switch Interface IC
Example: Calculating the power dissipation and temperature rise,
given:
Then:
Substituting in equation 8:
Substituting in equation 9:
I
OUTPUT1
R
I
I
OUTPUTx
SENSEx
SENSE1
I
V
INQ
ΔT = 46.75 mW × 140 °C/W = 6.5°C .
P
T
T
IN
D
A
J
= 25°C ,
= 5 V ,
= 5 mA ,
= I
= I
= R
= 5 V × 5 mA
= 46.75 mW .
= 25°C + 6.5°C = 31.5°C .
+ 0.525 V×15 mA+[5 V – (1.5 mA×2 kΩ)]×1.5 mA
+ 0.525 V×15 mA+[5 V – (1.5 mA×2 kΩ)]×1.5 mA
× R
OUTPUT2
OUTPUTx
SENSE2
DS(on)
= 2 kΩ , and
= 15 × 35 = 525 mV = V
= 15 mA ,
/10 = 1.5 mA ,
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
IN
– V
OUTPUTx
.
7