AD22151YR(Rev0) 查看數據表（PDF） - Analog Devices
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AD22151YR Datasheet PDF : 8 Pages
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PIN CONFIGURATION
TC1 1
8 VCC
TC2 2 AD22151 7 REF
TOP VIEW
TC3 3 (Not to Scale) 6 GAIN
GND 4
5 OUTPUT
AREA OF SENSITIVITY*
1
8
2
7
3
6
(Not to Scale)
4
5
* SHADED AREA REPRESENTS
MAGNETIC FIELD AREA OF
SENSITIVITY (20MILS ؋ 20MILS)
• POSITIVE B FIELD INTO TOP OF
PACKAGE RESULTS IN A POSITIVE
VOLTAGE RESPONSE
AD22151
Pin No.
1
2
3
4
5
6
7
8
PIN FUNCTION DESCRIPTIONS
Description
Temperature Compensation 1
Temperature Compensation 2
Temperature Compensation 3
Ground
Output
Gain
Reference
Positive Power Supply
Connection
Output
Output
Input/Output
Output
Input
Output
CIRCUIT OPERATION
The AD22151 consists of epi Hall plate structures located at
the center of the die. The Hall plates are orthogonally sampled
by commutation switches via a differential amplifier. The two
amplified Hall signals are synchronously demodulated to pro-
vide a resultant offset cancellation (see Figure 3). The demodu-
lated signal passes through a noninverting amplifier to provide
final gain and drive capability. The frequency at which the
output signal is refreshed is 50 kHz.
0.005
0.004
0.003
0.002
0.001
0
–0.001
–0.002
–0.003
–0.004
140 120 100
80 60 40 20
TEMPERATURE – ؇C
0 –20 –40
Figure 3. Relative Quiescent Offset vs. Temperature
TEMPERATURE DEPENDENCIES
The uncompensated gain temperature coefficient (GTCU) of the
AD22151 is the result of fundamental physical properties asso-
ciated with silicon bulk Hall plate structures. Low doped Hall
plates operated in current bias mode exhibit a temperature
relationship determined by the action of scattering mechanisms
and doping concentration.
The relative value of sensitivity to magnetic field can be altered
by the application of mechanical force upon silicon. The mecha-
nism is principally the redistribution of electrons throughout the
“valleys” of the silicon crystal. Mechanical force on the sensor
is attributable to package-induced stress. The package material
acts to distort the encapsulated silicon altering the Hall cell gain
by ± 2% and GTCU by ± 200 ppm.
Figure 4 shows the typical GTCU characteristic of the AD22151.
This is the observable alteration of gain with respect to tempera-
ture with Pin 3 (TC3) held at a constant 2.5 V (uncompensated).
If a permanent magnet source used in conjunction with the
sensor also displays an intrinsic TC (BTC), it will require factor-
ing into the total temperature compensation of the sensor
assembly.
Figures 5 and 6 represent typical overall temperature/gain per-
formance for a sensor and field combination (BTC = –200 ppm).
Figure 5 is the total drift in volts over a –40°C to +150°C tem-
perature range with respect to applied field. Figure 6 represents
typical percentage gain variation from +25°C. Figures 7 and 8
show similar data for a BTC = –2000 ppm.
14
12
10
8
6
4
2
0
–2
–4
–6
–40
10
60
110
160
TEMPERATURE – ؇C
Figure 4. Uncompensated Gain Variation (from +25°C) vs.
Temperature
REV. 0
–3–
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