HMC1051ZL Honeywell, HMC1051ZL Datasheet - Page 6

• Manufacturer Part Number: HMC1051ZL
• Manufacturer: Honeywell

Specifications of HMC1051ZL

• Lead Free Status / Rohs Status: Not Compliant

HMC1051Z / HMC1052
Alternating or Direct Current Sensing
The HMC1051 and HMC1052 sensors can be utilized in a novel way for moderate to high current sensing
applications using a nearby external conductor providing the sensed magnetic field to the bridge. Figure 5 shows a
HMC1051Z used as a current sensor with thermistor element performing a temperature compensation function for
greater accuracy over a wide range of operational temps. Selection of the temperature compensation (tempco)
resistors used depends on the thermistor chosen and is dependant on the thermistor’s %/°C shift of resistance. For
best op-amp compatibility, the thermistor resistance should be above about 1000 ohms. The use of a 9-volt alkaline
battery supply permits fairly common operational amplifiers such as the 4558 types to be used. Note that the circuit
must be calibrated based on the final displacement of the sensed conductor to the measuring bridge. Typically, an
optimally oriented measurement conductor can be placed about one centimeter away from the bridge and have
reasonable capability of measuring from tens of milliamperes to beyond 20 amperes of alternating or direct currents.
See application note AN-209 for the basic principles of current sensing using AMR bridges.
Solid State Electronics Center • www.magneticsensors.com • [phone] • Page 6
I
ac
Current Measured
Conductor to be
I
Vcc
5.0v
dc
Vcc = 9Vdc
standoff distance
set/reset
offset
set/reset
offset
U1
HMC1051
U1
HMC1051
Figure 4
.1uf
*
Low ESR Tantalum
FMMT717
FMMT617
5.00k
5.00k
Figure 5
1µf*
-
500k
+
5.00k
5.00k
.1µf
Vcc/2
Vcc
500k
.1uf
Vcc/2 ~ +4.5Vdc
-
+
TLC072
200Ω
10kΩ
10kΩ
.1µf
500k
-
+
*
0.1µf
0.1µf
RC4558
Low ESR Tantalum
U2
500k
10kΩ
1µf*
-
Si1553DL
set/reset
+
Vcc
Threshold Set
R
U2
10kΩ pot
b
Vcc =9Vdc
-
+
TLC072
U3
200Ω
S
tempco
network
-
+
RC4458
R
R
th
R
a
output
R
LED
LED
set/reset
SENSOR PRODUCTS
output