HMR4001 Honeywell Microelectronics & Precision Sensors, HMR4001 Datasheet - Page 3

• Manufacturer Part Number: HMR4001
• Description: MODULE SENSOR LINEAR POSITION
• Manufacturer: Honeywell Microelectronics & Precision Sensors

Specifications of HMR4001

• Rohs Status: RoHS non-compliant
• Other names: 342-1040; HMR4001-D00

HMR4001
Pin Configuration
Circuit Board Layout
Application Notes
Very high precision position measurements using weak magnetic fields should note the influence of the earth’s
magnetic field (~ 0.6 gauss) bias on the sensed magnet position.
The center-line of HMC1512 sensor integrated circuit U1 is determined to be midpoint (50% Pulse Width, 2.5v
Analog) for position sensing.
Only one of the two sensor bridges in the HMC1512 is used for sensing the external magnetic field. The other
magneto-resistive bridge network is used as temperature compensation network to retain precise positioning over a
broad temperature range. Thus the single bridge provides its linearity over a 90° sweep (+/- 45°) as opposed to when
both HMC1512 bridges are working together for a 180° (+/- 90°) sweep.
For best performance, a magnetic field of at least 80 gauss measured at the sensor location should be maintained. A
simple dipole magnet usually has the strongest field near its poles, and the field decreases with the distance. For
example: An AlNiCo cylindrical magnet with a 0.25” diameter has field strength of 700 gauss at its surface. With a
0.25” gap between the sensor and the magnet, the field at the sensor is about 170 gauss. This is enough field
strength to maintain the sensor in the saturation condition for most applications.
Web Site:
Email:
2001 HMR4001
Pin
PW
GD
VA
FS
V+
SL
www.magneticsensors.com
[e-mail]
Published Jun 2001
FREQUENCY SELECT INPUT
POWER SUPPLY INPUT
Page 3
SLEEP/WAKE INPUT
ANALOG OUTPUT
PWM OUTPUT
Function
GROUND
Analog Version of the PWM Output Using a Low Pass
Filter.
Digital Signal With the “1” Level Equivalent to the
Position of the Magnet. Period at 250 or 350 Hz.
Selects the Pulse Width Modulation Frequency:
1=350Hz, 0=250Hz (onboard pullup)
Power Supply Input of +6 to +20 Volts DC.
Selects the Wake or Sleep Mode: 1=Wake, 0=Sleep.
Onboard Pullup Resistor to Keep Board in Wake Mode.
Ground Reference for Supply and I/O
Description
Plymouth, Minnesota 55441-4799
Solid State Electronics Center
Advance Information
SENSOR PRODUCTS
12001 State Highway 55
1-800-323-8295
Honeywell