Programming Instructions

Transcription

1 Programming Instructions SA- Integrated -axis Hall Sensor General During the manufacturing process or after customer installation, sensor parameters like sensitivity, mismatch of sensitivity and phase between and, as well as any residual offset compensation can be one-time programmed. For the programming the SA- sensor includes a 6 Bit programming cell. The following parameters of the SA- sensor can be programmed: - Offset and - Sensitivity/Gain - Sensitivity Matching - Phase Matching ou can order either programmed sensors or unprogrammed sensors. For example order sensors that are optimised with an application specific sensitivity and the minimum offset. If you order unprogrammed sensors you can do the programming after the installation in your application. This allows you to optimise the sensor for your application by eliminating for example mechanical and geometrical tolerances of your application. Read this document to learn more about the advantages of programming the SA- sensor. Package: SOIC-8 Pin-out: Bx By ) CO_OUT, common output ) PC, programming clock 3) VDD 4) -OUT, -channel analog output 5) _OUT, -channel analog output 6) PD, programming data 7) PV, programming voltage 8) GND Note: Also available in chip form Page of 7

2 Set up your programming system Sentron Cable with SOIC-8 Test Socket Parallel Port Programming Toolkit PCB System requirements PC workstation with parallel port Windows 9x//NT/P Sentron Programming Toolkit contents: Case Programming Toolkit PCB Power supply Parallel port cable Sentron Cable with SOIC-8 socket Configuration connector Software Manual Programming System Please contact us to order a Programming Toolkit. Page of 7

3 Offset programming Gain Dependent Offset programming ranges from 35 to +35mV for both Outputs. Gain Independent Offset programming ranges from 35 to +35mV for Output. Gain Dependent Offset, Off (Gain=8) Off [mv] Bit6 Bit7 Bit8 Bit9 Bit Gain independent Offset, Off Off [mv] Bit3 Bit4 Bit Step to step procedure:. Set Gain/Sensitivity to a fixed value and keep it.. Use Gain Dependent Offset compensation to set the offset of the -Output to the optimum value. 3. By setting the Gain Dependent Offset compensation you influence the offset of the - Output also. Now use the Offset compensation to set the offset of the -Output to the optimum value. The step size of 5mV (3 Bits) allows you to set the Offset with a precision of +/-.5mV. Example: our sensor has an offset on Output of gauss and an offset on Output of gauss. This causes an angular of 4. Use an Offset programming of mv and an Offset programming of -mv to get an angular of <.. Offset and Angular Error Offset and Angular Error Sensor Output and [V Sensor Output and [V] Advantages: - Optimise the SA- sensor in complex systems, the sensor can be followed by amplifiers, ADC s, - Higher accuracy in angular position sensing. Page 3 of 7

4 Sensitivity/Gain programming According to the application specific magnetic field strength, the sensitivity of the SA- can be programmed to S= / 5 / 5 / V/T (Gain= / / 4 / 8) by Bits. Field B [mt] Sensitivity [V/T] Gain Bit 5 Bit 6 < >8* * for B >8mT the sensor output becomes less linear, but the sensor can still be used Sensitivty of SA- and 9 Output Voltage [mv] Vout(S=V/T) [V] Vout(S=5V/T) [V] Vout(S=V/T) [V] Magnetic Field [mt] Advantages: - Use the same application for different ranges of field strength and choose the range by programming the SA- sensor. - Extend the field range by factor 8 - Use smaller magnets Page 4 of 7

5 3 Sensitivity Matching programming The quality of the angular information does not depend upon the absolute level of the output signals, but on the matching between and output. Sensitivity Matching Programming adjusts the sensitivity of direction and direction to eliminate nd order angular s caused by sensitivity mismatch. Programmable Sensitivity Matching ranges from 9% to +9% in steps of 3% by 3 Bits. Sensitivity Matching SM SM [%] Bit3 Bit4 Bit Example: Vout,x=±V; Vout,y=±.4V, Sensitivity Mismatch=6.67%. This causes an angular of ±. Sensitivity Mismatch and Angular Error Sensor Output and [V Use the Sensitivity Match programming of 6% to get an angular of <.3 over the full 36. Sensitivity Mismatch and Angular Error Sensor Output and [V Advantage: - Higher accuracy in angular position sensing Page 5 of 7

6 3 Phase Matching programming Phase Matching Programming is used to adjust the phase shift between the Output and the Output to exactly 9. Phase mismatch causes a nd order angular. Programmable Phase Matching ranges from to + in steps of by 3 Bits. Phase Matching PM PM [ ] Bit Bit Bit Example: Vout,x=*sin(phi); Vout,y=*cos(phi+. ) this causes an angular of.. Phase Mismatch and Angular Error..9 Sensor Output and [V] Use Phase Match programming of to get an angular of.. Phase Mismatch and Angular Error..9 Sensor Output and [V] Advantage: - Higher accuracy in angular position sensing. Page 6 of 7

7 4 Organisation of 6 Bit Programming Cell Bit Description Value Phase Matching [] LSB Sensitivity Matching [] LSB 3% 3 Offset [3] sign +/- 4 Offset [] MSB mv 5 Offset [] LSB 5mV 6 Gain Dependent Offset [5] sign +/- 7 Gain Dependent Offset [4] MSB 4mV (G=8) 8 Gain Dependent Offset [3] mv (G=8) 9 Gain Dependent Offset [] mv (G=8) Gain Dependent Offset [] LSB 5mV (G=8) Phase Matching [3] sign +/- Phase Matching [] MSB 3 Sensitivity Matching [3] sign +/- 4 Sensitivity Matching [] MSB 6% 5 Gain; Sensitivity [] MSB x 4 6 Gain; Sensitivity [] LSB x 5 Block Diagram of SA- VDD GND Hall Element System Offset Cancellation Buffer & Filter _OUT analog (differential) Hall Element System Multiplexer Offset Cancellation Amplifier Demulti plexer Buffer & Filter CO_OUT analog (differential) _OUT Biasing Unit Programming Unit PV PC PD Page 7 of 7