IDT ZMID5201, ZMID5202, ZMID5203 User Manual For Getting Started

ZMID520x User Guide for Getting Started

Contents

1. Introduction ...................................................................................................................................................................................................3

2. Inductive Sensing Technology Introduction ..................................................................................................................................................3

2.1 Device Block Diagram .........................................................................................................................................................................6

3. Getting Started .............................................................................................................................................................................................7

3.1 LC Tank – Tx Front-End Tuning ..........................................................................................................................................................7

3.2 Device Initialization ..............................................................................................................................................................................8

3.2.1 Output Mode Selection .........................................................................................................................................................8

3.3 Offset Check for Rx Coils ....................................................................................................................................................................9

3.4 Gain Stage Setting ............................................................................................................................................................................11

3.5 Input Amplitude Offset Compensation ...............................................................................................................................................12

3.6 Output Calibration ..............................................................................................................................................................................13

3.7 Output Linearization ..........................................................................................................................................................................14

4. Internal Memory ..........................................................................................................................................................................................17

5. Programming the ZMID520x EEPROM ......................................................................................................................................................19

6. Glossary .....................................................................................................................................................................................................19

7. Revision History ..........................................................................................................................................................................................20

List of Figures

Figure 1. Tx Loop Magnetic Field .......................................................................................................................................................................3

Figure 2. Current Paths and Shapes for Coils – Example for Linear Position Sensing ......................................................................................4

Figure 3. Geometrical Illustration for Coils and Target – Example for Linear Position Sensing..........................................................................5

Figure 4. Main Internal Functional Block Diagram ..............................................................................................................................................6

Figure 5.

ZMID520x Transmitter LC Tank

..........................................................................................................................................................7

Figure 6. TX Oscillation and LF-U 5 Probe .........................................................................................................................................................8

Figure 7.

ZMID520x EEPROM Memory Values – ZMID5203 Example for the Linear Output Mode Settings

..................................................9

Figure 8.

ZMID520x EEPROM Gain Stage Setting – Example using the ZMID5203

........................................................................................9

Figure 9.

Coil Offset Reading – Example using the ZMID5203

........................................................................................................................10

Figure 10. Magnitude for Gain Selection – Example for the ZMID5203 .............................................................................................................11

Figure 11. ZMID520x Input Amplitude Offset Compensation – Example for the ZMID5203 ..............................................................................12

Figure 12.

Output Calibration

..............................................................................................................................................................................13

Figure 13.

Output Calibration Verification

...........................................................................................................................................................14

Figure 14.

Correction Mode Selection

................................................................................................................................................................14

Figure 15. Measured Value Readings

for

9 Linearization Points ........................................................................................................................15

Figure 16. Input Fields for the 9 Linearization Points Measured Values .............................................................................................................16

Figure 17. ZMID520x Internal Memory ...............................................................................................................................................................17

ZMID520x User Guide for Getting Started

List of Tables

Table 1. EEPROM and Shadow RAM Contents ..............................................................................................................................................17

ZMID520x User Guide for Getting Started

1. Introduction

This document describes the procedures for setting up the IDT ZMID520x internal memory and transmitter (Tx) front-end in order to start measurements with the device in user applications. It describes the settings needed to prepare the device for operation and then gives an internal memory overview.

The steps provided here are needed when configuring a new device in a user application. These procedures can also be applied to any of the ZMID520x application modules provided by IDT; however this is typically not needed because the sensor has been fully configured before the module is shipped.

Recommendation: Read the ZMID520x Datasheet before using this document for a better understanding of the ZMID520x:

https://www.idt.com/document/dst/zmid520x-datasheet

Information on the OWI interface can be found in the ZMID520x Technical Brief – One Wire Interface (OWI).

2. Inductive Sensing Technology Introduction

This section provides some basic principles for inductive position sensing using the ZMID520x family of products, and it covers how the required magnetic fields are generated.

In the application, an LC oscillator generates a magnetic field in the transmit wire loop. The frequency of the oscillation is tuned by the capacitance Ct. The polarity of the magnetic field depends on the direction of the current in the loop.

Figure 1. Tx Loop Magnetic Field

ZMID

520x

R1P

R1N

R2P

R2N

VDDT

Test_D

Test-Ena

VDDD

SOUT

VDDA

VSSE

VDDE

ZMID

520x

R1P

R1N

R2P

R2N

VDDT

Test_D

Test-Ena

VDDD

SOUT

VDDA

VSSE

VDDE

ZMID520x User Guide for Getting Started

The signal that is generated by the magnetic field of transmitter coil (Tx) is received by two receiver coils.

If a metallic target is placed over the coils, the transmitted energy below the target is dissipated as eddy currents in the target and does not induce a secondary voltage in the receiver coils in that area.

The two receiver coils are designed with a 90 phase shift, and the transmitter coil surrounds them. The target is placed on top of them and moves over a plane parallel to the plane containing all the coils, as shown in Figure 2 below. Depending on the coil’s shape, movement can be linear, arc, or rotary. The same physical principle is valid for different coils (and target) shapes.

The position of the target will be indicated through the differential phase and the amplitude of the signals measured on the Rx coils by the ZMID520x

Figure 2. Current Paths and Shapes for Coils – Example for Linear Position Sensing

Metallic Target

RxCos

RxSin

Sin Loop 1

(cw)

Sin Loop 2

(ccw)

Sin Loop 3

(cw)

Tx Loop

Cos Loop 2

(ccw)

Cos Loop 1

(cw)

The key parameters influencing the proper operation of coils with the ZMID520x are the following: the length and width of the Tx and Rx coils, the size of the target, and the airgap between the target and the printed circuit board (PCB) where the coils are integrated. Figure 3 provides an illustration of the length and width of the coils for linear position sensing.

ZMID520x User Guide for Getting Started

Figure 3. Geometrical Illustration for Coils and Target – Example for Linear Position Sensing

Note: The following display was created by the ZMID520x Inductive Coil Design Tool Software.

IDT provides a software tool to support coil design as illustrated in Figure 3:

 ZMID520x Inductive Coil Design Tool Software: https://www.idt.com/document/swr/zmid520x-inductive-coil-design-tool-software  ZMID520x User Guide – Inductive Coil Design Tool: https://www.idt.com/document/mas/zmid520x-user-guide-inductive-coil-design-tool

Reference designs for linear, arc and rotary position sensors are shown in the “Layout” section of the applicable Application Modules User Manual available on the following application module product pages, which also provide relevant Gerber design files:

ZMID520xMLIN Application Module:

www.idt.com/products/sensor-products/position-sensors/zmid5201mlin-zmid5201-inductive-linear-application-module-analog-output

www.idt.com/products/sensor-products/position-sensors/zmid5202mlin-zmid5202-inductive-linear-application-module-pwm-output

www.idt.com/products/sensor-products/position-sensors/zmid5203mlin-zmid5203-inductive-linear-application-module-sent-output

ZMID520xMARC Application Module:

www.idt.com/products/sensor-products/position-sensors/zmid5201marc-zmid5201-inductive-arc-application-module-analog-output

www.idt.com/products/sensor-products/position-sensors/zmid5202marc-zmid5202-inductive-arc-application-module-pwm-output

www.idt.com/products/sensor-products/position-sensors/zmid5203marc-zmid5203-inductive-arc-application-module-sent-output

ZMID520xMROT Application Module:

www.idt.com/products/sensor-products/position-sensors/zmid5201mrot-zmid5201-inductive-rotary-application-module-analog-output

www.idt.com/products/sensor-products/position-sensors/zmid5202mrot-zmid5202-inductive-rotary-application-module-pwm-output

www.idt.com/products/sensor-products/position-sensors/zmid5203mrot-zmid5203-inductive-rotary-application-module-sent-output

ZMID520x User Guide for Getting Started

2.1 Device Block Diagram

Refer to the ZMID520x Datasheet for the latest block diagram information.

The main building blocks include the following:

 Power management: power-on-reset (POR) circuit and low drop-out (LDO) regulators for internal supplies.  Oscillator: generation of the transmit coil signal.  Analog front-end: demodulator and gain control for the receive signals.  Analog-to-digital converter (ADC): conversion into digital domain.  Digital signal processing: offset correction; conversion of sine and cosine signals into angle and magnitude; angle range adjustment; and

linearization.

 EEPROM: nonvolatile storage of factory and user-programmable settings.  One-wire interface (OWI): programming of the chip through the output pin.  Interface options:

 Analog output for ZMID5201  PWM output for ZMID5202  SENT output for ZMID5203

 Protection: overvoltage, reverse polarity, short circuit protection.

Figure 4. Main Internal Functional Block Diagram

+ 14 hidden pages

IDT ZMID5201, ZMID5202, ZMID5203 User Manual For Getting Started

Specifications and Main Features

Frequently Asked Questions

User Manual