Data Sheet Supplement Differential Two-Wire Hall Effect Sensor IC TLE 4941-2 TLE 4941-2 C For all parameters not specified in this document the TLE 4941 data sheet is valid. P-SSO-2-1 Type Marking Ordering Code Package TLE 4941-2 4102E Q62705-K0629 P-SSO-2-1 TLE 4941-2C 41C2E Q62705-K0631 P-SSO-2-2 TLE 4941-2 - TLE 4941-2C Supplement 1 Functional description = peak detection offset= (max + min) / 2 d1 d1 d2 offset correction initial settling time d2 d2 1 2 3 4 5 PGA switching 6 7 phase shift change uncalibrated mode calibrated mode Fig. 1: example for startup behaviour Uncalibrated mode: Occasionally a short initial offset settling time td,input might delay the detection of the input signal. (The sensor is "blind"). The magnetic input signal is tracked by the speed ADC and monitored within the digital circuit. For detection the signal transient needs to exceed a threshold (digital noise constant d1). When the signal slope is identified as a rising edge (or falling edge), a trigger pulse is issued to a comparator. A second trigger pulse is issued as soon as a falling edge (or rising edge respectively) is detected (and vice versa). Depending on the initial state of the comparator the IC output is first triggered on the first or second detected edge. Between the startup of the magnetic input signal and the time when its second extreme is reached, the PGA (programmable gain amplifier) will switch to its appropriate position. This value is determined by the signal amplitude and initial offset value. The digital noise constant value is changing accordingly (d1 d2, related to the corresponding PGA states), leading to a change in phase shift between magnetic input signal and output signal. After that consecutive output edges should have a nominal delay of about 180. In rare cases one further switching of PGA can occur (see appendix B). During the uncalibrated mode the offset value is calculated by the peak detection algorithm as described in the TLE 4941 data sheet. TLE 4941-2 TLE 4941-2C Data Sheet Supplement 2 April 2001 TLE 4941-2 - TLE 4941-2C Supplement Transition to calibrated mode: In the calibrated mode the output will switch at zero-crossing of the input signal. The phase shift between input and output signal is no longer determined by the ratio between digital noise constant and signal amplitude. Therefore a sudden change in the phase shift may occur during the transition from uncalibrated to calibrated mode. Calibrated mode: See TLE 4941 data sheet. Additional notes: Unlike the TLE 4941 the first output edge might occur before the first zero-crossing of the magnetic input signal. Therefore the maximum number of edges until the calibrated mode is active is increased by one for TLE 4941-2. However, referring to the input signal the delay between startup of the signal and first calibrated output signal is identical with TLE 4941. Typically the phase error due to PGA-transition (row 7 to 15) reduces the error caused by switching the mode from uncalibrated to calibrated. The summed up change in phase error from the first output edge issued to the output edges in calibrated mode will not exceed +/- 90. TLE 4941-2 TLE 4941-2C Data Sheet Supplement 3 April 2001 TLE 4941-2 - TLE 4941-2C Supplement 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 2 180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 90...270 135..300 (PGA, uncal) 135..300 (PGA, uncal) 135..300 (PGA, uncal) 135..300 (PGA, uncal) 135..300 (PGA, uncal) 38s ...180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 38s ...180 (uncal) 3 4 5 6 7 8 9 10 180 (uncal) 150..200 150..200 150..200 180 (cal) 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 90...270 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (cal) 180 (cal) 180 (cal) 180 (cal) 180 (uncal) 180 (uncal) 90...270 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (cal) 180 (uncal) 180 (uncal) 180 (uncal) 90...270 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (uncal) 180 (uncal) 180 (uncal) 180 (uncal) 90...270 180...220 180 (uncal) 180 (uncal) 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) 180 (cal) 180 (cal) 180 (uncal) 180...220 150..200 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (cal) 180 (uncal) 180 (uncal) 90...270 150..200 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (uncal) 180 (uncal) 180 (uncal) 90...270 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (uncal) 180 (uncal) 180 (uncal) 180 (uncal) 90...270 180...260 (PGA, uncal) 180...260 (PGA, uncal) 180...260 (PGA, uncal) 180...260 (PGA, uncal) 180...220 180 (uncal) 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) 180 (cal) 180 (cal) 180 (uncal) 180...220 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (cal) 180 (uncal) 180 (uncal) 90...270 150..200 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) (cal/uncal) 180 (uncal) 180 (uncal) 180 (uncal) 90...270 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) 150..200 150..200 180 (cal) (cal/uncal) (cal/uncal) Table1: overview of the startup-behaviour. In the first row the edge number is given. The following rows show different possibilities for the nominal delays between the edges. Numbers are calculated for sinusoidal input signals. Additionally the specified tolerances have to be taken into account (e.g. Jitter) Rows 2..6: behaviour at small input amplitudes (B> approx. 3.5mT) Rows 7..11: behaviour at initial phases of -90 .. 0 Rows 12..15: behaviour at initial phases of 0.. 90 Remark: the additional PGA switching can only occur once per row. Therefore also the additional phase shift marked "150..200 (cal/uncal)" will only occur once per row. (see example) TLE 4941-2 TLE 4941-2C Data Sheet Supplement 4 April 2001 TLE 4941-2 - TLE 4941-2C Supplement B = 10mT sin (t + ). = 30 Example: Typical startup-behaviour at a sinusoidal input signal of 10mT amplitude, initial phase= 30. 1 43 2 3 4 5 6 7 8 9 10 133,9 333,2 513,2 693,2 900 1080 1260 1440 ... 90,9 (PGA, uncal) 133,3 (PGA, uncal) 180 (uncal) 180 (uncal) 206,8 (Offsetcorrection) 180 (cal) 180 (cal) 180 (cal) 180 (cal) This corresponds to row 14 in the table, behaviour similar to Fig. 1 As a special (and rare) case instead of an offset correction after edge number 5, a further (extra) PGA switching could occur before edge number 5. PGA switching inhibits an immediate offset update. It can happen if one of the signal peaks is exactly at a PGA switching threshold (speed-ADC overflow). In this case the offset update (switching from uncalibrated mode to calibrated mode) would be delayed by two to three further edges. The referring phase shifts of the example would then be as follows: 1 43 2 3 4 5 6 7 8 9 10 133,9 333,2 513,2 727,5 907,5 1087,5 1260 1440 ... 90,9 (PGA, uncal) 133,3 (PGA, uncal) 180 (uncal) 213,8 (extra PGA) 180 (uncal) 180 (uncal) 172,5 (Offsetcorrection) 180 (cal) 180 (cal) This corresponds to row 13 of the table. Circuit Description See TLE 4941 - TLE 4941 C data sheet TLE 4941-2 TLE 4941-2C Data Sheet Supplement 5 April 2001 TLE 4941-2 - TLE 4941-2C Supplement 2 Additions/Changes for TLE 4941-2 versus TLE 4941 (All values are valid for constant amplitude and offset of input signal, f<2500Hz) Parameter Signal behaviour after undervoltage or standstill>tStop Symbol min. typ. max. Unit Conditions Magnetic edge amplitude according to B nDZ-Start Limit, early startup Edges that occur before nDZ-Start can be suppressed 2 edges 1Hz f 2000Hz 3 edges f > 2000Hz td,input has to be taken into account Systematic phase error of output edges during startup- and uncalibrated mode Phase shift change during PGA switching Phase shift change during transition switch from uncalibrated to calibrated mode Number of edges in uncalibrated nDZ-Startup mode in rare cases (see appendix B) nDZ-Startup TLE 4941-2 TLE 4941-2C Data Sheet Supplement 38 s -88 +88 0 80 -90 +90 6 6 edges 8 edges Shortest time delay between input signal edge 1 and 2 td,input has to be taken into account Systematical phase error of "uncal" edge; nth vs. n+1th edge (does not include random phase error) nd after the 2 edge April 2001 TLE 4941-2 - TLE 4941-2C Supplement Parameter Symbol min. typ. max. Unit Jitter during uncalibrated mode SJitClose 3 % -40C Tamb 150C (1-value) 4 % 150C Tamb 170C SJitFar 5 % -40C Tamb 150C (1-value) 7 % 150CTamb 170C SJitAC 3 % see TLE 4941 data sheet (1-value) Magnetic differential field amplitude change necessary for early startup: B Limit, early startup B 0.7 1.76 3.3 mT Limit, early startup Permitted time for edges to exceed B Limit, early startup t Limit,slow 590 early startup ms Conditions These magnetic field changes are necessary for startup with the second edge necessary for startup with the second edge f < 1 Hz Behaviour at magnetic input signals slower than T stop (self-calibration time period): Unlike the TLE 4941 magnetic changes exceeding BLimit,earlystartup can cause output switching of the TLE 4941-2, even at f significantly lower than 1Hz. Whether an output transition is issued or not depends on signal amplitude and signal frequency. In quiescent condition the internal operation of the IC is divided into time intervals of length Tstop. At each Tstop a new self-calibration is started if no output transition has occurred. Whenever the magnetic field change exceeds the digital noise constant before the Tstop interval is finished, the output is set to the correct state. At the same time a new time interval of length Tstop is started without doing a new calibration. 3 Additional remarks All additional parameters for TLE 4941-2 are guaranteed by design, based on lab characterisations. For series production additional to the parameters of TLE4941 (standard type) only nDZ-start is tested. TLE 4941-2 TLE 4941-2C Data Sheet Supplement 7 April 2001 TLE 4941-2 - TLE 4941-2C Supplement Appendix B : TLE 4941-2 - TLE 4941-2C 1. Occurrence of initial calibration delay time td,input Identical to TLE 4941, TLE 4941 C Appendix B. 2. Magnetic input signal extremely close to a PGA switching threshold during signal startup: After signal startup normally all PGA switching into the appropriate gain state happens within less than one signal period. This is included in the calculation for nDZ-Startup. For the very rare case that the signal amplitude is extremely close to a switching threshold of the PGA and the full range of the following speed ADC respectively, a slight change of the signal amplitude can cause one further PGA switching. It can be caused by non-perfect magnetic signal (amplitude modulation due to tolerances of polewheel, tooth wheel or air gap variation). This additional PGA switching can result in a further delay of the output signal (nDZ-Startup) up to three magnetic edges leading to a worst case of nDZ-Start=9 and nDR-Startup=11. However, the speed signal startup, comprised of nDR-Startup and td,input is not affected by this behaviour for TLE 4941-2. TLE 4941-2 TLE 4941-2C Data Sheet Supplement 8 April 2001