TMF8805 datasheet(63/74 Pages) OSRAM

63 / 74 page

TMF8805

Application information

Datasheet

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DS000692

• v7-00 • 2023-Dec-01

63 / 74

7.2

Reference SPAD, TDC and histogram

There is an internal reference SPAD with associated TDC and histogram. This is used to

determine the start time of each pulse. The reference SPAD is processed during calibration.

The reference channel processing occurs internal to the device with no user interaction

required.

All histograms can be processed inside the TMF8805 and/or readout through the I²C interface.

As the readout is constrained by the I²C speed and the I²C bus utilization (TMF8805 can

support I²C speed up to 1 MHz), it is recommended to readout the histograms only for

debugging purposes.

Figure 11 shows a histogram obtained from TMF8805. The x-axis is scaled in bins, where the

nominal bin size is 100 ps per bin and each TDC has 256 bins. The y-axis is scaled in counts

represented by 16-bit values. The green line shows the reference histogram from TDC0 and its

peak marks the reference or zero distance. The other four lines (blue, cyan, red and violet) are

the histograms obtained from TDC1 to TDC4. A target at 20 cm is used to generate the peak

around bin 25.

Figure 11: Histogram

(1) The above histogram is used for general device information only. The actual histogram differ due to different bin size and

modes used.

7.3

Schematic

The TMF8805 needs only 3 small 0402 external capacitors for operation:

TMF8805 데이터시트(PDF) 63 Page - OSRAM GmbH