TDC-GPX acam messelectronic gmbh, TDC-GPX Datasheet - Page 35

• Manufacturer Part Number: TDC-GPX
• Description: Precision Time Interval Measurement
• Manufacturer: acam messelectronic gmbh

Derating by
Voltage
Temperature
Process
3.11 G-Mode Timing & Resolution
The delay parameters vary with voltage, temperature
and process tolerance. The following table lists the
derating factors.
With the stabilization of the resolution by the resolu-
tion adjust mode, the voltage of the core decreases
with decreasing temperature, and increases with in-
creasing temperature. The setting should be done in a
way that at maximum operating temperature the
maximum core voltage is reached, and that minimum
core voltage is reached at minimum operating tem-
perature. With this method you get two limits:
Best case process, deepest temperature, lowest volt-
age: 0.74 x 0.889 x 1.2 = 0.789
Worst case process, highest temperature, highest
voltage: 1.31 x 1.17 x 0.91 = 1.394
With a typical resolution of 40ps (typ. process, 25°C,
3.3V) you get two limits for the resolution:
The BIN or LSB width is defined by the setting of the
resolution adjust unit (1.6.1 Resolution adjust),
The standard deviation (1 ) of the result is typically 1
LSB + 4 ps * t/µs.
Resolution (of
combined chan-
nels)
acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de
Minimal
0.91 at 3.6V
0.889 at –40°C
0.74 at BC
Best
32 ps
Maximal
1.2 at 2.85V
1.17 at +125°C
1.31 at WC
Worst
56 ps
35
DNL
the TDC-GPX shows a moderate differential non-
linearity (DNL) because internal propagation delays
were used for the time measurement and because
those delays are different for rising and falling edges,
but the variation from channel to channel is system-
atic. The following diagram shows the DNL data at a
resolution of 37 ps:
60
50
40
30
20
10
0
9
8
7
6
5
4
3
2
1
0
0
Standard deviation, G-Mode, TTL-inputs
10
20
TDC-GPX: DNL, G-Mode
Figure 27
Figure 26
30
Delay t (µs)
Bin
40
TDC-GPX
50
60
70