TDC-GP2 acam messelectronic gmbh, TDC-GP2 Datasheet - Page 34

• Manufacturer Part Number: TDC-GP2
• Description: Precision Time Interval Measurement
• Manufacturer: acam messelectronic gmbh

Description
s.c.
s.c.
s.c.
s.c.
s.c.
DELVAL3
6.1.3 Measurement Flow
Power-on reset:
Send SO = 0x50
Configuration:
Send SO = 0x80338A68
Send SO = 0x81214000
Send SO = 0x82E03200
Send SO = 0x83083300
Send SO = 0x84203400
Send SO = 0x85080000
Calibrate Clock:
Send SO = 0x03 Start_Cal_Resonator
Check-loop INTN = 0?
Send SO = 0xB0, Read SI = RES_0
Correction factor = 488.28125/RES_0
Register 4
0x203400
acam-messelectronic gmbh - Am Hasenbiel 27 - D-76297 Stutensee-Blankenloch - Germany - www.acam.de
Value
416
x h
0
0
1
0
0
0
0
0
0
0
1
1
0
1
0
0
0
0
0
0
0
0
0
0
2
0
3
4
0
0
Description
CONF_FIRE
EN_STARTNOISE
DIS_Phasenoise
REPEAT_Fire
PHASE_FIRE
Register 5
0x000000
Value
off
off
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
x h
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
8
0
0
0
0
34
Measurement loop:
6.1.4 Current consumption
a. Time measurement
32.768kHz:
4 MHz:
active
TDC:
active time of the high-speed unit
With 2 measurements per second (forth and back flow)
the total consumption is < 3 µA.
b. Temperature measurement
A full measurement over all four ports takes less than
2.5 µAs current. Typically the temperature is measured
once in 30 seconds. The average current then is about
0.085 µA. This is about 50 times less than with
solutions without a TDC.
c. Quiescent current
Thanks to the current optimized 0.35µ technology the
quiescent current is less than 150 nA typ.
Temperature measurement every 30 seconds:
Send SO = 0x02 Start_Temp
Check-loop INTN = 0?
Send SO = 0xB4, Read SI = STAT
STAT&0x1E00 > 0: -> Error routine
Send SO = 0xB0, Read SI = RES_0
Send SO = 0xB1, Read SI = RES_1
Send SO = 0xB2, Read SI = RES_2
Send SO = 0xB3, Read SI = RES_3
R
R
Go to look-up table to get the temperatures
Time-of-flight measurement every half second:
Send SO = 0x70 Initialize TDC
Send SO = 0x01 Start_Cycle triggers fire-pulse
generator.
Check-loop INTN = 0?
Send SO = 0xB4, Read SI = STAT
STAT&0x0600 > 0: -> Error routine
Send SO = 0x81314000 calculate HIT2-Start
Wait for 4.6µs (ALU time)
Send SO = 0x81414000 calculate HIT3-Start
Wait for 4.6µs (ALU time)
Send SO = 0xB0, Read SI = RES_0
Send SO = 0xB1, Read SI = RES_1
Send SO = 0xB2, Read SI = RES_2
µP can now start the data post-processing and
calculate the flow and the heat.
hot
cold
/R
/R
ref
ref
= RES_0/RES_1
= RES_3/RES_2
< 150 nA if not active, 15 mA during
are provided by the µP: < 1.3 µA
0 µA in power down, 270 µA when
6.1 Ul trasoni c He atm e te r
TDC-GP2