Delta Tau GEO BRICK DRIVE User Manual
Geo Brick Drive User Manual
Pinouts and Software Setup
146
Setting up the Analog (DAC) Outputs
Differential DAC Output Signal
Single Ended DAC Output Signal
2
3
4
5
9
8
7
6
1
AGND
Analog
Device
DAC+
DAC-
2
3
4
5
9
8
7
6
1
AGND
Analog
Device
DAC+
The analog outputs on X9 through X12 are (12-bit) filtered PWM signals, therefore a PWM frequency in
the range of 30-40 KHz and a PWM deadtime of zero are suggested for a good quality analog output
signal (minimized ripple). A fully populated Brick can have one of three gates generating the clocks:
Servo IC 0 (I7000’s)
Servo IC 1 (I7100’s)
MACRO IC 0 (I6800’s)
I19 specifies which gate is the clock source master. I19 is equal to 7007 by default indicating that Servo
IC 0 is the master gate. However, the analog outputs on X9 through X12 are generated out of Servo IC1.
IC 0 is the master gate. However, the analog outputs on X9 through X12 are generated out of Servo IC1.
The relationship between the PWM clock frequency of Servo IC 1 (recipient) and the master gate
(generator), typically Servo IC 0, should always be respected in such a way that:
Where n is an integer
Examples:
With Servo IC 0 sourcing the clock at its default settings (4.5 KHz PWM), the following are suggested
Servo IC 1 clock settings which would provide a good analog output signal:
With Servo IC 0 sourcing the clock at its default settings (4.5 KHz PWM), the following are suggested
Servo IC 1 clock settings which would provide a good analog output signal:
Servo IC 0
Clock Settings
Resulting
Frequencies KHz
Servo IC 1
Clock Settings
Resulting
Frequencies KHz
I7000=6527
I7001=0
I7002=3
I7002=3
I10=3713991
PWM
PHASE
SERVO
4.5
9.0
9.0
2.25
I7100=816
I7101=7
I7102=3
I7104=0
I7102=3
I7104=0
PWM
PHASE
SERVO
PWM
PHASE
SERVO
PWM
Deadtime
36
9
2.25
0
Note that n=8 in this case