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NJU39612

Time

Time when motor is in
a compromise
position.

Time when micro
position is correct.

Write
signal.

Motor
position.

Writing to
channel 1.

Writing to
channel 2.

Write time = incorrect position

Actual data = true position
Normal resolution

Double pulse write signal

Ideal data = desired position

Useful time = correct
position

Time

Time when motor is in
an intermediate
position.

Time when micro
position is almost
correct.

Write
signal.

Motor position. Note
that position is always
a compromise.

Writing to
channel 1.

Writing to
channel 2.

Useful time = compromise position
with equally spaced angles

Actual data = true position
Note increased resolution

Single pulse write signal

"Ideal data" = desired
position

Useful time = almost
correct position

Figure 10. Double pulse programming, in- and output signals.

Figure 11. Single pulse programming, in- and output signals.

Содержание NJU39612

Страница 1: ...ivers Package EMP20 BLOCK DIAGRAM NJU39612E2 NJU39612 is a dual 7 bit sign Digital to Analog Converter DAC developed to be used in micro stepping applications together with the dual stepper motor driv...

Страница 2: ...o set data bit 5 in data word 9 D4 Data 4 TTL CMOS level input to set data bit 4 in data word 10 D3 Data 3 TTL CMOS level input to set data bit 3 in data word 11 D2 Data 2 TTL CMOS level input to set...

Страница 3: ...g time requires zero to full scale or full scale to zero output change Settling time is the time required from a code transition until the DAC output reaches within 1 2 LSB of the final output value F...

Страница 4: ...drop from pin to resistor Any VRef between 0 0 V and VDD can be applied but output might be non linear above 3 0 V Power on Reset This function automatically resets all internal flip flops at power o...

Страница 5: ...5 3 8 V Rise and fall time of WR tr tf 1 s ABSOLUTE MAXIMUM RATINGS Parameter Pin no Symbol Min Max Unit Voltage Supply 4 VDD 6 V Logic inputs 5 14 16 VI 0 3 VDD 0 3 V Reference input 1 VRef 0 3 VDD...

Страница 6: ...ycle length tWR 50 ns Reset cycle length tres 80 ns Reference Input Input resistance Rref 6 9 kohm Logic Outputs Logic HIGH output current IOH VO 2 4 V 13 5 mA Logic LOW output current IOL VO 0 4 V 2...

Страница 7: ...NJU39612 Figure 8 Timing Figure 9 Timing of Reset t t t t t t t CS A0 D0 D7 WR DA Sign cs ch as ah ds dh WR t DAC tpwr t t Reset Sign res pres...

Страница 8: ...it is heavily loaded with other tasks With a microprocessor data is stored in ROM RAM area or each step is successively calculated NJU39612 is connected like any peripheral addressable device All part...

Страница 9: ...Time Time when motor is in an intermediate position Time when micro position is almost correct Write signal Motor position Note that position is always a compromise Writing to channel 1 Writing to cha...

Страница 10: ...ulses to the device with the correct addressing in between keeping the delay between the pulses as short as possible Write signals will look as illustrated in figure10 The advantages are low torque ri...

Страница 11: ...n DA 1 1 NJU39612 Voltage Reference Control Logic Step Direction Clock Up Dn CE A0 WR CS Vref D0 D7 Counter PROM NJU39612 NJM3777 Figure 13 Typical application in a microprocessor based system Figure...