User manual ARIENS 924046

[. . . ] Power Supply Sensitivity Power supply sensitivity is a measure of the effect of power supply changes on the DAC full-scale output. Settling Time Full-scale current settling 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 ± 1/2LSB of the final output value. Full-scale Error Full-scale error is a measure of the output error between an ideal DAC and the actual device output. [. . . ] Differential Non-linearity The difference between any two consecutive codes in the transfer curve from the theoretical 1LSB, is differential non-linearity Monotonic If the output of a DAC increases for increasing digital input code, then the DAC is monotonic. A 7-bit DAC which is monotonic to 7 bits simply means that increasing digital input codes will produce an increasing analog output. s FUNCTIONAL DESCRIPTION Each DAC channel contains one register and a D/A converter. The sign outputs generate the phase shifts, i. e. , they reverse the current direction in the phase windings. Data Bus Interface NJU39612 is designed to be compatible with 8-bit microprocessors such as the 6800, 6801, 6803, 6808, 6809, 8051, 8085, Z80 and other popular types and their 16/32 bit counter parts in 8 bit data mode. The data bus interface consists of 8 data bits, write signal, chip select, and two address pins. The address pin control data transfer to the two internal D-type registers. Data is transferred according to figure 7 and on the positive edge of the write signal. Output Output Output Actual Gain error Correct Endpoint non-linearity More than 2 bits Less than 2 bits Negative difference Positive difference Offset error Input Input Full scale Input Figure 3. Differential non-linearity of more than Differential non-linearity of less than 1 bit, output is non-monotonic. Non-linearity, gain and offset errors. NJU39612 Current Direction, Sign1 & Sign2 These bits are transferred from D7 when writing in the respective DA register. Special care in layout, gives a very low voltage drop from pin to resistor. Without a microprocessor, a counter addresses a ROM where appropriate step data is stored. Step and Direction are the input signals which represent clock and up / down of counter. This is the ideal solution for a system where there is no microprocessor or it is heavily loaded with other tasks. With a microprocessor, data is stored in ROM / RAM area or each step is successively calculated. This is the ideal solution for a system where there is an available microprocessor with extra capacity and low cost is more essential than simplicity. s User Hints Never disconnect ICs or PC Boards when power is supplied. Select a motor that is rated for the current you need to establish desired torque. A high supply voltage will gain better stepping performance even if the motor is not rated for the VMM voltage, the current regulation in the drivers from New ARIENS will take care of it. A normal stepper motor might give satisfactory result, but while microstepping, a "microstepping-adapted" motor is recommended. This type of motor has smoother motion due to two major differences, the stator / rotor teeth relationship is non-equal and the static torque is lower. The NJU39612 can handle programs which generate microsteps at a desired resolution as well as quarter stepping, half stepping, full stepping, and wave drive. [. . . ] The NJU39612 can handle programs which generate microsteps at a desired resolution as well as quarter stepping, half stepping, full stepping, and wave drive. Ramping Every drive system has inertia which must be considered in the drive system. Unlike the DC motor, the stepper motor is a synchronous motor and does not change its speed due to load variations. Examining a typical stepper motor's torque-versus-speed curve indicates a sharp torque drop-off for the "start-stop without error" curve. [. . . ]