The AD and AD are monolithic, low cost, high performance, 8-bit and bit accurate, multiplying Details, datasheet, quote on part number: AD . AD Datasheet, AD PDF, AD Data sheet, AD manual, AD pdf, AD, datenblatt, Electronics AD, alldatasheet, free, datasheet. AD datasheet, AD circuit, AD data sheet: INTERSIL – 8-Bit, Multiplying D/A Converters,alldatasheet, datasheet, Datasheet search site for.
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PA can be set for Modes 0, 1, 2. Modes 1 and 2 are interrupt driven. PC has 2 4-bit parts: Improved dc driving capability Pinout: Two 8 bit ports PA, PB. Outputs latched, inputs buffered. Mode 1 Input and output data dwtasheet latched PC bits in input mode: STB-bar input is connected to external peripheral’s strobe output i.
PC2, PC4 pin to external strobe. INTE is internal connection. STB-bar is external connection. ACK-bar input is connected to external peripheral’s acknowledging output i. PC2, PC6 pin to external ack. ACK-bar is external connection. Mode 2 Only for PA Status: Interfacing a Microprocessor to Keyboard: For the following cases, what are the values of D3- D0 at Port 2? Scans and encodes up to a key keyboard.
Controls up to a digit numerical display. Keyboard section has a built-in FIFO 8 character buffer. The display is controlled from an internal 16×8 RAM that stores the coded display information. Pin out Definition A0: Output that blanks the displays. Used internally for timing. Max is 3 MHz. Chip select that enables programming, reading the keyboard, etc. Consists of bidirectional pins that connect to data bus on micro. Interrupt request, becomes 1 when a key is pressed, data is available.
Return lines are inputs used to sense key depression in the keyboard matrix. Shift connects to Shift key on keyboard. Scan line outputs scan both the keyboard and displays The keyboard matrix can be any size from 2×2 to 8×8. Pins SL2-SL0 sequentially scans each column through a counting operation. The 74LS drives 0’s on one line at a time. The scans RL pins synchronously with the scan. RL pins incorporate internal pull-ups, no need for external resistor pull-ups.
The must be programmed first. The first 3 bits of the byte sent to control port selects one of 8 control words.
First three bits given below select one of 8 control registers opcode. DD sets displays mode. MMM sets keyboard mode. DD field selects either: SL outputs are active-high, follow binary bit pattern or Decoded: SL outputs are active-low only one low at any time.
AD (INTERSIL) PDF技术资料下载 AD 供应信息 IC Datasheet 数据表 (3/9 页)
Z selects auto-increment for the address. BB works similarly except that they blank turn off half of the output pins. The previous example illustrates an encoded keyboard, external decoder used to drive matrix. Once done, a procedure is needed to read data from the keyboard. To determine if a character has been typed, the FIFO status register is checked. The CT and SH indicate whether the control or shift keys were pressed. The Strobed Keyboard code is just the state of the RLx bits at the time a 1 was strobed’ on the strobe input pin.
The stepping motor is a device which can transfer the incoming pulses to stepping motion of a predetermined angular displacement. By using suitable control circuitry the angular displacement can be made proportional to the number of pulses. Using microcomputer, one can have better control of the angular displacement resolution and angular speed of a stepping motor. In the past few years the stepping motor has improved in size reduction, speed and precision.
Stepping motor already have and will continue to have wide applications in industry. Stepping motors are suitable for translating digital inputs into mechanical motion. In general, there are three types of stepping motor: VR Variable Reluctance stepping motors 2. Hybrid Stepping motors 3. Here the A coil and B coil are perpendicular to each other. This is known as two-phase exception.
In figure 1 cthe excitation alternates between 1-phase and 2-phase, then the datashee will rotate according to 0, 45, 90,, sequence.
Stepping motor can rotate in clockwise or counter-clockwise direction depending on the current pulse sequence applied to the excitation coils of the motor. Referring to the truth tables of Figure 1 ab and cif signals are ad75523 to coil A and B according to step 1, 2, 3, 4, 5, 6, 7, 8, then counter-clockwise movement is achieved. And vice-versa is true. If signals are applied according to step 8, 7, 6, 5, 4, 3, 2, 1, then clockwise movement is achieved. Commercial stepping motor uses multimotor rotor, the rotor features two gear like PM cylinders that are turned one-half of tooth spacing.
One gear is South Pole; the other gear is North Pole. If a tooth rotor gear is used, the following movement sequence will proceed. Dattasheet stepping position will be 0, 1.
Ad77523 stepping position will be 0. The stepping position will be 0, 0. Since stepping motor makes step-by-step movement and each step is equidistant, the rotor and stator magnetic fields must be synchronous. During start-up and stopping, the two fields may not be synchronous, so it is suggested to slowly accelerate and decelerate the stepping motor during datssheet start-up or stopping period.
The digital interface with on MDA board: This part is the digital communication interface for any peripherals. As long as stepper motor or any other kind of motor draws a huge amount of current from the source, we cannot directly connect a stepper motor to the digital IC s, which have source and sink current limitation. Therefore, we use the logic output of the digital interface to drive a transistor- or MOS-driven motor driver, which are capable of supplying enough current to drive a motor. The Interface Careful connections should be made with consideration of the current ratings of the components.
Transistor-drive for stepper motor on board This interfacing circuit is shown below in Figure 4. For isolation; we used opt couplers so that the board s circuitry does not get damaged. Stepper motor is a device used to obtain an accurate position control of rotating shafts. A stepper motor employs rotation of its shaft in terms of steps, rather than continuous rotation as in case of AC or DC motor.
To rotate the shaft of the stepper motor, a sequence of pulses is needed to be applied to the windings of the stepper motor, in proper sequence. The numbers of pulses required for complete rotation of the shaft of the stepper motor are equal to the number of internal teeth on its rotor.
The stator teeth and the rotor teeth lock with each other to fix a position of the shaft. With a pulse applied to the winding input, the rotor rotates by one teeth position or an angle x. The typical schematic of a typical stepper motor with four windings is as shown below. The stepper motors have been designed to work with digital circuits. Binary level pulses of V are required at its winding inputs to obtain the rotation of the shafts. The sequence of the pulses can be decided, depending upon the required motion of the shaft.
By suitable sequence of the pulses the motor can be used in three modes of operation. The provides very less current which will not be able to drive stepper motor coils so each of the winding of a stepper motor needs to be interfaced using high speed switching Darlington transistors with max 1A, 80V rating with heat sink, with the output port of Output the sequence in correct ordertohavethedesireddirectiontorotatethemotor.
In most of the cases, the PIO is used for interfacing the analog to digital converters with a microprocessor. The analog to digital converter is treated as an input device by the microprocessor that sends an initializing signal to the ADC to start the analog to digital data conversion process. The process of analog to digital conversion is a slow process, and the microprocessor as to wait for the digital data till the conversion is over.
The selection of ADC for a particular application is done, keeping in mind the required speed, resolution and the cost factor.