The SGA is a high performance SiGe HBT. MMIC Amplifier. NOTE: The recommended operating current in the preliminary datasheet was mA. MOSFET are available at Mouser Electronics. Mouser offers inventory, pricing, & datasheets for MOSFET. Datasheet, In Stock. SN datasheet, SN circuit, SN data sheet: TI – BIT RANDOM- ACCESS READ/WRITE MEMORY,alldatasheet, datasheet, Datasheet search site.
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(PDF) 7489 Datasheet download
I have been learning about the memory chip. I had two of these that turned out to be broken see here for previous question on this. I got more and I have finally gotten everything to work. From this datasgeetI learned the basic idea of how to set up the circuit. So now I have the following schematics more or less copied from here.
The following works well! I am still new to digital electronics and I am just trying to learn. How can one determine an appropriate pull-up resistor? For example, in the answer to the earlier question, the resistors 77489, R2, R3, and R4, were suggested to be 2. Is all that matters what the Datasheef need or is there something relating to the that helps determine the size of the pull-up resistors?
schematics – Why are two LEDs on? is broken? – Electrical Engineering Stack Exchange
If it is only the LEDs forward voltage 2V and current 0. Also, for the inputs address and data input I did choose 4. What here determines the size? What should Datasheef be looking for in the datasheet? If the LEDs drop 2 volts, assume there is 3 volts across the resistors there’s be a bit less, because the datasheft pull its outputs quite to groundthen for 20 mA, you’d want Ohms.
LEDs aren’t very fussy about current, as long as it is less than their Absolute Maximum rating. Lower current gives less light, but for indicator light use I find tha 10 mA is more than enough, so I’d use Ohms or more. For high-speed signals, a lower value may be required to ensure that the signal changes fast enough when the signal should go high.
A resistor obeys Ohm’s law, and choosing a resistor value is a matter of the permissible voltage and current, and power voltage drop x current according to application. For your switched inputs, a pullup resistor ought not to burn up, nor prevent a logic LOW level suitable for the inputs 0. Switch resistance of 0. Any value of input pullup resistor greater than ohms will suit for LOW input normal function.
What MIGHT limit it, is the drive impedance with respect to input capacitance of the input pin; if there are transmission lines connected, a ohm pullup and ohm pulldown to ground gives good drive circa ohms to 3Vsuitable for the load of the cable. Low impedance also protects against accidental signal pickup stray capacitance, static discharge. For LED drive, you do the same thing: A shunt resistor in parallel with the LED will ensure lights-off, and may improve the high-side logic margin because of the up-to-2V offset from the LED.
This question has already been answered in some detail. Please look at the “Related” column to the right and click on “How do I calculate the required value for a pull-up resistor? I see that for the question on how big a pull-up resistor in general should be.
I will study these other answers. Most of today’s LEDs have a Vdrop of about 3. This IC can sink 12mA max per output pin.
At ohms the current is Thanks for the answer. I just want to make sure that I understand before I do any damage. Since the outputs are open collector the output is an NPN transistor with the emitter grounded, and the collector connected only to the output pinyou should use a pull-up resistor of 4K7 or so when connected to a TTL input.
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