Misunderstanding 6: The memory has so many control signals. My board only needs to use the OE and WE signals. The chip selection should be grounded so that the data comes out much faster during the read operation.
Summary: When the chip selection is valid, the power consumption of most memories (regardless of OE and WE) will be more than 100 times larger than when the chip selection is invalid. Therefore, CS should be used to control the chip as much as possible, and as long as other requirements are met. It is possible to shorten the width of the chip select pulse.
Misunderstanding 7: The power consumption of these small chips is very low, so don’t care about it.
Summary: It is difficult to determine the power consumption of the internal chip that is not too complicated. It is mainly determined by the current on the pin. An ABT16244 consumes less than 1 mA without load, but each pin can drive a load of 60 mA (such as matching resistance of tens of ohms), reaching a maximum power consumption of 60*16=960mA with a full load, albeit only the power supply current is so large, and the heat falls on the load.
Misunderstanding 8: Why do these signals have overshoot? As long as they are matched well, it can be eliminated.
Summary: Except for a few specific signals (such as 100BASE-T, CML), most signals have overshoot. As long as they are not very large, they do not necessarily need to be matched perfectly, and even if they are matched, it does not always need to be the best match. For example, the output impedance of TTL is less than 50 ohms, and in some cases, even 20 ohms. If a matching resistance of this size is used, the current will be very large, the power consumption will be unacceptable, and the signal amplitude will be too small to be usable. Additionally, the output impedance of a signal when outputting a high level and outputting a low level is not the same, making it impossible to achieve a complete match. Therefore, the matching of TTL, LVDS, 422, and other signals can be acceptable as long as the overshoot is within a reasonable range.
WellCircuits Limited is a manufacturer specializing in the production of high-precision double-sided, multi-layer and impedance, blind buried vias, and thick copper circuit boards. The product lineup includes HDI, thick copper, backplanes, rigid-flex, and buried capacitance, Golden Finger, and other types of circuit boards, all designed to meet the various needs of customers.
Summary: When the chip selection is valid, the power consumption of most memories (regardless of OE and WE) will be more than 100 times larger than when the chip selection is invalid. Therefore, CS should be used to control the chip as much as possible, and as long as other requirements are met. It is possible to shorten the width of the chip select pulse.
Misunderstanding 7: The power consumption of these small chips is very low, so don’t care about it.
Summary: It is difficult to determine the power consumption of the internal chip that is not too complicated. It is mainly determined by the current on the pin. An ABT16244 consumes less than 1 mA without load, but each pin can drive a load of 60 mA (such as matching resistance of tens of ohms), reaching a maximum power consumption of 60*16=960mA with a full load, albeit only the power supply current is so large, and the heat falls on the load.
Misunderstanding 8: Why do these signals have overshoot? As long as they are matched well, it can be eliminated.
Summary: Except for a few specific signals (such as 100BASE-T, CML), most signals have overshoot. As long as they are not very large, they do not necessarily need to be matched perfectly, and even if they are matched, it does not always need to be the best match. For example, the output impedance of TTL is less than 50 ohms, and in some cases, even 20 ohms. If a matching resistance of this size is used, the current will be very large, the power consumption will be unacceptable, and the signal amplitude will be too small to be usable. Additionally, the output impedance of a signal when outputting a high level and outputting a low level is not the same, making it impossible to achieve a complete match. Therefore, the matching of TTL, LVDS, 422, and other signals can be acceptable as long as the overshoot is within a reasonable range.
WellCircuits Limited is a manufacturer specializing in the production of high-precision double-sided, multi-layer and impedance, blind buried vias, and thick copper circuit boards. The product lineup includes HDI, thick copper, backplanes, rigid-flex, and buried capacitance, Golden Finger, and other types of circuit boards, all designed to meet the various needs of customers.
