8051F020 series, 5V tolerant input schematic?

Started by Joerg in sci.electronics.design9 years ago 89 replies

Folks, Got a Silicon Labs 8051Fxxx with 5V-tolerant ports. In the abs max it says 5.8V is the limit. Well, if one uses the typical diode...

Folks, Got a Silicon Labs 8051Fxxx with 5V-tolerant ports. In the abs max it says 5.8V is the limit. Well, if one uses the typical diode against the 5V rail it could go slightly above 6V in case of a really big jolt. Since this 8051 does not have a 5V supply but just VDD (which hangs on 3.3V in this case) there can't be any parasitic substrate diodes dumping into a rail. Does anyone kno...


Fast simple microcontroller

Started by Anthony William Sloman in sci.electronics.design1 year ago 165 replies

I've been thinking about Timo's inverter, and it looks as if a micro-controller that offered a 100MHz clock rate would be fast enough to do a...

I've been thinking about Timo's inverter, and it looks as if a micro-controller that offered a 100MHz clock rate would be fast enough to do a decent job of switching the Siliconix Si3440DV DMOSFet that I fancy. I've found a PIC part that's fast enough, and pretty cheap, but it is designed for digital signal processing, which makes it more complicated than necessary. A nice, dumb but quick 8051...


Uart through an audio transformer

Started by Martin Griffith in sci.electronics.design14 years ago 27 replies

Any rules of thumb about sending a 9600 baud UARTsignal ,from an 8051 through a telecom type V90 audio transformer, (LT spice K L1 L2 1 @ 4mH Rs...

Any rules of thumb about sending a 9600 baud UARTsignal ,from an 8051 through a telecom type V90 audio transformer, (LT spice K L1 L2 1 @ 4mH Rs = 10R) I only need about 8 bytes of data, and LTspice seems to need a square wave for about a millisecond before it settles down. So a long sync word of 010101 etc then a start byte? I'll pad the sig down to 100mV or so martin


Hack a datalogger into existing design

Started by mpm in sci.electronics.design2 years ago 4 replies

Pretty sure the answer is "Yes", but let me ask it anyway.... Situation: Need to add a datalogger to an existing design, but there are no free...

Pretty sure the answer is "Yes", but let me ask it anyway.... Situation: Need to add a datalogger to an existing design, but there are no free ports left on the microcontroller. The microcontroller is an AT89LP51ED2. (An 8-bit, 8051 variant) Port-0 outputs data ONLY to (3) D-Type transparent octal latches (74ACT573N), which are individually latched via some pins on Port-2 of the microcont...