LPC3180 ARM uC power supply

Started by kalyanamsaritha in comp.arch.embedded12 years ago 11 replies

LPC3180 is a ARM926EJS core which uses a 1.2V for the core, sdram, etc, and 1.8V/3.0V for IO. What power supply/regulators would be...

LPC3180 is a ARM926EJS core which uses a 1.2V for the core, sdram, etc, and 1.8V/3.0V for IO. What power supply/regulators would be recommended? Would a single regulator be recommened to achieve these multiple voltages? And how? Thanks.


how to separate ground potential

Started by Saul Bernstein in comp.arch.embedded11 years ago 21 replies

Hi, I have to design a printed circuit board for a high-voltage environment. Hence, the "ground potential" of the board has to be on 4 kV. Du...

Hi, I have to design a printed circuit board for a high-voltage environment. Hence, the "ground potential" of the board has to be on 4 kV. Du to the fact that the absolute potential values don't matter, one could say that the 2 kV are virtually my ground potential. The problem arises by reason of the power supply. I have to power my board with 5 V and for the mains adapter ground is r...


enumaration of cypress device

Started by puniths_d in comp.arch.embedded11 years ago 2 replies

I have an fx2 device .I have developed a firmware for it . When I download the firmware the device takes a long time to enumarate or some times...

I have an fx2 device .I have developed a firmware for it . When I download the firmware the device takes a long time to enumarate or some times it goes a known device .Some times it quickly enumarates. Is the power supply current has got something to do with the enumaration process. The enumaration process is getting distrubed some how. I appriciate some help thanks in advance punitha


Power Supply Question

Started by syr123 in comp.arch.embedded11 years ago 1 reply

Perhaps someone with more electronics experience than myself can give me an idea of roughly what sort of power supply I need for the...

Perhaps someone with more electronics experience than myself can give me an idea of roughly what sort of power supply I need for the following scenario: I am looking to power: 11 PIC16F690 microcontrollers which run on +5V 1 cold cathode light which runs on +12V (these are the specs given: Input voltage of inverter: 12v, Output voltage of inverter: 680v, Current draw: 5.0mAv) 1 +3.3V acce...


In-circuit Test: how to test Op. Amps

Started by Anonymous in comp.arch.embedded11 years ago 3 replies

Hi, does anybody know how to carry out In-circuit Tests of Operational Amplifiers? for the sake of knoledge: In-circuit tests are carried...

Hi, does anybody know how to carry out In-circuit Tests of Operational Amplifiers? for the sake of knoledge: In-circuit tests are carried out by ATE machines with the target unpowered (i.e. no power supply) I read many Teradyne's articles but couldn't find anything useful. thanks for any help, Enrico


Advice for the best Touch Panel A/N circuit (or resistance-to-digital)

Started by whygee in comp.arch.embedded11 years ago 7 replies

Hello, I want to digitize some sensors and a touch panel with a FPGA. FPGA allow a certain flexibility but good external analog parts are...

Hello, I want to digitize some sensors and a touch panel with a FPGA. FPGA allow a certain flexibility but good external analog parts are necessary. In my context, the trouble comes from the screen's touch panel (classic low-value resistor type with 4 wires). I know that it is very sensitive to the environment (temperature, power supply, interferences...) and drift is very annoying (1% ...


USB communication hung

Started by mahesh.himane in comp.arch.embedded11 years ago 1 reply

I am using ISP1582 USB device controller. I have connected TYPE-B connecor. I have used BLM21P220 inductor in between USB ground and board...

I am using ISP1582 USB device controller. I have connected TYPE-B connecor. I have used BLM21P220 inductor in between USB ground and board ground. I have also placed another BLM21P220 at sheild and board ground. Whenever I remove or plugin Laptop power supply while communication is going on inbetween laptop and board, USB communication is hanging. Following things I observed 1) when I rem...


Power MOSFET Circuit Help

Started by eeboarder in comp.arch.embedded11 years ago 4 replies

What is the purpose of using a power MOSFET in the main voltage input of a circuit? Why not just directly connect the main voltage input to a...

What is the purpose of using a power MOSFET in the main voltage input of a circuit? Why not just directly connect the main voltage input to a power supply? Why go through the MOSFET? I am trying to understand a circuit that goes directly from a 12V battery to Drain of a P-channel power MOSFET. The Gate is connected to ground through a 1MOhm resistor and connected to Source through a Zener diode...


Use of MAX232 as power supply for operational amplifier in 5V powered system?

Started by wzab in comp.arch.embedded10 years ago 7 replies

Hi, I need to add simple amplifier to my digital system which is powered from a single 5V battery. To achieve proper operation of the...

Hi, I need to add simple amplifier to my digital system which is powered from a single 5V battery. To achieve proper operation of the operational amplifier I need at least +8V and -8V voltages. I can build a simple voltage multiplier and inverter like shown here: http://upload.wikimedia.org/wikipedia/en/thumb/b/ba/Stacked_Villard_cascade.svg/400px-Stacked_Vi llard_cascade.svg.png using th


Data I/O equipment/parts needed

Started by 1 Lucky Texan in comp.arch.embedded10 years ago

the board on our Promaster 2500 (circa 1994 or so) burned up. Seems to be an on board power supply section. Dunno what took it out. We have no...

the board on our Promaster 2500 (circa 1994 or so) burned up. Seems to be an on board power supply section. Dunno what took it out. We have no board-level schematics (just some assembly diagrams). Anyone have a line on a similar unit or parts for this one? (personally, I think they should let this one go - but if it could be back up quickly, cheaply enough - we'd prefer to do that, at least...


Switch Mode Power Supply: a varistor between Earth and the secondary's ground

Started by Enrico in comp.arch.embedded9 years ago

Hi, I'm developing a 20-watt switch mode power supply. The PWM controller is the Viper 27. So far everything is going fine. I noticed on a...

Hi, I'm developing a 20-watt switch mode power supply. The PWM controller is the Viper 27. So far everything is going fine. I noticed on a competitor's power supply the presence of a Disc Varistor (56 Volt) between Earth and the ground of the secondary. This is quite surprinsig for me. Can anybody explain me the reason of that choice? Thanks in advance, Enrico


Spartan-6 MGT/GTP power supply

Started by YH in comp.arch.embedded9 years ago 1 reply

Hello, I am going to use the 4 of the GTP interfaces. I calculated I need a dedicated,2V@3A supply. I checked the EVB from Avnet for the...

Hello, I am going to use the 4 of the GTP interfaces. I calculated I need a dedicated,2V@3A supply. I checked the EVB from Avnet for the Spartan-6 150T and they implemented two options: whether a switching relator LMZ from National whether a TPS54317 LDO from TI. I like the LMZxxxx solution because the design is simple and my PCB is already pretty busy. It seems the maximum ripple voltage...


Flyback Transformer: sleeving question

Started by Enrico in comp.arch.embedded8 years ago 6 replies

Hi, I'm designing a flyback transformer of a 25 W power supply. The power supply will be UL tested in Europe. The norm that will...

Hi, I'm designing a flyback transformer of a 25 W power supply. The power supply will be UL tested in Europe. The norm that will be followed is the UL 60950. The UL safety engineer told that the Hi-Pot test will be carried out after leaving the power supply in the humid room for 12 hours at 93% of humidity. He suggested me to add sleeving to the transformer. My question is: on w...


race condition? between relays and 89C51 uC

Started by Mak in comp.arch.embedded8 years ago 7 replies

hello everyone, I have a RS485 based slave relay driver with 8 relays. The relays turn on at logic 0. Since the 89C51 has all ports as HIGH...

hello everyone, I have a RS485 based slave relay driver with 8 relays. The relays turn on at logic 0. Since the 89C51 has all ports as HIGH during reset, my relays should remain off. The problem that I am facing is that when I turn the power supply on, all the relays turn on momentarily and then back off. Is there a race condition during which the microcontroller is not gaining control of ...


External Micro/Mini USB Power supply

Started by Anonymous in comp.arch.embedded8 years ago 2 replies

I am looking at designing a new product which will use a external DC power supply and because it has USB ports I was thinking of using a...

I am looking at designing a new product which will use a external DC power supply and because it has USB ports I was thinking of using a 5V supply and therefore a mini or micro usb type charger psu and am not sure which one I should go for and what the maximum current capability of the connector is. For some chargers it is 1amp at 5V but I have found at least one supply rated at 5V 1.8amp. Mo...


SATA power for embedded widgets

Started by Theo Markettos in comp.arch.embedded7 years ago 11 replies

Been doing a lot of stuff recently that requires 3.3V and 12V at moderate currents. The simplest commodity way to do this seems to be a PC...

Been doing a lot of stuff recently that requires 3.3V and 12V at moderate currents. The simplest commodity way to do this seems to be a PC power supply. The 24 way ATX connector is a bit clumsy and you only get one per PSU, so it seems simpler to use SATA connectors as a handy ecosystem of 3.3/5/12v power at up to 4.5A per rail. A scattering of these provides the necessary few hundred watt...


Low cost mains power supply

Started by Nomen Nescio in comp.arch.embedded7 years ago 11 replies

In most DIY stores you can find these cheap Chinese digital timers to turn you lamps or appliances on at specified time. The thing I'm wondering...

In most DIY stores you can find these cheap Chinese digital timers to turn you lamps or appliances on at specified time. The thing I'm wondering is, how do they power the digital circuitry from 110VAC in a device costing only $5-$10? Are they using a transformer or are they directly powering the digital circuitry from the AC voltage?


US Regulatory

Started by bbhack in comp.arch.embedded7 years ago 3 replies

Hypothetical: If I have a product that plugs in, has power supply, micro, and SSR, can I sell this as a *kit*, even shipping the parts...

Hypothetical: If I have a product that plugs in, has power supply, micro, and SSR, can I sell this as a *kit*, even shipping the parts separately, with hypothetical purpose when assembled - without ETL mark, and not incur stupid liability? ImNAL, and I understand that there is no such thing as no liability. The purpose for doing so is to test the demand for such a thing, without tos...


USB Embedded Master: requirement on power supply?

Started by pozz in comp.arch.embedded4 years ago 3 replies

I'm going to design a board with an embedded USB Host connector (managed by Atmel SAM D21 MCU). I will use that connection only for data...

I'm going to design a board with an embedded USB Host connector (managed by Atmel SAM D21 MCU). I will use that connection only for data communication with a smartphone or a pendrive. I don't need to recharge the battery of the smartphone. Of course, I need to supply the pendrive. On my board I have to generate a +5V rail only for the USB, but I don't know what is its requirement. Co...


SPI Flash: don't work high-speed read at 48MHz

Started by pozz in comp.arch.embedded2 years ago 4 replies

I'm using Microchip SST26VF064B SPI Flash memory with an LPC1768 from LPC. It works until I change the SPI clock frequency from 24MHz to...

I'm using Microchip SST26VF064B SPI Flash memory with an LPC1768 from LPC. It works until I change the SPI clock frequency from 24MHz to 48MHz. I'm using HIGH-SPEED READ command that should work up to 104MHz (the power supply is 3.3V). For example I read 0x28 0x26 when they should be 0x51 0x4C. 0010 1000 0010 0110 -> 0x28 0x26 0101 0001 0100 1100 -> 0x51 0x4C They appears s