поискавой системы для электроныых деталей |
|
ADC0820CIWM датащи(PDF) 9 Page - National Semiconductor (TI) |
|
|
ADC0820CIWM датащи(HTML) 9 Page - National Semiconductor (TI) |
9 / 22 page Description of Pin Functions Pin Name Function 1V IN Analog input; range =GND ≤V IN≤VCC 2 DB0 TRI-STATE data output — bit 0 (LSB) 3 DB1 TRI-STATE data output — bit 1 4 DB2 TRI-STATE data output — bit 2 5 DB3 TRI-STATE data output — bit 3 6WR /RDY WR-RD Mode WR: With CS low, the conversion is started on the falling edge of WR. Approximately 800 ns (the preset internal time out, t I) after the WR rising edge, the result of the conversion will be strobed into the output latch, provided that RD does not occur prior to this time out (see Figures 3, 4 ). RD Mode RDY: This is an open drain output (no internal pull-up device). RDY will go low after the falling edge of CS; RDY will go TRI-STATE when the result of the conversion is strobed into the output latch. It is used to simplify the interface to a microprocessor system (see Figure 2 ). 7 Mode Mode: Mode selection input — it is internally tied to GND through a 50 µA current source. RD Mode: When mode is low WR-RD Mode: When mode is high 8RD WR-RD Mode With CS low, the TRI-STATE data outputs (DB0-DB7) will be activated when RD goes low (see Figure 5 ). RD can also be used to increase the speed of the converter by reading data prior to the preset internal time out (t I, z800 ns). If this is done, the data result transferred to output latch is latched after the falling edge of the RD (see Figures 3, 4 ). RD Mode With CS low, the conversion will start with RD going low, also RD will enable the TRI-STATE data outputs at the completion of the conversion. RDY going TRI-STATE and INT going low indicates the completion of the conversion (see Figure 2 ). Pin Name Function 9 INT WR-RD Mode INT going low indicates that the conversion is completed and the data result is in the output latch. INT will go low, z800 ns (the preset internal time out, t I) after the rising edge of WR (see Figure 4 ); or INT will go low after the falling edge of RD , if RD goes low prior to the 800 ns time out (see Figure 3). INT is reset by the rising edge of RD or CS (see Figures 3, 4 ). RD Mode INT going low indicates that the conversion is completed and the data result is in the output latch. INT is reset by the rising edge of RD or CS (see Figure 2 ). 10 GND Ground 11 V REF(−) The bottom of resistor ladder, voltage range: GND ≤V REF(−)≤VREF(+) (Note 5) 12 V REF(+) The top of resistor ladder, voltage range: V REF(−)≤VREF(+)≤VCC (Note 5) 13 CS CS must be low in order for the RD or WR to be recognized by the converter. 14 DB4 TRI-STATE data output — bit 4 15 DB5 TRI-STATE data output — bit 5 16 DB6 TRI-STATE data output — bit 6 17 DB7 TRI-STATE data output — bit 7 (MSB) 18 OFL Overflow output — If the analog input is higher than the V REF(+), OFL will be low at the end of conversion. It can be used to cascade 2 or more devices to have more resolution (9, 10-bit). This output is always active and does not go into TRI-STATE as DB0–DB7 do. 19 NC No connection 20 V CC Power supply voltage 1.0 Functional Description 1.1 GENERAL OPERATION The ADC0820 uses two 4-bit flash A/D converters to make an 8-bit measurement ( Figure 1 ). Each flash ADC is made up of 15 comparators which compare the unknown input to a reference ladder to get a 4-bit result. To take a full 8-bit read- ing, one flash conversion is done to provide the 4 most sig- nificant data bits (via the MS flash ADC). Driven by the 4 MSBs, an internal DAC recreates an analog approximation of the input voltage. This analog signal is then subtracted from the input, and the difference voltage is converted by a second 4-bit flash ADC (the LS ADC), providing the 4 least significant bits of the output data word. The internal DAC is actually a subsection of the MS flash converter. This is accomplished by using the same resistor www.national.com 9 |
Аналогичный номер детали - ADC0820CIWM |
|
Аналогичное описание - ADC0820CIWM |
|
|
ссылки URL |
Конфиденциальность |
ALLDATASHEETRU.COM |
Вашему бизинису помогли Аллдатащит? [ DONATE ] |
Что такое Аллдатащит | реклама | контакт | Конфиденциальность | обмен ссыками | поиск по производителю All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |