Os motores de busca de Datasheet de Componentes eletrônicos |
|
ML2252BCP Folha de dados(PDF) 8 Page - Micro Linear Corporation |
|
ML2252BCP Folha de dados(HTML) 8 Page - Micro Linear Corporation |
8 / 13 page ML2252, ML2259 8 Another advantage of the capacitor array approach used in the ML2252 and ML2259 is the inherent sample-and-hold function. This true S/H allows an accurate conversion to be done on the input even if the analog signal is not stable. Linearity and accuracy are maintained for analog signals up to 1/2 the sampling frequency. As a result, input signals up to 50kHz can be converted without degradation in linearity or accuracy. The sequence of events during a conversion is shown in figure 5. The rising edge of a START pulse resets the internal registers and initiates a conversion on the next rising edge of CLK providing that (tSS) start pulse setup time is satisfied. If this setup time is not met, start conversion will have an uncertainty of one clock pulse. The input is then sampled for the next half CLK period until EOC goes low. EOC goes low on the falling edge of the next CLK pulse indicating that the conversion is now beginning. The actual conversion now takes place for the next eight CLK pulses, one bit for each CLK pulse. After the conversion is done, the data is updated on DB0–DB7 and EOC goes high on the rising edge of the 9th CLK pulse, indicating that the conversion has been completed and data is valid on DB0–DB7. The data will stay valid on DB0–DB7 until the next conversion updates the data word on the next rising edge of EOC. A conversion can be interrupted and restarted at any time by a new START pulse. 1.3 ANALOG INPUTS AND SAMPLE/HOLD The ML2252 and ML2259 have a true sample-and-hold circuit which samples both the selected input and ground simultaneously. These analog to digital converters can reject AC common mode signals from DC–50kHz as well as maintain linearity for signals from DC–50kHz. The plot in Figure 6 shows a 2048 point FFT of the ML2259 converting a 50kHz, 0 to 5V, low distortion sine wave input. The ML2252 and ML2259 sample and digitize, at their specified accuracy, dynamic input signals with frequency components up to the Nyquist frequency (one-half the sampling rate). The output spectra yields precise measurements of input signal level, harmonic components, and signal to noise ratio up to the 8-bit level. The near ideal signal to noise ratio is maintained independent of increasing analog input frequencies to 50kHz. The signal at the analog input is sampled during the interval when the sampling switch is open prior to conversion start. The sampling window (S/H acquisition time) is one half CLK period long and occurs one half CLK period after START goes low. When the sampling switch closes at the start of the S/H acquisition time, 8pF of capacitance is thrown onto the analog input. One half CLK period later, the sampling switch opens, the signal present at analog input is stored and conversion starts. Since any error on the analog input at the end of the S/H acquisition time will cause additional conversion error, care should be taken to insure adequate settling and charging time from the source. If more charging or settling time is needed to reduce these analog input errors, a longer CLK period can be used. Each analog input has dual diodes to the supply rails, and a minimum of ±25mA (±100mA typically) can be injected into each analog input without causing latchup. Figure 5. Timing Diagram 1/fCLK tSS tWS tWALE tH tS tIH, tOH CLK START ALE ADDR0–ADDR2 EOC DB0–DB7 OE 12 4 35 6 7 8 9 PREVIOUS DATA DATA tC tEOC tHI, tHO |
Nº de peça semelhante - ML2252BCP |
|
Descrição semelhante - ML2252BCP |
|
|
Ligação URL |
Privacy Policy |
ALLDATASHEETPT.COM |
ALLDATASHEET é útil para você? [ DONATE ] |
Sobre Alldatasheet | Publicidade | Contato conosco | Privacy Policy | roca de Link | Lista de Fabricantes 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 |