Zakładka z wyszukiwarką danych komponentów |
|
AD7742YR Arkusz danych(PDF) 8 Page - Analog Devices |
|
AD7742YR Arkusz danych(HTML) 8 Page - Analog Devices |
8 / 12 page REV. 0 AD7741/AD7742 –8– As can be seen from Table II, the AD7741 has one input range configuration whereas the AD7742 has unipolar/bipolar as well as gain options depending on the status of the GAIN and UNI/ BIP pins. The transfer function for the AD7741 is shown in Figure 3. Figure 4 shows the AD7742 transfer function for unipolar input range configuration while the AD7742 transfer function for bipolar input range configuration is shown in Figure 5. OUTPUT FREQUENCY fOUT fOUTMAX (0.45 fCLKIN) fOUTMIN (0.05 fCLKIN) 0 INPUT VOLTAGE VIN REFIN Figure 3. AD7741 Transfer Characteristic for Input Range from 0 to VREF OUTPUT FREQUENCY fOUT fOUTMAX (0.45 fCLKIN) fOUTMIN (0.05 fCLKIN) 0 VREF GAIN + DIFFERENTIAL INPUT VOLTAGE Figure 4. AD7742 Transfer Characteristic for Unipolar Differential Input Range: 0 V to VREF/Gain; the input common-mode range must be between +0.5 V and VDD – 1.75 V. UNI/BIP pin tied to VDD. Table II. AD7741/AD7742 Input Range Selection VIN(Min) VIN(Max) UNI/ BIP GAIN Gain, G fOUT = 0.05 fCLKIN fOUT = 0.45 fCLKIN Part N/A N/A X1 0 +VREF AD7741 00X1 –VREF +VREF AD7742 01X2 –VREF/2 +VREF/2 AD7742 10X1 0 +VREF AD7742 11X2 0 +VREF/2 AD7742 OUTPUT FREQUENCY fOUT fOUTMAX (0.45 fCLKIN) fOUTMIN (0.05 fCLKIN) DIFFERENTIAL INPUT VOLTAGE VREF GAIN + VREF GAIN – Figure 5. AD7742 Transfer Characteristic for Bipolar Differential Input Range: –VREF/Gain to +VREF/Gain; the common-mode range must be between +0.5 V and VDD – 1.75 V. UNI/BIP pin tied to GND. VFC Modulator The analog input signal to the AD7741/AD7742 is continu- ously sampled by a switched capacitor modulator whose sam- pling rate is set by a master clock input that may be supplied externally or by a crystal-controlled on-chip clock oscillator. However, the input signal is buffered on-chip before being ap- plied to the sampling capacitor of the modulator. This isolates the sampling capacitor charging currents from the analog input pins. This system is a negative feedback loop that tries to keep the net charge on the integrator capacitor at zero, by balancing charge injected by the input voltage with charge injected by the VREF. The output of the comparator provides the digital input for the 1-bit DAC, so that the system functions as a negative feedback loop that tries to minimize the difference signal (see Figure 6). INTEGRATOR COMPARATOR + – CLK 1-BIT STREAM + INPUT +VREF –VREF – Figure 6. AD7741/AD7742 Modulator Loop |
Podobny numer części - AD7742YR |
|
Podobny opis - AD7742YR |
|
|
Link URL |
Polityka prywatności |
ALLDATASHEET.PL |
Czy Alldatasheet okazała się pomocna? [ DONATE ] |
O Alldatasheet | Reklama | Kontakt | Polityka prywatności | Linki | Lista producentów 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 |