Electronic Components Datasheet Search |
|
ADS7831U Datasheet(PDF) 9 Page - Burr-Brown (TI) |
|
|
ADS7831U Datasheet(HTML) 9 Page - Burr-Brown (TI) |
9 / 10 page 9 ® ADS7831 FIGURE 4a. Circuit Diagram With External Hardware Trim. FIGURE 4b. Circuit Diagram Without External Hardware Trim. CALIBRATION The ADS7831 can be trimmed in hardware or software. The offset should be trimmed before the gain since the offset directly affects the gain. Hardware Calibration To calibrate the offset and gain of the ADS7831, install the proper resistors and potentiometers as shown in Figure 4a. The calibration range is ±12mV for the offset and ±30mV for full scale. Potentiometer P 1 and resistor R 1 form the offset adjust circuit and P 2 and R2 the gain adjust circuit. The exact values are not critical. R 1 and R2 should not be made any larger than the value shown. They can easily be made smaller to provide increased adjustment range. Reducing these below 15% of the indicated values could begin to adversely affect the operation of the converter. P 1 and P2 can also be made larger to reduce power dissipa- tion. However, larger resistances will push the useful adjust- ment range to the edges of the potentiometer. P 1 should probably not exceed 20k Ω and P2 100kΩ in order to main- tain reasonable sensitivity. Software Calibration or No Calibration The ADS7831 does not require external resistors for its basic operation. However, the component is designed to be used with an external 50 Ω resistor on the input, and the specifications apply to this condition. If this resistor is not used, the only specification that will be affected is total unadjusted error. With the 50 Ω resistor, the nominal input voltage range is ±2.5V and the total unadjusted error is ±10LSBs guaran- teed. Without the 50 Ω resistor, the nominal input voltage range will be ±2.46V and the total unadjusted error is not guaranteed. While it will typically be much less, the total unadjusted error could be as high as ±20LSBs. 50 Ω AGND2 CAP REF AGND1 V IN + 0.1µF 10µF V IN NOTE: Use 1% metal film resistors. Trim offset at 0V first, then trim gain at 2.5V. FIGURE 3. Using CS to Control Conversion and Read Timing. t 9 Hi-Z State BUSY CS R/C DATA BUS MODE Acquire Data Valid HI Z State Convert t 7 t 2 t 6 t 3 t 4 t 11 t 5 Acquire t 13 t 11 t 1 t 11 t 11 50 Ω AGND2 CAP REF AGND1 V IN + 0.1µF 10µF V IN +5V R 1 20k Ω R 2 604k Ω –5V P 1 5k Ω P 2 5k Ω +5V |
Similar Part No. - ADS7831U |
|
Similar Description - ADS7831U |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |