поискавой системы для электроныых деталей |
|
AD7237A датащи(PDF) 6 Page - Analog Devices |
|
AD7237A датащи(HTML) 6 Page - Analog Devices |
6 / 12 page AD7237A/AD7247A REV. 0 –6– TERMINOLOGY RELATIVE ACCURACY (LINEARITY) Relative Accuracy, or endpoint linearity, is a measure of the maximum deviation of the DAC transfer function from a straight line passing through the endpoints of the transfer func- tion. It is measured after allowing for zero and full-scale errors and is expressed in LSBs or as a percentage of full-scale reading. DIFFERENTIAL NONLINEARITY Differential Nonlinearity is the difference between the measured change and the ideal 1 LSB change between any two adjacent codes. A specified differential nonlinearity of ±1 LSB or less over the operating temperature range ensures monotonicity. SINGLE SUPPLY LINEARITY AND GAIN ERROR The output amplifiers of the AD7237A/AD7247A can have true negative offsets even when the part is operated from a single +12 V to +15 V supply. However, because the negative supply rail (VSS) is 0 V, the output cannot actually go negative. Instead, when the output offset voltage is negative, the output voltage sits at 0 V, resulting in the transfer function shown in Figure 1. This “knee” is an offset effect, not a linearity error, and the transfer function would have followed the dotted line if the out- put voltage could have gone negative. Figure 1. Effect of Negative Offset (Single Supply) Normally, linearity is measured between zero (all 0s input code) and full scale (all 1s input code) after offset and full scale have been adjusted out or allowed for, but this is not possible in single supply operation if the offset is negative, due to the knee in the transfer function. Instead, linearity of the AD7237A/ AD7247A in the unipolar mode is measured between full scale and the lowest code which is guaranteed to produce a positive output voltage. This code is calculated from the maximum specification for negative offset, i.e., linearity is measured be- tween Codes 3 and 4095. UNIPOLAR OFFSET ERROR Unipolar Offset Error is the measured output voltage from VOUTA or VOUTB with all zeros loaded into the DAC latches when the DACs are configured for unipolar output. It is a com- bination of the offset errors of the DAC and output amplifier. BIPOLAR ZERO ERROR Bipolar Zero Error is the voltage measured at VOUTA or VOUTB when the DAC is connected in the bipolar mode and loaded with code 2048. It is due to a combination of offset errors in the DAC, amplifier offset and mismatch in the application resistors around the amplifier. FULL-SCALE ERROR Full-Scale Error is a measure of the output error when the amplifier output is at full scale (for the bipolar output range full scale is either positive or negative full scale). It is measured with respect to the reference input voltage and includes the offset errors. DIGITAL FEEDTHROUGH Digital Feedthrough is the glitch impulse injected for the digital inputs to the analog output when the data inputs change state, but the data in the DAC latches is not changed. For the AD7237A it is measured with LDAC held high. For the AD7247A it is measured with CSA and CSB held high. DIGITAL CROSSTALK Digital crosstalk is the glitch impulse transferred to the output of one converter due to a change in digital code to the DAC latch of the other converter. It is specified in nV secs. DIGITAL-TO-ANALOG GLITCH IMPULSE This is the voltage spike that appears at the output of the DAC when the digital code changes before the output settles to its fi- nal value. The energy in the glitch is specified in nV secs and is measured for a 1 LSB change around the major carry transition (0111 1111 1111 to 1000 0000 0000). |
Аналогичный номер детали - AD7237A_15 |
|
Аналогичное описание - AD7237A_15 |
|
|
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 |