Os motores de busca de Datasheet de Componentes eletrônicos |
|
AD7118TQ2 Folha de dados(PDF) 4 Page - Analog Devices |
|
AD7118TQ2 Folha de dados(HTML) 4 Page - Analog Devices |
4 / 6 page AD7118 REV. A –4– CIRCUIT DESCRIPTION GENERAL CIRCUIT INFORMATION The AD7118 consists of a 17-bit R-2R CMOS multiplying D/A converter with extensive digital input logic. The logic translates the 6-bit binary input into a 17-bit word which is used to drive the D/A converter. Table I gives the nominal output voltages (and levels relative to 0 dB = 10 V) for all possible input codes. The transfer function for the circuit of Figure 1 is given by: VO =−V IN10exp− 1.5N 20 or VO V IN dB =−1.5N where N is the binary input for values 0 to 57. For 60 ≤ N ≤ 63 the output is zero. See note 3 at bottom of Table I. Figure 1. Typical Circuit Configuration EQUIVALENT CIRCUIT ANALYSIS Figure 2 shows a simplified circuit of the D/A converter section of the AD7118 and Figure 3 gives an approximate equivalent circuit. The current source ILEAKAGE is composed of surface and junc- tion leakages and as with most semiconductor devices, roughly doubles every 10 °C–see Figure 10. The resistor R O as shown in Figure 3 is the equivalent output resistance of the device which varies with input code (excluding all 0’s code) from 0.8R to 2R. R is typically 12 k Ω. C OUT is the capacitance due to the N-channel switches and varies from about 50 pF to 80 pF de- pending upon the digital input. For further information on CMOS multiplying D/A converters refer to “Application Guide to CMOS Multiplying D/A Converters” which is available from Analog Devices, Publication Number G479–15–8/78. Figure 2. Simplified D/A Circuit of AD7118 Figure 3. Equivalent Analog Output Circuit of AD7118 Digital Input Attenuation ND5 D0 dB VOUT 1 N Digital Input Attenuation VOUT 1 00 00 00 00 00.0 10.00 31 01 11 11 46.5 0.0473 01 00 00 01 01.5 8.414 32 10 00 00 48.0 0.0398 02 00 00 10 03.0 7.079 33 10 00 01 49.5 0.0335 03 00 00 11 04.5 5.957 34 10 00 10 51.0 0.0282 04 00 01 00 06.0 5.012 35 10 00 11 52.5 0.0237 05 00 01 01 07.5 4.217 36 10 01 00 54.0 0.0200 06 00 01 10 09.0 3.548 37 10 01 01 55.5 0.0168 07 00 01 11 10.5 2.985 38 10 01 10 57.0 0.0141 08 00 10 00 12.0 2.512 39 10 01 11 58.5 0.0119 09 00 10 01 13.5 2.113 40 10 10 00 60.0 0.0100 10 00 10 10 15.0 1.778 41 10 10 01 61.5 0.00841 11 00 10 11 16.5 1.496 42 10 10 10 63.0 0.00708 12 00 11 00 18.0 1.259 43 10 10 11 64.5 0.00596 13 00 11 01 19.5 1.059 44 10 11 00 66.0 0.00501 14 00 11 10 21.0 0.891 45 10 11 01 67.5 0.00422 15 00 11 11 22.5 0.750 46 10 11 10 69.0 0.00355 16 01 00 00 24.0 0.631 47 10 11 11 70.5 0.00299 17 01 00 01 25.5 0.531 48 11 00 00 72.0 0.00251 18 01 00 10 27.0 0.447 49 11 00 01 73.5 0.00211 19 01 00 11 28.5 0.376 50 11 00 10 75.0 0.00178 20 01 01 00 30.0 0.316 51 11 00 11 76.5 0.00150 21 01 01 01 31.5 0.266 52 11 01 00 78.0 0.00126 22 01 01 10 33.0 0.224 53 11 01 01 79.5 0.00106 23 01 01 11 34.5 0.188 54 11 01 10 81.0 0.000891 24 01 10 00 36.0 0.158 55 11 01 11 82.5 0.000750 25 01 10 01 37.5 0.133 56 11 10 00 84.0 0.000631 26 01 10 10 39.0 0.112 57 11 10 01 85.5 0.000531 27 01 10 11 40.5 0.0944 58 11 10 10 87.0 0.000447 28 01 11 00 42.0 0.0794 59 11 10 11 88.5 0.000376 29 01 11 01 43.5 0.0668 60 11 11 XX2 ∞ 30 01 11 10 45.0 0.0562 NOTES 1V IN = –10 V dc 2X = 1 or 0. Output is fully muted for N ≥ 60 3Monotonic operation is not guaranteed for N = 58, 59 Table I. Ideal Attenuation vs. Input Code |
Nº de peça semelhante - AD7118TQ2 |
|
Descrição semelhante - AD7118TQ2 |
|
|
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 |