công cụ tìm kiếm bảng dữ liệu linh kiện điện tử |
|
AD569 bảng dữ liệu(PDF) 10 Page - Analog Devices |
|
AD569 bảng dữ liệu(HTML) 10 Page - Analog Devices |
10 / 12 page AD569 REV. A –10– Table I. AD569 Truth Table CS HBE LBE LDAC OPERATION 1 X X X No Operation X 1 1 1 No Operation 0 0 1 1 Enable 8 MSBs of First Rank 0 1 0 1 Enable 8 LSBs of First Rank 0 1 1 0 Enable 16-Bit DAC Register 0 0 0 0 All Latches Transparent All four control inputs latches are level-triggered and active low. When the DAC register is loaded directly from a bus, the data at the digital inputs will be reflected in the output any time CS, LDAC , LBE and HBE are low. Should this not be the desired case, bring LDAC (or HBE or LBE) high before changing the data. Alternately, use a second write cycle to transfer the data to the DAC register or delay the write strobe pulse until the appro- priate data is valid. Be sure to observe the appropriate data setup and hold times (see Timing Characteristics). Whenever possible, the write strobe signal should be applied to HBE and LBE with the AD569’s decoded address applied to CS . A minimum pulse width of 60 ns at HBE and LBE allows the AD569 to interface to the fastest microprocessors. Actually, data can be latched with narrower pulses, but the data setup and hold times must be lengthened. 16-Bit Microprocessor Interfaces Since 16-bit microprocessors supply the AD569’s complete 16- bit input in one write cycle, the DAC register is often unneces- sary. If so, it should be made transparent by grounding LDAC. The DAC’s decoded address should be applied to CS, with the write strobe applied to HBE and LBE as shown in the 68000 in- terface in Figure 19. Figure 19. AD569/68000 Interface DIGITAL CIRCUIT CONNECTIONS The AD569’s truth table appears in Table I. The High Byte En- able (HBE) and Low Byte Enable (LBE) inputs load the upper and lower bytes of the 16-bit input when Chip Select (CS) is valid (low). A similar strobe to Load DAC (LDAC) loads the 16-bit input into the DAC register and completes the DAC up- date. The DAC register can either be loaded with a separate write cycle or synchronously with either of the 8-bit registers in the first rank. A simultaneous update of several AD569s can be achieved by controlling their LDAC inputs with a single control signal. under worst-case conditions (hex input code 0000), feedthrough remains below –100 dB at ac reference frequencies up to 10 kHz. Figure 16. Multiplying Feedthrough BYPASSING AND GROUNDING RULES It is generally considered good engineering practice to use bypass capacitors on the device supply voltage pins and to insert small valued resistors in the supply lines to provide a measure of decou- pling between various circuits in a system. For the AD569, bypass capacitors of at least 4.7 µF and series resistors of 10 Ω are recom- mended. The supply voltage pins should be decoupled to Pin 18. NOISE In high-resolution systems, noise is often the limiting factor. A 16-bit DAC with a 10 volt span has an LSB size of 152 µV (–96 dB). Therefore, the noise floor must remain below this level in the frequency ranges of interest. The AD569’s noise spectral density is shown in Figures 17 and 18. The lowband noise spectrum in Figure 17 shows the 1/f corner frequency at 1.2 kHz and Figure 18 shows the wideband noise to be below 40 nV/ Hz . Figure 17. Lowband Noise Spectrum Figure 18. Wideband Noise Spectrum |
Số phần tương tự - AD569_15 |
|
Mô tả tương tự - AD569_15 |
|
|
Link URL |
Chính sách bảo mật |
ALLDATASHEET.VN |
Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không? [ DONATE ] |
Alldatasheet là | Quảng cáo | Liên lạc với chúng tôi | Chính sách bảo mật | Trao đổi link | Tìm kiếm theo nhà sản xuất 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 |