数据搜索系统,热门电子元器件搜索
  Chinese  ▼
ALLDATASHEETCN.COM

X  

AD7304BN 数据表(PDF) 11 Page - Analog Devices

部件名 AD7304BN
功能描述  3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
Download  14 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
制造商  AD [Analog Devices]
网页  http://www.analog.com
标志 AD - Analog Devices

AD7304BN 数据表(HTML) 11 Page - Analog Devices

Back Button AD7304BN Datasheet HTML 6Page - Analog Devices AD7304BN Datasheet HTML 7Page - Analog Devices AD7304BN Datasheet HTML 8Page - Analog Devices AD7304BN Datasheet HTML 9Page - Analog Devices AD7304BN Datasheet HTML 10Page - Analog Devices AD7304BN Datasheet HTML 11Page - Analog Devices AD7304BN Datasheet HTML 12Page - Analog Devices AD7304BN Datasheet HTML 13Page - Analog Devices AD7304BN Datasheet HTML 14Page - Analog Devices  
Zoom Inzoom in Zoom Outzoom out
 11 / 14 page
background image
–11–
AD7304/AD7305
REV. A
CIRCUIT OPERATION
The AD7304/AD7305 are a set of four-channel, 8-bit, voltage-
output, digital-to-analog converters differing primarily in digital
logic interface and number of reference inputs. Both parts share
the same internal DAC design and true rail-to-rail output buff-
ers. The AD7304 contains four independent multiplying refer-
ence inputs, while the AD7305 has one common reference input.
The AD7304 uses a 3-wire SPI compatible serial data interface,
while the AD7305 offers a 8-bit parallel data interface.
D/A Converter Section
Each part contains four voltage-switched R-2R ladder DACs.
Figure A shows a typical equivalent DAC. These DACs are
designed to operate both single-supply or dual supply, depend-
ing on whether the user supplies a negative voltage on the VSS
pin. In a single-supply application the VSS is tied to ground. In
either mode the DAC output voltage is determined by the VREF
input voltage and the digital data (D) loaded into the corre-
sponding DAC register according to Equation 1.
VOUT = VREF
× D/256
(1)
Note that the output full-scale polarity is the same as the VREF
polarity for dc reference voltages.
VREF
DB7
2R
VDD
VSS
VOUT
R
2R
DB6
2R
DB0
2R
Figure 29. Typical Equivalent DAC Channel
These DACs are also designed to accommodate ac reference
input signals. As long as the ac signals are maintained between
VSS < VREF <VDD, the user can expect 50 kHz of full-power
multiplying bandwidth performance. In order to use negative
input reference voltages, the VSS pin must be biased with a nega-
tive voltage of equal or greater magnitude than the reference
voltage.
The reference inputs are code-dependent, exhibiting worst case
minimum resistance values specified in the parametric specifica-
tion table. The DAC outputs VOUTA, B, C, D are each capable
of driving 2 k
Ω loads in parallel with up to 500 pF loads. Output
source and sink current is shown in Figures 6 and 7. The output
slew rate is nominally 3.6 V/
µs while operating from ±5 V sup-
plies. The low output impedance of the buffers minimizes
crosstalk between analog input channels. At 100 kHz, 65 dB of
channel-to-channel isolation exists (Figure 22). Output voltage
noise is plotted in Figure 19. In order to maintain good analog
performance, power supply bypassing of 0.01
µF in parallel with
1
µF is recommended. The true rail-to-rail capability of the
AD7304/AD7305 allows the user to connect the reference inputs
directly to the same supply as the VDD or VSS pin (Figure 30).
Under these conditions clean power supply voltages (low ripple,
avoid switching supplies) appropriate for the application should
be used.
VDD
VSS
VOUTX
120k
Q1
Q2
Figure 30. Equivalent DAC Amplifier Output Circuit
AD7304 SERIAL DATA INTERFACE
The AD7304 uses a 3-wire (CS, SDI, CLK) SPI compatible
serial data interface. New serial data is clocked into the serial
input register in a 12-bit data-word format. MSB bits are loaded
first. Table II defines the 12 data-word bits. Data is placed on
the SDI/SHDN pin and clocked into the register on the positive
clock edge of CLK subject to the data setup and data hold time
requirements specified in the TIMING SPECIFICATIONS.
Data can only be clocked in while the CS chip select pin is
active low. Only the last 12-bits clocked into the serial register
will be interrogated when the CS pin returns to the logic high
state, extra data bits are ignored. Since most microcontrollers
output serial data in 8-bit bytes, two right justified data bytes
can be written to the AD7304. Keeping the CS line low between
the first and second byte transfer will result in a successful serial
register update.
Once the data is properly aligned in the shift register the positive
edge of the CS initiates either the transfer of new data to the
target DAC register, determined by the decoding of address bits
A1 and A0, or the shutdown features will be activated based on
the SAC or SDC bits. When either SAC or SDC pins are set
(Logic = 0) the loading of new data determined by Bits B9 to
B0 are still loaded, but the results do not appear on the buffer
outputs until the device is brought out of the shutdown state.
The selected DAC output voltages become high impedance with
a nominal resistance of 120 k
Ω to ground, Figure 30. If both
SAC and SDC pins are set, all channels are still placed in the
shutdown mode. When the AD7304 has been programmed into
the power shutdown state, the present DAC register data is
maintained as long as VDD remains greater than 2.7 volts. The
remaining characteristics of the software serial interface are
defined by Tables I, II and Figure 3 timing diagram.
Two additional pins CLR and LDAC on the AD7304 provide
hardware control over the clear function and the DAC Register
loading. If these functions are not needed the CLR pin can be
tied to logic high, and the LDAC pin can be tied to logic low.
The asynchronous input CLR pin forces all input and DAC
registers to the zero-code state. The asynchronous LDAC pin
can be strobed to active low when all DAC Registers need to be
updated simultaneously from their respective Input Registers.
The LDAC pin places the DAC Register in a transparent mode
while in the logic low state.


类似零件编号 - AD7304BN

制造商部件名数据表功能描述
logo
Analog Devices
AD7304BR AD-AD7304BR Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD7304BR AD-AD7304BR Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD7304BR AD-AD7304BR Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD7304BR-REEL AD-AD7304BR-REEL Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD7304BR-REEL AD-AD7304BR-REEL Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
More results

类似说明 - AD7304BN

制造商部件名数据表功能描述
logo
Analog Devices
AD7304 AD-AD7304_15 Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD7305BRZ-REEL AD-AD7305BRZ-REEL Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD7305BRUZ AD-AD7305BRUZ Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD7305BRZ AD-AD7305BRZ Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD7305 AD-AD7305_15 Datasheet
902Kb / 20P
   3 V/5 V, Rail-to-Rail Quad, 8-Bit DAC
REV. C
AD5300 AD-AD5300_15 Datasheet
221Kb / 13P
   2.7 V to 5.5 V, 140 A, Rail-to-Rail Output 8-Bit DAC in a SOT-23
REV. D
logo
Maxim Integrated Produc...
MAX533 MAXIM-MAX533 Datasheet
146Kb / 16P
   2.7V, Low-Power, 8-Bit Quad DAC with Rail-to-Rail Output Buffers
Rev 0; 6/96
logo
Analog Devices
AD5300 AD-AD5300 Datasheet
202Kb / 12P
   2.7 V to 5.5 V, 140 uA, Rail-to-Rail Output 8-Bit DAC in an SOT-23
REV. C
AD5300BRMZ-REEL7 AD-AD5300BRMZ-REEL7 Datasheet
221Kb / 13P
   2.7 V to 5.5 V, 140 muA, Rail-to-Rail Output 8-Bit DAC in a SOT-23
REV. D
logo
Maxim Integrated Produc...
MAX534 MAXIM-MAX534 Datasheet
125Kb / 16P
   5V, Low-Power, 8-Bit Quad DAC with Rail-to-Rail Output Buffers
Rev 0; 8/96
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14


数据表 下载

Go To PDF Page


链接网址




隐私政策
ALLDATASHEETCN.COM
ALLDATASHEET是否为您带来帮助?  [ DONATE ] 

关于 Alldatasheet   |   广告服务   |   联系我们   |   隐私政策   |   链接交换   |   制造商名单
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
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