AD7804/AD7805/AD7808/AD7809
–25–REV. A
Dual External Reference Input Capability
It is possible to operate the AD7804/AD7805/AD7808/AD7809
with two externally applied references. Figure 45 shows the
connections for the AD7804. Reference one, the AD589, is
connected to the REFIN pin of the part; the second reference,
the AD780, is used to overdrive the internal VDD/2 reference
which is provided at the COMP pin of the device. With the
circuit shown in Figure 45 it is possible to configure two of the
channels for operation with the AD780 2.5 V reference and the
other two with the AD589 1.23 V reference. The channel con-
trol register allows the user to select the reference for the indi-
vidual channels.
DV
DD
0.01mF
0.1mF
10mF
AD589
+5V
0.1mF
AD780
V
IN
GND
V
O
6.8kV
SERIAL
INTERFACE
AD7804
AV
DD
V
OUT
A
V
OUT
B
V
OUT
C
V
OUT
D
AGNDDGND
LDAC
CLR
COMP
FSIN
SDIN
CLKIN
DV
DD
REFOUT
REFIN
Figure 45. Two Externally Applied References
+5V
0.01mF
AD7805
AV
DD
DV
DD
V
OUT
A
V
OUT
B
V
OUT
C
V
OUT
D
AGNDDGND
LDAC
CLR
COMP
MODE
D9
D0
CS
WR
DV
DD
0.1mF
10mF
0.01mF
IN
1
V
C
1
IN
2
V
C
2
IN
3
V
C
3
IN
4
V
C
4
SSM2164
+15V
–15V
–V
V
IN
3V
IN
4
500V
560pF
30kV
30kV
500V
560pF
V
IN
2
V
IN
1
+V
100pF
30kV
+15V
–15V
V
OUT
A
1/2
OP275
500V
560pF
500V
560pF
30kV
30kV
100pF
30kV
+15V
–15V
V
OUT
B
1/2
OP275
Figure 44. Low Cost, Two-Channel Mixer
Low Cost, Two-Channel Mixer Using AD7805, SSM2164 and
OP275
The SSM2164 is a quad voltage controlled amplifier (VCA)
with 120 dB of gain control range. Each VCA in the package is
a current in, current out device with a –33 mV/dB voltage con-
trol input port. Figure 44 shows a basic application circuit
which can be used to implement a low cost stereo, two channel
mixer. A 30 k resistor converts the input voltage to an input
current for the VCA. The 500 resistor and 560 pF capacitor
on the input are added to ensure stable operation of the
SSM2164. The I
OUT
pin of the SSM2164 should be maintained
at virtual ground and thus the OP275 is operated in its inverting
mode. Its wide bandwidth, high slew rate and low power make it
ideal for a current to voltage converter. A 30 k feedback resis-
tor is chosen to match the input resistor and thus give unity gain
for a zero volt control voltage input. The 100 pF capacitors
reduce high frequency noise and can be increased to reduce the
low pass cutoff frequency for further noise reduction. The
AD7805 in the circuit is used to control the attenuation of the
VCA, this application circuit only gives attenuation. The voltage
output from the AD7805 provides a low impedance drive to the
SSM2164 so attenuation can be controlled accurately. With a
5 V V
DD
and a V
BIAS
of V
DD
/2 the AD7805 has an LSB size of
approximately 4.5 mV. Therefore, the attenuation can be con-
trolled with a resolution of 0.136 dB/bit and thus 750 codes are
required to provide the full 100 dB of attenuation.
AD7804/AD7805/AD7808/AD7809
REV. A–26–
PAGE INDEX
(AD7804/AD7808 SERIAL INTERFACE PART)
Topic Page No.
Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2, 3
Timing Information
Timing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . 6
Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Terminology
Relative Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Differential Nonlinearity . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Bias Offset Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Gain Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Zero-Scale Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Digital-to-Analog Glitch Impulse . . . . . . . . . . . . . . . . . . . . 9
Digital Feedthrough . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Digital Crosstalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Analog Crosstalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Power Supply Rejection Ratio . . . . . . . . . . . . . . . . . . . . . . 9
Interface Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
System Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Channel Control Register . . . . . . . . . . . . . . . . . . . . . . . . . 11
SUB DAC Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Power-Up Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Clear Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Power-Down and Standby Functions . . . . . . . . . . . . . . . . . 16
LDAC Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Transfer Functions
Pictorial View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Twos Complement (Main DAC) . . . . . . . . . . . . . . . . . . . 16
Twos Complement (Sub DAC) . . . . . . . . . . . . . . . . . . . . 17
Complete Channel Transfer Function . . . . . . . . . . . . . . . 17
Offset Binary (Main DAC) . . . . . . . . . . . . . . . . . . . . . . . . 18
Offset Binary (Sub DAC) . . . . . . . . . . . . . . . . . . . . . . . . . 19
Grounding and Layout Techniques . . . . . . . . . . . . . . . . . . . 20
Reference Settling Time . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Typical Performance Characteristics . . . . . . . . . . . . . . . . . . 21
Microprocessor Interfacing
ADSP-2101/ADSP-2103 . . . . . . . . . . . . . . . . . . . . . . . . . 22
68HC11/68L11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
80C51/80L51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Applications
Opto-Isolated Interface . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Decoding Multiple ICs . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Outline Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27, 28
PAGE INDEX
(AD7805/AD7809 PARALLEL INTERFACE PART)
Topic Page No.
Functional Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2, 3
Timing Information
Timing Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . 6
Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Pin Function Description . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Terminology
Relative Accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Differential Nonlinearity . . . . . . . . . . . . . . . . . . . . . . . . . 9
Bias Offset Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Gain Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Zero-Scale Error . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Digital-to-Analog Glitch Impulse . . . . . . . . . . . . . . . . . . . 9
Digital Feedthrough . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Digital Crosstalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Analog Crosstalk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Power Supply Rejection Ratio . . . . . . . . . . . . . . . . . . . . . 9
Interface Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
System Control Registers . . . . . . . . . . . . . . . . . . . . . . . . 14
Channel Control Register . . . . . . . . . . . . . . . . . . . . . . . . 14
Power-Up Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Clear Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Power-Down and Standby Functions . . . . . . . . . . . . . . . . 16
LDAC Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Analog Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Transfer Functions
Pictorial View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Twos Complement (Main DAC) . . . . . . . . . . . . . . . . . . 16
Twos Complement (Sub DAC) . . . . . . . . . . . . . . . . . . . 17
Complete Channel Transfer Function . . . . . . . . . . . . . . 17
Offset Binary (Main DAC) . . . . . . . . . . . . . . . . . . . . . . . 18
Offset Binary (Sub DAC) . . . . . . . . . . . . . . . . . . . . . . . . 19
Grounding and Layout Techniques . . . . . . . . . . . . . . . . . . 20
Reference Settling Time . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Typical Performance Characteristics . . . . . . . . . . . . . . . . . 21
Microprocessor Interfacing
ADSP-2101/ADSP-2103 . . . . . . . . . . . . . . . . . . . . . . . . 23
TMS32020 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
8051/8088 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Applications
Programmable Window Detector . . . . . . . . . . . . . . . . . . 24
Low Cost Two-Channel Mixer . . . . . . . . . . . . . . . . . . . 25
Dual External Reference Input Capability . . . . . . . . . . . 25
Outline Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . 27, 28
AD7804/AD7805/AD7808/AD7809
–27–REV. A
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
Plastic DIP (N-28)
PIN 1
0.580 (14.73)
0.485 (12.32)
1
14
1528
0.625 (15.87)
0.600 (15.24)
0.015 (0.381)
0.008 (0.204)
0.195 (4.95)
0.125 (3.18)
0.250
(6.35)
MAX
0.022 (0.558)
0.014 (0.356)
0.100
(2.54)
BSC
0.200 (5.05)
0.125 (3.18)
0.070 (1.77)
MAX
0.060 (1.52)
0.015 (0.38)
0.150
(3.81)
MIN
SEATING
PLANE
1.565 (39.70)
1.380 (35.10)
SOIC (R-28)
PIN 1
0.2992 (7.60)
0.2914 (7.40)
0.4193 (10.65)
0.3937 (10.00)
1
28 15
14
0.0125 (0.32)
0.0091 (0.23)
0.0500 (1.27)
0.0157 (0.40)
8°
0°
0.0291 (0.74)
0.0098 (0.25)
x 45°
0.0192 (0.49)
0.0138 (0.35)
0.0500 (1.27)
BSC
0.1043 (2.65)
0.0926 (2.35)
0.7125 (18.10)
0.6969 (17.70)
0.0118 (0.30)
0.0040 (0.10)
SSOP (RS-28)
1. LEAD NO. 1 IDENTIFIED BY A DOT.
2. LEADS WILL BE EITHER TIN PLATED OR SOLDER DIPPED
IN ACCORDANCE WITH MIL-M-38510 REQUIREMENTS
0.009 (0.229)
0.005 (0.127)
0.03 (0.762)
0.022 (0.558)
8°
0°
0.0256 (0.65)
BSC
0.407 (10.34)
0.397 (10.08)
0.008 (0.203)
0.002 (0.050)
0.07 (1.78)
0.066 (1.67)
PIN 1
15
14
1
28
0.311 (7.9)
0.301 (7.64)
0.212 (5.38)
0.205 (5.207)
0.015 (0.38)
0.010 (0.25)
Plastic DIP (N-16)
16
18
9
0.840 (21.33)
0.745 (18.93)
0.280 (7.11)
0.240 (6.10)
PIN 1
SEATING
PLANE
0.022 (0.558)
0.014 (0.356)
0.060 (1.52)
0.015 (0.38)
0.210 (5.33)
MAX
0.130
(3.30)
MIN
0.070 (1.77)
0.045 (1.15)
0.100
(2.54)
BSC
0.160 (4.06)
0.115 (2.93)
0.325 (8.25)
0.300 (7.62)
0.015 (0.381)
0.008 (0.204)
0.195 (4.95)
0.115 (2.93)
SOIC (R-16)
16 9
81
0.4133 (10.50)
0.3977 (10.00)
0.4193 (10.65)
0.3937 (10.00)
0.2992 (7.60)
0.2914 (7.40)
PIN 1
SEATING
PLANE
0.0118 (0.30)
0.0040 (0.10)
0.0192 (0.49)
0.0138 (0.35)
0.1043 (2.65)
0.0926 (2.35)
0.0500
(1.27)
BSC
0.0125 (0.32)
0.0091 (0.23)
0.0500 (1.27)
0.0157 (0.40)
8°
0°
0.0291 (0.74)
0.0098 (0.25)
x 45°

AD7805BNZ

Mfr. #:
Manufacturer:
Description:
Digital to Analog Converters - DAC 3.3V-5V Quad/ Octal 10-Bit
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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