Datenblatt-pdf.com


DAC8420EP Schematic ( PDF Datasheet ) - Analog Devices

Teilenummer DAC8420EP
Beschreibung Quad 12-Bit Serial Voltage Output DAC
Hersteller Analog Devices
Logo Analog Devices Logo 




Gesamt 16 Seiten
DAC8420EP Datasheet, Funktion
a
Quad 12-Bit Serial
Voltage Output DAC
FEATURES
Guaranteed Monotonic Over Temperature
Excellent Matching Between DACs
Unipolar or Bipolar Operation
Buffered Voltage Outputs
High Speed Serial Digital Interface
Reset to Zero- or Center-Scale
Wide Supply Range, +5 V-Only to ؎15 V
Low Power Consumption (35 mW max)
Available in 16-Pin DIP and SOL Packages
APPLICATIONS
Software Controlled Calibration
Servo Controls
Process Control and Automation
ATE
GENERAL DESCRIPTION
The DAC8420 is a quad, 12-bit voltage-output DAC with serial
digital interface, in a 16-pin package. Utilizing BiCMOS tech-
nology, this monolithic device features unusually high circuit
density and low power consumption. The simple, easy-to-use
serial digital input and fully buffered analog voltage outputs
require no external components to achieve specified performance.
The three-wire serial digital input is easily interfaced to micro-
processors running at 10 MHz rates, with minimal additional
circuitry. Each DAC is addressed individually by a 16-bit serial
word consisting of a 12-bit data word and an address header.
The user-programmable reset control CLR forces all four DAC
outputs to either zero or midscale, asynchronously overriding
the current DAC register values. The output voltage range, de-
termined by the inputs VREFHI and VREFLO, is set by the
user for positive or negative unipolar or bipolar signal swings
within the supplies allowing considerable design flexibility.
DAC8420
FUNCTIONAL BLOCK DIAGRAM
SDI 10
CS 12
CLK 11
NC 13
VREFHI
5
RREEGG DAC A
AA
12
VDD
1
7 VOUTA
SHIFT
REGISTER
REG DAC B
B
6 VOUTB
4
REG DAC C
C
3 VOUTC
LD 14
DECODE
2
REG DAC D
D
2 VOUTD
9
GND
16 15
CLSEL CLR
4
VREFLO
8
VSS
The DAC8420 is available in 16-pin epoxy DIP, cerdip, and
wide-body SOL (small-outline surface mount) packages. Opera-
tion is specified with supplies ranging from +5 V-only to ± 15 V,
with references of +2.5 V to ± 10 V respectively. Power dissipa-
tion when operating from ± 15 V supplies is less than 255 mW
(max), and only 35 mW (max) with a +5 V supply.
For applications requiring product meeting MIL-STD-883,
contact your local sales office for the DAC8420/883 data sheet,
which specifies operation over the –55°C to +125°C tempera-
ture range.
REV. 0
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700
Fax: 617/326-8703






DAC8420EP Datasheet, Funktion
DAC8420
DIP
PIN CONFIGURATIONS
SOL
VDD 1
16 CLSEL
VOUTD 2
15 CLR
VOUTC 3
VREFLO 4
VREFHI 5
VOUTB 6
DAC8420
TOP VIEW
(Not to Scale)
14 LD
13 NC
12 CS
11 CLK
VOUTA 7
10 SDI
VSS 8
9 GND
NC = NO CONNECT
VDD 1
16 CLSEL
VOUTD 2 DAC-8420 15 CLR
VOUTC
VREFLO
3
4
TOP VIEW 14
(DNDAoAtCtCo-88S44c2a20le0) 13
TOP VIEW
LD
NC
TOP VIEW
VREFHI 5
(Not to Scale) 12 CS
(Not to Scale)
VOUTB 6
11 CLK
VOUTA 7
10 SDI
VSS 8
9 GND
NC = NO CONNECT
PIN FUNCTION DESCRIPTION
Power Supplies
Clock
Control Inputs
Data Input
Reference Inputs
Analog Outputs
VDD: Positive Supply, +5 V to +15 V.
VSS: Negative Supply, 0 V to –15 V.
GND: Digital Ground.
CLK: System Serial Data Clock Input, TTL/CMOS levels. Data presented to the input SDI is shifted into
the internal serial-parallel input register on the rising edge of clock. This input is logically ORed with CS.
(All are CMOS/TTL compatible.)
CLR: Asynchronous Clear, active low. Sets internal data registers A-D to zero or midscale, depending on cur-
rent state of CLSEL. The data in the serial input shift register is unaffected by this control.
CLSEL: Determines action of CLR. If HIGH, a Clear command will set the internal DAC registers A-D to
midscale (800H). If LOW, the registers are set to zero (000H).
CS: Device Chip Select, active low. This input is logically ORed with the clock and disables the serial data
register input when HIGH. When LOW, data input clocking is enabled, see the Control Function Table.
LD: Asynchronous DAC Register Load Control, active low. The data currently contained in the serial input
shift register is shifted out to the DAC data registers on the falling edge of LD, independent of CS. Input data
must remain stable while LD is LOW.
(All are CMOS/TTL compatible.)
SDI: Serial Data Input. Data presented to this pin is loaded into the internal serial-parallel shift register, which
shifts data in beginning with DAC address Bit A1. This input is ignored when CS is HIGH.
The format of the 16-bit serial word is:
(FIRST)
(LAST)
B0 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13 B14 B15
A1 A0 NC NC D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
—Address Word—
(MSB)
—DAC Data Word—
(LSB)
NC = Don’t Care.
VREFHI: Upper DAC ladder reference voltage input. Allowable range is (VDD – 2.5 V) to (VVREFLO +2.5 V).
VREFLO: Lower DAC ladder reference voltage input, equal to zero scale output. Allowable range is VSS to
(VVREFHI – 2.5 V).
VOUTA through VOUTD: Four buffered DAC voltage outputs.
–6– REV. 0

6 Page









DAC8420EP pdf, datenblatt
DAC8420
single supply operation is obtained with the output load
connected to ground, so the output stage does not have to sink
current.
Like all amplifiers, the DAC8420 output buffers do generate
voltage noise, 52 nV/Hz typically. This is easily reduced by
adding a simple RC low-pass filter on each output.
Reference Configuration
The two reference inputs of the DAC8420 allow a great deal of
flexibility in circuit design. The user must take care, however, to
observe the minimum voltage input levels on VREFHI and
VREFLO to maintain the accuracy shown in the data sheet.
These input voltages can be set anywhere across a wide range
within the supplies, but must be a minimum of 2.5 V apart in
any case. See Figure 1. A wide output voltage range can be
obtained with ± 5 V references, which can be provided by the
AD588 as shown in Figure 28. Many applications utilize the
DACs to synthesize symmetric bipolar wave forms, which
requires an accurate, low drift bipolar reference. The AD588
provides both voltages and needs no external components. Ad-
ditionally, the part is trimmed in production for 12-bit accuracy
over the full temperature range without user calibration. Per-
forming a Clear with the reset select CLSEL HIGH allows the
user to easily reset the DAC outputs to midscale, or zero volts in
these applications.
When driving the reference inputs VREFHI and VREFLO, it is
important to note that VREFHI both sinks and sources current,
and that the input currents of both are code dependent. Many
voltage reference products have limited current sinking capabil-
ity and must be buffered with an amplifier to drive VREFHI, in
order to maintain overall system accuracy. The input VREFLO,
however, has no such requirement.
1µF
7
6 43
+15V SUPPLY
+5V
VREFHI
5
1
0.1µF
RB
A1
R1
R2
R3
A2
5 96
10
AD588
R4
R5
A3 1
14
A4 15
R6
8 12 11 13
+VS 2
–VS 16
0.1µF
0.1µF
+5V
–5V
+15V
SUPPLY
SYSTEM
GROUND
–15V
SUPPLY
DAC-8420
DAC A
DAC B
7 VOUTA
6 VOUTB
DIGITAL
CONTROL
DAC C
DAC D
3 VOUTC
2 VOUTD
10 11 12 14 15 16
DIGITAL INPUTS
94
8
GND VREFLO
–5V
0.1µF
Figure 28. ±10 V Bipolar Reference Configuration Using the AD588
–15V SUPPLY
–12–
REV. 0

12 Page





SeitenGesamt 16 Seiten
PDF Download[ DAC8420EP Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
DAC8420EPQuad 12-Bit Serial Voltage Output DACAnalog Devices
Analog Devices
DAC8420EQQuad 12-Bit Serial Voltage Output DACAnalog Devices
Analog Devices
DAC8420ESQuad 12-Bit Serial Voltage Output DACAnalog Devices
Analog Devices

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche