|
|
Número de pieza | MC1408-8 | |
Descripción | 8-bit Multiplying D/A Converter | |
Fabricantes | ON Semiconductor | |
Logotipo | ||
Hay una vista previa y un enlace de descarga de MC1408-8 (archivo pdf) en la parte inferior de esta página. Total 9 Páginas | ||
No Preview Available ! MC1408−8
8−bit Multiplying D/A
Converter
The MC1408−8 is an 8−bit monolithic digital−to−analog converter
which provides high−speed performance with low cost. It is designed
for use where the output current is a linear product of an 8−bit digital
word and an analog reference voltage.
Features
• Fast Settling Time: 70 ns (typ)
• Relative Accuracy ±0.19% (max error)
• Non−inverting Digital Inputs are TTL and CMOS Compatible
• High−speed Multiplying Rate 4.0 mA/ms (Input Slew)
• Output Voltage Swing +0.5 V to −5.0 V
• Standard Supply Voltages +5.0 V and −5.0 V to −15 V
• Pb−Free Packages are Available*
Applications
• Tracking A−to−D Converters
• 2 1/2−Digit Panel Meters and DVMs
• Waveform Synthesis
• Sample−and−Hold
• Peak Detector
• Programmable Gain and Attenuation
• CRT Character Generation
• Audio Digitizing and Decoding
• Programmable Power Supplies
• Analog−Digital Multiplication
• Digital−Digital Multiplication
• Analog−Digital Division
• Digital Addition and Subtraction
• Speech Compression and Expansion
• Stepping Motor Drive Modems
• Servo Motor and Pen Drivers
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
© Semiconductor Components Industries, LLC, 2006
May, 2006 − Rev. 2
1
http://onsemi.com
MARKING DIAGRAMS
1 SOIC−16
D SUFFIX
CASE 751B
16
MC1408−8DG
AWLYWW
1
16
MC1408−8N
AWLYYWWG
1
PDIP−16 1
N SUFFIX
CASE 648 A = Assembly Location
WL = Wafer Lot
YY, Y = Year
WW = Work Week
G = Pb−Free Package
PIN CONNECTIONS
N Package
NC 1
GND 2
VEE 3
IO 4
MSB A1 5
A2 6
A3 7
A4 8
16 COMPEN
15 VREF(−)
14 VREF(+)
13 VCC
12 A8 LSB
11 A7
10 A6
9 A5
D Package*
VCC 1
VREF(+) 2
VREF(−) 3
COMPEN 4
NC 5
GND 6
VEE 7
IO 8
16 A8 LSB
15 A7
14 A6
13 A5
12 A4
11 A3
10 A2
9 A1 MSB
(Top View)
*SO and non−standard pinouts.
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 8 of this data sheet.
Publication Order Number:
MC1408−8/D
1 page MC1408−8
Circuit Description
The MC1408−8 consists of a reference current amplifier,
an R−2R ladder, and 8 high−speed current switches. For
many applications, only a reference resistor and reference
voltage need be added.
The switches are non−inverting in operation; therefore, a
high state on the input turns on the specified output current
component.
The switch uses current steering for high speed, and a
termination amplifier consisting of an active load gain stage
with unity gain feedback. The termination amplifier holds
the parasitic capacitance of the ladder at a constant voltage
during switching, and provides a low impedance
termination of equal voltage for all legs of the ladder.
The R−2R ladder divides the reference amplifier current
into binary−related components, which are fed to the
remainder current which is equal to the least significant bit.
This current is shunted to ground, and the maximum output
current is 255/256 of the reference amplifier current, or
1.992 mA for a 2.0 mA reference amplifier current if the
NPN current source pair is perfectly matched.
Functional Description
Reference Amplifier Drive and Compensation
The reference amplifier input current must always flow
into Pin 14. regardless of the setup method or reference
supply voltage polarity.
Connections for a positive reference voltage are shown in
Figure 3. The reference voltage source supplies the full
reference current. For bipolar reference signals, as in the
multiplying mode, R15 can be tied to a negative voltage
corresponding to the minimum input level. R15 may be
eliminated and Pin 15 grounded, with only a small sacrifice
in accuracy and temperature drift.
The compensation capacitor value must be increased with
increasing values of R14 to maintain proper phase margin.
For R14 values of 1.0, 2.5, and 5.0 kW, minimum capacitor
values are 15, 37, and 75 pF. The capacitor may be tied to
either VEE or ground, but using VEE increases negative
supply rejection. (Fluctuations in the negative supply have
more effect on accuracy than do any changes in the positive
supply.)
A negative reference voltage may be used if R14 is
grounded and the reference voltage is applied to R15, as
shown in Figure 4. A high input impedance is the main
advantage of this method. The negative reference voltage
must be at least 3.0 V above the VEE supply. Bipolar input
signals may be handled by connecting R14 to a positive
reference voltage equal to the peak positive input level at
Pin 15.
Capacitive bypass to ground is recommended when a DC
reference voltage is used. The 5.0 V logic supply is not
recommended as a reference voltage, but if a well regulated
5.0 V supply which drives logic is to be used as the
reference, R14 should be formed of two series resistors and
the junction of the two resistors bypassed with 0.1 mF to
ground. For reference voltages greater than 5.0 V, a clamp
diode is recommended between Pin 14 and ground.
If Pin 14 is driven by a high impedance such as a transistor
current source, none of the above compensation methods
apply and the amplifier must be heavily compensated,
decreasing the overall bandwidth.
VCC
VCC
A1 5
A2 6
A3 7
8
A4
9
A5
10
A6
A7 11
A8 12
13
14
15
1
MC1408 2
4
16
3
R14 = R15
R14
(+)VREF
R15
RL
IO
C
VEE SEE TEXT FOR VALUES OF C.
Figure 3. Positive VREF
A1 5
A2 6
A3 7
8
A4
9
A5
10
A6
A7 11
A8 12
13
14
15
1
MC1408 2
4
16
3
R14 = R15
R14
R15
RL
IO
C
(−)VREF
SEE TEXT FOR VALUES OF C.
VEE
Figure 4. Negative VREF
http://onsemi.com
5
5 Page |
Páginas | Total 9 Páginas | |
PDF Descargar | [ Datasheet MC1408-8.PDF ] |
Número de pieza | Descripción | Fabricantes |
MC1408-8 | 8-bit multiplying D/A converter | NXP Semiconductors |
MC1408-8 | (MC1508-8 / MC1408-8) 8-Bit Multiplying D/A Converter | NXP Semiconductors |
MC1408-8 | 8-bit Multiplying D/A Converter | ON Semiconductor |
MC1408-8D | 8-bit multiplying D/A converter | NXP Semiconductors |
Número de pieza | Descripción | Fabricantes |
SLA6805M | High Voltage 3 phase Motor Driver IC. |
Sanken |
SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
Analog Devices |
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |