DSC-11520
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®
16-BIT PIN PROGRAMMABLE
D/S OR D/R CONVERTER
FEATURES
•
Complete D/S or D/R Converter
•
Accuracy up to ± 1 Minute
•
DC-Coupled Reference - Accepts
Most Waveforms
•
Generates SIN/COS DC or Rotating
PPI Sweep
•
High-Rel CMOS D/R Chip
•
8-Bit/16-Bit Double-Buffered
Transparent Latches
DESCRIPTION
The DSC-11520 is a versatile multiplying Digital-to-Synchro/Resolver con-
verter. The digital input represents an angle and the output is pin program-
mable for either resolver type SIN/COS or three-line synchro output. The
device will accept most of the commonly used waveshapes as reference,
even a sawtooth input in the case of a CRT drive application. Because the
reference is DC-coupled to the output, the DSC-11520 can be used in many
configurations:
• Digital-to-Synchro or Digital-to-Resolver converter (using a sinusoidal
reference input)
• Hybrid Digital-to-SIN/COS DC converter (using a DC reference input)
• Polar to rectangular coordinates converter (using a reference input
proportional to the radius vector)
• Generate a cartwheel rotating sweep for PPI displays (using a saw-
tooth reference input and a rotating digital input)
Packaged in a 36-pin double DIP, the DSC-11520 is a complete D/S and D/R
converter in one hybrid module.
The DSC-11520 is a light, low power, very highly reliable device with a wide
operating temperature range. The internal hybrid circuit design results in high
accuracy and reduces the output scale factor so that the output can drive
displays directly. The output line-to-line voltage can be scaled by external
resistors. The reference input provides high AC and DC common mode rejec-
tion.
APPLICATIONS
The DSC-11520's high reliability, small size, and low power consumption
make it an ideal solution for most stringent and sever applications (industrial,
military ground vehicles, aircraft avionics, etc.). Among the many other pos-
sible applications are computer based systems in which digital information is
processed, such as simulators, flight trainers, flight instrumenation, fire con-
trol systems, radar and navigation systems, and PPI displays including mov-
ing target indicators. All versions of the DSC-11520 are available with MIL-
PRF-38534 processing as a standard ordering option.
FOR MORE INFORMATION CONTACT:
Data Device Corporation
105 Wilbur Place
Bohemia, New York 11716
631-567-5600 Fax: 631-567-7358
www.ddc-web.com
Technical Support:
1-800-DDC-5757 ext. 7771
All trademarks are the property of their respective owners.
©
1985, 1999 Data Device Corporation
TABLE 1. DSC-11520 SPECIFICATIONS
Apply over temperature range, power supply ranges, reference voltage
and frequency range and 10% harmonic distortion in the reference.
PARAMETER
RESOLUTION
ACCURACY AND
DYNAMICS
Output Accuracy
Differential Linearity
Output Settling Time
DIGITAL INPUT
Logic Type
16 bits
VALUE
POwER SUPPLY CYCLING
Power supply cycling of the DDC converter should follow the
guidelines below to avoid any potential problems. Strictly main-
tain proper sequencing of supplies and signals per typical CMOS
circuit guidelines:
1. Apply power supplies (+15V, -15V and ground)
2. Apply digital control signals
3. Apply analog signals
The reverse sequence should be followed during power down of
the circuit.
±8 minutes to ±1 min. (See Ordering Info.)
±1 LSB max
Less than 20 µsec for any digital step change.
Natural binary angle parallel positive logic CMOS and
TTL compatible.
Inputs are CMOS transient protected. Each input has
a 20 µA max pull down to GND.
V = +4.5 V to +15 V supply
Logic 0 = 0 to +0.8 V
Logic 1 = 2 V to 1/3 of VDD +10%
20 µA max (bit 1-16)
65 µA (LL, LM, LA) See Timing Diagram
(FIGURE 2)
Two differential solid-state inputs, one for standard
26 V input and one programmable.
DC to 1000 Hz
Standard Input
Programmable input
26 V ±10%
1.3 V min for full output;
higher voltages are scaled by
adding two series resistors
100 kΩ ± 0.5%
200 kΩ ± 0.5%
5 kΩ ± 0.5%
10 kΩ ± 0.5%
Logic Voltage Level
Load Current
OUTPUT SCALING AND REF. LEVEL ADJUSTMENT
The DSC-11520 operates like a multiplying D/A converter in that
the voltage of each output line is directly proportional to the refer-
ence voltage.
The maximum line-to-line levels are determined by the output
amplifiers and are nominally 11.8 Vrms for synchro output and
6.81 Vrms for resolver output.The RH, RL set of reference inputs
are designed to provide this nominal output for the standard 26
Vrms reference level. The scaling adjustment is made by two
internal 100 kΩ resistors in series with the reference conditioner
input (see Figure 1). The maximum output levels without distor-
tion are 10% greater than the nominal 11.8 Vrms and 6.81 V rms
levels.
The RH', RL' reference inputs have 5 kΩ internal resistors in
series with the reference conditioner input, so that nominal line-
to-line output is obtained for a reference input of 1.3 Vrms. For
higher reference voltages, two resistors R' must be inserted in
series with the inputs as shown in FIGURE 2. These resistors
scale the DSC-11520 outputs to the nominal 11.8 Vrms and 6.81
Vrms levels stated above, or to lower voltages if desired. The
magnitude of the resistors R' in ohms is calculated as follows:
R' = 5000 (VR - 1.3)
1.3
L-L VOLTAGE LEVEL
(
NOMINAL L-L VOLTAGE LEVEL
)
DESIRED
REFERENCE INPUT
Type
Frequency Range
Voltage
Input Impedance
Single Ended
Differential
ANALOG OUTPUT
Type
Output current
Max Output Voltage (Tracks
Reference Input Voltage)
Transformation Ratio Tol. +
Scale Factor Variation
DC Offset Each Line to
GND
POWER SUPPLIES
Voltage
Voltage Limits
Max Voltage Without
Damage
Current or impedance
Pin programmable for synchro or resolver mode.
2 mA rms max.
11.8 V rms L-L ±0.25%nominal in synchro mode
6.81 V rms L-L ±0.25%nominal resolver mode
±0.6% max
±15 mV standard, varies with input angle
±5 mV available- Consult Factory
+15 V
±5%
+18 V
-15 V
±5%
-18 V
20 mA max
20 mA max
No Vl required; +5 V logic levels are derived
internally.
TEMPERATURE RANGES
(CASE)
Operating
-1 Option
-3 Option
Storage
PHYSICAL
CHARACTERISTICS
Type
Size
Weight
OUTPUT PHASING AND OUTPUT SCALE FACTOR
The analog output signals have the following phasing:
Synchro output
S1 — S3 = (RH-RL) Ao (1 + A(θ)) sin
θ
S3 — S2 = (RH-RL) Ao (1 + A(θ)) sin (θ + 120°)
S2 — S1 = (RH-RL) Ao (1 + A(θ)) sin (θ + 240°)
Resolver output
S1 — S3 = (RH-RL) Ao (1 + A(θ)) sin
θ
S2 — S4 = (RH-RL) Ao (1 + A(θ)) cos
θ
The output amplitudes simultaneously track reference voltage
fluctuations because they are proportional to (RH-RL). The trans-
formation ratio Ao is 11.8/26 for 11.8 V rms L-L output. The term
A (θ) represents the variation of the amplitude with the digital
input angle. A (θ), which is called the scale factor variation, is a
smooth function of
θ
without discontinuities.
Because the amplitude factor (RH-RL) Ao (1 + A(θ)) varies simul-
taneously on all output lines, it will not be a source of error when
the DSC-11520 is to drive a ratiometric system such as a synchro
or resolver. However, if the outputs are used independently, as in
X-Y plotters, the amplitude variations must be taken into
account.
3
DSC-11520
P-06/09-0
-55°C to +125°C
0°C to +70°C
-55°C to 135°C
36-pin double DIP
0.78 X 1.9 X 0.21inch (2.0 X 4.8 X 0.53 cm)
0.85 oz (24g)
INTRODUCTION
As shown in Figure 1, the signal conversion in the DSC-11520 is
performed by a high accuracy Digital-to-Resolver converter
whose SIN and COS outputs have a low scale factor variation as
a function of the digital input angle. This resolver output is either
multiplied by scaling amplifiers for resolver output, or is both mul-
tiplied and converted to a synchro output by an electronic Scott-T.
The output line currents are limited to 2 mA rms max, which is
sufficient for driving S/D converters, solid-state control transform-
ers, and displays. Output power amplifiers will be required for
driving electro-mechanical devices such as synchros and resolv-
ers.
Data Device Corporation
www.ddc-web.com
TABLE 2. PIN CONNECTIONS
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
FUNCTION
NC
+15 V
GND
-15 V
NC
NC
-R
RL
RL'
RH
RH'
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1 (MSB)
Bit 15
Bit 16 (LSB)
LM
LL
LA
NC
S1
S2'
S3'
S3 (+SIN)
S2 (+COS)
No Connect (no internal wire connection)
+15 VDC power supply voltage
Ground
-15 VDC power supply voltage
No Connect (no internal wire connection)
No Connect (no internal wire connection)
Test point used to detect whether a reference signal is present (see Figure 1). A signal between 6 V rms and 7.5 V rms
indicates that a reference input signal is present.
Reference input Lo (respective to RH)
Reference input Lo' (respective to RH')
Reference input Hi. Provides the maximum synchro or resolver output voltage for a standard 26 V rms reference input.
Reference input Hi'. Can be used to scale the output for other reference voltage levels. Series resistors can be added to the
reference input either to accomodate lower reference levels for full output, or to reduce the output level.
Angle data word Bit 14
Angle data word Bit 13
Angle data word Bit 12
Angle data word Bit 11
Angle data word Bit 10
Angle data word Bit 9
Angle data word Bit 8
Angle data word Bit 7
Angle data word Bit 6
Angle data word Bit 5
Angle data word Bit 4
Angle data word Bit 3
Angle data word Bit 2
Angle data word Bit 1 (MSB)
Angle data word Bit 15
Angle data word Bit 16 (LSB)
Active low control signal for latching angle data word bits 1 - 8. May be left unconnected when not used. (See Figure 3B for
timing diagrams).
Active low control signal for latching angle data word bits 9 - 16. May be left unconnected when not used. (See Figure 3B for
timing diagrams).
Active low control signal for latching angle data word bits 1 - 16. May be left unconnected when not used. (See Figure 3B for
timing diagrams).
No Connect (no internal wire connection)
Pin jumper programmable for synchro or single-ended resolver output. (see Figure 4)
Pin jumper programmable for synchro or single-ended resolver output. (see Figure 4)
Pin jumper programmable for synchro or single-ended resolver output. (see Figure 4)
Pin jumper programmable for synchro or single-ended resolver output. (see Figure 4)
Pin jumper programmable for synchro or single-ended resolver output. (see Figure 4)
DESCRIPTION
Data Device Corporation
www.ddc-web.com
5
DSC-11520
P-06/09-0
京公网安备 11010802033920号
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