Cadeka CDK3402 8-bit, 100/150msps, triple video dac Datasheet

Data Sheet
A m p l i fy t h e H u m a n E x p e r i e n c e
CDK3402/CDK3403
General Description
features
n
8-bit resolution
n
150 megapixels per second
n
±0.2% linearity error
n
Sync and blank controls
n
1.0Vpp video into 37.5Ω or 75Ω load
n
Internal bandgap voltage reference
n
Double-buffered data for low distortion
n
TTL-compatible inputs
n
Low glitch energy
n
Single +5V power supply
CDK3402/3401 products are low-cost triple D/A converters that are tailored
to fit graphics and video applications where speed is critical. Two speed
grades are available: CDK3402 at 100MSPS and CDK3403 at 150MSPS.
Few external components are required, just the current reference resistor,
current output load resistors, and decoupling capacitors.
Applications
n
Package is a 48-lead TQFP. Fabrication technology is CMOS. Performance is
guaranteed from 0 to 70°C.
Video signal conversion
– RGB
– YCBCR
– Composite, Y, C
n
Multimedia systems
n
Image processing
n
True-color graphics systems
TTL-level inputs are converted to analog current outputs that can drive
25-37.5Ω loads corresponding to doubly-terminated 50-75Ω loads. A sync
current following SYNC input timing is added to the IOG output. BLANK
will override RGB inputs, setting IOG, IOB and IOR currents to zero when
BLANK = L. Although appropriate for many applications, the internal 1.235V
reference voltage can be overridden by the VREF input.
Block Diagram
SYNC
SYNC
BLANK
G7-0
R7-0
8-bit D/A
Converter
IO G
8
8-bit D/A
Converter
IO B
8
8-bit D/A
Converter
IO R
CLOCK
Rev 1B
B7-0
8
COMP
R REF
V REF
+1.235V
Ref
Ordering Information
Part Number
Package
Pb-Free
RoHS Compliant
Operating Temp Range
Packaging Method Package Quantity
CDK3402CTQ48
TQFP-48
Yes
Yes
0°C to +70°C
Tray
250
CDK3402CTQ48Y
TQFP-48
Yes
Yes
0°C to +70°C
Tray
1,250
CDK3403CTQ48
TQFP-48
Yes
Yes
0°C to +70°C
Tray
250
CDK3403CTQ48Y
TQFP-48
Yes
Yes
0°C to +70°C
Tray
1,250
Moisture sensitivity level for all parts is MSL-3.
©2008 CADEKA Microcircuits LLC CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
8-bit, 100/150MSPS, Triple Video DACs
www.cadeka.com
Data Sheet
Pin Configuration
GND
R7
R6
R5
R4
R3
R2
R1
R0
GND
GND
NC
TQFP-48
48
47
46
45
44
43
42
41
40
39
38
37
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
1
2
3
4
5
6
7
8
9
10
11
12
TQFP
CDK3402/3403
36
35
34
33
32
31
30
29
28
27
26
25
RREF
VREF
COMP
IOR
IOG
VDD
VDD
IOB
GND
GND
CLOCK
NC
NC
GND
GND
B0
B1
B2
B3
B4
B5
B6
B7
NC
13
14
15
16
17
18
19
20
21
22
23
24
GND
G0
G1
G2
G3
G4
G5
G6
G7
BLANK
SYNC
VDD
Pin Assignments
Pin No.
Pin Name
Description
Clock and Pixel I/O
26
CLK
Clock Input
47-40
R7-0
Red Pixel Data Inputs
9–2
G7-0
Green Pixel Data Inputs
23–16
B7-0
Blue Pixel Data Inputs
11
SYNC
Sync Pulse Input
10
BLANK
Blanking Input
Controls
Rev 1B
Video Outputs
33
IOR
Red Current Output
32
IOG
Green Current Output
29
IOB
Blue Current Output
Voltage Reference
35
VREF
Voltage Reference Output/Input
36
RREF
Current-Setting Resistor
34
COMP
Compensation Capacitor
Power and Ground
12, 30, 31
VDD
Power Supply
1, 14, 15,
27, 28, 38,
39, 48
GND
Ground
13, 24, 25,
37
NC
©2008 CADEKA Microcircuits LLC No Connect
www.cadeka.com
2
Data Sheet
Absolute Maximum Ratings
The safety of the device is not guaranteed when it is operated above the “Absolute Maximum Ratings”. The device
should not be operated at these “absolute” limits. Adhere to the “Recommended Operating Conditions” for proper device
function. The information contained in the Electrical Characteristics tables and Typical Performance plots reflect the
operating conditions noted on the tables and plots.
Power Supply Voltage
VDD (Measured to GND)
Inputs
Applied Voltage (measured to GND)(2)
Forced Current(3,4)
Outputs
Applied Voltage (measured to GND)(2)
Forced Current(3,4)
Short Circuit Duration (single output in HIGH state to GND)
Temperature
Operating, Ambient
Junction
Lead Soldering (10 seconds)
Vapor Phase Soldering (1 minute)
Storage
Min
Max
Unit
-0.5
7.0
V
-0.5
-10.0
VDD + 0.5
10.0
V
mA
-0.5
-60.0
VDD + 0.5
60.0
unlimited
V
mA
sec
-20
110
150
300
220
150
°C
°C
°C
°C
°C
-65
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
Parameter
Notes:
1. Functional operation under any of these conditions is NOT implied. Performance and reliability are guaranteed only if Operating Conditions are not exceeded.
2. Applied voltage must be current limited to specified range.
3. Forcing voltage must be limited to specified range.
4. Current is specified as conventional current flowing into the device.
Recommended Operating Conditions
Parameter
Min
Typ
Max
Unit
VDD
Power Supply Voltage
4.75
5.0
fS
Conversion Rate
5.25
100
150
tPWH
CLK Pulsewidth, HIGH
tPWL
CLK Pulsewidth, LOW
tW
CLK Pulsewidth
tS
Input Data Setup Time
Input Date Hold Time
Reference Voltage, External
Compensation Capacitor
Output Load
Input Voltage, Logic HIGH
Input Voltage, Logic LOW
Ambient Temperature, Still Air
1.235
0.1
37.5
1.5
V
MSPS
MSPS
ns
ns
ns
ns
ns
ns
ns
ns
V
µF
Ω
V
V
°C
th
VREF
CC
RL
VIH
VIL
TA
©2008 CADEKA Microcircuits LLC CDK3402
CDK3403
CDK3402
CDK3403
CDK3402
CDK3403
CDK3402
CDK3403
3.1
2.5
3.1
2.5
10
6.6
1.7
0
1.0
2.0
GND
0
VDD
0.8
70
www.cadeka.com
Rev 1B
Symbol
3
Data Sheet
Electrical Characteristics
(TA = 25°C, VDD = +5V, VREF = 1.235V, RL = 37.5Ω, RREF = 540Ω; unless otherwise noted)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
Power Supply Current
PD
Total Power Dissipation(1)
VDD = 5.25V, TA = 0°C
125
mA
VDD = 5.25V, TA = 0°C
655
mW
RO
Output Resistance
CO
Output Capacitance
IOUT = 0mA
30
pF
IIH
Input Current, HIGH
VDD = 5.25V, VIN = 2.4V
-5
µA
IIL
Input Current, LOW
VDD = 5.25V, VIN = 0.4V
5
µA
IREF
VREF Input Bias Current
±100
µA
VREF
Reference Voltage Output
VOC
Output Compliance
CDI
Digital Input Capacitance
100
0
kΩ
1.235
Referred to VDD
-0.4
V
0
+1.5
V
4
10
pF
Typ
Max
Units
10
15
ns
1
2
ns
Notes:
1. 100% tested at 25°C.
2. Parameter is guaranteed (but not tested) by design and characterization data.
Switching Characteristics
(TA = 25°C, VDD = +5V, VREF = 1.235V, RL = 37.5Ω, RREF = 590Ω; unless otherwise noted)
Symbol
Parameter
Conditions
Min
tD
Clock to Output Delay
tSKEW
Output Skew
VDD = 4.75V, TA = 0°C
tR
Output Risetime
10% to 90% of Full Scale
3
ns
tF
Output Falltime
90% to 10% of Full Scale
3
ns
Typ
Max
Units
Notes:
1. 100% production tested at +25°C.
2. Parameter is guaranteed (but not tested) by design and characterization data.
System Performance Characteristics
(TA = 25°C, VDD = +5V, VREF = 1.235V, RL = 37.5Ω, RREF = 590Ω; unless otherwise noted)
Symbol
Parameter
Conditions
Min
Integral Linearity Error
±0.2
±0.3
%/FS
DNL
Differential Linearity Error
±0.2
±0.3
%/FS
EDM
DAC to DAC Matching
PSRR
Power Supply Rejection Ratio
5
10
%
0.05
%/%
Notes:
1. 100% production tested at +25°C.
2. Parameter is guaranteed (but not tested) by design and characterization data.
©2008 CADEKA Microcircuits LLC www.cadeka.com
4
Rev 1B
INL
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
IDD
(1)
Data Sheet
Table 1. Output Voltage vs. Input Code, SYNC and BLANK, VREF = 1.235V, RREF = 590Ω, RL = 37.5Ω
RGB7-0 (MSB…LSB)
BLUE AND RED
GREEN
BLANK
VOUT
SYNC
BLANK
VOUT
1111 1111
X
1
0.7140
1
1
1.0000
1111 1111
X
1
0.7140
0
1
0.7140
1111 1110
X
1
0.7134
1
1
0.9994
1111 1101
X
1
0.7127
1
1
0.9987
•
•
•
•
•
•
•
•
•
•
•
•
•
•
0000 0000
X
1
0.3843
1
1
0.6703
1111 1111
X
1
0.3837
1
1
0.6697
•
•
•
•
•
•
•
•
•
•
•
•
•
•
0000 0010
X
1
0.0553
1
1
0.3413
0000 0001
X
1
0.0546
1
1
0.3406
0000 0000
X
1
0.0540
1
1
0.3400
0000 0000
X
1
0.0540
0
1
0.054
XXXX XXXX
X
0
0.0000
1
0
0.2860
XXXX XXXX
X
0
0.0000
0
0
0.0000
XXXX XXXX
X
1
valid
0
1
valid
tPWL
tPWH
ts
tH
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
SYNC
1/fs
CLK
Data N
Data N+1
Data N+2
Rev 1B
Pixel Data
and Controls
3%/FS
tD
OUTPUT
90%
tSET
tF
50%
tR
10%
Figure 1. CDK3402/3403 Timing Diagram
©2008 CADEKA Microcircuits LLC www.cadeka.com
5
Data Sheet
Functional Description
Digital Inputs
All digital inputs are TTL-compatible. Data is registered
on the rising edge of the CLK signal. Following one stage
of pipeline delay, the analog output changes tDO after the
rising edge of CLK.
Clock Input - CLK
The clock input is TTL-compatible and all pixel data is
registered on the rising edge of CLK. It is recommended
that CLK be driven by a dedicated TTL buffer to avoid
reflection induced jitter, overshoot, and undershoot.
Pixel Data Inputs - R7-0, B7-0, G7-0
TTL-compatible Red, Green and Blue Data Inputs are registered on the rising edge of CLK.
SYNC and BLANK
Data: 660mV max.
Pedestal: 54mV
Sync: 286mV
Figure 2. Normal Output Levels
BLANK gates the D/A inputs and sets the pedestal voltage.
If BLANK = HIGH, the D/A inputs are added to a pedestal
©2008 CADEKA Microcircuits LLC Bringing SYNC LOW, turns off a 40 IRE (7.62mA) current
source which forms a sync pulse on the Green D/A converter output. SYNC is registered on the rising edge of
CLK with the same pipeline latency as BLANK and pixel
data. SYNC does not override any other data and should
be used only during the blanking interval.
Since this is a single-supply D/A and all signals are positive-going, sync is added to the bottom of the Green D/A
range. So turning SYNC OFF means turning the current
source ON. When a sync pulse is desired, the current
source is turned OFF. If the system does not require sync
pulses from the Green D/A converter, SYNC should connected to GND.
Blanking Input - BLANK
When BLANK is LOW, pixel inputs are ignored and the
D/A converter outputs fall to the blanking level. BLANK
is registered on the rising edge of CLK and has the same
pipeline latency as SYNC.
D/A Outputs
Each D/A output is a current source. To obtain a voltage
output, a resistor must be connected to ground. Output
voltage depends upon this external resistor, the reference
voltage, and the value of the gain-setting resistor connected between RREF and GND.
Normally, a source termination resistor of 75Ω is connected between the D/A current output pin and GND near the
D/A converter. A 75Ω line may then be connected with another 75Ω termination resistor at the far end of the cable.
This “double termination” presents the D/A converter with
a net resistive load of 37.5Ω.
The CDK3402/3403 may also be operated with a single
75Ω terminating resistor. To lower the output voltage
swing to the desired range, the nominal value of the
resistor on RREF should be doubled.
R, G, and B Current Outputs - IOR, IOG, IOB
The R, G, and B current source outputs of the D/A
converters are capable of driving RS-343A/SMPTE-170M
compatible levels into doubly-terminated 75Ω lines. Sync
pulses may be added to the Green D/A output.
www.cadeka.com
6
Rev 1B
SYNC and BLANK inputs control the output level (Figure 2
and Table 1, on the previous page) of the D/A converters
during CRT retrace intervals. BLANK forces the D/A outputs
to the blanking level while SYNC = L turns off a current
source that is connected to the green D/A converter. SYNC
= H adds a 40 IRE sync pulse to the green output, SYNC =
L sets the green output to 0.0V during the sync tip. SYNC
and BLANK are registered on the rising edge of CLK.
Sync Pulse Input - SYNC
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
Within the CDK3402/3403 are three identical 8-bit D/A
converters, each with a current source output. External
loads are required to convert the current to voltage outputs. Data inputs RGB7-0 are overridden by the BLANK
input. SYNC = H activates, sync current from IOS for syncon-green video signals.
which offsets the current output. If BLANK = Low, data
inputs and the pedestal are disabled.
Data Sheet
Current-Setting Resistor - RREF
A 0.1µF capacitor must be connected between the COMP
Full-scale output current of each D/A converter is determined by the value of the resistor connected between
RREF and GND. Nominal value of RREF is found from:
pin and VDD to stabilize internal bias circuitry and ensure
low-noise operation.
RREF = 9.1 (VREF/IFS)
An internal voltage source of +1.235V is output on the
where IFS is the full-scale (white) output current (in amps)
from the D/A converter (without sync). Sync is 0.4 * IFS.
VREF pin. An external +1.235V reference may be applied
here which overrides the internal reference. Decoupling
VREF to GND with a 0.1µF ceramic capacitor is required.
IFS = VFS/RL
Where VFS is the white voltage level and RL is the total
resistive load (Ω) on each D/A converter. VFS is the blank
to full-scale voltage.
Voltage Reference
All three D/A converters are supplied with a common
voltage reference. Internal bandgap voltage reference
voltage is +1.235V with a 3kΩ source resistance. An
external voltage reference may be connected to the VREF
pin, overriding the internal voltage reference.
Power and Ground
Required power is a single +5.0V supply. To minimize power
supply induced noise, analog +5V should be connected
to VDD pins with 0.1µF and 0.01µF decoupling capacitors
placed adjacent to each VDD pin or pin pair.
The high slew-rate of digital data makes capacitive coupling to the outputs of any D/A converter a potential
problem. Since the digital signals contain high-frequency
components of the CLK signal, as well as the video output signal, the resulting data feedthrough often looks
like harmonic distortion or reduced signal-to-noise performance. All ground pins should be connected to a common
solid ground plane for best performance.
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
D/A full-scale (white) current may also be calculated from:
Voltage Reference Output/Input - VREF
Rev 1B
©2008 CADEKA Microcircuits LLC www.cadeka.com
7
Data Sheet
Equivalent Circuits
V DD
V DD
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
p
n
p
Digital
Input
V DD
n
OUT
GND
GND
Figure 3. Equivalent Digital Input Circuit
Figure 4. Equivalent Analog Output Circuit
V DD
p
p
R REF
V REF
GND
Rev 1B
Figure 5. Equivalent Analog Input Circuit
©2008 CADEKA Microcircuits LLC www.cadeka.com
8
Data Sheet
Typical Application Diagrams
1
IOR
IN1
OUT1
8
75Ω
220µF
7
75Ω
220µF
6
75Ω
220µF
75Ω
Video Cables
2
IOG
OUT2
IN2
3
IOB
75Ω
IN3
G
75Ω
CLC3800
75Ω
OUT3
B
75Ω
+3V or +5V
4
1.0µF
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
75Ω
75Ω
CDK3402/
CDK3403
R
GND
+Vs
5
0.1µF
AC-Coupling Caps
are Optional
DVD Player or STB
Figure 6. Standard Definition Video Output Circuit Diagram
+Vs
IOR
CDK3402/
CDK3403
+
75Ω
75Ω
1/3
CLC3605
-
75Ω
Video Cables
330Ω
IOG
75Ω
330Ω
IOB
-Vs
Figure 7. Graphics Output Driver Circuit Diagram
Rev 1B
+Vs
IOR
CDK3402/
CDK3403
+
75Ω
75Ω
1/3
CLC3605
-
330Ω
IOG
75Ω
330Ω
IOB
-Vs
75Ω
75Ω
Video Cables
75Ω
Video Cables
75Ω
Video Cables
75Ω
75Ω
75Ω
Figure 8. Standard Definition Video Distribution Circuit Diagram
©2008 CADEKA Microcircuits LLC www.cadeka.com
9
Data Sheet
Applications Dicussion
Grounding
It is important that the CDK3402/3403 power supply is well+5V
10µF
0.1µF
VDD
RED PIXEL
INPUT
R7-0
GREEN PIXEL
INPUT
G7-0
BLUE PIXEL
INPUT
B7-0
CLOCK
SYNC
BLANK
GND
Red
IOR
IOG
IOB
CDK3402/3403
Zo = 75Ω
Zo = 75Ω
Blue
75Ω
Zo = 75Ω
75Ω
75Ω
75Ω
Triple 8-bit D/A Converter
+5V
COMP
CLK
SYNC
BLANK
Green w/Sync
75Ω
75Ω
0.1µF
3.3kΩ
(not required without external reference)
V REF
R REF
LM185-1.2
590Ω
0.1µF
(Optional)
Figure 9. Typical Interface Circuit Diagram
Printed Circuit Board Layout
1. Keep the critical analog traces (VREF, IREF, COMP, IOS,
IOR, IOG) as short as possible and as far as possible
from all digital signals. The CDK3402/3403 should be
located near the board edge, close to the analog out-put
connectors.
2. Power plane for the CDK3402/3403 should be separate
from that which supplies the digital circuitry. A single
power plane should be used for all of the VDD pins. If
the power supply for the CDK3402/3403 is the same
as that of the system’s digital circuitry, power to the
CDK3402/3403 should be decoupled with 0.1µF and
0.01µF capacitors and iso-lated with a ferrite bead.
©2008 CADEKA Microcircuits LLC 4. If the digital power supply has a dedicated power plane
layer, it should not be placed under the CDK3402/3403,
the voltage reference, or the analog outputs. Capacitive
coupling of digital power supply noise from this layer
to the CDK3402/3403 and its related analog circuitry can
have an adverse effect on performance.
5. CLK should be handled carefully. Jitter and noise on this
clock will degrade performance. Terminate the clock line
carefully to eliminate overshoot and ringing.
Evaluation boards are available (CEB3402 and CEB3403),
contact CADEKA for more information.
Related Products
n
n
CDK3400/3401 Triple 10-bit 100/150MSPS DACs
CDK3404 Triple 8-bit 180MSPS DAC
www.cadeka.com
10
Rev 1B
Designing with high-performance mixed-signal circuits
demands printed circuits with ground planes. Overall
system performance is strongly influenced by the board
layout. Capacitive coupling from digital to analog circuits
may result in poor D/A conversion. Consider the following
suggestions when doing the layout:
3. The ground plane should be solid, not cross-hatched.
Connections to the ground plane should have very short
leads.
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
Figure 9 below illustrates a typical CDK3402/3403 interface
circuit. In this example, an optional 1.2V bandgap reference is connected to the VREF output, overriding the internal voltage reference source.
regulated and free of high-frequency noise. Careful power
supply decoupling will ensure the highest quality video
signals at the output of the circuit. The CDK3402/3403 has
separate analog and digital circuits. To keep digital system
noise from the D/A converter, it is recommended that
power supply voltages (VDD) come from the system analog
power source and all ground connections (GND) be made
to the analog ground plane. Power supply pins should be
individually decoupled at the pin.
Data Sheet
Mechanical Dimensions
TQFP-48 Package
CDK3402/CDK3403 8-bit, 100/150MSPS, Triple Video DACs
Rev 1B
For additional information regarding our products, please visit CADEKA at: cadeka.com
CADEKA Headquarters Loveland, Colorado
T: 970.663.5452
T: 877.663.5452 (toll free)
CADEKA, the CADEKA logo design, COMLINEAR and the COMLINEAR logo design are trademarks or registered trademarks of CADEKA
Microcircuits LLC. All other brand and product names may be trademarks of their respective companies.
CADEKA reserves the right to make changes to any products and services herein at any time without notice. CADEKA does not assume any
responsibility or liability arising out of the application or use of any product or service described herein, except as expressly agreed to in
writing by CADEKA; nor does the purchase, lease, or use of a product or service from CADEKA convey a license under any patent rights,
copyrights, trademark rights, or any other of the intellectual property rights of CADEKA or of third parties.
Copyright ©2008 by CADEKA Microcircuits LLC. All rights reserved.
A m p l i fy t h e H u m a n E x p e r i e n c e
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