MAXIM MAX5018BIPG

19-1204; Rev 0; 3/97
8-Bit, High-Speed DAC
____________________________Features
The MAX5018 is a monolithic, 8-bit digital-to-analog
converter (DAC) capable of accepting video data at
165Msps or 275Msps. Complete with video controls
(sync, blank, reference white (force high), and bright),
the MAX5018 directly drives doubly terminated 50Ω or
75Ω loads to standard composite video levels.
Standard setup level is 7.5IRE. The MAX5018 is pin
compatible with the HDAC10180 and the TDC1018,
with improved performance. The MAX5018 contains
data and control input registers, video control logic, reference buffer, and current switches.
Two performance grades of the MAX5018 are available.
Both are packaged in a 24-pin PDIP in the -20°C to
+85°C industrial temperature range.
♦ 275Msps Conversion Rate (MAX5018A)
165Msps Conversion Rate (MAX5018B)
________________________Applications
♦ ESD-Protected Data and Control Inputs
♦ TDC1018 and HDAC10180 Compatible with
Improved Performance
♦ RS-343-A Compatible
♦ Complete Video Controls: Sync, Blank, Bright,
and Reference White (force high)
♦ ECL Compatible
♦ Single Power Supply
♦ Registered Data and Video Controls
♦ Differential Current Outputs
High-Resolution Color or Monochrome Raster
Graphics Displays to 1500 x 1800 Pixels
Medical Electronics: CAT, PET, and MRI Displays
CAD/CAE Workstations
Solids Modeling
General-Purpose, High-Speed Digital-to-Analog
Conversion
Digital Synthesizers
Automated Test Equipment
______________Ordering Information
PART
TEMP. RANGE
PIN-PACKAGE
MAX5018AIPG
-20°C to +85°C
24 Plastic DIP
MAX5018BIPG
-20°C to +85°C
24 Plastic DIP
Digital Transmitters/Modulators
__________________Pin Configuration
________________Functional Diagram
TOP VIEW
D3 1
24 D4
D2 2
23 D5
D1 3
22 D6
D0 4
VEE 5
21 D7
MAX5018
20 VEE
CONV 6
19 Out+
CONV 7
18 Out-
FT 8
17 VCC
VCC 9
MAX5018
16 COMP
FH 10
15 Ref+
Blank 11
14 Ref-
BRT 12
13 Sync
DIP
________________________________________________________________ Maxim Integrated Products
For the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
1
MAX5018
_______________General Description
MAX5018
8-Bit, High-Speed DAC
ABSOLUTE MAXIMUM RATINGS
Supply Voltage
VEE (measured to VCC)..........................................-7.0V to 0.5V
Input Voltages
CONV, Data, and Controls (measured to VCC)........VEE to 0.5V
Ref+ (measured to VCC) ..........................................VEE to 0.5V
Ref- (measured to VCC)............................................VEE to 0.5V
Operating Temperature Ranges
Ambient .............................................................-20°C to +85°C
Junction..........................................................................+175°C
Lead Temperature (soldering, 10sec) .............................+300°C
Storage Temperature Range .............................-60°C to +150°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(VCC = ground, VEE = -5.2V ±0.3V, CC = 0pF, ISET = 1.105mA, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
TEST
LEVEL
Integral Linearity Error
ILE
1.0mA < ISET < 1.3mA
VI
Differential Linearity Error
DLE
1.0mA < ISET < 1.3mA
VI
MIN
TYP
MAX
UNITS
-0.37
-0.95
-0.2
-0.5
0.37
0.95
0.2
0.5
% Full Scale
LSB
% Full Scale
LSB
-6.5
6.5
% Full Scale
Gain Error
VI
Gain-Error Tempco
V
150
ppm/°C
V
5
pF
Input Capacitance,
Ref+, Ref-
CREF
Compliance Voltage,
Positive Output
VI
-1.2
1.5
V
Compliance Voltage,
Negative Output
VI
-1.2
1.5
V
20
Equivalent Output
Resistance
ROUT
VI
Output Capacitance
kΩ
COUT
V
Maximum Current,
Positive Output
IO+(MAX)
IV
45
mA
Maximum Current,
Negative Output
IO-(MAX)
IV
-45
mA
Output Offset Current
IOS
VI
Input Voltage, Logic High
VIH
VI
Input Voltage, Logic Low
VIL
VI
Convert Voltage,
Common-Mode Range
IV
Convert Voltage,
Differential
IV
12
0.05
pF
0.5
-1.0
LSB
V
-1.5
V
-0.5
-2.5
V
0.4
1.2
V
Input Current, Logic Low,
Data and Controls
IIL
VI
35
120
µA
Input Current, Logic High,
Data and Controls
IIH
VI
40
120
µA
ICONV
VI
2
60
µA
Input Current, Convert
2
_______________________________________________________________________________________
8-Bit, High-Speed DAC
MAX5018
DC ELECTRICAL CHARACTERISTICS (continued)
(VCC = ground, VEE = -5.2V ±0.3V, CC = 0pF, ISET = 1.105mA, TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER
Input Capacitance, Data
and Controls
Power-Supply Sensitivity
Supply Current
SYMBOL
CONDITIONS
TEST
LEVEL
CIN
V
IEE
VI
VI
MIN
TYP
MAX
3
UNITS
pF
-120
20
155
120
220
µA/V
mA
MIN
TYP
MAX
UNITS
AC ELECTRICAL CHARACTERISTICS
(RL = 37.5Ω, CL = 5pF, ISET = 1.105mA, TA = +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
MAX5018B
MAX5018A
Maximum Conversion Rate
Rise Time
CONDITIONS
tR
10% to 90% G.S., TA = TMIN to TMAX
10% to 90% G.S., RL = 25Ω
To 0.2% G.S.
To 0.8% G.S.
To 0.2% G.S., RL = 25Ω
Current Settling Time,
Clocked Mode
tSI
Clock to Output Delay,
Clocked Mode
tDSC
TA = TMIN to TMAX
Data to Output Delay,
Transparent Mode
tDST
TA = TMIN to TMAX
Convert Pulse Width,
(low or high)
tPWL,
tPWH
B Grade
A Grade
Area = 1/2VT
Glitch Energy
Reference Bandwidth, -3dB
Setup Time, Data and
Controls
tS
Hold Time, Data and
Controls
tH
Slew Rate
Clock Feedthrough
TA = +25°C
TA = TMIN to TMAX
TA = +25°C
TA = TMIN to TMAX
20% to 80% G.S., TA = +25°C
TA = TMIN to TMAX
TA = TMIN to TMAX
TEST
LEVEL
III
III
III
IV
V
V
V
V
III
IV
III
IV
III
III
V
V
III
IV
III
IV
III
IV
III
IV
165
275
Msps
Msps
1.6
2.0
1.0
7.0
5.5
4.5
2.2
3.2
ns
ns
4.0
4.5
6.0
6.0
3.0
1.8
ns
ns
ns
4
1.0
pV-s
MHz
1.0
1.0
0.5
0.5
390
325
ns
ns
V/µs
-48
-48
dB
_______________________________________________________________________________________
3
MAX5018
8-Bit, High-Speed DAC
TEST-LEVEL CODES
TEST LEVEL
TEST PROCEDURE
All electrical characteristics are subject to
the following conditions:
I
II
All parameters having min/max specifications are guaranteed. The Test Level column
indicates the specific device testing actually
performed during production and Quality
Assurance inspection. Any blank section in
the data column indicates that the specification is not tested at the specified condition.
III
IV
100% production tested at the specified temperature.
100% production tested at TA = +25°C, and sample
tested at the specified temperatures.
QA sample tested at only the specified temperatures.
Parameter is guaranteed (but not tested) by design
and characterization data.
Parameter is a typical value for reference only.
100% production tested at TA = +25°C. Parameter is
guaranteed over specified temperature range.
V
VI
Unless otherwise noted, all tests are pulsed
tests; therefore, Tj = TC = TA.
______________________________________________________________Pin Description
4
PIN
NAME
FUNCTION
1, 2, 3
D3, D2, D1
4
D0
Data Bit 0 (LSB)
5, 20
VEE
Negative Supply
6
CONV
Convert Clock Input
7
CONV
Convert-Clock-Input Complement
8
FT
9, 17
VCC
Positive Supply
10
FH
Data Force-High Control
11
Blank
Video Blank Input
12
BRT
Video Bright Input
13
Sync
Video Sync Input
14
Ref-
Reference Current, Negative Input
15
Ref+
Reference Current, Positive Input
16
COMP
18
Out-
Output Current Negative
19
Out+
Output Current Positive
21
D7
22, 23, 24
D6, D5, D4
Data Bits 3, 2, and 1
Register Feedthrough Control
Compensation Input
Data Bit 7 (MSB)
Data Bits 6, 5, and 4
_______________________________________________________________________________________
8-Bit, High-Speed DAC
MSB currents are then summed with the LSBs that contribute one-sixteenth of full-scale to provide the 256 distinct analog output levels.
The video-control inputs drive weighted current sinks,
which are added to the output current to produce composite video-output levels. These controls (sync, blank,
reference white (force high), and bright) are required in
video applications.
A feature that similar video DACs do not have is feedthrough control. The feedthrough pin (FT) allows registered or unregistered operation of the video control and
data inputs. In registered mode, the composite functions are latched to the pixel data to prevent screenedge distortions (generally found on unregistered video
DACs).
Table 1. The MAX5018 Family and
Speed Designations
PART
UPDATE
COMMENTS
MAX5018A
275Msps
Suitable for 1200 x 1500 to
1500 x 1800 displays at
60Hz to 90Hz update rate.
MAX5018B
165Msps
Suitable for 1024 x 1280 to
1200 x 1500 displays at
60Hz to 90Hz update rate.
__________Applications Information
General
Figure 1 shows a typical application using the MAX5018
in a color-raster circuit. The MAX5018 requires few external components and is extremely easy to use. The
MAX5018’s very high operating speeds require good circuit layout, supply decoupling, and proper transmissionline design. For best performance, note the following
considerations.
Input Considerations
Video-input data and controls can be directly connected to the MAX5018. Note that all ECL inputs are
terminated as closely to the device as possible to
reduce ringing, crosstalk, and reflections. Maxim recommends that stripline or microstrip techniques be
used for all ECL interfaces. A convenient and commonly used microstrip impedance is about 130Ω, which is
easily terminated using a 330Ω resistor to VEE and a
220Ω resistor to ground. This arrangement gives a
Thevenin-equivalent termination of 130Ω to -2V without
the need for a -2V supply. Standard single in-line package (SIP) 220/330 resistor networks are available for
this purpose.
Figure 2 shows equivalent input circuits.
Output Considerations
The analog outputs are designed to directly drive a
dual 50Ω or 75Ω load-transmission system as shown in
Figure 1. The MAX5018 output source impedances are
high-impedance current sinks. The load impedance
(RL) must be 25Ω or 37.5Ω to attain standard RS-343-A
video levels. Any deviation from this impedance affects
the resulting video output levels proportionally. As with
the data interface, it is important that all analog transmission lines have matched impedance throughout,
including connectors and transitions between printed
wiring and coaxial cable. The combination of matched
source-termination resistor RS and load terminator RL
minimizes reflections of both forward and reverse traveling waves in the analog transmission system.
Power Considerations
The MAX5018 has two analog power-supply pins and
operates from a standard -5.2V single supply. Proper
supply bypassing augments the MAX5018’s inherent
supply-noise-rejection characteristics. As shown in
Figure 1, each supply pin should be bypassed as
close to the device as possible with 0.01µF and 10µF
capacitors.
_______________________________________________________________________________________
5
MAX5018
_______________Detailed Description
The MAX5018 is an ultra-high-speed video digital-toanalog converter (DAC) capable of up to 275Msps conversion rates. This high speed makes the device
suitable for driving 1500 x 1800 pixel displays at 70Hz
to 90Hz update rates.
The MAX5018 is separated into different conversionrate categories, as shown in Table 1.
The MAX5018 has ECL logic-level-compatible video
controls and data inputs. The complementary analog
output currents produced by the devices are proportional to the product of the digital control and data
inputs in conjunction with the analog reference current.
The MAX5018 is segmented so that the input data’s
four MSBs are separated into a parallel thermometer
code. From here, fifteen identical current sinks are driven to fabricate sixteen coarse output levels. The
remaining four LSBs drive four binary-weighted current
switches.
MAX5018
8-Bit, High-Speed DAC
Figure 1. Typical Interface Circuit
This device also has two analog ground pins (VCC). Tie
both ground pins to the analog ground plane. All power
and ground pins must be connected in any application.
If a +5V power source is required, the VCC ground pins
become the positive supply pins, while the VEE supply
pins become the ground pins. The relative polarities of
the other input and output voltages must be maintained.
Reference Considerations
The MAX5018 has two reference inputs (Ref+ and Ref-).
The input pins are connected to the inverting and noninverting inputs of an internal amplifier that serves as a
reference buffer amplifier.
The buffer amplifier’s output is the reference for the current sinks. The amplifier feedback loop is connected
6
around one of the current sinks for better accuracy.
(See Figure 3.)
Since the analog output currents are proportional to the
digital input data and ISet, full-scale output can be
adjusted by varying the reference current. ISet is controlled through the MAX5018’s Ref+ input. Figure 1
shows the method and the necessary equations for setting I Set . The MAX5018 uses an external negativevoltage reference. The external reference must be
stable to achieve a satisfactory output, and Ref- should
be driven through a resistor to minimize offsets caused
by bias current. To change the full-scale output, vary
the value for ISet with the 500Ω trimmer. A double 50Ω
load (25Ω) can be driven if ISet is increased by 50% for
doubly terminated 75Ω video applications.
_______________________________________________________________________________________
8-Bit, High-Speed DAC
MAX5018
VCC
Ref In
Conv
ISet
Reference
Segment
Switch
Conv
I Bias
VEE
IBias
IBias
IBias
VEE
Data and
Controls
V
80 kΩ
VEE
Figure 2. Equivalent Input Circuits—Data, Clock, Controls, and Reference
Compensation
The MAX5018 provides an external compensation input
(COMP) for the reference buffer amplifier. To use this
pin correctly, connect a capacitor between COMP and
VEE, as shown in Figure 1. Keep lead lengths as short
as possible. Use a large capacitor (0.01µF) if the reference is to be kept as a constant. The capacitor’s value
determines the amplifier’s bandwidth. If reference modulation is required, smaller capacitance values can be
used to achieve up to a 1MHz bandwidth.
Data Inputs and Video Controls
The MAX5018 has standard, single-ended data inputs.
The inputs are registered to produce the lowest differential data-propagation delay (skew) to minimize glitching. Also, four video-control inputs generate composite
video outputs: sync, blank, bright, and reference white
(force high). Feedthrough control is also provided. All
of the controls and data inputs are ECL compatible. In
addition, all have internal pulldown resistors to leave
them at a logic low so the pins are inactive when not
used. This feature is useful if the devices are applied as
standard DACs without the need for video controls, or if
fewer than eight bits are used.
The MAX5018 is usually configured in synchronous
mode. In this mode, the controls and data are synchronized to prevent pixel dropout. This reduces screenedge distortions and provides the lowest output noise
while maintaining the highest conversion rate. With the
FT control open (low), each rising edge of the convert
clock (CONV) latches decoded data and control values
into a D-type internal register. The switched-current
_______________________________________________________________________________________
7
MAX5018
8-Bit, High-Speed DAC
Figure 3. Reference Buffer and DAC Output Circuit
sinks convert the registered data into the appropriate
analog output. When FT is tied high, the control inputs
and data are not registered. The analog output asynchronously tracks the input data and video controls.
Feedthrough itself is asynchronous and is usually used
as a DC control.
To be registered synchronously, control and data inputs
must be present at the input pins for a specific setup
time (t s ) before and a specific hold time (t H ) after
CONV’s rising edge. Setup and hold times are not important in asynchronous mode. The minimum pulse widths
high (tPWH) and low (tPWL), as well as settling time,
become the limiting factors (Figure 4).
The video controls produce the output levels needed
for horizontal blanking, frame synchronization, etc., to
be compatible with video-system standards as
described in RS-343-A. Table 2 shows the videocontrol effects on the analog output. Internal logic governs blank, sync, and force high so that they override
the data inputs as needed in video applications. Sync
overrides both the data and other controls to produce
full negative video output (Figure 5).
Reference-white, video-level output is provided by force
high, which drives the internal digital data to full-scale
output (100IRE units). Bright gives an additional 10% of
full-scale value to the output level. This function can be
used in graphic displays for highlighting menus, cursors,
or warning messages. If the devices are used in nonvideo applications, the video controls can be left open.
8
Convert Clock
For best performance, the clock should be differentially
ECL driven by using CONV and CONV (Figure 6).
Driving the clock in this manner minimizes clock noise
and power-supply/output intermodulation. The clock’s
rising edge synchronizes the data and control inputs to
the MAX5018. Since CONV determines the actual
switching threshold of CONV, the clock can be driven
single-ended by connecting a bias voltage to CONV.
This bias voltage sets the converter clock’s switching
threshold.
Analog Outputs
The MAX5018 has two analog outputs that are highimpedance, complementary current sinks. The outputs
vary in proportion to the input data, controls, and reference-current values so that the full-scale output can be
changed by setting ISet.
In video applications, the outputs can drive a doubly
terminated 50Ω or 75Ω load to standard video levels. In
the standard configuration shown in Figure 7, the output voltage is the product of the output current and
load impedance and is between 0V and -1.07V. Out(Figure 5) provides a video output waveform with the
Sync pulse bottom at -1.07V. Out+ is inverted with
Sync up.
_______________________________________________________________________________________
8-Bit, High-Speed DAC
MAX5018
tPWH
CONV
-1.3 V
CONV
tPWL
tH
tS
Data Control
Inputs
-1.3 V
tDST
1/2 LSB
tDSC
OUT -
AAAA
OUT +
AAAAAAAA
AAAAAAAA
tSI
1/2 LSB
Figure 4. Timing Diagram
IRE
110
100
0 mV
-73 mV
Bright
Normal High (White)
Video
256 Gray Levels
Normal Low (Black)
7.5
0
-728 mV
-781 mV
-40
-1071 mV
Blank
Sync
Figure 5. Video-Output Waveform for Standard Load
_______________________________________________________________________________________
9
MAX5018
8-Bit, High-Speed DAC
Table 2. Video-Control Operation (output values for setup: 10IRE, 75Ω standard load)
SYNC
BLANK
REF
WHITE
BRIGHT
DATA
INPUT
OUT- (mA)
OUT- (V)
OUT- (IRE)
1
X
X
X
X
28.57
-1.071
-40
Sync Level
0
1
X
X
X
20.83
-0.781
0
Blank Level
0
0
1
1
X
0.00
0.000
110
Enhanced High Level
0
0
1
0
X
1.95
-0.073
100
Normal High Level
0
0
0
0
000...
19.40
-0.728
7.5
Normal Low Level
0
0
0
0
111...
1.95
-0.073
100
Normal High Level
0
0
0
1
000...
17.44
-0.654
17.5
Enhanced Low Level
0
0
0
1
111...
0.00
0.000
110
Enhanced High Level
DESCRIPTION
Figure 6. CONV, CONV Switching Levels
10
______________________________________________________________________________________
8-Bit, High-Speed DAC
MAX5018
a)
MAX5018
b)
Figure 7. Standard Load (a) and Test Load (b)
______________________________________________________________________________________
11
________________________________________________________Package Information
PDIPN.EPS
MAX5018
8-Bit, High-Speed DAC
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
12 __________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 (408) 737-7600
© 1997 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.