Datasheet MAX5140IPG Datasheet (Maxim)

________________General Description

The MAX5140 is a monolithic, 8-bit digital-to-analog
converter (DAC) capable of accepting video data at
400Msps. Complete with video controls (sync, blank,
reference white (force high), and bright), the MAX5140
directly drives doubly terminated 50Ω or 75Ω loads to
standard composite video levels. Standard setup level
is 7.5IRE. The MAX5140 includes an internal precision
bandgap reference that can drive two other MAX5140s
in an RGB graphics system.

The MAX5140 is available in a 24-pin PDIP package in
the -20°C to +85°C industrial temperature range.

________________________Applications

Raster Graphics
High-Resolution Color or Monochrome Displays

to 2k x 2k Pixels
Medical Electronics: CAT, PET, and MR Imaging

Displays
CAD/CAE Workstations
Solids Modeling
General-Purpose, High-Speed Digital-to-Analog

Conversion
Digital Synthesizers
Automated Test Equipment
Digital Transmitters/Modulators

____________________________Features

♦ 400Msps Nominal Conversion Rate
♦ 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
♦ Stable On-Chip Bandgap Reference
♦ 50Ω and 75Ω Output Drive
♦ ESD-Protected Data and Control Inputs

MAX5140

8-Bit, Ultra-High-Speed DAC

________________________________________________________________

Maxim Integrated Products

1

Sync, Blank, Bright, Ref - White

D0 - D3

D4 - D7
(MSBs)

4 To 15
Decode

Output

Current

Switches

Out +

Out -

Bandgap

Reference

Video Controls In

Video Data In

Feedthrough

Convert

Ref In

Ref Out

I

Set

Video Data In

4

4

4

4

2

4

Ref

Buffer

Register

Pin Configuration

24
23
22
21
20
19
18
17

1
2
3
4
5
6
7
8

D4
D5
D6
D7D0

D1

D2

D3

TOP VIEW

V

EE

Out+
Out­V

CC

FT

CONV

CONV

V

EE

16
15
14
13

9
10
11
12

I

Set

Ref In
Ref Out
SyncBRT

Blank

FH

V

CC

DIP

MAX5140

Functional Diagram

19-1205; Rev 2; 5/98

PART

MAX5140IPG -20°C to +85°C

TEMP. RANGE PIN-PACKAGE

24 Plastic DIP

Ordering Information

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
For small orders, phone [phone] ext. 3468.

MAX5140

8-Bit, Ultra-High-Speed DAC

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= ground, VEE= -5.2V ±0.3V, CC= 0pF, I

SET

= 1.105mA, TA= T

MIN

to T

MAX

, unless otherwise noted.)

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.

Supply Voltage

V

EE

(measured to VCC)..........................................-7.0V to 0.5V

Input Voltages

CONV, Data, and Controls (measured to V

CC

)........VEEto 0.5V

Ref+ (measured to V

CC

) ..........................................VEEto 0.5V

Ref- (measured to V

CC

)............................................VEEto 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

CONDITIONS

V0.4 1.2

Convert Voltage,
Differential

V-0.5 -2.5

Convert Voltage,
Common-Mode Range

V-1.5V

IL

Input Voltage, Logic Low

V-1.0V

IH

Input Voltage, Logic High

LSB0.05 0.5I

OS

Output Offset Current

mA-45I

O-(MAX)

Maximum Current,
Negative Output

mA45I

O+(MAX)

Maximum Current,
Positive Output

pF9C

OUT

Output Capacitance

kΩ20R

OUT

Equivalent Output
Resistance

V-1.2 1.5

Compliance Voltage,
Negative Output

% Full Scale-6.5 6.5Gain Error

ppm/°C100Bandgap Tempco

pF5C

REF

Input Capacitance,
I

SET

, Ref Out

V-1.2 1.5

Compliance Voltage,
Positive Output

UNITSMIN TYP MAXSYMBOLPARAMETER

IV

IV

IV

V

VI

VI

VI

VI

VI

V
V

VI

VI

IV

TEST

LEVEL

µA35 120I

IL

Input Current, Logic Low,
Data and Controls

VI

µA40 120I

IH

Input Current, Logic High,
Data and Controls

VI

µA2 60I

CONV

Input Current, Convert VI

1.0mA < I

SET

< 1.3mA

% Full Scale -0.37 0.37

ILEIntegral Linearity Error VI

1.0mA < I

SET

< 1.3mA

% Full Scale -0.2 0.2

DLEDifferential Linearity Error VI

-0.95 0.95

-0.5 0.5

LSB

LSB

ppm/°C150Gain-Error Tempco V

MAX5140

8-Bit, Ultra-High-Speed DAC

_______________________________________________________________________________________ 3

DC ELECTRICAL CHARACTERISTICS (continued)

(VCC= ground, VEE= -5.2V ±0.3V, CC= 0pF, I

SET

= 1.105mA, TA= T

MIN

to T

MAX

, unless otherwise noted.)

AC ELECTRICAL CHARACTERISTICS

(RL= 37.5Ω, CL= 5pF, I

SET

= 1.105mA, TA= +25°C, unless otherwise noted.)

CONDITIONS

mA155 220I

EE

Supply Current

V-1.3 -1.2 -1.0V

REF

Reference Voltage
(measured to V

CC

)

pF3C

IN

Input Capacitance, Data
and Controls

µA/V-120 20 120Power-Supply Sensitivity

UNITSMIN TYP MAXSYMBOLPARAMETER

VI

VI

V

VI

TEST

LEVEL

TA= T

MIN

to T

MAX

10% to 90% G.S.

To 0.2% G.S.

TA= T

MIN

to T

MAX

CONDITIONS

Msps385 400Maximum Conversion Rate

ns

3.2 6

t

DST

Data to Output Delay,
Transparent Mode

ps

900

t

R

Rise Time

ns

4

t

SI

Current-Settling Time,
Clocked Mode

ns

2.2 4

t

DSC

Clock to Output Delay,
Clocked Mode

UNITSMIN TYP MAXSYMBOLPARAMETER

IV

III

IV

V

III

TEST

LEVEL

Area = 1/2VT pV-s4Glitch Energy V

MHz1.25-3dBReference Bandwidth V

ns1.3

t

PWH

,

t

PWL

Convert Pulse Width III

ns0.5t

H

Hold Time, Data and
Controls

III

ns1.0t

S

Setup Time, Data and
Controls

III

dB-48Clock Feedthrough III

20% to 80% G.S. V/µs700Slew Rate V

µA-50I

REF

Reference Output Current VI

600

IV

IV

4.5

6

TEST-LEVEL CODES

All electrical characteristics are subject to
the following conditions:

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.

Unless otherwise noted, all tests are pulsed
tests; therefore, T

j

= TC= TA.

TEST LEVEL

I

II

III
IV

V

VI

TEST PROCEDURE

100% production tested at the specified temperature.
100% production tested at T

A

= +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.
100% production tested at T

A

= +25°C. Parameter is

guaranteed over specified temperature range.

RL= 25Ω

RL= 25Ω 3

MAX5140

8-Bit, Ultra-High-Speed DAC

4 _______________________________________________________________________________________

______________________________________________________________Pin Description

Detailed Description

The MAX5140 is an ultra-high-speed video digital-to­analog converter (DAC) capable of up to 400Msps con­version rates. This high speed makes the device
suitable for driving 2048 x 2048 pixel displays at 60Hz
to 90Hz update rates.

In addition, the MAX5140 includes an internal bandgap
reference, which may be used to drive two other
MAX5140s, if desired.

The MAX5140 has ECL logic-level-compatible video
control 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 MAX5140 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.

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).

PIN

Data Bits 3, 2, and 1D3, D2, D11, 2, 3

FUNCTIONNAME

Data Bit 0 (LSB)D04

Convert Clock InputCONV6

Negative SupplyV

EE

5, 20

Register Feedthrough ControlFT8

Data Force-High ControlFH10

Positive SupplyV

CC

9, 17

Convert-Clock-Input Complement

CONV

7

Video Bright InputBRT12

Reference OutputRef Out14

Video Sync InputSync13

Reference CurrentI

Set

16

Output Current NegativeOut-18

Reference InputRef In15

Video Blank InputBlank11

Data Bits 6, 5, and 4D6, D5, D422, 23, 24

Data Bit 7 (MSB)D721

Output Current PositiveOut+19

MAX5140

8-Bit, Ultra-High-Speed DAC

_______________________________________________________________________________________ 5

Figure 1. Typical Interface Circuit

Applications Information

General

Figure 1 shows a typical interface circuit using the
MAX5140 in a color-raster application. The MAX5140
requires few external components and is extremely
easy to use. The MAX5140’s ultra-high operating
speeds require good circuit layout, supply decoupling,
and proper transmission-line design. For best perfor­mance, note the following considerations.

Input Considerations

Video-input data and controls can be directly con­nected to the MAX5140. 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 V

EE

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.

*An external reference can be used, or the Ref Out reference

can drive three MAX5140s.

Output Considerations

The analog outputs are designed to directly drive a
doubly terminated 50Ω or 75Ω load-transmission sys­tem as shown. The MAX5140 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 RSand

load terminator R

L

minimizes reflections of both forward
and reverse traveling waves in the analog transmission
system.

Power Considerations

The MAX5140 has two analog power-supply pins and
operates from a standard -5.2V single supply. Proper
supply bypassing augments the MAX5140’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.

MAX5140

8-Bit, Ultra-High-Speed DAC

6 _______________________________________________________________________________________

Figure 2. Equivalent Input Circuits—Data, Clock, Controls, and Reference

I

Bias

V

EE

Conv

Conv

I

Bias

V

EE

V

CC

Reference

Segment

Switch

Ref In

I

Set

I

Bias

I

Bias

80 kΩ

V

EE

V

Data and

Controls

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 VCCground
pins become the positive supply pins, while the V

EE

supply pins become the ground pins. The relative
polarities of the other input and output voltages must
be maintained.

Reference Considerations

The MAX5140 has two reference inputs (Ref In and I

Set

)
and one reference output (Ref Out). The input pins are
connected to the inverting and noninverting inputs of
an internal amplifier that serves as a reference buffer.

The buffer amplifier’s output is the reference for the cur­rent sinks. The amplifier feedback loop is connected
around one of the current sinks to achieve better accu­racy. (See Figure 3.)

Since the analog output currents are proportional to the
digital input data and I

Set

, full-scale output can be

adjusted by varying the reference current. I

Set

is con-

trolled through the MAX5140’s I

Set

input. Figure 1
shows the method and the necessary equations for set­ting I

Set

. The MAX5140 can use an external negative­voltage reference. The external reference must be sta­ble to achieve a satisfactory output, and Ref In should
be driven through a resistor to minimize offsets caused
by bias current. To change the full-scale output,
vary the value for I

Set

with the 500Ω to 1kΩ trimmer.

A double 50Ω load (25Ω) can be driven if I

Set

is

increased by 50% for doubly terminated 75Ω video
applications.

Data Inputs and Video Controls

The MAX5140 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 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 MAX5140 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
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.

MAX5140

8-Bit, Ultra-High-Speed DAC

_______________________________________________________________________________________ 7

Figure 3. Reference Buffer and DAC Output Circuit

MAX5140

To be registered synchronously, control and data inputs
must be present at the input pins for a specific setup
time (ts) before and a specific hold time (tH) after
CONV’s rising edge. Setup and hold times are not impor­tant in asynchronous mode. The minimum pulse widths
high (t

PWH

) and low (t

PWL

), 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 1 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 full­scale 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.

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 MAX5140. 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 MAX5140 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 I

Set

.

8-Bit, Ultra-High-Speed DAC

8 _______________________________________________________________________________________

-1.3 V

CONV

CONV

1/2 LSB

t

PWL

t

H

t

S

t

PWH

t

SI

OUT +

OUT -

1/2 LSB

-1.3 V

t

DSC

t

DST

Data Control

Inputs

Figure 4. Timing Diagram

MAX5140

8-Bit, Ultra-High-Speed DAC

_______________________________________________________________________________________ 9

1 X0 X X 20.83 -0.781 0 Blank Level
0 10 1 X 0.00

BLANK

X

0.000 110 Enhanced High Level

SYNC

REF

WHITE

X1

0 00 0 111... 1.95

0

-0.073 100 Normal High Level

0 00 0 000...

BRIGHT

X

19.40 -0.728 7.5 Normal Low Level

10 0 X 1.95 -0.073 100 Normal High Level

DATA

INPUT

X

0 00 1 111... 0.00 0.000 110

OUT- (mA)

28.57

Enhanced High Level

0 00 1 000... 17.44 -0.654 17.5 Enhanced Low Level

OUT- (V)

-1.071

OUT- (IRE)

-40

DESCRIPTION

Sync Level

Table 1. Video-Control Operation (output values for setup: 10IRE, 75Ω standard load)

256 Gray Levels

Normal Low (Black)

Sync

Video

Blank

Bright

Normal High (White)

110

100

7.5
0

-40

IRE

0 mV

-73 mV

-728 mV

-781 mV

-1071 mV

Figure 5. Video-Output Waveform for Standard Load

MAX5140

8-Bit, Ultra-High-Speed DAC

10 ______________________________________________________________________________________

Figure 6. CONV, CONV Switching Levels

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.

Typical RGB Graphics System

In an RGB graphics system, the color displayed is
determined by the combined intensities of the red,
green, and blue (RGB) DAC outputs. A change in gain
or offset in any of the RGB outputs affects the apparent
hue displayed on the CRT screen. Thus, it is very
important that the DAC’s outputs track each other over
a wide range of operating conditions. Since the DAC

output is proportional to the product of the reference
and digital input code, use a common reference to
drive all three DACs in an RGB system to minimize
RGB DAC-to-DAC mismatch and improve TC tracking.

The MAX5140 contains an internal precision-bandgap
reference that completely eliminates the need for an
external reference. The reference can supply up to
50µA to an external load, such as two other DAC refer­ence inputs.

The circuits shown in Figure 8 show how a single
MAX5140 can be used as a master reference in a sys­tem with multiple DACs (such as RGB). The other DACs
are simply slaved from the MAX5140’s reference
output.

MAX5140

8-Bit, Ultra-High-Speed DAC

______________________________________________________________________________________ 11

MAX5140

Figure 7. Standard Load (a) and Test Load (b)

MAX5140

(MASTER)

MAX5140

(SLAVE)

MAX5140

(SLAVE)

Figure 8. Typical RGB Graphics System

a)

b)

MAX5140

8-Bit, Ultra-High-Speed DAC

________________________________________________________Package Information

PDIPW.EPS

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

© 1998 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.