MAXIM MAX5888

19-2726; Rev 3; 12/03
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
♦ Single 3.3V Supply Operation
♦ Excellent SFDR and IMD Performance
SFDR = 76dBc at fOUT = 40MHz (to Nyquist)
IMD = -85dBc at fOUT = 10MHz
ACLR = 73dB at fOUT = 61MHz
♦ 2mA to 20mA Full-Scale Output Current
♦ Differential, LVDS-Compatible Digital and Clock
Inputs
♦ On-Chip 1.2V Bandgap Reference
♦ Low 130mW Power Dissipation
♦ 68-Lead QFN-EP Package
Ordering Information
PART
MAX5888AEGK
-40°C to +85°C
68 QFN-EP*
MAX5888EGK
-40°C to +85°C
68 QFN-EP*
*EP = Exposed paddle.
68
Applications
Communications: LMDS, MMDS, Point-to-Point
Microwave
Digital Signal Synthesis
Automated Test Equipment (ATE)
Instrumentation
63 62 61 60 59 58
B10N
B10P
B9P
B9N
B8P
B8N
B7P
B7N
DGND
DVDD
DGND
B6N
67 66 65 64
B6P
B5P
B5N
Pin Configuration
TOP VIEW
Base Stations: Single-/Multicarrier UMTS,
CDMA, GSM
PINPACKAGE
TEMP RANGE
B4P
The digital and clock inputs of the MAX5888 are
designed for differential low-voltage differential signal
(LVDS)-compatible voltage levels. The MAX5888 is
available in a 68-lead QFN package with an exposed
paddle (EP) and is specified for the extended industrial
temperature range (-40°C to +85°C).
Refer to the MAX5887 and MAX5886 data sheets for
pin-compatible 14- and 12-bit versions of the MAX5888.
♦ 500Msps Output Update Rate
B4N
The MAX5888 utilizes a current-steering architecture,
which supports a full-scale output current range of 2mA
to 20mA, and allows a differential output voltage swing
between 0.1VP-P and 1VP-P.
The MAX5888 features an integrated 1.2V bandgap reference and control amplifier to ensure high accuracy
and low noise performance. Additionally, a separate
reference input pin enables the user to apply an external reference source for optimum flexibility and to
improve gain accuracy.
Features
57 56 55 54 53 52
EP
B3P
1
B3N
2
50 B11P
B2P
3
49 B12N
B2N
4
48 B12P
B1P
5
47 B13N
B1N
6
46 B13P
B0P
7
45 B14N
B0N
8
DGND
9
51 B11N
44 B14P
MAX5888
43 B15N
DVDD 10
42 B15P
VCLK 11
41 DGND
CLKGND 12
40 DVDD
CLKP 13
39 SEL0
CLKN 14
38 N.C.
CLKGND 15
37 N.C.
VCLK 16
36 N.C.
PD 17
35 N.C.
N.C.
AGND
AVDD
AGND
AVDD
AVDD
AGND
IOUTP
IOUTN
AVDD
AGND
N.C.
DACREF
FSADJ
REFIO
AVDD
AGND
18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
QFN
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX5888
General Description
The MAX5888 is an advanced, 16-bit, 500Msps digitalto-analog converter (DAC) designed to meet the
demanding performance requirements of signal synthesis applications found in wireless base stations and
other communications applications. Operating from a
single 3.3V supply, this DAC offers exceptional dynamic performance such as 76dBc spurious-free dynamic
range (SFDR) at fOUT = 40MHz. The DAC supports
update rates of 500Msps and a power dissipation of
only 250mW.
MAX5888
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
ABSOLUTE MAXIMUM RATINGS
Continuous Power Dissipation (TA = +70°C)
68-Lead QFN-EP (derate 41.7mW/°C above +70°C) ...3333mW
Thermal Resistance (θJA) ..............................................+24°C/W
Operating Temperature Range ..........................-40°C to +85°C
Junction Temperature .....................................................+150°C
Storage Temperature Range ............................-60°C to +150°C
Lead Temperature (soldering, 10s) ................................+300°C
AVDD, DVDD, VCLK to AGND................................-0.3V to +3.9V
AVDD, DVDD, VCLK to DGND ...............................-0.3V to +3.9V
AVDD, DVDD, VCLK to CLKGND ...........................-0.3V to +3.9V
AGND, CLKGND to DGND....................................-0.3V to +0.3V
DACREF, REFIO, FSADJ to AGND.............-0.3V to AVDD + 0.3V
IOUTP, IOUTN to AGND................................-1V to AVDD + 0.3V
CLKP, CLKN to CLKGND...........................-0.3V to VCLK + 0.3V
B0P/B0N–B15P/B15N, SEL0,
PD to DGND ...........................................-0.3V to DVDD + 0.3V
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.
ELECTRICAL CHARACTERISTICS
(AVDD = DVDD = VCLK = 3.3V, AGND = DGND = CLKGND = 0, external reference, VREFIO = 1.25V, differential transformer-coupled
analog output, 50Ω double terminated (Figure 7), IOUT = 20mA, TA = TMIN to TMAX, unless otherwise noted. ≥+25°C guaranteed by
production test, <+25°C guaranteed by design and characterization. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
STATIC PERFORMANCE
Resolution
Integral Nonlinearity
16
INL
MAX5888A___, measured differentially,
TA ≥ +25°C
-0.008
Offset Error
DNL
MAX5888A___, measured differentially,
TA ≥ +25°C
±0.006
-0.006
-0.025
±0.003
+0.025
±50
GEFS
Gain Drift
Full-Scale Output Current
+0.006
±0.003
Offset Drift
Full-Scale Gain Error
±0.002
% FS
MAX5888___, measured differentially,
TA ≥ +25°C
OS
+0.008
% FS
MAX5888___, measured differentially,
TA ≥ +25°C
Differential
Nonlinearity
±0.004
Bits
IOUT
Min Output Voltage
Max Output Voltage
External reference, TA ≥ +25°C
-3.1
+1.1
Internal reference
±100
External reference
±50
(Note 1)
2
-0.5
Single ended
%FS
ppm/°C
20
Single ended
%FS
ppm/°C
mA
V
1.1
V
Output Resistance
ROUT
1
MΩ
Output Capacitance
COUT
5
pF
DYNAMIC PERFORMANCE
Output Update Rate
fCLK
Noise Spectral Density
Spurious-Free Dynamic Range to
Nyquist
2
SFDR
1
500
fCLK = 300MHz
fOUT = 16MHz, -12dB FS
-165
fCLK = 500MHz
fOUT = 16MHz, -12dB FS
-164
fCLK = 100MHz
fOUT = 1MHz, 0dB FS
88
fOUT = 1MHz, -6dB FS
89
fOUT = 1MHz, -12dB FS
85
_______________________________________________________________________________________
Msps
dB FS/
Hz
dBc
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
(AVDD = DVDD = VCLK = 3.3V, AGND = DGND = CLKGND = 0, external reference, VREFIO = 1.25V, differential transformer-coupled
analog output, 50Ω double terminated (Figure 7), IOUT = 20mA, TA = TMIN to TMAX, unless otherwise noted. ≥+25°C guaranteed by
production test, <+25°C guaranteed by design and characterization. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
fCLK = 100MHz
Spurious-Free Dynamic Range to
Nyquist
2-Tone IMD
fOUT = 30MHz, -12dB FS
79
fOUT = 10MHz, -12dB FS
73
SFDR
69
fOUT = 50MHz, -12dB FS
72
66
fOUT = 10MHz, -12dB FS
67
fOUT = 30MHz, -12dB FS
65
fOUT = 50MHz, -12dB FS
65
fOUT = 80MHz, -12dB FS
63
fCLK = 150MHz fOUT = 20MHz, -12dB FS
82
fCLK = 100MHz
fOUT1 = 9MHz, -6dB FS,
fOUT2 = 10MHz, -6dB FS
-85
fCLK = 300MHz
fOUT1 = 49MHz, -12dB FS,
fOUT2 = 50MHz, -12dB FS
-83
TTIMD
MAX
UNITS
77
fOUT = 80MHz, -12dB FS
fCLK = 500MHz
Spurious-Free Dynamic Range,
25MHz Bandwidth
TYP
82
fOUT = 16MHz, -12dB FS,
fCLK = 200MHz TA ≥ +25°C
SFDR
MIN
fOUT = 10MHz, -12dB FS
dBc
dBc
dBc
4-Tone IMD, 1MHz Frequency
Spacing, GSM Model
FTIMD
fCLK = 300MHz fOUT = 32MHz, -12dB FS
-78
dBc
Adjacent Channel Leakage
Power Ratio, 4.1MHz Bandwidth,
WCDMA Model
ACLR
fCLK =
184.32MHz
73
dB
450
MHz
Output Bandwidth
BW-1dB
fOUT = 61.44MHz
(Note 2)
REFERENCE
Internal Reference Voltage Range
VREFIO
Reference Voltage Drift
TCOREF
Reference Input Compliance
Range
VREFIOCR
Reference Input Resistance
RREFIO
1.13
1.22
1.3
±50
0.125
V
ppm/°C
1.250
V
10
kΩ
ANALOG OUTPUT TIMING
Output Fall Time
tFALL
90% to 10% (Note 3)
375
ps
Output Rise Time
tRISE
10% to 90% (Note 3)
375
ps
Output Voltage Settling Time
Output Propagation Delay
tSETTLE
tPD
Output settles to 0.025% FS (Note 3)
11
ns
(Note 3)
1.8
ns
1
pV-s
Glitch Energy
Output Noise
NOUT
IOUT = 2mA
30
IOUT = 20mA
30
pA/√Hz
_______________________________________________________________________________________
3
MAX5888
ELECTRICAL CHARACTERISTICS (continued)
MAX5888
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
ELECTRICAL CHARACTERISTICS (continued)
(AVDD = DVDD = VCLK = 3.3V, AGND = DGND = CLKGND = 0, external reference, VREFIO = 1.25V, differential transformer-coupled
analog output, 50Ω double terminated (Figure 7), IOUT = 20mA, TA = TMIN to TMAX, unless otherwise noted. ≥+25°C guaranteed by
production test, <+25°C guaranteed by design and characterization. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TIMING CHARACTERISTICS
Data to Clock Setup Time
tSETUP
Referenced to rising edge of clock (Note 4)
-0.8
Data to Clock Hold Time
tHOLD
Referenced to rising edge of clock (Note 4)
1.8
ns
ns
Data Latency
3.5
Clock
cycles
Minimum Clock Pulse Width High
tCH
CLKP, CLKN
Minimum Clock Pulse Width Low
tCL
CLKP, CLKN
LVDS LOGIC INPUTS (B0N–B15N, B0P–B15P)
0.9
0.9
ns
ns
Differential Input Logic High
VIH
Differential Input Logic Low
VIL
Common-Mode Voltage Range
100
VCOM
1.125
Differential Input Resistance
RIN
85
Input Capacitance
CIN
mV
100
-100
mV
1.375
V
125
5
Ω
pF
CMOS LOGIC INPUTS (PD, SEL0)
Input Logic High
VIH
Input Logic Low
VIL
Input Leakage Current
IIN
Input Capacitance
CIN
0.7 ✕
DVDD
V
0.3 ✕
DVDD
-15
+15
5
V
µA
pF
CLOCK INPUTS (CLKP, CLKN)
Differential Input Voltage Swing
VCLK
Sine wave
≥1.5
Square wave
≥0.5
(Note 5)
>100
V/µs
VP-P
Differential Input Slew Rate
SRCLK
Common-Mode Voltage Range
VCOM
1.5
±20%
V
Input Resistance
RCLK
5
kΩ
Input Capacitance
CCLK
5
pF
POWER SUPPLIES
Analog Supply Voltage Range
AVDD
3.135
3.3
3.465
V
Digital Supply Voltage Range
DVDD
3.135
3.3
3.465
V
Clock Supply Voltage Range
VCLK
3.135
3.3
3.465
V
Analog Supply Current
IAVDD
Digital Supply Current
IDVDD
Clock Supply Current
4
IVCLK
fCLK = 100Msps, fOUT = 1MHz
27
Power-down
0.3
mA
fCLK = 100Msps, fOUT = 1MHz
7
Power-down
10
µA
fCLK = 100Msps, fOUT = 1MHz
5.6
mA
Power-down
10
µA
_______________________________________________________________________________________
mA
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
(AVDD = DVDD = VCLK = 3.3V, AGND = DGND = CLKGND = 0, external reference, VREFIO = 1.25V, differential transformer-coupled
analog output, 50Ω double terminated (Figure 7), IOUT = 20mA, TA = TMIN to TMAX, unless otherwise noted. ≥+25°C guaranteed by
production test, <+25°C guaranteed by design and characterization. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
Power Dissipation
PDISS
Power-Supply Rejection Ratio
PSRR
Note 1:
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
CONDITIONS
MIN
TYP
fCLK = 100Msps, fOUT = 1MHz
MAX
UNITS
130
Power-down
mW
1
AVDD = VCLK = DVDD = 3.3V ±5% (Note 6)
-1
+1
%FS/V
Nominal full-scale current IOUT = 32 ✕ IREF.
This parameter does not include update-rate depending effects of sin(x)/x filtering inherent in the MAX5888.
Parameter measured single ended into a 50Ω termination resistor.
Parameter guaranteed by design.
A differential clock input slew rate of >100V/ms is required to achieve the specified dynamic performance.
Parameter defined as the change in midscale output caused by a ±5% variation in the nominal supply voltage.
Typical Operating Characteristics
(AVDD = DVDD = VCLK = 3.3V, external reference, VREFIO = 1.25V, RL = 50Ω, IOUT = 20mA, TA = +25°C, unless otherwise noted.)
80
80
0dB FS
50
40
60
-12dB FS
50
0dB FS
40
50
40
30
30
20
20
20
10
10
10
0
20
30
40
50
fOUT (MHz)
fT1 = 9.0252MHz
fT2 = 10.0417MHz
-20
fT2
-40
-50
-60
-70
-90
-12dB FS
-80
-70
-60
-6dB FS
2 x fT2 - fT1
2 x fT1 - fT2
-80
-100
TWO-TONE IMD (dBc)
fT1
-30
0
100
150
200
250
2-TONE INTERMODULATION DISTORTION
(fCLK = 450MHz)
0
AOUT = -6dB FS
BW = 5MHz
-10
fT1 = 79.2114MHz
fT2 = 80.0903MHz
-20
fT1
-30
fT2
-40
-50
-60
2 x fT2 - fT1
2 x fT1 - fT2
-70
-50
-80
-40
-100
-90
50
fOUT (MHz)
MAX5888 toc05
AOUT = -6dB FS
BW = 5MHz
MAX5888 toc04
0
-10
10 20 30 40 50 60 70 80 90 100
fOUT (MHz)
2-TONE IMD vs. OUTPUT FREQUENCY
(1MHz CARRIER SPACING, fCLK = 300MHz)
2-TONE INTERMODULATION DISTORTION
(fCLK = 100MHz)
0dB FS
0
0
2-TONE IMD (dBm)
10
-12dB FS
60
30
0
-6dB FS
70
SFDR (dBc)
-6dB FS
60
0
2-TONE IMD (dBm)
90
70
SFDR (dBc)
SFDR (dBc)
70
100
MAX5888 toc03
80
-6dB FS
90
SPURIOUS-FREE DYNAMIC RANGE
vs. OUTPUT FREQUENCY (fCLK = 500MHz)
MAX5888 toc02
-12dB FS
90
100
MAX5888 toc01
100
SPURIOUS-FREE DYNAMIC RANGE
vs. OUTPUT FREQUENCY (fCLK = 200MHz)
MAX5888 toc06
SPURIOUS-FREE DYNAMIC RANGE
vs. OUTPUT FREQUENCY (fCLK = 100MHz)
-90
-100
7
8
9
10
fOUT (MHz)
11
12
0
25
50
75
fOUT (MHz)
100
77
78
79
80
81
82
fOUT (MHz)
_______________________________________________________________________________________
5
MAX5888
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(AVDD = DVDD = VCLK = 3.3V, external reference, VREFIO = 1.25V, RL = 50Ω, IOUT = 20mA, TA = +25°C, unless otherwise noted.)
SFDR vs. OUTPUT FREQUENCY
(fCLK = 200MHz, AOUT = -6dB FS)
fOUT = 10MHz
fOUT = 40MHz
82
4.5
MAX5888toc9
90
MAX5888toc08
IOUT = 20mA
80
INTEGRAL NONLINEARITY
vs. DIGITAL INPUT CODE
SFDR vs. TEMPERATURE
(fCLK = 300MHz, AOUT = -6dB FS, IOUT = 20mA)
MAX5888toc07
100
3.0
60
IOUT = 10mA
40
20
66
fOUT = 120MHz
-1.5
58
-3.0
fOUT = 80MHz
0
-4.5
50
0
10 20 30 40 50 60 70
80 90 100
-40
fOUT (MHz)
-15
10
35
60
0 10000 20000 30000 40000 50000 60000 70000
85
DIGITAL INPUT CODE
TEMPERATURE (°C)
8-TONE MULTITONE POWER RATIO PLOT
(fCLK = 300MHz, fCENTER = 31.9702MHz)
DIFFERENTIAL NONLINEARTIY
vs. DIGITAL INPUT CODE
0
MAX5888toc10
3.0
0
AOUT = -18dB FS
BW = 12MHz
-10
-20
8-TONE MTPR (dBm)
1.5
DNL (LSB)
0
MAX5888 toc11
IOUT = 5mA
74
INL (LSB)
SFDR (dBc)
1.5
SFDR (dBc)
-1.5
fT5
fT1
-30
fT2
-40
fT6
fT3
-50
fT7
fT4
-60
fT8
-70
-80
-90
-100
-3.0
26
0 10000 20000 30000 40000 50000 60000 70000
28
30
DIGITAL INPUT CODE
fT1 = 28.0151MHz
fT2 = 29.0405MHz
fT3 = 30.0659MHz
fT4 = 31.0181MHz
200
160
38
fT5 = 33.06881MHz
fT6 = 34.0209MHz
fT7 = 35.0464MHz
fT8 = 36.0718MHz
132
EXTERNAL REFERENCE
128
INTERNAL REFERENCE
124
120
120
116
80
100
200
300
fCLK (MHz)
6
36
MAX5888toc13
240
34
136
POWER DISSIPATION (mW)
MAX5888toc12
280
32
fOUT (MHz)
POWER DISSIPATION vs. SUPPLY VOLTAGE
(fCLK = 100MHz, fOUT = 10MHz, IFS = 20mA)
POWER DISSIPATION vs. CLOCK FREQUENCY
(fOUT = 10MHz, AOUT = 0dB FS, IOUT = 20mA)
POWER DISSIPATION (mW)
MAX5888
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
400
500
3.135 3.190
3.245 3.300
3.355 3.410
SUPPLY VOLTAGE (V)
_______________________________________________________________________________________
3.465
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
PIN
NAME
1
B3P
Data Bit 3
FUNCTION
2
B3N
Complementary Data Bit 3
3
B2P
Data Bit 2
4
B2N
Complementary Data Bit 2
5
B1P
Data Bit 1
6
B1N
Complementary Data Bit 1
7
B0P
Data Bit 0 (LSB)
8
B0N
Complementary Data Bit 0 (LSB)
9, 41, 60, 62
DGND
Digital Ground
10, 40, 61
DVDD
Digital Supply Voltage. Accepts a supply voltage range of 3.135V to 3.465V. Bypass each pin with a
0.1µF capacitor to the nearest DGND.
11, 16
VCLK
Clock Supply Voltage. Accepts a supply voltage range of 3.135V to 3.465V. Bypass each pin with a
0.1µF capacitor to the nearest CLKGND.
12, 15
CLKGND
13
CLKP
14
CLKN
Complementary Converter Clock Input. Negative input terminal for the differential converter clock.
17
PD
Power-Down Input. PD pulled high enables the DAC’s power-down mode. PD pulled low allows for
normal operation of the DAC. This pin features an internal pulldown resistor.
18, 24, 29,
30, 32
AVDD
Analog Supply Voltage. Accepts a supply voltage range of 3.135V to 3.465V. Bypass each pin with a
0.1µF capacitor to the nearest AGND.
19, 25, 28,
31, 33, EP
AGND
Analog Ground. Exposed paddle (EP) must be connected to AGND.
20
REFIO
Reference I/O. Output of the internal 1.2V precision bandgap reference. Bypass with a 1µF capacitor
to AGND. Can be driven with an external reference source.
21
FSADJ
Full-Scale Adjust Input. This input sets the full-scale output current of the DAC. For 20mA full-scale
output current, connect a 2kΩ resistor between FSADJ and DACREF.
22
DACREF
Return Path for the Current Set Resistor. For 20mA full-scale output current, connect a 2kΩ resistor
between FSADJ and DACREF.
23, 34–38
N.C.
26
IOUTN
Complementary DAC Output. Negative terminal for differential current output. The full-scale output
current range can be set from 2mA to 20mA.
27
IOUTP
DAC Output. Positive terminal for differential current output. The full-scale output current range can
be set from 2mA to 20mA.
39
SEL0
Mode Select Input SEL0. Set high to activate the segment shuffling function. Since this pin features an
internal pulldown resistor, it can be left open or pulled low to disable the segment-shuffling function.
See Segment Shuffling in the Detailed Description section for more information.
42
B15P
Data Bit 15 (MSB)
43
B15N
Complementary Data Bit 15 (MSB)
44
B14P
Data Bit 14
Clock Ground
Converter Clock Input. Positive input terminal for the differential converter clock.
Not Connected. Do not connect to these pins. Do not tie these pins together.
_______________________________________________________________________________________
7
MAX5888
Pin Description
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
MAX5888
Pin Description (continued)
PIN
NAME
45
B14N
Complementary Data Bit 14
FUNCTION
46
B13P
Data Bit 13
47
B13N
Complementary Data Bit 13
48
B12P
Data Bit 12
49
B12N
Complementary Data Bit 12
50
B11P
Data Bit 11
51
B11N
Complementary Data Bit 11
52
B10P
Data Bit 10
53
B10N
54
B9P
55
B9N
Complementary Data Bit 9
56
B8P
Data Bit 8
57
B8N
Complementary Data Bit 8
58
B7P
Data Bit 7
59
B7N
Complementary Data Bit 7
63
B6P
Data Bit 6
64
B6N
Complementary Data Bit 6
65
B5P
Data Bit 5
66
B5N
Complementary Data Bit 5
67
B4P
Data Bit 4
68
B4N
Complementary Data Bit 4
Complementary Data Bit 10
Data Bit 9
Detailed Description
Architecture
The MAX5888 is a high-performance, 16-bit, currentsteering DAC (Figure 1) capable of operating with clock
speeds up to 500MHz. The converter consists of separate input and DAC registers, followed by a currentsteering circuit. This circuit is capable of generating
differential full-scale currents in the range of 2mA to
20mA. An internal current-switching network in combination with external 50Ω termination resistors convert
the differential output currents into a differential output
voltage with a peak-to-peak output voltage range of
0.1V to 1V. An integrated 1.2V bandgap reference, control amplifier, and user-selectable external resistor
determine the data converter’s full-scale output range.
Reference Architecture and Operation
The MAX5888 supports operation with the on-chip 1.2V
bandgap reference or an external reference voltage
source. REFIO serves as the input for an external, lowimpedance reference source, and as the output if the
DAC is operating with the internal reference. For stable
8
operation with the internal reference, REFIO should be
decoupled to AGND with a 0.1µF capacitor. Due to its
limited output drive capability REFIO must be buffered
with an external amplifier, if heavier loading is required.
The MAX5888’s reference circuit (Figure 2) employs a
control amplifier, designed to regulate the full-scale
current IOUT for the differential current outputs of the
DAC. Configured as a voltage-to-current amplifier, the
output current can be calculated as follows:
IOUT = 32 ✕ IREFIO - 1LSB
IOUT = 32 ✕ IREFIO - (IOUT / 216)
where IREFIO is the reference output current (IREFIO =
VREFIO/RSET) and IOUT is the full-scale output current of
the DAC. Located between FSADJ and DACREF, RSET
is the reference resistor, which determines the amplifier’s output current for the DAC. See Table 1 for a matrix
of different IOUT and RSET selections.
_______________________________________________________________________________________
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
DGND
SEL0
FUNCTION
SELECTION
BLOCK
1.2V
REFERENCE
MAX5888
DVDD
PD
AGND
AVDD
MAX5888
REFIO
IOUTP
IOUTN
CURRENT-STEERING
DAC
REFADJ
CLKN
CLKP
SEGMENT SHUFFLING/LATCH
DECODER
LVDS RECEIVER INPUT/LATCH
16
DIFFERENTIAL DIGITAL INPUT B0 THROUGH B15
Figure 1. Simplified MAX5888 Block Diagram
Table 1. IOUT and RSET Selection Matrix Based on a Typical 1.200V Reference Voltage
FULL-SCALE CURRENT
IOUT (mA)
REFERENCE CURRENT
IREF (µA)
RSET (kΩ)
CALCULATED
1% EIA STD
OUTPUT VOLTAGE
VIOUTP/N* (mVP-P)
2
62.5
19.2
19.1
100
5
156.25
7.68
7.5
250
10
312.5
3.84
3.83
500
15
468.75
2.56
2.55
750
20
625
1.92
1.91
1000
*Terminated into a 50Ω load.
Analog Outputs (IOUTP, IOUTN)
The MAX5888 outputs two complementary currents
(IOUTP, IOUTN) that can be operated in a singleended or differential configuration. A load resistor can
convert these two output currents into complementary
single-ended output voltages. The differential voltage
existing between IOUTP and IOUTN can also be con-
verted to a single-ended voltage using a transformer or
a differential amplifier configuration. If no transformer is
used, the output should have a 50Ω termination to the
analog ground and a 50Ω resistor between the outputs.
Although not recommended, because of additional
noise pickup from the ground plane, for single-ended
_______________________________________________________________________________________
9
MAX5888
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
AVDD
1.2V
REFERENCE
AVDD
CURRENT
SOURCES
10kΩ
REFIO
CURRENT
SWITCHES
0.1µF
IOUTP
FSADJ
IREF
RSET
CURRENT-STEERING
DAC
IOUT
IOUTN
DACREF
IOUT
IOUTN
IOUTP
IREF = VREFIO/RSET
Figure 2. Reference Architecture, Internal Reference
Configuration
operation IOUTP should be selected as the output, with
IOUTN connected to AGND. Note that a single-ended
output configuration has a higher 2nd-order harmonic
distortion at high output frequencies than a differential
output configuration.
Figure 3 displays a simplified diagram of the internal
output structure of the MAX5888.
Figure 3. Simplified Analog Output Structure
WIDEBAND RF TRANSFORMER
PERFORMS SINGLE-ENDED TO
DIFFERENTIAL CONVERSION.
10
CLKP
25Ω
TO
DAC
1:1
SINGLE-ENDED
CLOCK SOURCE
(e.g., HP 8662A)
25Ω
Clock Inputs (CLKP, CLKN)
The MAX5888 features a flexible differential clock input
(CLKP, CLKN) operating from separate supplies
(VCLK, CLKGND) to achieve the lowest possible jitter
performance. The two clock inputs can be driven from
a single-ended or a differential clock source. For single-ended operation, CLKP should be driven by a logic
source, while CLKN should be bypassed to AGND with
a 0.1µF capacitor.
The CLKP and CLKN pins are internally biased to 1.5V.
This allows the user to AC-couple clock sources directly
to the device without external resistors to define the DC
level. The input resistance of CLKP and CLKN is >5kΩ.
See Figure 4 for a convenient and quick way to apply a
differential signal created from a single-ended source
(e.g., HP 8662A signal generator) and a wideband
transformer. These inputs can also be driven from an
LVDS-compatible clock source; however, it is recommended to use sinewave or AC-coupled ECL drive for
best performance.
0.1µF
0.1µF
CLKN
CLKGND
Figure 4. Differential Clock Signal Generation
Data Timing Relationship
Figure 5 shows the timing relationship between differential, digital LVDS data, clock, and output signals. The
MAX5888 features a 1.4ns hold, a -1ns setup, and a
1.8ns propagation delay time. There is a 3.5 clockcycle latency between CLKP/CLKN transitioning
high/low and IOUTP/IOUTN.
LVDS-Compatible Digital Inputs
(B0P–B15P, B0N–B15N)
The MAX5888 features LVDS receivers on the bus input
interface. These LVDS inputs (B0P/N through B15P/N)
allow for a low-differential voltage swing with low constant power consumption across a large range of
______________________________________________________________________________________
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
B0 TO B15
OUTPUT DATA IS UPDATED ON
THE FALLING EDGE OF CLKP
N
N-1
tSETUP
MAX5888
DIGITAL DATA IS LATCHED ON
THE RISING EDGE OF CLKP
N+1
tHOLD
N+2
tCH
tCL
CLKP
CLKN
tPD
IOUT
N-5
N-4
N-3
N-2
N-1
Figure 5. Detailed Timing Relationship
frequencies. Their differential characteristic supports
the transmission of high-speed data patterns without
the negative effects of electromagnetic interference
(EMI). All MAX5888 LVDS inputs feature on-chip termination with differential 100Ω resistors. See Figure 6 for
a simplified block diagram of the LVDS inputs.
A common-mode level of 1.25V and an 800mV differential input swing can be applied to these inputs.
Segment Shuffling (SEL0)
Segment shuffling can improve the SFDR of the
MAX5888. The improvement is most pronounced at
higher output frequencies and amplitudes. Note that an
improvement in SFDR can only be achieved at the cost
of a slight increase in the DAC’s noise floor.
Pin SEL0 controls the segment-shuffling function. If
SEL0 is pulled low, the segment-shuffling function of
the DAC is disabled. SEL0 can also be left open,
because an internal pulldown resistor helps to deactivate the segment-shuffling feature. To activate the
MAX5888 segment-shuffling function, SEL0 must be
pulled high.
Power-Down Operation (PD)
The MAX5888 also features an active-high power-down
mode, which allows the user to cut the DAC’s digital
current consumption to less than 6µA and the analog
current consumption to less than 0.3mA. A single pin
(PD) is used to control the power-down mode (PD = 1)
or reactivate the DAC (PD = 0) after power-down.
B0P–B15P
D
Q
TO DECODE
LOGIC
100Ω
D
Q
B0N–B15N
CLOCK
Figure 6. Simplified LVDS-Compatible Input Structure
Enabling the power-down mode of the MAX5888 allows
the overall power consumption to be reduced to less
than 1mW. The MAX5888 requires 10ms to wake up
from power-down and enter a fully operational state.
Applications Information
Differential Coupling Using a
Wideband RF Transformer
The differential voltage existing between IOUTP and
IOUTN can also be converted to a single-ended voltage using a transformer (Figure 7) or a differential
amplifier configuration. Using a differential transformer
coupled output, in which the output power is limited to
0dBm, can optimize the dynamic performance.
However, make sure to pay close attention to the transformer core saturation characteristics when selecting a
transformer for the MAX5888. Transformer core saturation can introduce strong 2nd-harmonic distortion,
especially at low output frequencies and high signal
______________________________________________________________________________________
11
MAX5888
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
AVDD
DVDD
VCLK
50Ω
T2, 1:1
VOUT, SINGLE ENDED
IOUTP
B0–B15
100Ω
MAX5888
IOUTN
16
T1, 1:1
AGND
DGND
WIDEBAND RF TRANSFORMER T2
PERFORMS THE DIFFERENTIAL TO
SINGLE-ENDED CONVERSION.
50Ω
CLKGND
Figure 7. Differential to Single-Ended Conversion Using a Wideband RF Transformer
AVDD
DVDD
VCLK
50Ω
OUTP
IOUTP
B0–B15
100Ω
MAX5888
IOUTN
16
AGND
DGND
CLKGND
OUTN
50Ω
Figure 8. MAX5888 Differential Output Configuration
amplitudes. It is also recommended to center tap the
transformer to ground. If no transformer is used, each
DAC output should be terminated to ground with a 50Ω
resistor. Additionally, a 100Ω resistor should be placed
between the outputs (Figure 8).
If a single-ended unipolar output is desirable, IOUTP
should be selected as the output, with IOUTN grounded. However, driving the MAX5888 single ended is not
recommended since additional noise is added (from
the ground plane) in such configurations.
The distortion performance of the DAC depends on the
load impedance. The MAX5888 is optimized for a 50Ω
double termination. It can be used with a transformer
output as shown in Figure 7 or just one 50Ω resistor
from each output to ground and one 50Ω resistor
between the outputs. This produces a full-scale output
power of up to 0dBm depending on the output current
setting. Higher termination impedance can be used at
the cost of degraded distortion performance and
increased output noise voltage.
12
Adjacent Channel Leakage Power Ratio
(ACLR) Testing for CDMA- and
WCDMA-Based Base Station
Transceiver Systems (BTS)
The transmitter sections of BTS applications serving
CDMA and WCDMA architectures must generate carriers with minimal coupling of carrier energy into the adjacent channels. Similar to the GSM/EDGE model (see the
Multitone Testing for GSM/EDGE Applications section in
the Applications section), a transmit mask (Tx mask)
exists for this application. The spread-spectrum modulation function applied to the carrier frequency generates a
spectral response, which is uniform over a given bandwidth (up to 4MHz) for a WCDMA-modulated carrier.
A dominant specification is ACLR, a parameter which
reflects the ratio of the power in the desired carrier
band to the power in an adjacent carrier band. The
specification covers the first two adjacent bands, and is
measured on both sides of the desired carrier.
According to the transmit mask for CDMA and WCDMA
architectures, the power ratio of the integrated carrier
channel energy to the integrated adjacent channel
energy must be >45dB for the first adjacent carrier slot
(ACLR 1) and >50dB for the second adjacent carrier
slot (ACLR 2). This specification applies to the output of
the entire transmitter signal chain. The requirement for
only the DAC block of the transmitter must be tighter,
with a typical margin of >15dB, requiring the DAC’s
ACLR 1 to be better than 60dB. Adjacent channel leakage is caused by a single-spread spectrum carrier,
which generates intermodulation (IM) products
between the frequency components located within the
carrier band. The energy at one end of the carrier band
generates IM products with the energy from the opposite end of the carrier band. For single-carrier WCDMA
modulation, these IMD products are spread 3.84MHz
over the adjacent sideband. Four contiguous WCDMA
______________________________________________________________________________________
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
-25
-30
-40
The transmitter sections of multicarrier base station
transceiver systems for GSM/EDGE usually present
communication DAC manufacturers with the difficult
task of providing devices with higher resolution, while
simultaneously reducing noise and spurious emissions
over a desired bandwidth.
To specify noise and spurious emissions from base stations, a GSM/EDGE Tx mask is used to identify the DAC
requirements for these parameters. This mask shows
that the allowable levels for noise and spurious emissions are dependent on the offset frequency from the
transmitted carrier frequency. The GSM/EDGE mask
and its specifications are based on a single active carrier with any other carriers in the transmitter being disabled. Specifications displayed in Figure 11 support
per-carrier output power levels of 20W or greater.
Lower output power levels yield less stringent emission
requirements. For GSM/EDGE applications, the DAC
demands spurious emission levels of less than -80dBc
for offset frequencies ≥6MHz. Spurious products from
the DAC can combine with both random noise and spurious products from other circuit elements. The spurious products from the DAC should therefore be backed
off by 6dB more to allow for these other sources and
still avoid signal clipping.
-30
fCENTER = 61.44MHz
fCLK = 184.32Mbps
ACLR = 73dB
-40
-50
OUTPUT POWER (dBm)
-50
OUTPUT POWER (dBm)
Multitone Testing for GSM/EDGE
Applications
-60
-70
-80
-90
-100
-60
-70
-80
-90
-100
-110
-110
-120
-120
-125
fCENTER = 61.44MHz
fCLK = 184.32Mbps
ACLR = 65dB
-130
3.5MHz/div
Figure 9. ACLR for WCDMA Modulation, Single Carrier
3.5MHz/div
Figure 10. ACLR for WCDMA Modulation, Four Carriers
*Note that due to their own IM effects and noise limitations, spectrum analyzers introduce ACLR errors, which can falsify the measurement. For a single-carrier ACLR measurement greater than 70dB, these measurement limitations are significant, becoming even more
restricting for multicarrier measurement. Before attempting an ACLR measurement, it is recommended consulting application notes provided by major spectrum analyzer manufacturers that provide useful tips on how to use their instruments for such tests.
______________________________________________________________________________________
13
MAX5888
carriers spread their IM products over a bandwidth of
20MHz on either side of the 20MHz total carrier bandwidth. In this four-carrier scenario, only the energy in
the first adjacent 3.84MHz side band is considered for
ACLR 1. To measure ACLR, drive the converter with a
WCDMA pattern. Make sure that the signal is backed
off by the peak-to-average ratio, such that the DAC is
not clipping the signal. ACLR can then be measured
with the ACLR measurement function built into your
spectrum analyzer.
Figure 9 shows the ACLR performance for a single
WCDMA carrier (fCLK = 184.32MHz, fOUT = 61.44MHz)
applied to the MAX5888 (including measurement system limitations*).
Figure 10 illustrates the ACLR test results for the
MAX5888 with a four-carrier WCDMA signal at an output frequency of 61.44MHz and sampling frequency of
184.32MHz. Again, the noise floor of the instrument
restricts the signal’s real dynamic range of the signal,
and the measured ACLR 1 understates the actual by
more than 2.5dB. Considerable care must be taken to
ensure accurate measurement of this parameter.
MAX5888
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
The number of carriers and their signal levels with
respect to the full scale of the DAC are important as
well. Unlike a full-scale sine wave, the inherent nature of
a multitone signal contains higher peak-to-RMS ratios,
raising the prospect for potential clipping, if the signal
level is not backed off appropriately. If a transmitter
operates with four/eight in-band carriers, each individual carrier must be operated at less than
-12dB FS/-18dB FS to avoid waveform clipping.
The noise density requirements (Table 2) for a
GSM/EDGE-based system can again be derived from
the system’s Tx mask. With a worst-case noise level of
-80dBc at frequency offsets of ≥6MHz and a measurement bandwidth of 100kHz, the minimum noise density
per hertz is calculated as follows:
SNRMIN = -80dBc - 10 ✕ log10(100 ✕ 103Hz)
SNRMIN = -130dBc/Hz
Since random DAC noise adds to both the spurious tones
and to random noise from other circuit elements, it is recommended reducing the specification limits by about
10dB to allow for these additional noise contributions
while maintaining compliance with the Tx mask values.
Other key factors in selecting the appropriate DAC for
the Tx path of a multicarrier GSM/EDGE system is the
converter’s ability to offer superior IMD and MTPR performance. Multiple carriers in a designated band generate
unwanted intermodulation distortion between the individual carrier frequencies. A multitone test vector usually
consists of several equally spaced carriers, usually four,
with identical amplitudes. Each of these carriers is representative of a channel within the defined bandwidth of
interest. To verify MTPR, one or more tones are
removed such that the intermodulation distortion perfor-
Table 2. GSM/EDGE Noise Requirements
for Multicarrier Systems
NUMBER OF
CARRIERS
CARRIER
POWER LEVEL
(dB FS)
DAC NOISE DENSITY
REQUIREMENT
(dB FS/Hz)
2
-6
-146
4
-12
-152
8
-18
-158
mance of the DAC can be evaluated. Nonlinearities
associated with the DAC create spurious tones, some
of which may fall back into the area of the removed
tone, limiting a channel’s carrier-to-noise ratio. Other
spurious components falling outside the band of interest can also be important, depending on the system’s
spectral mask and filtering requirements. Going back to
the GSM/EDGE Tx mask, the IMD specification for adjacent carriers varies somewhat among the different GSM
standards. For the PCS1800 and GSM850 standards,
the DAC must meet an average IMD of -70dBc.
Table 3 summarizes the dynamic performance requirements for the entire Tx signal chain in a four-carrier
GSM/EDGE-based system and compares the previously established converter requirements with a new-generation high dynamic performance DAC.
The four-tone MTPR plot in Figure 12 demonstrates the
MAX5888’s excellent dynamic performance. The center
frequency (fCENTER = 31.97MHz) has been removed to
allow detection and analysis of intermodulation or spurious components falling back into this empty spot from
adjacent channels. The four carriers are observed over
a 12MHz bandwidth and are equally spaced at 1MHz.
Each individual output amplitude is backed off to -12dB
FS. Under these conditions, the DAC yields an MTPR
performance of -78dBc.
Table 3. Summary of Important AC Performance Parameters for Multicarrier GSM/EDGE
Systems
SPECIFICATION
SYSTEM TRANSMITTER
OUTPUT LEVELS
DAC REQUIREMENTS WITH
MARGINS
MAX5888 SPECIFICATIONS
SFDR
80dBc
86dBc
82dBc*
SNR
-130dBc/Hz
-152dB FS/Hz
-165dB/Hz
IMD
-70dBc
-75dBc
-78dBc
N/S
-12dB FS
-12dB FS
Carrier Amplitude
*Measured within a 25MHz window.
14
______________________________________________________________________________________
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
MAX5888
4-TONE MULTITONE POWER RATIO PLOT
(fCLK = 300MHz, fCENTER = 31.9702MHz)
0
AOUT = -12dB FS
BW = 12MHz
-10
INBAND
30kHz 100kHz
-60
-20
4-TONE MTPR (dBm)
MEASUREMENT BANDWIDTH
-30
OUTBAND
TRANSMITTER EDGE
AMPLITUDE (dBc)
O
fT3
fT1
-30
fT4
fT2
-40
-50
-60
-70
IMD REQUIREMENT: < -70dBc
-70
-73
-75
-80
-80
WORST-CASE
NOISE LEVEL
-90
-90
-100
26
0.2 0.4 0.6
1.2
1.8
28
30
6.0
FREQUENCY OFFSET FROM CARRIER (MHz)
Figure 11. GSM/EDGE Tx Mask
Grounding, Bypassing, and Power-Supply
Considerations
Grounding and power-supply decoupling can strongly
influence the performance of the MAX5888. Unwanted
digital crosstalk may couple through the input, reference, power supply, and ground connections, affecting
dynamic performance. Proper grounding and powersupply decoupling guidelines for high-speed, high-frequency applications should be closely followed. This
reduces EMI and internal crosstalk that can significantly affect the dynamic performance of the MAX5888.
Use of a multilayer printed circuit (PC) board with separate ground and power-supply planes is recommended. High-speed signals should run on lines directly
above the ground plane. Since the MAX5888 has separate analog and digital ground buses (AGND,
CLKGND, and DGND, respectively), the PC board
should also have separate analog and digital ground
sections with only one point connecting the two planes.
Digital signals should be run above the digital ground
plane and analog/clock signals above the analog/clock
ground plane. Digital signals should be kept as far
away from sensitive analog inputs, reference inputs
sense lines, common-mode input, and clock inputs as
fT1 = 30.0659MHz
fT2 = 31.0181MHz
fT3 = 33.0688MHz
fT4 = 34.0209MHz
32
34
36
38
fOUT (MHz)
Figure 12. 4-Tone MTPR Test Results, fCENTER = 31.97MHz,
fCLK = 300MHz
practical. A symmetric design of clock input and analog output lines is recommended to minimize 2nd-order
harmonic distortion components and optimize the
DAC’s dynamic performance. Digital signal paths
should be kept short and run lengths matched to avoid
propagation delay and data skew mismatches.
The MAX5888 supports three separate power-supply
inputs for analog (AVDD), digital (DVDD), and clock
(VCLK) circuitry. Each AVDD, DVDD, and VCLK input
should at least be decoupled with a separate 0.1µF
capacitor as close to the pin as possible and their
opposite ends with the shortest possible connection to
the corresponding ground plane (Figure 13). Try to
minimize the analog and digital load capacitances for
optimized operation. All three power-supply voltages
should also be decoupled at the point they enter the
PC board with tantalum or electrolytic capacitors.
Ferrite beads with additional decoupling capacitors
forming a pi network could also improve performance.
The analog and digital power-supply inputs AV DD ,
VCLK, and DVDD of the MAX5888 allow a supply voltage range of 3.3V ±5%.
______________________________________________________________________________________
15
MAX5888
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
DAC. An array of at least 4 ✕ 4 vias (≤0.3mm diameter
per via hole and 1.2mm pitch between via holes) is recommended for this 68-lead QFN-EP package.
The MAX5888 is packaged in a 68-lead QFN-EP
package (package code: G6800-4), providing greater
design flexibility, increased thermal efficiency**, and
optimized AC performance of the DAC. The exposed
pad (EP) enables the user to implement grounding
techniques, which are necessary to ensure highest performance operation. The EP must be soldered down
to AGND.
In this package, the data converter die is attached to
an EP lead frame with the back of this frame exposed at
the package bottom surface, facing the PC board side
of the package. This allows a solid attachment of the
package to the PC board with standard infrared (IR)
flow soldering techniques. A specially created land pattern on the PC board, matching the size of the EP (6mm
✕ 6mm), ensures the proper attachment and grounding
of the DAC. Designing vias*** into the land area and
implementing large ground planes in the PC board
design allow for highest performance operation of the
Static Performance Parameter Definitions
Integral Nonlinearity (INL)
Integral nonlinearity is the deviation of the values on an
actual transfer function from either a best straight line fit
(closest approximation to the actual transfer curve) or a
line drawn between the end points of the transfer function, once offset and gain errors have been nullified. For
a DAC, the deviations are measured at every individual
step.
Differential Nonlinearity (DNL)
Differential nonlinearity is the difference between an
actual step height and the ideal value of 1 LSB. A DNL
error specification of less than 1 LSB guarantees no
missing codes and a monotonic transfer function.
**Thermal efficiency is not the key factor, since the MAX5888 features low-power operation. The exposed pad is the key element to
ensure a solid ground connection between the DAC and the PC board’s analog ground layer.
***Vias connect the land pattern to internal or external copper planes. It is important to connect as many vias as possible to the analog
ground plane to minimize inductance.
BYPASSING—DAC LEVEL
BYPASSING—BOARD LEVEL
AVDD
AVDD
VCLK
FERRITE BEAD
1µF
0.1µF
0.1µF
AGND
10µF
47µF
ANALOG POWERSUPPLY SOURCE
47µF
DIGITAL POWERSUPPLY SOURCE
47µF
CLOCK POWERSUPPLY SOURCE
CLKGND
DVDD
OUTP
B0–B15
FERRITE BEAD
MAX5888
1µF
16
10µF
OUTN
0.1µF
VCLK
FERRITE BEAD
DGND
1µF
DVDD
10µF
Figure 13. Recommended Power-Supply Decoupling and Bypassing Circuitry
16
______________________________________________________________________________________
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
Gain Error
A gain error is the difference between the ideal and the
actual full-scale output voltage on the transfer curve,
after nullifying the offset error. This error alters the slope
of the transfer function and corresponds to the same
percentage error in each step.
Settling Time
The settling time is the amount of time required from the
start of a transition until the DAC output settles its new
output value to within the converter’s specified accuracy.
Glitch Energy
Glitch impulses are caused by asymmetrical switching
times in the DAC architecture, which generates undesired output transients. The amount of energy that
appears at the DAC’s output is measured over time and
usually specified in the pV-s range.
Dynamic Performance Parameter
Definitions
Signal-to-Noise Ratio (SNR)
For a waveform perfectly reconstructed from digital samples, the theoretical maximum SNR is the ratio of the fullscale analog output (RMS value) to the RMS quantization
error (residual error). The ideal, theoretical minimum can
be derived from the DAC’s resolution (N bits):
SNRdB = 6.02dB ✕ N + 1.76dB
Spurious-Free Dynamic Range (SFDR)
SFDR is the ratio of RMS amplitude of the carrier frequency (maximum signal components) to the RMS
value of their next-largest distortion component. SFDR
is usually measured in dBc and with respect to the carrier frequency amplitude or in dB FS with respect to the
DAC’s full-scale range. Depending on its test condition,
SFDR is observed within a predefined window or
to Nyquist.
Two-/Four-Tone Intermodulation
Distortion (IMD)
The two-tone IMD is the ratio expressed in dBc (or dB
FS) of either input tone to the worst 3rd-order (or higher) IMD products. Note that 2nd-order IMD products
usually fall at frequencies that can be easily removed
by digital filtering; therefore, they are not as critical as
3rd-order IMDs. The two-tone IMD performance of the
MAX5888 was tested with the two individual input tone
levels set to at least -6dB FS and the four-tone performance was tested according to the GSM model at an
output frequency of 32MHz and amplitude of -12dB FS.
Adjacent Channel Leakage
Power Ratio (ACLR)
Commonly used in combination with WCDMA, ACLR
reflects the leakage power ratio in dB between the
measured power within a channel relative to its adjacent channel. ACLR provides a quantifiable method of
determining out-of-band spectral energy and its influence on an adjacent channel when a bandwidth-limited
RF signal passes through a nonlinear device.
Chip Information
TRANSISTOR COUNT: 10,629
PROCESS: CMOS
However, noise sources such as thermal noise, reference noise, clock jitter, etc., affect the ideal reading;
therefore, SNR is computed by taking the ratio of the
RMS signal to the RMS noise, which includes all spectral components minus the fundamental, the first four
harmonics, and the DC offset.
______________________________________________________________________________________
17
MAX5888
Offset Error
The offset error is the difference between the ideal and
the actual offset current. For a DAC, the offset point is
the value at the output for the two midscale digital input
codes with respect to the full scale of the DAC. This
error affects all codes by the same amount.
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
68L QFN.EPS
MAX5888
3.3V, 16-Bit, 500Msps High Dynamic
Performance DAC with Differential LVDS Inputs
PACKAGE OUTLINE, 68L QFN, 10x10x0.9 MM
1
C
21-0122
2
*
*MAX5888 Package Code
PACKAGE OUTLINE, 68L QFN, 10x10x0.9 MM
1
C
21-0122
2
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