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19-3515; Rev 0; 2/05
KIT ATION EVALU BLE AVAILA
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs
General Description
The MAX5875 is an advanced 16-bit, 200Msps, dual digital-to-analog converter (DAC). This DAC meets the demanding performance requirements of signal synthesis applications found in wireless base stations and other communications applications. Operating from +3.3V and +1.8V supplies, this dual DAC offers exceptional dynamic performance such as 78dBc spurious-free dynamic range (SFDR) at fOUT = 16MHz and supports update rates of 200Msps, with a power dissipation of only 260mW. The MAX5875 utilizes a current-steering architecture that supports a 2mA to 20mA full-scale output current range, and allows a 0.1VP-P to 1VP-P differential output voltage swing. The device features an integrated +1.2V bandgap reference and control amplifier to ensure high-accuracy and low-noise performance. A separate reference input (REFIO) allows for the use of an external reference source for optimum flexibility and improved gain accuracy. The digital and clock inputs of the MAX5875 accept 3.3V CMOS voltage levels. The device features a flexible input data bus that allows for dual-port input or a single-interleaved data port. The MAX5875 is available in a 68-pin QFN package with an exposed paddle (EP) and is specified for the extended temperature range (-40C to +85C). Refer to the MAX5873 and MAX5874 data sheets for pin-compatible 12-bit and 14-bit versions of the MAX5875, respectively. Refer to the MAX5878 data sheet for an LVDS-compatible version of the MAX5875.
Features
200Msps Output Update Rate Noise Spectral Density = -162dBFS/Hz at fOUT = 16MHz Excellent SFDR and IMD Performance SFDR = 78dBc at fOUT = 16MHz (to Nyquist) SFDR = 75dBc at fOUT = 80MHz (to Nyquist) IMD = -86dBc at fOUT = 10MHz IMD = -76dBc at fOUT = 80MHz ACLR = 75dB at fOUT = 61MHz 2mA to 20mA Full-Scale Output Current CMOS-Compatible Digital and Clock Inputs On-Chip +1.20V Bandgap Reference Low 260mW Power Dissipation Compact 68-Pin QFN-EP Package (10mm x 10mm) Evaluation Kit Available (MAX5875EVKIT)
MAX5875
Ordering Information
PART MAX5875EGK TEMP RANGE -40C to +85C PINPACKAGE 68 QFN-EP** PKG CODE G6800-4
**EP = Exposed pad.
Pin Configuration
TOP VIEW
A10 A11 A12 A13 A14 A15 A9
68 67 66 65 64
Base Stations: Single/Multicarrier UMTS, CDMA, GSM Communications: Fixed Broadband Wireless Access, Point-to-Point Microwave Direct Digital Synthesis (DDS) Cable Modem Termination Systems (CMTS) Automated Test Equipment (ATE) Instrumentation
DVDD1.8
Applications
B0
B1
B2
B3
B4
B5
B6
B7
63 62 61 60 59 58
57 56 55 54 53 52 51 50 49 48 47 46 45 44
A8 A7 A6 A5 A4 A3 A2 A1 A0 GND DVDD3.3 GND GND AVDD3.3 GND REFIO FSADJ
B8
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
B9 B10 B11 B12 B13 B14 B15 SELIQ GND XOR DORI PD TORB CLKP CLKN GND AVCLK
Selector Guide
PART MAX5873 MAX5874 MAX5875 MAX5876* MAX5877* MAX5878 RESOLUTION (Bits) 12 14 16 12 14 16 UPDATE RATE (Msps) 200 200 200 250 250 250 LOGIC INPUTS CMOS CMOS CMOS LVDS LVDS LVDS
MAX5875
43 42 41 40 39 38 37 36 35
AVDD1.8
GND
OUTQP
GND
GND
GND
GND
OUTQN
OUTIN
DACREF
AVDD3.3
AVDD3.3
OUTIP
AVDD3.3
AVDD3.3
GND
*Future product--contact factory for availability.
QFN
________________________________________________________________ Maxim Integrated Products
AVDD1.8
1
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.
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs MAX5875
ABSOLUTE MAXIMUM RATINGS
Continuous Power Dissipation (TA = +70C) AVDD1.8, DVDD1.8 to GND, DACREF ..................-0.3V to +2.16V AVDD3.3, DVDD3.3, AVCLK to GND, DACREF ........-0.3V to +3.9V 68-Pin QFN-EP REFIO, FSADJ to GND, DACREF ........-0.3V to (AVDD3.3 + 0.3V) (derate 41.7mW/C above +70C) (Note 1) ............3333.3mW OUTIP, OUTIN, OUTQP, OUTQN to Thermal Resistance JA (Note 1)...................................+24C/W Operating Temperature Range ...........................-40C to +85C GND, DACREF....................................-1V to (AVDD3.3 + 0.3V) CLKP, CLKN to GND, DACREF..............-0.3V to (AVCLK + 0.3V) Junction Temperature ......................................................+150C A15/B15-A0/B0, XOR, SELIQ to Storage Temperature Range .............................-60C to +150C GND, DACREF .....................................-0.3V to (DVDD3.3 + 0.3V) Lead Temperature (soldering, 10s) .................................+300C TORB, DORI, PD to GND, DACREF ....-0.3V to (DVDD3.3 + 0.3V) Note 1: Thermal resistors based on a multilayer board with 4 x 4 via array in exposed paddle area.
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
(AVDD3.3 = DVDD3.3 = AVCLK = +3.3V, AVDD1.8 = DVDD1.8 = +1.8V, GND = 0, fCLK = fDAC, external reference VREFIO = +1.25V, output load 50 double-terminated, transformer-coupled output, IOUTFS = 20mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 2)
PARAMETER STATIC PERFORMANCE Resolution Integral Nonlinearity Differential Nonlinearity Offset Error Offset-Drift Tempco Full-Scale Gain Error Gain-Drift Tempco Full-Scale Output Current Output Compliance Output Resistance Output Capacitance DYNAMIC PERFORMANCE Clock Frequency Output Update Rate Noise Spectral Density fCLK fDAC fDAC = fCLK / 2, single-port mode fDAC = fCLK, dual-port mode fDAC = 150MHz fDAC = 200MHz fOUT = 16MHz, -12dBFS fOUT = 80MHz, -12dBFS 1 1 1 -162 -160 200 100 200 MHz Msps dBFS/Hz ROUT COUT IOUTFS GEFS External reference Internal reference External reference (Note 3) Single-ended 2 -0.5 1 5 INL DNL OS Measured differentially Measured differentially -0.025 16 3 2 0.001 10 1 100 50 20 +1.1 +0.025 Bits LSB LSB %FS ppm/C %FS ppm/C mA V M pF SYMBOL CONDITIONS MIN TYP MAX UNITS
2
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16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs
ELECTRICAL CHARACTERISTICS (continued)
(AVDD3.3 = DVDD3.3 = AVCLK = +3.3V, AVDD1.8 = DVDD1.8 = +1.8V, GND = 0, fCLK = fDAC, external reference VREFIO = +1.25V, output load 50 double-terminated, transformer-coupled output, IOUTFS = 20mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 2)
PARAMETER SYMBOL CONDITIONS fOUT = 1MHz, 0dBFS fOUT = 1MHz, -6dBFS fDAC = 100MHz fOUT = 1MHz, -12dBFS fOUT = 10MHz, -12dBFS Spurious-Free Dynamic Range to Nyquist fOUT = 30MHz, -12dBFS SFDR fOUT = 10MHz, -12dBFS fOUT = 16MHz, -12dBFS, TA +25oC fOUT = 16MHz, 0dBFS fOUT = 50MHz, -12dBFS fOUT = 80MHz, -12dBFS Spurious-Free Dynamic Range, 25MHz Bandwidth SFDR fDAC = 150MHz fDAC = 100MHz Two-Tone IMD TTIMD fDAC = 200MHz Four-Tone IMD, 1MHz Frequency Spacing, GSM Model Adjacent Channel Leakage Power Ratio 3.84MHz Bandwidth, W-CDMA Model Output Bandwidth INTER-DAC CHARACTERISTICS Gain Matching Gain-Matching Tempco Phase Matching Phase-Matching Tempco Channel-to-Channel Crosstalk REFERENCE Internal Reference Voltage Range Reference Input Compliance Range Reference Input Resistance Reference Voltage Drift VREFIO VREFIOCR RREFIO TCOREF 1.14 0.125 10 25 1.2 1.26 1.250 V V k ppm/C Gain Gain/C Phase fOUT = 60MHz Phase/C fOUT = 60MHz fCLK = 200MHz, fOUT = 50MHz fOUT = DC - 80MHz 0.2 20 0.25 0.002 -70 dB ppm/C Degrees Degrees/ C dB FTIMD fDAC = 150MHz fDAC = 184.32MHz (Note 4) fOUT = 16MHz, -12dBFS fOUT1 = 9MHz, -7dBFS; fOUT2 = 10MHz, -7dBFS fOUT1 = 79MHz, -7dBFS; fOUT2 = 80MHz, -7dBFS fOUT = 16MHz, -12dBFS 71 MIN TYP 88 84 82 81 79 80 78 87 78 75 84 -86 dBc -76 -86 dBc dBc dBc MAX UNITS
MAX5875
fDAC = 200MHz
ACLR BW-1dB
fOUT = 61.44MHz
75 240
dB MHz
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3
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs MAX5875
ELECTRICAL CHARACTERISTICS (continued)
(AVDD3.3 = DVDD3.3 = AVCLK = +3.3V, AVDD1.8 = DVDD1.8 = +1.8V, GND = 0, fCLK = fDAC, external reference VREFIO = +1.25V, output load 50 double-terminated, transformer-coupled output, IOUTFS = 20mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 2)
PARAMETER Output Fall Time Output Rise Time Output Propagation Delay Glitch Impulse Output Noise TIMING CHARACTERISTICS Data to Clock Setup Time Data to Clock Hold Time Single-Port (Interleaved Mode) Data Latency Dual-Port (Parallel Mode) Data Latency Minimum Clock Pulse-Width High Minimum Clock Pulse-Width Low tCH tCL CLKP, CLKN CLKP, CLKN 0.7 x DVDD3.3 0.3 x DVDD3.3 1 VPD = VTORB = VDORI = 3.3V CIN Sine wave Square wave SRCLK VCOM RCLK CCLK AVDD3.3 AVDD1.8 DVDD3.3 DVDD1.8 3.135 1.710 3.135 1.710 (Note 7) 1.5 2.5 >1.5 >0.5 >100 AVCLK / 2 0.3 5 2.5 3.3 1.8 3.3 1.8 3.465 1.890 3.465 1.890 20 tSETUP tHOLD Referenced to rising edge of clock (Note 6) Referenced to rising edge of clock (Note 6) Latency to I output Latency to Q output -0.6 2.1 -1.2 1.5 9 8 5.5 2.4 2.4 ns ns Clock Cycles Clock Cycles ns ns nOUT SYMBOL tFALL tRISE tPD CONDITIONS 90% to 10% (Note 5) 10% to 90% (Note 5) Excluding data latency (Note 5) Measured differentially IOUTFS = 2mA IOUTFS = 20mA MIN TYP 0.7 0.7 1.1 1 30 30 MAX UNITS ns ns ns pV*s pA/Hz
ANALOG OUTPUT TIMING (See Figure 4)
CMOS LOGIC INPUTS (A15/B15-A0/B0, XOR, SELIQ, PD, TORB, DORI) Input-Logic High Input-Logic Low Input Leakage Current PD, TORB, DORI Internal Pulldown Resistance Input Capacitance CLOCK INPUTS (CLKP, CLKN) Differential Input Voltage Swing Differential Input Slew Rate External Common-Mode Voltage Range Input Resistance Input Capacitance POWER SUPPLIES Analog Supply Voltage Range Digital Supply Voltage Range V V VP-P V/s V k pF VIH VIL IIN V V A M pF
4
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16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs
ELECTRICAL CHARACTERISTICS (continued)
(AVDD3.3 = DVDD3.3 = AVCLK = +3.3V, AVDD1.8 = DVDD1.8 = +1.8V, GND = 0, fCLK = fDAC, external reference VREFIO = +1.25V, output load 50 double-terminated, transformer-coupled output, IOUTFS = 20mA, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25C.) (Note 2)
PARAMETER SYMBOL IAVDD3.3 Analog Supply Current IAVDD1.8 IDVDD3.3 Digital Supply Current IDVDD1.8 Power Dissipation Power-Supply Rejection Ratio PDISS PSRR Power-down fDAC = 200Msps, fOUT = 1MHz Power-down fDAC = 200Msps, fOUT = 1MHz Power-down fDAC = 200Msps, fOUT = 1MHz Power-down fDAC = 200Msps, fOUT = 1MHz Power-down AVDD3.3 = AVCLK = DVDD3.3 = +3.3V 5% (Notes 7, 8) -0.1 CONDITIONS fDAC = 200Msps, fOUT = 1MHz MIN TYP 53 0.002 25 0.001 0.5 0.001 22 0.001 260 14 +0.1 300
mW
MAX5875
MAX 56 32 3 25
UNITS
mA
mA
W %FS/V
Note 2: Specifications at TA +25C are guaranteed by production testing. Specifications at TA < +25C are guaranteed by design and characterization data. Note 3: Nominal full-scale current IOUTFS = 32 x IREF. Note 4: This parameter does not include update-rate depending effects of sin(x)/x filtering inherent in the MAX5875. Note 5: Parameter measured single-ended into a 50 termination resistor. Note 6: Not production tested. Guaranteed by design and characterization data. Note 7: A differential clock input slew rate of >100V/s is required to achieve the specified dynamic performance. Note 8: Parameter defined as the change in midscale output caused by a 5% variation in the nominal supply voltage.
Typical Operating Characteristics
(AVDD3.3 = DVDD3.3 = AVCLK = +3.3V, AVDD1.8 = DVDD1.8 = +1.8V, external reference, VREFIO = +1.25V, RL = 50 double-terminated, IOUTFS = 20mA, TA = +25C, unless otherwise noted.)
SINGLE-TONE SFDR vs. OUTPUT FREQUENCY (fCLK = 50Msps)
MAX5875 toc01
SINGLE-TONE SFDR vs. OUTPUT FREQUENCY (fCLK = 100Msps)
MAX5875 toc02
SINGLE-TONE SFDR vs. OUTPUT FREQUENCY (fCLK = 150Msps)
0dBFS 80 -12dBFS SFDR (dBc) 60 -6dBFS
MAX5875 toc03
100
0dBFS
100 0dBFS 80 -12dBFS -6dBFS SFDR (dBc) 60
100
80 -12dBFS -6dBFS SFDR (dBc) 60
40
40
40
20
20
20
0 0 5 10 15 20 25 fOUT (MHz)
0 0 10 20 30 40 50 fOUT (MHz)
0 0 15 30 45 60 75 fOUT (MHz)
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5
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs MAX5875
Typical Operating Characteristics (continued)
(AVDD3.3 = DVDD3.3 = AVCLK = +3.3V, AVDD1.8 = DVDD1.8 = +1.8V, external reference, VREFIO = +1.25V, RL = 50 double-terminated, IOUTFS = 20mA, TA = +25C, unless otherwise noted.)
SINGLE-TONE SFDR vs. OUTPUT FREQUENCY (fCLK = 200Msps)
MAX5875 toc04
TWO-TONE IMD vs. OUTPUT FREQUENCY (1MHz CARRIER SPACING, fCLK = 100Msps)
MAX5875 toc05
TWO-TONE INTERMODULATION DISTORTION (fCLK = 100Msps)
BW = 12MHz fT1 = 29.8706MHz fT2 = 30.9937MHz fT1 fT2
MAX5875 toc06 MAX5875 toc09
100 0dBFS 80 -12dBFS -6dBFS SFDR (dBc) 60
-40 -50 TWO-TONE IMD (dBc) -60 -70 -80 -90 -6dBFS -100 -12dBFS
0
-20 OUTPUT POWER (dBFS)
-40
40
-60 2 x fT1 - fT2 -80 2 x fT2 - fT1
20
0 0 20 40 60 80 100 fOUT (MHz)
-100 5 10 15 20 25 30 35 40 24 26 28 30 fOUT (MHz) 32 34 36 fOUT (MHz)
TWO-TONE IMD vs. OUTPUT FREQUENCY (1MHz CARRIER SPACING, fCLK = 200Msps)
MAX5875 toc07
SFDR vs. FULL-SCALE OUTPUT CURRENT (fCLK = 200MHz)
AOUT = -6dBFS 20mA 80 10mA 5mA
MAX5875 toc08
SFDR vs. TEMPERATURE (fCLK = 200MHz)
95 90 85 AOUT = -6dBFS TA = +25C TA = +85C
-40 -50 TWO-TONE IMD (dBc) -60 -70 -80 -90 -6dBFS -100 0 10 20 30 40 50 60 70 -12dBFS
100
SFDR (dBc)
60
SFDR (dBc)
80 75 70 TA = -40C
40
20 65 0 80 0 20 40 60 80 100 fOUT (MHz) fOUT (MHz) 60 0 20 40 60 80 100 fOUT (MHz)
6
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16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs
Typical Operating Characteristics (continued)
(AVDD3.3 = DVDD3.3 = AVCLK = +3.3V, AVDD1.8 = DVDD1.8 = +1.8V, external reference, VREFIO = +1.25V, RL = 50 double-terminated, IOUTFS = 20mA, TA = +25C, unless otherwise noted.)
INTEGRAL NONLINEARITY vs. DIGITAL INPUT CODE
MAX5875 toc10
MAX5875
DIFFERENTIAL NONLINEARITY vs. DIGITAL INPUT CODE
MAX5875 toc11
POWER DISSIPATION vs. CLOCK FREQUENCY (fOUT = 10MHz)
AOUT = 0dBFS
MAX5875 toc12
+4 +3 +2
+4 +3 +2 DNL (LSB) +1 0 -1 -2 -3 -4
280
INL (LSB)
+1 0 -1 -2 -3 -4 6000 18,000 30,000 42,000 DIGITAL INPUT CODE 54,000 66,000
POWER DISSIPATION (mW)
260
240
220
200
180 6000 18,000 30,000 42,000 DIGITAL INPUT CODE 54,000 66,000 30 50 70 90 110 130 150 170 190 fCLK (MHz)
POWER DISSIPATION vs. SUPPLY VOLTAGE (fCLK = 100MHz, fOUT = 10MHz)
MAX5875 toc13
FOUR-TONE POWER RATIO PLOT (fCLK = 150MHz)
MAX5875 toc14
ACLR FOR W-CDMA MODULATION TWO CARRIER
-30 ANALOG OUTPUT POWER (dBm) -40 -50 -60 -70 -80 -90 -100 -110 fCLK = 184.32MHz fCENTER = 30.72MHz ACLR = +76dB
MAX5875 toc15
240
AOUT = 0dBFS
0
BW = 12MHz
fT2 fT3
POWER DISSIPATION (mW)
230 EXTERNAL REFERENCE
-20 OUTPUT POWER (dBFS) fT1 -40
fT1 = 29.9997MHz fT2 = 31.0251MHz fT3 = 32.0640MHz fT4 = 32.9829MHz fT4
220
210 INTERNAL REFERENCE
-60
200
-80
190 3.135
-100 3.235 3.335 3.435 26 28 30 32 fOUT (MHz) 34 36 38 SUPPLY VOLTAGE (V)
-120 3.05MHz/div
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7
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs MAX5875
Typical Operating Characteristics (continued)
(AVDD3.3 = DVDD3.3 = AVCLK = +3.3V, AVDD1.8 = DVDD1.8 = +1.8V, external reference, VREFIO = +1.25V, RL = 50 double-terminated, IOUTFS = 20mA, TA = +25C, unless otherwise noted.)
ACLR FOR W-CDMA MODULATION, SINGLE CARRIER
MAX5875 toc16
W-CDMA BASEBAND ACLR
84 83 82 ACLR (dB) 81 80 79 78 77 76 79.4 78.8 80.4 80.1 79.0 80.5 82.5 ADJACENT 84.0 ALTERNATE
MAX5875 toc17
-20 -30 ANALOG OUTPUT POWER (dBm) -40 -50 -60 -70 -80 -90 -100 -110 -120 DC 9.2MHz/div fCARRIER = 61.44MHz fCLK = 184.32MHz ACLR = +75dB
85
92.16MHz
1
2
3
4
NUMBER OF CARRIERS
Pin Description
PIN 1-9 NAME A8, A7, A6, A5, A4, A3, A2, A1, A0 FUNCTION Data Bits A8-A0. In dual-port mode, data is directed to the Q-DAC. In single-port mode, data bits are not used. Connect bits A8-A0 to GND in single-port mode.
10, 12, 13, 15, 20, 23, 26, 27, 30, 33, 36, 43 11 14, 21, 22, 31, 32 16 17 18 19, 34 24 25 28 29 35
GND
Ground Digital Supply Voltage. Accepts a 3.135V to 3.465V supply voltage range. Bypass with a 0.1F capacitor to GND. Analog Supply Voltage. Accepts a 3.135V to 3.465V supply voltage range. Bypass each pin with a 0.1F capacitor to GND. Reference I/O. Output of the internal 1.2V precision bandgap reference. Bypass with a 1F capacitor to GND. REFIO can be driven with an external reference source. Full-Scale Adjust Input. This input sets the full-scale output current of the DAC. For a 20mA fullscale output current, connect a 2k resistor between FSADJ and DACREF. Current-Set Resistor Return Path. Internally connected to GND. Do not use an external ground connection. Analog Supply Voltage. Accepts a 1.71V to 1.89V supply voltage range. Bypass each pin with a 0.1F capacitor to GND. Complementary Q-DAC Output. Negative terminal for current output. Q-DAC Output. Positive terminal for current output. Complementary I-DAC Output. Negative terminal for current output. I-DAC Output. Positive terminal for current output. Clock Supply Voltage. Accepts a 3.135V to 3.465V supply voltage range. Bypass with a 0.1F capacitor to GND.
DVDD3.3 AVDD3.3 REFIO FSADJ DACREF AVDD1.8 OUTQN OUTQP OUTIN OUTIP AVCLK
8
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16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs
Pin Description (continued)
PIN 37 38 NAME CLKN CLKP FUNCTION Complementary Converter Clock Input. Negative input terminal for differential converter clock. Internally biased to AVCLK / 2. Converter Clock Input. Positive input terminal for differential converter clock. Internally biased to AVCLK / 2. Two's-Complement/Binary Select Input. Set TORB to a CMOS-logic-high level to indicate a two'scomplement input format. Set TORB to a CMOS-logic-low level to indicate a binary input format. TORB has an internal pulldown resistor. Power-Down Input. Set PD high to force the DAC into power-down mode. Set PD low for normal operation. PD has an internal pulldown resistor. Dual-(Parallel)/Single-(Interleaved) Port Select Input. Set DORI high to configure as a dual-port DAC. Set DORI low to configure as a single-port interleaved DAC. DORI has an internal pulldown resistor. DAC Exclusive-OR Select Input. Set XOR low to allow the data stream to pass unchanged to the DAC input. Set XOR high to invert the input data into the DAC. If unused, connect XOR to GND. DAC Select Input. Set SELIQ low to direct data into the Q-DAC inputs. Set SELIQ high to direct data into the I-DAC inputs. If unused, connect SELIQ to GND. SELIQ's logic state is only valid in single-port (interleaved) mode.
MAX5875
39
TORB
40
PD
41
DORI
42
XOR
44
SELIQ
45-60
B15, B14, B13, B12, B11, B10, Data Bits B15-B0. In dual-port mode, data is directed to the I-DAC. In single-port mode, the state B9, B8, B7, B6, of SELIQ determines where the data bits are directed. B5, B4, B3, B2, B1, B0 DVDD1.8 A15, A14, A13, A12, A11, A10, A9 EP Digital Supply Voltage. Accepts a 1.71V to 1.89V supply voltage range. Bypass with a 0.1F capacitor to GND. Data Bits A15-A9. In dual-port mode, data is directed to the Q-DAC. In single-port mode, data bits are not used. Connect bits A15-A9 to GND in single-port mode. Exposed Pad. Must be connected to GND through a low-impedance path.
61
62-68 --
Detailed Description
Architecture
The MAX5875 high-performance, 16-bit, dual currentsteering DAC (Figure 1) operates with DAC update rates up to 200Msps. The converter consists of input registers and a demultiplexer for single-port (interleaved) mode, followed by a current-steering array. During operation in interleaved mode, the input data registers demultiplex the single-port data bus. The current-steering array generates differential full-scale currents in the 2mA to 20mA range. An internal current-switching network, in combination with external 50 termination resistors, converts the differential output currents into dual differential output voltages with a 0.1V to 1V peak-to-peak output voltage
range. 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 MAX5875 supports operation with the internal +1.2V bandgap reference or an external reference voltage source. REFIO serves as the input for an external, low-impedance reference source. REFIO also serves as a reference output when the DAC operates in internal reference mode. For stable operation with the internal reference, decouple REFIO to GND with a 1F capacitor. Due to its limited output-drive capability, buffer REFIO with an external amplifier when driving large external loads.
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9
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs MAX5875
DVDD3.3
GND
DVDD1.8
AVDD1.8
AVDD3.3 OUTIP
TORB DORI SELIQ DATA15- DATA0 XOR LATCH XOR/ DECODE LATCH LATCH DAC OUTQN AVCLK CLKP CLKN GND CLK INTERFACE DACREF +1.2V REFERENCE REFIO FSADJ CMOS RECEIVER LATCH OUTQP LATCH XOR/ DECODE LATCH LATCH DAC OUTIN
MAX5875
POWER-DOWN BLOCK
PD
GND
Figure 1. MAX5875 High-Performance, 16-Bit, Dual Current-Steering DAC
The MAX5875's reference circuit (Figure 2) employs a control amplifier to regulate the full-scale current IOUTFS for the differential current outputs of the DAC. Calculate the full-scale output current as follows: IOUTFS = 32 x VREFIO 1 x 1 - 16 RSET 2
single-ended output voltages. A transformer or a differential amplifier configuration converts the differential voltage existing between OUTIP (OUTQP) and OUTIN (OUTQN) to a single-ended voltage. If not using a transformer, the recommended termination from the output is a 25 termination resistor to ground and a 50 resistor between the outputs.
where I OUTFS is the full-scale output current of the DAC. R SET (located between FSADJ and DACREF) determines the amplifier's full-scale output current for the DAC. See Table 1 for a matrix of different IOUTFS and RSET selections.
Table 1. IOUTFS and RSET Selection Matrix Based on a Typical +1.200V Reference Voltage
FULL-SCALE CURRENT IOUTFS (mA) 2 5 10 15 20 RSET () CALCULATED 19.2k 7.68k 3.84k 2.56k 1.92k 1% EIA STD 19.1k 7.5k 3.83k 2.55k 1.91k
Analog Outputs (OUTIP, OUTIN, OUTQP, OUTQN)
Each MAX5875 DAC outputs two complementary currents (OUTIP/N, OUTQP/N) that operate in a singleended or differential configuration. A load resistor converts these two output currents into complementary
10
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16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs MAX5875
AVDD +1.2V REFERENCE
AVDD CURRENT SOURCES CURRENT SWITCHES
10k REFIO 1F OUTIP FSADJ IREF RSET DACREF IREF = VREFIO / RSET CURRENT-SOURCE ARRAY DAC OUTIN
IOUT OUTIN OUTIP
IOUT
Figure 2. Reference Architecture, Internal Reference Configuration
Figure 3. Simplified Analog Output Structure
To generate a single-ended output, select OUTIP (or OUTQP) as the output and connect OUTIN (or OUTQN) to GND. SFDR degrades with single-ended operation. Figure 3 displays a simplified diagram of the internal output structure of the MAX5875.
Table 2. DAC Output Code Table
DIGITAL INPUT CODE OFFSET BINARY TWO'S COMPLEMENT OUT_P 0 IOUTFS OUT_N IOUTFS 0
Clock Inputs (CLKP, CLKN)
The MAX5875 features flexible differential clock inputs (CLKP, CLKN) operating from a separate supply (AV CLK) to achieve the optimum jitter performance. Drive the differential clock inputs from a single-ended or a differential clock source. For single-ended operation, drive CLKP with a logic source and bypass CLKN to GND with a 0.1F capacitor. CLKP and CLKN are internally biased to AVCLK / 2. This facilitates the AC-coupling of clock sources directly to the device without external resistors to define the DC level. The dynamic input resistance from CLKP and CLKN to ground is >5k.
0000 0000 0000 0000 1000 0000 0000 0000 1111 1111 1111 1111 0111 1111 1111 1111
0111 1111 1111 1111 0000 0000 0000 0000 IOUTFS / 2 IOUTFS / 2
CMOS-Compatible Digital Inputs
Input Data Format Select (TORB, DORI) The TORB input selects between two's-complement or binary digital input data. Set TORB to a CMOS-logichigh level to indicate a two's-complement input format. Set TORB to a CMOS-logic-low level to indicate a binary input format. The DORI input selects between a dual-port (parallel) or single-port (interleaved) DAC. Set DORI high to configure the MAX5875 as a dual-port DAC. Set DORI low to configure the MAX5875 as a single-port DAC. In dual-port mode, connect SELIQ to ground. CMOS DAC Inputs (A15/B15-A0/B0, XOR, SELIQ) The MAX5875 latches input data on the rising edge of the clock in a user-selectable two's-complement or binary format. A logic-high voltage on TORB selects two'scomplement and a logic-low selects offset binary format.
Data Timing Relationship
Figure 4 displays the timing relationship between digital CMOS data, clock, and output signals. The MAX5875 features a 1.5ns hold, a -1.2ns setup, and a 1.1ns propagation delay time. A nine (eight)-clock-cycle latency exists between CLKP/CLKN and OUTIP/OUTIN (OUTQP/OUTQN) when operating in single-port (interleaved) mode. In dual-port (parallel) mode, the clock latency is 5.5 clock cycles for both channels. Table 2 shows the DAC output codes.
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11
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs MAX5875
DATA15-DATA0, XOR
N0 - 1
N
N0 + 1
N0 + 2
tS
tH
CLK tPD DAC OUTPUT N0 - 6 N0 - 5 N0 - 4 N0 - 3
N0 - 2
(a) DUAL-PORT (PARALLEL) TIMING DIAGRAM
CLK
DATAIN
I0
Q0
I1
Q1
I2
Q2
I3
Q3
SELIQ tS tH I0 - 5 I OUT I0 - 6 I0 - 4 I0 - 3 I0 - 2
Q OUT
Q0 - 6 tPD
Q0 - 5 Q0 - 4 Q0 - 3 (b) SINGLE-PORT (INTERLEAVED) TIMING DIAGRAM Q0 - 2
Figure 4. Timing Relationships Between Clock and Input Data for (a) Dual-Port (Parallel) Mode and (b) Single-Port (Interleaved) Mode
The MAX5875 includes a single-ended, CMOS-compatible XOR input. Input data (all bits) are compared with the bit applied to XOR through exclusive-OR gates. Pulling XOR high inverts the input data. Pulling XOR low leaves the input data noninverted. By applying a previously encoded pseudo-random bit stream to the data input and applying decoding to XOR, the digital input data can be decorrelated from the DAC output, allowing for the troubleshooting of possible spurious or harmonic distortion degradation due to digital feedthrough on the PC board.
A15/B15-A0/B0, XOR, and SELIQ are latched on the rising edge of the clock. In single-port mode (DORI pulled low) a logic-high signal on SELIQ directs the B15-B0 data onto the I-DAC inputs. A logic-low signal at SELIQ directs data to the Q-DAC inputs. In dual-port (parallel) mode (DORI pulled high), data on pins A15-A0 are directed onto the Q-DAC inputs and B15-B0 are directed onto the I-DAC inputs. Power-Down Operation (PD) The MAX5875 also features an active-high powerdown mode that reduces the DAC's digital current consumption from 22.5mA to less than 2A and the
12
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16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs
WIDEBAND RF TRANSFORMER PERFORMS SINGLE-ENDED-TODIFFERENTIAL CONVERSION 25 SINGLE-ENDED CLOCK SOURCE (e.g., HP 8662A) 1:1 25 0.1F CLKN TO DAC 0.1F CLKP
GND
fied noise density. For that reason, the CLKP/CLKN input source must be designed carefully. The differential clock (CLKN and CLKP) input can be driven from a single-ended or a differential clock source. Differential clock drive is required to achieve the best dynamic performance from the DAC. For single-ended operation, drive CLKP with a low noise source and bypass CLKN to GND with a 0.1F capacitor. Figure 5 shows 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. Alternatively, these inputs may be driven from a CMOS-compatible clock source; however, it is recommended to use sinewave or AC-coupled differential ECL/PECL drive for best dynamic performance.
MAX5875
Figure 5. Differential Clock-Signal Generation
Differential-to-Single-Ended Conversion Using a Wideband RF Transformer
Use a pair of transformers (Figure 6) or a differential amplifier configuration to convert the differential voltage existing between OUTIP/OUTQP and OUTIN/OUTQN to a single-ended voltage. Optimize the dynamic performance by using a differential transformer-coupled output to limit the output power to <0dBm full scale. Pay close attention to the transformer core saturation characteristics when selecting a transformer for the MAX5875. Transformer core saturation can introduce strong 2nd-order harmonic distortion, especially at low output frequencies and high signal amplitudes. For best results, center tap the transformer to ground. When not using a transformer, terminate each DAC output to ground with a 25 resistor. Additionally, place a 50 resistor between the outputs (Figure 7). For a single-ended unipolar output, select OUTIP (OUTQP) as the output and ground OUTIN (OUTQN) to
analog current consumption from 78mA to less than 3A. Set PD high to power down the MAX5875. Set PD low for normal operation. When powered down, the power consumption of the MAX5875 is reduced to less than 14W. The MAX5875 requires 10ms to wake up from power-down and enter a fully operational state. The PD integrated pulldown resistor activates the MAX5875 if PD is left floating.
Applications Information
CLK Interface
The MAX5875 features a flexible differential clock input (CLKP, CLKN) with a separate supply (AV CLK ) to achieve optimum jitter performance. Use an ultra-low jitter clock to achieve the required noise density. Clock jitter must be less than 0.5psRMS for meeting the speci-
50 DATA15-DATA0 OUTIP/OUTQP 100 T2, 1:1
VOUT, SINGLE-ENDED
MAX5875
16 OUTIN/OUTQN
T1, 1:1 50
GND
WIDEBAND RF TRANSFORMER T2 PERFORMS THE DIFFERENTIAL-TO-SINGLE-ENDED CONVERSION
Figure 6. Differential to Single-Ended Conversion Using a Wideband RF Transformer ______________________________________________________________________________________ 13
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs
The MAX5875 requires five separate power-supply inputs for analog (AVDD1.8 and AVDD3.3), digital (DVDD1.8 and DVDD3.3), and clock (AVCLK) circuitry. Decouple each AVDD, DVDD, and AVCLK input pin with a separate 0.1F capacitor as close to the device as possible with the shortest possible connection to the ground plane (Figure 8). Minimize the analog and digital load capacitances for optimized operation. Decouple all three power-supply voltages 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 AVDD3.3, AVCLK, and DVDD3.3 allow a +3.135V to +3.465V supply voltage range. The analog and digital power-supply inputs AVDD1.8 and DVDD1.8 allow a +1.71V to +1.89V supply voltage range. The MAX5875 is packaged in a 68-pin QFN-EP package, providing greater design flexibility and optimized DAC AC performance. The EP enables the use of necessary grounding techniques to ensure highest performance operation. Thermal efficiency is not the key factor, since the MAX5875 features low-power operation. The exposed pad ensures a solid ground connection between the DAC and the PC board's ground layer.
MAX5875
25 DATA15-DATA0 OUTIP/OUTQP 50 OUTN 25 GND OUTP
MAX5875
16 OUTIN/OUTQN
Figure 7. Differential Output Configuration
GND. Driving the MAX5875 single-ended is not recommended since additional noise and distortion will be added. The distortion performance of the DAC depends on the load impedance. The MAX5875 is optimized for 50 differential double termination. It can be used with a transformer output as shown in Figure 6 or just one 25 resistor from each output to ground and one 50 resistor between the outputs (Figure 7). This produces a fullscale output power of up to -2dBm, depending on the output current setting. Higher termination impedance can be used at the cost of degraded distortion performance and increased output noise voltage.
Grounding, Bypassing, and PowerSupply Considerations
Grounding and power-supply decoupling can strongly influence the MAX5875 performance. Unwanted digital crosstalk couples through the input, reference, power supply, and ground connections, and affects dynamic performance. High-speed, high-frequency applications require closely followed proper grounding and powersupply decoupling. These techniques reduce EMI and internal crosstalk that can significantly affect the MAX5875 dynamic performance. Use a multilayer printed circuit (PC) board with separate ground and power-supply planes. Run high-speed signals on lines directly above the ground plane. Keep digital signals as far away from sensitive analog inputs and outputs, reference inputs sense lines, and clock inputs as practical. Use a controlled-impedance symmetric design of clock input and the analog output lines to minimize 2nd-order harmonic-distortion components, thus optimizing the DAC's dynamic performance. Keep digital signal paths short and run lengths matched to avoid propagation delay and data skew mismatches.
14
BYPASSING--DAC LEVEL AVDD1.8
AVDD3.3
AVCLK
0.1F
0.1F
0.1F
DATA15-DATA0
OUTIP/OUTQP
MAX5875
16 OUTIN/OUTQN
0.1F
0.1F
DVDD1.8
DVDD3.3
*BYPASS EACH POWER-SUPPLY PIN INDIVIDUALLY.
Figure 8. Recommended Power-Supply Decoupling and Bypassing Circuitry
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16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs
The data converter die attaches 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 for a solid attachment of the package to the PC board with standard infrared reflow (IR) soldering techniques. A specially created land pattern on the PC board, matching the size of the EP (6mm x 6mm), ensures the proper attachment and grounding of the DAC. Refer to the MAX5875 EV kit data sheet. Designing vias into the land area and implementing large ground planes in the PC board design allow for the highest performance operation of the DAC. Use an array of at least 4 x 4 vias (0.3mm diameter per via hole and 1.2mm pitch between via holes) for this 68-pin QFN-EP package. Connect the MAX5875 exposed paddle to GND. Vias connect the land pattern to internal or external copper planes. Use as many vias as possible to the ground plane to minimize inductance. error (residual error). The ideal, theoretical minimum can be derived from the DAC's resolution (N bits): SNRdB = 6.02dB x N + 1.76dB 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. 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 dBFS 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 dBFS) of the worst 3rd-order (or higher) IMD product(s) to either output tone; 2nd-order IMD products usually fall at frequencies that digital filtering easily removes. Therefore, they are not as critical as 3rd-order IMDs. The two-tone IMD performance of the MAX5875 is tested with the two individual output tone levels set to at least -6dBFS, and the four-tone performance was tested according to the GSM model at an output frequency of 16MHz and amplitude of -12dBFS. Adjacent Channel Leakage Power Ratio (ACLR) Commonly used in combination with wideband codedivision multiple-access (W-CDMA), 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. 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 Impulse A glitch is generated when a DAC switches between two codes. The largest glitch is usually generated around the midscale transition, when the input pattern transitions from 011...111 to 100...000. The glitch impulse is found by integrating the voltage of the glitch at the midscale transition over time. The glitch impulse is usually specified in pV*s.
MAX5875
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 a monotonic transfer function. Offset Error The offset error is the difference between the ideal and the actual offset current. For a DAC, the offset point is the average 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. 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.
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
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15
16-Bit, 200Msps, High-Dynamic-Performance, Dual DAC with CMOS Inputs MAX5875
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
PACKAGE OUTLINE, 68L QFN, 10x10x0.9 MM 1 C 21-0122 2
PACKAGE OUTLINE, 68L QFN, 10x10x0.9 MM 1 C 21-0122 2
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.
16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2005 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products, Inc.

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