Rainbow Electronics MAX1121 User Manual
General Description
The MAX1121 is a monolithic 8-bit, 250Msps analog-todigital converter (ADC) optimized for outstanding
dynamic performance at high IF frequencies up to
500MHz. The product operates with conversion rates of
up to 250Msps while consuming only 477mW.
At 250Msps and an input frequency of 100MHz, the
MAX1121 achieves a spurious-free dynamic range
(SFDR) of 68dBc. Its excellent signal-to-noise ratio
(SNR) of 48.9dB at 10MHz remains flat (within 0.5dB)
for input tones up to 500MHz. This makes the MAX1121
ideal for wideband applications such as digital predistortion in cellular base-station transceiver systems.
The MAX1121 requires a single 1.8V supply. The analog input is designed for either differential or singleended operation and can be AC- or DC-coupled. The
ADC also features a selectable on-chip divide-by-2
clock circuit, which allows the user to apply clock frequencies as high as 500MHz. This helps to reduce the
phase noise of the input clock source. A differential
LVDS sampling clock is recommended for best performance. The converter’s digital outputs are LVDS compatible, and the data format can be selected to be
either two’s complement or offset binary.
The MAX1121 is available in a 68-pin QFN with
exposed paddle (EP) and is specified over the industrial (-40°C to +85°C) temperature range.
For pin-compatible, higher resolution versions of the
MAX1121, refer to the MAX1122 (170Msps), the
MAX1123 (210Msps), and the MAX1124 (250Msps)
data sheets.
Applications
Wireless and Wired Broadband Communication
Digital Oscilloscopes
Digital Predistortion Receivers
Communications Test Equipment
Radar and Satellite Subsystems Antenna Array
Processing
Instrumentation
Features
♦ 250Msps Conversion Rate
♦ SNR = 48.8dB/48.7dB at fIN= 100MHz/500MHz
♦ SFDR = 68dBc/63.8dBc at f
IN
= 100MHz/500MHz
♦ Single 1.8V Supply
♦ 477mW Power Dissipation at 250Msps
♦ On-Chip Track-and-Hold and Internal Reference
♦ On-Chip Selectable Divide-by-2 Clock Input
♦ LVDS Digital Outputs with Data Clock Output
♦ Evaluation Kit Available (Order MAX1124EVKIT)
MAX1121
1.8V, 8-Bit, 250Msps Analog-to-Digital Converter
with LVDS Outputs for Wideband Applications
________________________________________________________________ Maxim Integrated Products 1
5859606162 5455565763
38
39
40
41
42
43
44
45
46
47
AV
CC
AGND
AV
CC
TOP VIEW
AVCCOGND
OVCCORP
ORN
D7P
D7N
D6P
D6N
5253
D5P
D5N
AGND
AGND
AV
CC
CLKN
CLKP
AV
CC
AGND
OV
CC
OGND
N.C.
OV
CC
N.C.
N.C.
N.C.
D2P
D2N
OGND
OV
CC
DCLKP
DCLKN
OV
CC
D1P
D1N
D0P
35
36
37
D0N
N.C.
N.C.
AGND
INN
INP
AGND
AV
CC
AGND
AGND
AV
CC
AV
CC
AV
CC
AGND
REFADJ
REFIO
AGND
48 D3N
AV
CC
64
AGND
656667
AGND
AGND
AV
CC
68
T/B
2322212019 2726252418 2928 323130
N.C.
N.C.
3433
49
50
D4N
D3P
51 D4P
11
10
9
8
7
6
5
4
3
2
16
15
14
13
12
1
CLKDIV 17
MAX1121
EP
Pin Configuration
Ordering Information
19-3077; Rev 1; 2/04
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.
PART TEMP RANGE PIN-PACKAGE
MAX1121EGK -40°C to +85°C 68 QFN-EP*
*EP = Exposed paddle.
MAX1121
1.8V, 8-Bit, 250Msps Analog-to-Digital Converter
with LVDS Outputs for Wideband Applications
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
AVCCto AGND ......................................................-0.3V to +2.1V
OV
CC
to OGND .....................................................-0.3V to +2.1V
AV
CC
to OVCC.......................................................-0.3V to +2.1V
AGND to OGND ....................................................-0.3V to +0.3V
Analog Inputs to AGND ...........................-0.3V to (AV
CC
+ 0.3V)
Digital Inputs to AGND.............................-0.3V to (AV
CC
+ 0.3V)
REF, REFADJ to AGND............................-0.3V to (AV
CC
+ 0.3V)
Digital Outputs to OGND.........................-0.3V to (OV
CC
+ 0.3V)
ESD on All Pins (Human Body Model).............................±2000V
Continuous Power Dissipation (TA= +70°C)
68-Pin QFN (derate 41.7mW/°C above +70°C) .........3333mW
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
Maximum Current into Any Pin............................................50mA
ELECTRICAL CHARACTERISTICS
(AVCC= OVCC= 1.8V, AGND = OGND = 0, f
SAMPLE
= 250MHz, differential sine-wave clock input drive, 0.1µF capacitor on REFIO,
internal reference, digital output pins differential R
L
= 100Ω ±1%, CL= 5pF, TA= T
MIN
to T
MAX
, unless otherwise noted. ≥25°C guar-
anteed by production test, <25°C guaranteed by design and characterization. Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS MIN
TYP
MAX
UNITS
DC ACCURACY
Resolution 8 Bits
Integral Nonlinearity INL (Note 1) -0.6
LSB
Differential Nonlinearity DNL No missing codes (Note 1) -0.9
LSB
Transfer Curve Offset V
OS
(Note 1) -10 +10 LSB
Offset Temperature Drift ±20
µV/°C
ANALOG INPUTS (INP, INN)
Full-Scale Input Voltage Range V
FS
(Note 1)
mV
P-P
Full-Scale Range Temperature
Drift
130
ppm/°C
Common-Mode Input Range V
CM
V
Input Capacitance C
IN
3pF
Differential Input Resistance R
IN
4.4 6.5 kΩ
Full-Power Analog Bandwidth FPBW Figure 8 600
MHz
REFERENCE (REFIO, REFADJ)
Reference Output Voltage V
REFIO
V
Reference Temperature Drift 90
ppm/°C
REFADJ Input High Voltage
Used to disable the internal reference
AV
CC
-
0.3
V
SAMPLING CHARACTERISTICS
Maximum Sampling Rate
250
MHz
Minimum Sampling Rate
20
MHz
±0.2 +0.6
±0.1 +0.9
1100 1250 1375
V
REFADJ
f
SAMPLE
f
SAMPLE
1.38
±0.18
3.00
1.18 1.24 1.30
MAX1121
1.8V, 8-Bit, 250Msps Analog-to-Digital Converter
with LVDS Outputs for Wideband Applications
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(AVCC= OVCC= 1.8V, AGND = OGND = 0, f
SAMPLE
= 250MHz, differential sine-wave clock input drive, 0.1µF capacitor on REFIO,
internal reference, digital output pins differential R
L
= 100Ω ±1%, CL= 5pF, TA= T
MIN
to T
MAX
, unless otherwise noted. ≥25°C guar-
anteed by production test, <25°C guaranteed by design and characterization. Typical values are at T
A
= +25°C.)
PARAMETER
CONDITIONS MIN
UNITS
Clock Duty Cycle Set by clock management circuit
%
Aperture Delay t
AD
350 ps
Aperture Jitter t
AJ
0.2
ps
RMS
CLOCK INPUTS (CLKP, CLKN)
Differential Clock Input Amplitude
(Note 2) 200 500
mV
P-P
Clock Input Common-Mode
Voltage Range
1.25
V
Clock Differential Input
Resistance
R
CLK
11
kΩ
Clock Differential Input
Capacitance
C
CLK
5pF
DYNAMIC CHARACTERISTICS (at -0.5dBFS)
fIN = 10MHz, TA ≥ +25°C
fIN = 100MHz, TA ≥ +25°C
fIN = 180MHz
Signal-to-Noise Ratio SNR
f
IN
= 500MHz
dB
fIN = 10MHz, TA ≥ +25°C
fIN = 100MHz, TA ≥ +25°C
fIN = 180MHz
Signal-to-Noise
and Distortion
SINAD
f
IN
= 500MHz
dB
fIN = 10MHz, TA ≥ +25°C6069
fIN = 100MHz, TA ≥ +25°C5968
fIN = 180MHz
Spurious-Free
Dynamic Range
SFDR
f
IN
= 500MHz
dBc
fIN = 10MHz
fIN = 100MHz
fIN = 180MHz
Worst Harmonics
(HD2 or HD3)
f
IN
= 500MHz
dBc
IMD
100
f
IN1
= 99MHz at -7dBFS,
f
IN2
= 101MHz at -7dBFS
-70
Two-Tone Intermodulation
Distortion
IMD
500
f
IN1
= 498.5MHz at -7dBFS,
f
IN2
= 502.5MHz at -7dBFS
-56
dBc
LVDS DIGITAL OUTPUTS (D0P/N–D7P/N, DCLKP/N)
Differential Output Voltage |VOD| 250 400 mV
SYMBOL
47.2 48.9
46.2 48.8
47.1 48.8
46.1 48.7
TYP MAX
40 to 60
±0.25
±25%
48.8
48.7
48.7
48.6
69.1
63.8
-74.6
-68.4
-69.1
-63.8
MAX1121
1.8V, 8-Bit, 250Msps Analog-to-Digital Converter
with LVDS Outputs for Wideband Applications
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(AVCC= OVCC= 1.8V, AGND = OGND = 0, f
SAMPLE
= 250MHz, differential sine-wave clock input drive, 0.1µF capacitor on REFIO,
internal reference, digital output pins differential R
L
= 100Ω ±1%, CL= 5pF, TA= T
MIN
to T
MAX
, unless otherwise noted. ≥25°C guar-
anteed by production test, <25°C guaranteed by design and characterization. Typical values are at T
A
= +25°C.)
PARAMETER
CONDITIONS
UNITS
Output Offset Voltage OV
OS
V
LVCMOS DIGITAL INPUTS (CLKDIV, T/B)
Digital Input Voltage Low V
IL
0.2 x
V
Digital Input Voltage High V
IH
0.8 x
V
TIMING CHARACTERISTICS
CLK to Data Propagation Delay t
PDL
Figure 4 1.5 ns
CLK to DCLK Propagation Delay
t
CPDL
Figure 4
ns
Data Valid to DCLK Rising Edge
t
CPDL
-
t
PDL
Figure 4 (Note 2)
ns
LVDS Output Rise-Time t
RISE
20% to 80%, CL = 5pF
ps
LVDS Output Fall-Time t
FALL
20% to 80%, CL = 5pF
ps
Output Data Pipeline Delay
8
Clock
cycles
POWER REQUIREMENTS
Analog Supply Voltage Range AV
CC
V
Digital Supply Voltage Range OV
CC
V
Analog Supply Current
I
AVCCfIN
= 100MHz
mA
Digital Supply Current I
OVCCfIN
= 100MHz 45 75 mA
Analog Power Dissipation P
DISSfIN
= 100MHz
mW
Offset 1.6
mV/V
Power-Supply Rejection Ratio
(Note 3)
PSRR
Gain 1.9
%FS/V
Note 1: Static linearity and offset parameters are computed from a best-fit straight line through the code transition points. The full-
scale range is defined as 1023 x slope of the line.
Note 2: Parameter guaranteed by design and characterization; T
A
= T
MIN
to T
MAX
.
Note 3: PSRR is measured with both analog and digital supplies connected to the same potential.
SYMBOL
MIN TYP MAX
1.125 1.310
AV
CC
AV
CC
2.85
0.92 1.35 1.86
460
460
t
LATENCY
1.70 1.80 1.90
1.70 1.80 1.90
220 290
477 657
MAX1121
1.8V, 8-Bit, 250Msps Analog-to-Digital Converter
with LVDS Outputs for Wideband Applications
_______________________________________________________________________________________ 5
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
FFT PLOT (8192-POINT DATA RECORD,
COHERENT SAMPLING)
MAX1121 toc01
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
040608020 100 140120
f
SAMPLE
= 250.0057MHz
f
IN
= 11.5054MHz
A
IN
= -0.4885MHz
SNR = 48.9dB
SFDR = 71.5dBc
HD2 = -79.2dBc
HD3 = -74.6dBc
HD2
HD3
-90
-80
-60
-70
-40
-50
-30
-10
-20
0
FFT PLOT (8192-POINT DATA RECORD,
COHERENT SAMPLING)
MAX1121 toc02
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
040608020 100 140120
f
SAMPLE
= 250.0057MHz
f
IN
= 60.0294MHz
A
IN
= -0.4885MHz
SNR = 49dB
SFDR = 71.1dBc
HD2 = -79.5dBc
HD3 = -71.9dBc
HD2
HD3
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
040608020 100 140120
FFT PLOT (8192-POINT DATA RECORD,
COHERENT SAMPLING)
MAX1121 toc03
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
f
SAMPLE
= 250.0057MHz
f
IN
= 183.5064MHz
A
IN
= -0.5245MHz
SNR = 48.8dB
SFDR = 69.1dBc
HD2 = -77.2dBc
HD3 = -69.1dBc
HD2
HD3
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
FFT PLOT (8192-POINT DATA RECORD,
COHERENT SAMPLING)
MAX1121 toc04
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
040608020 100 140120
HD3
HD2
f
SAMLE
= 250.0057MHz
f
IN
= 500.516MHz
A
IN
= -0.5235MHz
SNR = 48.8dB
SFDR = 63.8dBc
HD2 = -70.8dBc
HD3 = -63.8dBc
FUNDAMENTAL
SNR vs. ANALOG INPUT FREQUENCY
(f
SAMPLE
= 250.0057MHz, AIN = -0.5dBFS)
MAX1121 toc05
f
IN
(MHz)
SNR (dB)
400300200100
46
49
47
48
50
45
0500
SFDR vs. ANALOG INPUT FREQUENCY
(f
SAMPLE
= 250.0057MHz, AIN = -0.5dBFS)
MAX1121 toc06
f
IN
(MHz)
SFDR (dBc)
400300200100
62
56
68
74
80
50
0500
HD2/HD3 vs. ANALOG INPUT FREQUENCY
(f
SAMPLE
= 250.0057MHz, AIN = -0.5dBFS)
MAX1121 toc07
f
IN
(MHz)
HD2/HD3 (dBc)
400300200100
-90
-80
-70
-60
-50
-100
0500
HD3
HD2
20
30
25
40
35
45
50
-30 -15 -10-25 -20 -5 0
SNR vs. ANALOG INPUT AMPLITUDE
(f
SAMPLE
= 250.0057MHz, fIN = 60.0294MHz)
MAX1121 toc08
ANALOG INPUT AMPLITUDE (dBFS)
SNR (dB)
30
50
40
45
35
65
60
55
70
75
-30 -15 -10-25 -20 -5 0
SFDR vs. ANALOG INPUT AMPLITUDE
(f
SAMPLE
= 250.0057MHz, fIN = 60.0294MHz)
MAX1121 toc09
ANALOG INPUT AMPLITUDE (dBFS)
SFDR (dBc)
Typical Operating Characteristics
(AVCC= OVCC= 1.8V, AGND = OGND = 0, f
SAMPLE
= 250.0057MHz, -0.5dBFS; see TOCs for detailed information on test conditions, differential input drive, differential sine-wave clock input drive, 0.1µF capacitor on REFIO, internal reference, digital output pins
differential RL= 100Ω, TA= +25°C.)
MAX1121
1.8V, 8-Bit, 250Msps Analog-to-Digital Converter
with LVDS Outputs for Wideband Applications
6 _______________________________________________________________________________________
-90
-65
-75
-85
-70
-80
-50
-55
-60
-40
-45
-35
-30
-30 -20 -15-25 -10 -5 0
HD2/HD3 vs. ANALOG INPUT AMPLITUDE
(f
SAMPLE
= 250.0057MHz, fIN = 60.0294MHz)
MAX1121 toc10
ANALOG INPUT AMPLITUDE (dBFS)
HD2/HD3 (dBc)
HD3
HD2
SNR vs. f
SAMPLE
(fIN = 60.0294MHz, AIN = -0.5dBFS)
MAX1121 toc11
f
SAMPLE
(MHz)
SNR (dB)
60
47.0
47.5
48.0
48.5
49.0
46.5
20 260180140100 220
SFDR vs. f
SAMPLE
(fIN = 60.0294MHz, AIN = -0.5dBFS)
MAX1121 toc12
f
SAMPLE
(MHz)
SFDR (dBc)
22014010060
50
60
70
80
90
40
20 260180
HD2/HD3 vs. f
SAMPLE
(fIN = 60.03294MHz, AIN = -0.5dBFS)
MAX1121 toc13
f
SAMPLE
(MHz)
HD2/HD3 (dBc)
22018014010060
-92
-84
-76
-68
-60
-100
20 260
HD3
HD2
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
TWO-TONE IMD PLOT (8192-POINT
DATA RECORD, COHERENT SAMPLING)
MAX1121 toc14
ANALOG INPUT FREQUENCY (MHz)
AMPLITUDE (dB)
040608020 100 140120
f
SAMPLE
= 250.0057MHz
f
IN1
= 99.0318MHz
f
IN2
= 101.046MHz
A
IN1
= A
IN2
= -7dBFS
IMD = -70dBc
2f
IN1
- f
IN2
2f
IN2
-
f
IN1
f
IN1
f
IN2
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
64 96320 128 160 192 224 256
INTEGRAL NONLINEARITY
vs. DIGITAL OUTPUT CODE
MAX1121 toc15
DIGITAL OUTPUT CODE
INL (LSB)
-0.5
-0.4
-0.2
0.1
0.3
0.5
0.4
0
-0.3
-0.1
0.2
64 96320128160 192 224 256
DIFFERENTIAL NONLINEARITY
vs. DIGITAL OUTPUT CODE
MAX1121 toc16
DIGITAL OUTPUT CODE
DNL (LSB)
2
0
-2
-4
-6
-8
-10
-12
10 100 1000
GAIN BANDWIDTH PLOT
(f
SAMPLE
= 250.0057MHz, AIN = -0.5dBFS)
MAX1121 toc17
ANALOG INPUT FREQUENCY (MHz)
GAIN (dB)
SNR vs. TEMPERATURE (fIN = 65.0108MHz,
f
SAMPLE
= 249.856MHz, AIN = -0.5dBFS)
MAX1121 toc18
TEMPERATURE (°C)
SNR (dB)
603510-15
47.0
46.5
48.0
47.5
49.0
48.5
49.5
50.0
46.0
-40 85
Typical Operating Characteristics (continued)
(AVCC= OVCC= 1.8V, AGND = OGND = 0, f
SAMPLE
= 250.0057MHz, -0.5dBFS; see TOCs for detailed information on test conditions, differential input drive, differential sine-wave clock input drive, 0.1µF capacitor on REFIO, internal reference, digital output pins
differential RL= 100Ω, TA= +25°C.)
Loading...