Rainbow Electronics MAX1213 User Manual

General Description
The MAX1213 is a monolithic, 12-bit, 170Msps analog­to-digital converter (ADC) optimized for outstanding dynamic performance at high-IF frequencies up to 300MHz. The product operates with conversion rates up to 170Msps while consuming only 975mW.
At 170Msps and an input frequency up to 250MHz, the MAX1213 achieves a spurious-free dynamic range (SFDR) of 71.4dBc. Its excellent signal-to-noise ratio (SNR) of 65.5dB at 10MHz remains flat (within 3dB) for input tones up to 250MHz. This ADC yields an excellent low-noise floor of -68dBFS, which makes it ideal for wideband applications such as cable head-end receivers and power-amplifier predistortion in cellular base-station transceivers.
The MAX1213 requires a single 1.8V supply. The analog input is designed for either differential or single-ended 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 340MHz. This helps to reduce the phase noise of the input clock source. A low-voltage differential signal (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 MAX1213 is available in a 68-pin QFN package with exposed paddle (EP) and is specified over the industrial (-40°C to +85°C) temperature range.
Pin-compatible 8-bit and 10-bit versions of the MAX1213 are also available. Refer to the MAX1121 (8 bits, 250Msps), MAX1122 (10 bits, 170Msps), MAX1123 (10 bits, 210Msps), and the MAX1124 (10 bits, 250Msps) data sheets for more information. See Table 2.
Applications
Base-Station Power-Amplifier Linearization Cable Head-End Receivers Wireless and Wired Broadband Communication Communications Test Equipment Radar and Satellite Subsystems
Features
170Msps Conversion RateLow Noise Floor of -68dBFSExcellent Low-Noise Characteristics
SNR = 65.2dB at fIN= 65MHz SNR = 62.8dB at fIN= 250MHz
Excellent Dynamic Range
SFDR = 78dBc at fIN= 65MHz SFDR = 71.4dBc at fIN= 250MHz
62.2dB NPR for f
NOTCH
= 22MHz and a Noise
Bandwidth of 35MHz
Single 1.8V Supply975mW Power Dissipation at f
SAMPLE
= 170Msps
and fIN= 65MHz
On-Chip Track-and-Hold AmplifierInternal 1.24V-Bandgap ReferenceOn-Chip Selectable Divide-by-2 Clock InputLVDS Digital Outputs with Data Clock OutputMAX1213 EV Kit Available
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
________________________________________________________________ Maxim Integrated Products 1
Pin Configuration
Ordering Information
5859606162 5455565763
38
39
40
41
42
43
44
45
46
47
AV
CC
AGND
AV
CC
TOP VIEW
AVCCOGND
OVCCORP
ORN
D11P
D11N
D10P
D10N
5253
D9P
D9N
AGND
AGND
AV
CC
CLKN
CLKP
AV
CC
AGND
OV
CC
OGND
D0N
OV
CC
D1N
D0P
D1P
D6P D6N OGND OV
CC
DCLKP DCLKN OV
CC
D5P D5N D4P
35
36
37
D4N D3P D3N
AGND
INN
INP
AGND
AV
CC
AGND
AGND
AV
CC
AV
CC
AV
CC
AGND
REFADJ
REFIO
AGND
48 D7N
AV
CC
64
AGND
656667
AGND
AGND
AV
CC
68
T/B
2322212019 2726252418 2928 323130
D2N
D2P
3433
49
50
D8N D7P
EP
51 D8P
11
10
9
8
7
6
5
4
3
2
16
15
14
13
12
1
CLKDIV 17
MAX1213
QFN
19-1003; Rev 0; 7/04
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.
* EP = Exposed paddle.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-PACKAGE
MAX1213EGK -40°C to +85°C 68 QFN-EP*
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(AV
CC
= OV
CC
= 1.8V, AGND = OGND = 0, f
SAMPLE
= 170MHz, differential sine-wave clock input drive, 0.1µF capacitor on REFIO,
internal reference, digital output pins differential R
L
= 100±1%, TA= T
MIN
to T
MAX
, unless otherwise noted. +25°C guaranteed by
production test, <+25°C guaranteed by design and characterization. Typical values are at T
A
= +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
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)
All Digital Inputs to AGND........................-0.3V to (AV
CC
+ 0.3V)
REFIO, REFADJ to AGND ........................-0.3V to (AV
CC
+ 0.3V)
All Digital Outputs to OGND ....................-0.3V to (OV
CC
+ 0.3V)
ESD on All Pins (Human Body Model) .............................±2000V
Continuous Power Dissipation (T
A
= +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
Maximum Current into Any Pin............................................50mA
Lead Temperature (soldering,10s) ..................................+300°C
DC ACCURACY
Resolution 12 Bits Integral Nonlinearity
(Note 1)
Differential Nonlinearity (Note 1) DNL
Transfer Curve Offset V Offset Temperature Drift 40 mV/°C
ANALOG INPUTS (INP, INN)
Full-Scale Input Voltage Range V Full-Scale Range Temperature
Drift Common-Mode Input Range V
Input Capacitance C Differential Input Resistance R Full-Power Analog Bandwidth FPBW 900 MHz
REFERENCE (REFIO, REFADJ)
Reference Output Voltage V Reference Temperature Drift 90 ppm/°C REFADJ Input High Voltage V
SAMPLING CHARACTERISTICS
Maximum Sampling Rate f Minimum Sampling Rate f Clock Duty Cycle Set by clock-management circuit 40–60 % Aperture Delay t Aperture Jitter t
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
INL
OS
FS
CM
IN IN
REFIO
REFADJ
SAMPLE SAMPLE
AD
AJ
f
= 10MHz, TA = +25°C -1.5 ±0.5 +1.5
IN
f
= 10MHz (Note 2) -2.35 ±0.5 +2.35
IN
TA = +25°C-1±0.25 +1 No missing codes (Note 2) -1 ±0.25 +1.5 TA = +25°C (Note 1) -2.5 +2.5 mV
TA = +25°C (Note 1) 1375 1485 1585 mV
TA = +25°C 1.18 1.24 1.30 V
Used to disable the internal reference AV
130 ppm/°C
1.365 ±0.15 V 3pF
3.00 4.3 6.25 k
- 0.3 V
CC
170 Msps
20 Msps
620 ps
0.2 ps
LSB
LSB
P-P
RMS
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(AV
CC
= OV
CC
= 1.8V, AGND = OGND = 0, f
SAMPLE
= 170MHz, differential sine-wave clock input drive, 0.1µF capacitor on REFIO,
internal reference, digital output pins differential R
L
= 100±1%, TA= T
MIN
to T
MAX
, unless otherwise noted. +25°C guaranteed by
production test, <+25°C guaranteed by design and characterization. Typical values are at T
A
= +25°C.)
CLOCK INPUTS (CLKP, CLKN)
Differential Clock Input Amplitude (Note 2) 200 500 mV Clock Input Common-Mode
Voltage Range Clock Differential Input
Resistance Clock Differential Input
Capacitance
DYNAMIC CHARACTERISTICS (at -2dBFS)
Signal-to-Noise Ratio
Signal-to-Noise and Distortion
Spurious-Free Dynamic Range
Worst Harmonics (HD2 or HD3)
Two-Tone Intermodulation Distortion
Noise Power Ratio NPR
LVDS DIGITAL OUTPUTS (D0P/N–D11P/N, ORP/N)
Differential Output Voltage |VOD|RL = 100Ω ±1% 250 400 mV Output Offset Voltage OV
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
R
CLK
C
CLK
SNR
SINAD
SFDR
TTIMD
OS
fIN = 10MHz, TA = +25°C6465.5 fIN = 65MHz, TA = +25°C6465.2 fIN = 190MHz 64 f
= 250MHz 62.8
IN
fIN = 10MHz, TA = +25°C6465.4 fIN = 65MHz, TA = +25°C 63.5 64.9 fIN = 190MHz 62.9 fIN = 250MHz 62.3 fIN = 10MHz, TA = +25°C7785 fIN = 65MHz, TA = +25°C7378 fIN = 190MHz 69.7
= 250MHz 71.4
f
IN
fIN = 10MHz, TA = +25°C -85 -77 fIN = 65MHz, TA = +25°C -78 -73 fIN = 190MHz -69.7 fIN = 250MHz -71.4
f
= 209MHz at -7dBFS,
IN1
f
= 210MHz at -7dBFS
IN2
f
= 22MHz ±1MHz,
NOTCH
noise BW = 35MHz, A
RL = 100Ω ±1% 1.125 1.310 V
= -9.1dBFS
IN
1.15 ±0.25 V
11
±25%
5pF
-66.7 dBc
62.2 dB
P-P
k
dB
dB
dBc
dBc
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(AV
CC
= OV
CC
= 1.8V, AGND = OGND = 0, f
SAMPLE
= 170MHz, differential sine-wave clock input drive, 0.1µF capacitor on REFIO,
internal reference, digital output pins differential R
L
= 100±1%, TA= T
MIN
to T
MAX
, unless otherwise noted. +25°C guaranteed by
production test, <+25°C guaranteed by design and characterization. Typical values are at T
A
= +25°C.)
Note 1: Static linearity and offset parameters are computed from a best-fit straight line through the code transition points. The full-
scale range (FSR) is defined as 4095 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.
LVCMOS DIGITAL INPUTS (CLKDIV, T/B)
Digital Input Voltage Low V Digital Input Voltage High V
TIMING CHARACTERISTICS
CLK-to-Data Propagation Delay t CLK-to-DCLK Propagation Delay t DCLK-to-Data Propagation Delay t LVDS Output Rise Time t LVDS Output Fall Time t
Output Data Pipeline Delay t
POWER REQUIREMENTS
Analog Supply Voltage Range AV Digital Supply Voltage Range OV Analog Supply Current I Digital Supply Current I Analog Power Dissipation P
Power-Supply Rejection Ratio (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
PDL
IL IH
PDL
CPDL
- t
CPDL
RISE
FALL
LATENCY
CC CC
AVCC
OVCC
DISS
PSRR
Figure 4 1.85 ns Figure 4 4.815 ns Figure 4 (Note 2) 2.5 2.965 3.4 ns 20% to 80%, CL = 5pF 460 ps 20% to 80%, CL = 5pF 460 ps
fIN = 65MHz 483 555 mA fIN = 65MHz 58 67 mA fIN = 65MHz 975 1120 mW Offset 1.8 mV/V Gain 1.5 %FS/V
0.2 x AV
0.8 x AV
CC
11
1.70 1.80 1.90 V
1.70 1.80 1.90 V
CC
V V
Clock
cycles
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
_______________________________________________________________________________________ 5
Typical Operating Characteristics
(AV
CC
= OV
CC
= 1.8V, AGND = OGND = 0, f
SAMPLE
= 170MHz, A
IN
= -1dBFS; see each TOC 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 R
L
= 100, TA= +25°C.)
0
-10
-20
-30
-40
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
-110
0
-10
-20
-30
-40
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
-110
FFT PLOT
(16,384-POINT DATA RECORD)
fIN = 13.0015039MHz
= 170.005299MHz
f
SAMPLE
= -1.073dBFS
A
IN
SNR = 66.6dB SINAD = 66.5dB SFDR = 84.5dBc HD2 = -89.5dBc HD3 = -84.5dBc
3
2
20 30100
ANALOG INPUT FREQUENCY (MHz)
4
50
FFT PLOT
(16,384-POINT DATA RECORD)
fIN = 249.9131855MHz
= 170.005299MHz
f
SAMPLE
= -1.051dBFS
A
IN
SNR = 64.4dB SINAD = 63.3dB SFDR = 71dBc HD2 = -90.4dBc HD3 = -71dBc
6
2
4
20 30100
ANALOG INPUT FREQUENCY (MHz)
7
50
(16,384-POINT DATA RECORD)
0
fIN = 65.1112825MHz
-10
-20
MAX1213 toc01
-30
-40
-50
-60
AMPLITUDE (dB)
-70
7
6
5
80
706040
-80
-90
-100
-110
= 170.005299MHz
f
SAMPLE
= -1.099dBFS
A
IN
SNR = 66.3dB SINAD = 66.2dB SFDR = 74.8dBc HD2 = -82.4dBc HD3 = -75.6dBc
5
20 30100
ANALOG INPUT FREQUENCY (MHz)
TWO-TONE IMD PLOT
(16,384-POINT DATA RECORD)
0
-10
-20
MAX1213 toc04
-30
-40
3
5
80
706040
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
-110
f
IN1
2f
- f
IN1
20 30100
ANALOG INPUT FREQUENCY (MHz)
FFT PLOT
FFT PLOT
(16,384-POINT DATA RECORD)
0
-10
-20
MAX1213 toc02
-30
-40
-50
3
7
2
6
50
4
80
706040
-60
AMPLITUDE (dB)
-70
-80
-90
-100
-110
ANALOG INPUT FREQUENCY (MHz)
20 30100
fIN = 190.0004293MHz f
SAMPLE
= -1.092dBFS
A
IN
SNR = 65dB SINAD = 64.1dB SFDR = 73.3dBc HD2 = -78.2dBc HD3 = -73.3dBc
2
7
TWO-TONE IMD PLOT
(16,384-POINT DATA RECORD)
0
-10
-20
-30
-40
-50 2f
IN2
-60
AMPLITUDE (dB)
-70
-80
-90
-100
-110
f
IN1
f
IN2
f
SAMPLE
A
IN1
IN1
20 30100
IMD = -65.5dBc
f
IN2
2f
IN1
f
IN1
- f
ANALOG INPUT FREQUENCY (MHz)
IN2
f
= 29.5205735MHz
IN1
= 30.5166983MHz
f
IN2
= 170.005299MHz
f
SAMPLE
= A
A
IN1
IN2
IMD = -81.8dBc
f
IN2
2f
- f
IN2
IN1
50
= -7dBFS
706040
MAX1213 toc05
80
= 170.005299MHz
3
5
6
50
706040
= 200.0031825MHz = 201.0200599MHz
= 170.005299MHz
= A
= -7dBFS
IN2
- f
IN2
50
706040
4
80
80
MAX1213 toc03
MAX1213 toc06
SNR/SINAD vs. ANALOG INPUT FREQUENCY
= 170.0053MHz, AIN = -1dBFS)
(f
SAMPLE
70
67
64
61
SNR/SINAD (dB)
58
55
0 250
ANALOG INPUT FREQUENCY (MHz)
SNR
SINAD
SFDR vs. ANALOG INPUT FREQUENCY
= 170.0053MHz, AIN = -1dBFS)
(f
SAMPLE
90 85
MAX1213 toc07
80 75 70 65
SFDR (dBc)
60 55 50 45
20015010050
40
0 250
ANALOG INPUT FREQUENCY (MHz)
20015010050
MAX1213 toc08
HD2/HD3 vs. ANALOG INPUT FREQUENCY
= 170.0053MHz, AIN = -1dBFS)
(f
SAMPLE
-60
-65
-70
-75
-80
HD2/HD3 (dBc)
-85
-90
-95
-100 0 250
ANALOG INPUT FREQUENCY (MHz)
HD3
MAX1213 toc09
HD2
20015050 100
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(AV
CC
= OV
CC
= 1.8V, AGND = OGND = 0, f
SAMPLE
= 170MHz, A
IN
= -1dBFS; see each TOC 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 R
L
= 100, TA= +25°C.)
SNR/SINAD vs. ANALOG INPUT AMPLITUDE
(f
SAMPLE
= 170.0053MHz, fIN = 65.1113MHz)
MAX1213 toc10
ANALOG INPUT AMPLITUDE (dBFS)
SNR/SINAD (dB)
-5-10-15-20-25
38
44
50
56
62
68
32
-30 0
SNR
SINAD
SFDR vs. ANALOG INPUT AMPLITUDE
(f
SAMPLE
= 170.0053MHz, fIN = 65.1113MHz)
MAX1213 toc11
ANALOG INPUT AMPLITUDE (dBFS)
SFDR (dBc)
-5-10-15-20-25
55
60
65
70
75
80
50
-30 0
HD2/HD3 vs. ANALOG INPUT AMPLITUDE
(f
SAMPLE
= 170.0053MHz, fIN = 65.1113MHz)
MAX1213 toc12
ANALOG INPUT AMPLITUDE (dBFS)
HD2/HD3 (dBc)
-5-10-15-20-25
-90
-80
-70
-60
-50
-100
-30 0
HD3
HD2
SNR/SINAD vs. f
SAMPLE
(fIN = 65MHz, AIN = -1dBFS)
MAX1213 toc13
f
SAMPLE
(MHz)
SNR/SINAD (dB)
17014050 80 110
61
62
63
64
65
66
67
68
60
20 200
SNR
SINAD
SFDR vs. f
SAMPLE
(fIN = 65MHz, AIN = -1dBFS)
MAX1213 toc14
f
SAMPLE
(MHz)
SFDR (dBc)
17014050 80 110
55
60
65
70
75
80
85
90
50
20 200
HD2/HD3 vs. f
SAMPLE
(fIN = 65MHz, AIN = -1dBFS)
MAX1213 toc15
f
SAMPLE
(MHz)
HD2/HD3 (dBc)
180160120 14060 80 10040
-105
-100
-95
-90
-85
-80
-75
-70
-65
-60
-110 20 200
HD3
HD2
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
_______________________________________________________________________________________ 7
Typical Operating Characteristics (continued)
(AV
CC
= OV
CC
= 1.8V, AGND = OGND = 0, f
SAMPLE
= 170MHz, A
IN
= -1dBFS; see each TOC 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 R
L
= 100, TA= +25°C.)
TOTAL POWER DISSIPATION vs. f
SAMPLE
(fIN = 65MHz, AIN = -1dBFS)
MAX1213 toc16
f
SAMPLE
(MHz)
P
DISS
(mW)
180160120 14060 80 10040
910
920
930
940
950
960
970
980
990
1000
900
20 200
INL vs. DIGITAL OUTPUT CODE
(1,048,576-POINT DATA RECORD)
MAX1213 toc17
DIGITAL OUTPUT CODE
INL (LSB)
358430722048 25601024 1536512
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0 0 4096
fIN = 13.0015039MHz
DNL vs. DIGITAL OUTPUT CODE
(1,048,576-POINT DATA RECORD)
MAX1213 toc18
DIGITAL OUTPUT CODE
DNL (LSB)
358430722048 25601024 1536512
-0.4
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
0.4
0.5
-0.5 0 4096
fIN = 13.0015039MHz
HD2/HD3 vs. TEMPERATURE
(f
SAMPLE
= 170MHz, AIN = -2dBFS)
MAX1213 toc21b
TEMPERATURE (°C)
HD2/HD3 (dBc)
6035-15 10
-95
-90
-85
-80
-70
-75
-65
-60
-100
-40 85
HD3
HD2
fIN = 65MHz
GAIN (dB)
SFDR (dBc)
GAIN BANDWIDTH PLOT
= 170.0053MHz, AIN = -1dBFS)
(f
SAMPLE
1
0
-1
-2
-3
-4
-5
-6
-7 10 1000
ANALOG INPUT FREQUENCY (MHz)
100
SFDR vs. TEMPERATURE
= 170MHz, AIN = -2dBFS)
(f
SAMPLE
82 81 80 79 78 77 76 75 74 73 72
-40 85 TEMPERATURE (°C)
fIN = 65MHz
603510-15
MAX1213 toc19
MAX1213 toc21a
SNR/SINAD vs. TEMPERATURE
= 170MHz, AIN = -2dBFS)
(f
SAMPLE
67
66
65
64
SNR/SINAD (dB)
63
62
61
SNR
SINAD
fIN = 65MHz
-40 85 TEMPERATURE (°C)
6035-15 10
MAX1213 toc20
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(AV
CC
= OV
CC
= 1.8V, AGND = OGND = 0, f
SAMPLE
= 170MHz, A
IN
= -1dBFS; see each TOC 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 R
L
= 100, TA= +25°C.)
SNR/SINAD vs. SUPPLY VOLTAGE
(f
IN
= 65.1113MHz, AIN = -1dBFS)
MAX1213 toc22
SUPPLY VOLTAGE (V)
SNR/SINAD (dB)
2.22.11.7 1.8 1.9 2.0
61
62
63
64
65
66
67
68
60
1.6 2.3
AVCC = OV
CC
INTERNAL REFERENCE
vs. SUPPLY VOLTAGE
MAX1213 toc23
SUPPLY VOLTAGE (V)
V
REFIO
(V)
2.22.12.01.91.81.7
1.2400
1.2410
1.2420
1.2430
1.2440
1.2390
1.6 2.3
MEASURED AT REFIO REFADJ = AV
CC
= OV
CC
t
PDL/tCPDL
vs. TEMPERATURE
MAX1213 toc24
TEMPERATURE (°C)
t
PDL
/t
CPDL
(dBc)
6035-15 10
2
1
3
4
5
6
0
-40 85
t
PDL
t
CPDL
NPR vs. ANALOG INPUT POWER
MAX1213 toc25
ANALOG INPUT POWER (dBFS)
NPR (dB)
-8-9-10-11-12-13-14-15
49
53
57
61
65
45
-16 -7
f
NOTCH
= 22MHz ±1MHz
NOISE-POWER RATIO PLOT
(WIDE NOISE BANDWIDTH: 50MHz)
MAX1213 toc26
ANALOG INPUT FREQUENCY (MHz)
NPR (dB)
30 3540452551015 20
-80
-70
-60
-50
-40
-30
-20
-10
-90 0
f
NOTCH
= 22MHz
50
NOISE-POWER RATIO PLOT
(NARROW NOISE BANDWIDTH: 35MHz)
MAX1213 toc27
ANALOG INPUT FREQUENCY (MHz)
NPR (dB)
5
10 15
25 302035
-80
-70
-60
-50
-40
-30
-20
-10
-90 0
f
NOTCH
= 22MHz
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
_______________________________________________________________________________________ 9
Pin Description
PIN NAME FUNCTION
1, 6, 11–14, 20,
25, 62, 63, 65
2, 5, 7, 10, 15, 16,
18, 19, 21, 24,
64, 66, 67
3 REFIO
4 REFADJ
8 INP Positive Analog Input Terminal 9 INN Negative Analog Input Terminal
17 CLKDIV
22 CLKP
23 CLKN
26, 45, 61 OGND Digital Converter Ground. Ground connection for digital circuitry and output drivers.
27, 28, 41, 44, 60 OV
29 D0N Complementary Output Bit 0 (LSB) 30 D0P True Output Bit 0 (LSB) 31 D1N Complementary Output Bit 1 32 D1P True Output Bit 1 33 D2N Complementary Output Bit 2 34 D2P True Output Bit 2 35 D3N Complementary Output Bit 3 36 D3P True Output Bit 3
AV
CC
AGND Analog Converter Ground
CC
Analog Supply Voltage. Bypass each pin with a parallel combination of 0.1µF and 0.22µF capacitors for best decoupling results.
Reference Input/Output. With REFADJ pulled high, this I/O port allows an external reference source to be connected to the MAX1213. With REFADJ pulled low, the internal 1.24V bandgap reference is active.
Reference Adjust Input. REFADJ allows for FSR adjustments by placing a resistor or trim potentiometer between REFADJ and AGND (decreases FSR) or REFADJ and REFIO (increases FSR). If REFADJ is connected to AVCC, the internal reference can be overdriven with an external source connected to REFIO. If REFADJ is connected to AGND, the internal reference is used to determine the FSR of the data converter.
Clock Divider Input. This LVCMOS-compatible input controls which speed the converter’s digital outputs are updated with. CLKDIV has an internal pulldown resistor. CLKDIV = 0: ADC updates digital outputs at one-half the input clock rate. CLKDIV = 1: ADC updates digital outputs at input clock rate.
True Clock Input. This input requires an LVDS-compatible input level to maintain the converter’s excellent performance.
Complementary Clock Input. This input requires an LVDS-compatible input level to maintain the converter’s excellent performance.
Digital Supply Voltage. Bypass with a 0.1µF capacitor for best decoupling results.
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
10 ______________________________________________________________________________________
Pin Description (continued)
PIN NAME FUNCTION
37 D4N Complementary Output Bit 4 38 D4P True Output Bit 4 39 D5N Complementary Output Bit 5 40 D5P True Output Bit 5
42 DCLKN
43 DCLKP
46 D6N Complementary Output Bit 6 47 D6P True Output Bit 6 48 D7N Complementary Output Bit 7 49 D7P True Output Bit 7 50 D8N Complementary Output Bit 8 51 D8P True Output Bit 8 52 D9N Complementary Output Bit 9 53 D9P True Output Bit 9 54 D10N Complementary Output Bit 10 55 D10P True Output Bit 10 56 D11N Complementary Output Bit 11 (MSB) 57 D11P True Output Bit 11 (MSB)
58 ORN
59 ORP
Complementary Clock Output. This output provides an LVDS-compatible output level and can be used to synchronize external devices to the converter clock.
True Clock Output. This output provides an LVDS-compatible output level and can be used to synchronize external devices to the converter clock.
Complementary Output for Out-of-Range Control Bit. If an out-of-range condition is detected, bit ORN flags this condition by transitioning low.
True Output for Out-of-Range Control Bit. If an out-of-range condition is detected, bit ORP flags this condition by transitioning high.
Two’s Complement or Binary Output Format Selection. This LVCMOS-compatible input controls
68 T/B
—EP
the digital output format of the MAX1213. T/B has an internal pulldown resistor.
T/B = 0: Two’s complement output format. T/B = 1: Binary output format.
Exposed Paddle. The exposed paddle is located on the backside of the chip and must be connected to analog group for optimum performance.
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
______________________________________________________________________________________ 11
Detailed Description—
Theory of Operation
The MAX1213 uses a fully differential pipelined archi­tecture that allows for high-speed conversion, opti­mized accuracy, and linearity while minimizing power consumption and die size.
Both positive (INP) and negative/complementary ana­log input terminals (INN) are centered around a com­mon-mode voltage of 1.365V, and accept a differential analog input voltage swing of ±0.371V each, resulting in a typical differential full-scale signal swing of 1.485V
P-P
. Inputs INP and INN are buffered prior to entering each T/H stage and are sampled when the differential sam­pling clock signal transitions high.
Each pipeline converter stage converts its input voltage to a digital output code. At every stage, except the last, the error between the input voltage and the digital out­put code is multiplied and passed along to the next pipeline stage. Digital error correction compensates for ADC comparator offsets in each pipeline stage and ensures no missing codes. The result is a 12-bit parallel digital output word in user-selectable two’s complement or offset binary output formats with LVDS-compatible output levels. See Figure 1 for a more detailed view of the MAX1213 architecture.
Analog Inputs (INP, INN)
INP and INN are the fully differential inputs of the MAX1213. Differential inputs usually feature good rejection of even-order harmonics, which allows for enhanced AC performance as the signals are pro­gressing through the analog stages. The MAX1213 analog inputs are self-biased at a common-mode volt­age of 1.365V and allow a differential input voltage
swing of 1.485V
P-P
(Figure 2). Both inputs are self- biased through 2kresistors, resulting in a typical dif­ferential input resistance of 4k. It is recommended to drive the analog inputs of the MAX1213 in AC-coupled configuration to achieve best dynamic performance. See the Single-Ended, AC-Coupled Analog Input sec­tion for a detailed discussion of this configuration.
Figure 1. Simplified MAX1213 Block Diagram
Figure 2. Simplified Analog Input Architecture and Allowable
Input Voltage Range
CLKDIV
CLKP
CLKN
INP
INN
2.2k
CLOCK­DIVIDER
CONTROL
2.2k
INPUT BUFFER
COMMON-MODE BUFFER
CLOCK
MANAGEMENT
T/H
REFERENCE
REFIO REFADJ
DCLKP DCLKN
12-BIT PIPELINE
QUANTIZER
CORE
INP
2.2k
TO COMMON MODE
MAX1213
LVDS
DATA PORT
D0P/N–D11P/N
12
ORP ORN
TO COMMON MODE
INP
P-P
1.485V DIFFERENTIAL FSR
INN
+371mV
-371mV
+371mV
-371mV
COMMON-MODE VOLTAGE (1.365V)
COMMON-MODE VOLTAGE (1.365V)
2.2k
AV
INN
AGND
CC
P-P
742mV
P-P
742mV
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
12 ______________________________________________________________________________________
On-Chip Reference Circuit
The MAX1213 features an internal 1.24V bandgap refer­ence circuit (Figure 3), which in combination with an inter­nal reference-scaling amplifier determines the FSR of the MAX1213. Bypass REFIO with a 0.1µF capacitor to AGND. To compensate for gain errors or increase the ADC’s FSR, the voltage of this bandgap reference can be indirectly adjusted by adding an external resistor (e.g., 100ktrim potentiometer) between REFADJ and AGND or REFADJ and REFIO. See the Applications Information section for a detailed description of this process.
To disable the internal reference, connect REFADJ to AVCC. In this configuration, an external, stable refer­ence must be applied to REFIO to set the converter’s full scale. To enable the internal reference, connect REFADJ to AGND.
Clock Inputs (CLKP, CLKN)
Designed for a differential LVDS clock input drive, it is recommended to drive the clock inputs of the MAX1213 with an LVDS-compatible clock to achieve the best dynamic performance. The clock signal source must be a high-quality, low-phase noise to avoid any degradation in the noise performance of the ADC. The clock inputs (CLKP, CLKN) are internally biased to 1.15V, accept a typical differential signal swing of 0.5V
P-P
, and are usual-
ly driven in AC-coupled configuration. See the
Differential, AC-Coupled PECL-Compatible Clock Input
section for more circuit details on how to drive CLKP and CLKN appropriately. Although not recommended, the clock inputs also accept a single-ended input signal.
The MAX1213 also features an internal clock-manage­ment circuit (duty-cycle equalizer) that ensures that the clock signal applied to inputs CLKP and CLKN is processed to provide a 50% duty-cycle clock signal that desensitizes the performance of the converter to variations in the duty cycle of the input clock source. Note that the clock duty-cycle equalizer cannot be turned off externally and requires a minimum clock fre­quency of >20MHz to work appropriately and accord­ing to data sheet specifications.
Clock Outputs (DCLKP, DCLKN)
The MAX1213 features a differential clock output, which can be used to latch the digital output data with an external latch or receiver. Additionally, the clock output can be used to synchronize external devices (e.g., FPGAs) to the ADC. DCLKP and DCLKN are differential outputs with LVDS-compatible voltage levels. There is a
4.815ns delay time between the rising (falling) edge of CLKP (CLKN) and the rising edge of DCLKP (DCLKN). See Figure 4 for timing details.
Divide-by-2 Clock Control (CLKDIV)
The MAX1213 offers a clock control line (CLKDIV), which supports the reduction of clock jitter in a system. Connect CLKDIV to OGND to enable the ADC’s internal divide-by-2 clock divider. Data is now updated at one­half the ADC’s input clock rate. CLKDIV has an internal pulldown resistor and can be left open for applications that require this divide-by-2 mode. Connecting CLKDIV to OVCCdisables the divide-by-2 mode.
Figure 3. Simplified Reference Architecture
ADC FULL SCALE = REFT-REFB
REFERENCE
1V
REFT: TOP OF REFERENCE LADDER. REFB: BOTTOM OF REFERENCE LADDER.
BUFFER
CONTROL LINE TO
DISABLE REFERENCE BUFFER
AV
CC
REFT
REFB
REFERENCE SCALING AMPLIFIER
G
REFIO
REFADJ
100*
MAX1213
AVCC/2
0.1µF
*REFADJ MAY BE SHORTED TO AGND DIRECTLY
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
______________________________________________________________________________________ 13
System Timing Requirements
Figure 4 depicts the relationship between the clock
input and output, analog input, sampling event, and data output. The MAX1213 samples on the rising (falling) edge of CLKP (CLKN). Output data is valid on the next rising (falling) edge of the DCLKP (DCLKN) clock, but has an internal latency of 11 clock cycles.
Digital Outputs (D0P/N–D11P/N, DCLKP/N,
ORP/N) and Control Input
T
/B
Digital outputs D0P/N–D11P/N, DCLKP/N, and ORP/N are LVDS compatible, and data on D0P/N–D11P/N is presented in either binary or two’s-complement format (Table 1). The T/B control line is an LVCMOS-compati­ble input, which allows the user to select the desired output format. Pulling T/B low outputs data in two’s complement and pulling it high presents data in offset binary format on the 12-bit parallel bus. T/B has an internal pulldown resistor and may be left unconnected in applications using only two’s complement output for-
mat. All LVDS outputs provide a typical voltage swing of 0.371V around a common-mode voltage of roughly
1.2V, and must be terminated at the far end of each transmission line pair (true and complementary) with 100. The LVDS outputs are powered from a separate power supply, which can be operated between 1.7V and 1.9V.
The MAX1213 offers an additional differential output pair (ORP, ORN) to flag out-of-range conditions, where out-of-range is above positive or below negative full scale. An out-of-range condition is identified with ORP (ORN) transitioning high (low).
Note: Although a differential LVDS output architecture reduces single-ended transients to the supply and ground planes, capacitive loading on the digital out­puts should still be kept as low as possible. Using LVDS buffers on the digital outputs of the ADC when driving larger loads may improve overall performance and reduce system-timing constraints.
Figure 4. System and Output Timing Diagram
SAMPLING EVENT
INN
SAMPLING EVENT
SAMPLING EVENT SAMPLING EVENT
INP
t
AD
CLKN
N
CLKP
t
CPDL
DCLKP
N-8
DCLKN
t
PDL
D0P/N– D11P/N
ORP/N
t
- t
~ 0.4 x t
PDL
PDL
NOTE: THE ADC SAMPLES ON THE RISING EDGE OF CLKP. THE RISING EDGE OF DCLKP CAN BE USED TO EXTERNALLY LATCH THE OUTPUT DATA.
SAMPLE
WITH t
N-8
SAMPLE
= 1/f
SAMPLE
t
LATENCY
N+1
N-7
N-7 N-1
t
CH
N+8
t
CPDL
t
CL
N+9
N
- t
PDL
N
N+1
N+1
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
14 ______________________________________________________________________________________
Applications Information
FSR Adjustments Using the Internal
Bandgap Reference
The MAX1213 supports a full-scale adjustment range of 10% (±5%). To decrease the full-scale signal range, an external resistor value ranging from 13kto 1Mmay be added between REFADJ and AGND. A similar approach can be taken to increase the ADC’s full-scale signal range. Adding a variable resistor, potentiometer, or predetermined resistor value between REFADJ and REFIO increases the FSR of the data converter. Figure 6a shows the two possible configurations and their impact on the overall full-scale range adjustment of the MAX1213. Do not use resistor values of less than 13k to avoid instability of the internal gain regulation loop for the bandgap reference. See Figure 6b for the results of the adjustment range for a selection of resis­tors used to trim the full-scale range of the MAX1213.
Table 1. MAX1213 Digital Output Coding
Figure 5. Simplified LVDS Output Architecture
Figure 6a: Circuit Suggestions to Adjust the ADC’s Full-Scale
Range
Figure 6b: FS Adjustment Range vs. FS Adjustment Resistor
INP ANALOG
INPUT VOLTAGE
LEVEL
> VCM + 0.371V < VCM - 0.371V 1 (0)
VCM + 0.371V VCM - 0.371V 0 (1) 1111 1111 1111 (+FS) 0111 1111 1111 (+FS)
V
CM
VCM - 0.371V VCM + 0.371V 0 (1) 0000 0000 0000 (-FS) 1000 0000 0000 (-FS)
< VCM + 0.371V > V
INN ANALOG
INPUT VOLTAGE
LEVEL
V
CM
- 0.371V 1 (0)
CM
V
OP
2.2k
V
ON
2.2k
OUT-OF-RANGE
ORP (ORN)
0 (1)
OV
CC
BINARY DIGITAL OUTPUT
CODE (D11P/N–D0P/N)
1111 1111 1111 (exceeds +FS, OR set)
1000 0000 0000 or 0111 1111 1111 (FS/2)
00 0000 0000 (exceeds -FS, OR set)
ADC FULL SCALE = REFT-REFB
REFERENCE BUFFER
1V
CONTROL LINE
REFERENCE BUFFER
TWO’S COMPLEMENT DIGITAL OUTPUT CODE (D11P/N–D0P/N)
0111 1111 1111 (exceeds +FS, OR set)
0000 0000 0000 or 1111 1111 1111 (FS/2)
10 0000 0000 (exceeds -FS, OR set)
REFT
G
REFB
TO DISABLE
REFERENCE SCALING AMPLIFIER
REFIO
REFADJ
0.1µF 13k TO
1M
13k TO 1M
OGND
MAX1213
REFT: TOP OF REFERENCE LADDER. REFB: BOTTOM OF REFERENCE LADDER.
AV
CC
AVCC/2
FS VOLTAGE vs. FS ADJUST RESISTOR
1.35
1.33
1.31 RESISTOR VALUE APPLIED BETWEEN
1.29
REFADJ AND REFIO INCREASES V
1.27
(V)
1.25
FS
V
1.23
1.21
1.19
1.17
1.15
RESISTOR VALUE APPLIED BETWEEN REFADJ AND AGND DECREASES V
0 1000
FS ADJUST RESISTOR ()
MAX1213 fig06b
FS
FS
875750500 625250 375125
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
______________________________________________________________________________________ 15
Differential, AC-Coupled,
PECL-Compatible Clock Input
The MAX1213 dynamic performance depends on the use of a very clean clock source. The phase noise floor of the clock source has a negative impact on the SNR performance. Spurious signals on the clock signal source also affect the ADC’s dynamic range. The pre­ferred method of clocking the MAX1213 is differentially with LVDS- or PECL-compatible input levels. The fast data transition rates of these logic families minimize the clock-input circuitry’s transition uncertainty, thereby improving the SNR performance. To accomplish this, a 50reverse-terminated clock signal source with low phase noise is AC-coupled into a fast differential receiver such as the MC100LVEL16 (Figure 7). The receiver produces the necessary PECL output levels to drive the clock inputs of the data converter.
Transformer-Coupled, Differential Analog
Input Drive
In general, the MAX1213 provides the best SFDR and THD with fully differential input signals and it is not re-
commended to drive the ADC inputs in single-ended configuration. In differential input mode, even-order harmonics are usually lower since INP and INN are bal­anced, and each of the ADC inputs only requires half the signal swing compared to a single-ended configu­ration. Wideband RF transformers provide an excellent solution to convert a single-ended signal to a fully dif­ferential signal, required by the MAX1213 to reach its optimum dynamic performance.
A secondary-side termination of a 1:1 transformer (e.g., Mini-Circuit’s ADT1-1WT) into two separate 24.9±1% resistors (use tight resistor tolerances to minimize effects of imbalance; 0.5% would be an ideal choice) placed between top/bottom and center tap of the trans­former is recommended to maximize the ADC’s dynam­ic range. This configuration optimizes THD and SFDR performance of the ADC by reducing the effects of transformer parasitics. However, the source imped­ance combined with the shunt capacitance provided by a PC board and the ADC’s parasitic capacitance limit the ADC’s full-power input bandwidth to approxi­mately 600MHz.
Figure 7. Differential, AC-Coupled, PECL-Compatible Clock Input Configuration
V
CLK
0.1µF
SINGLE-ENDED
INPUT TERMINAL
0.1µF 2
8
0.1µF
7
50
MC100LVEL16
3
510510
45
0.01µF VGND
150
0.1µF
6
150
INP
INN
CLKN
CLKP
MAX1213
AGND
AV
CC
OGND
OV
CC
D0P/N–D11P/N
12
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
16 ______________________________________________________________________________________
To further enhance THD and SFDR performance at high-input frequencies (>100MHz), a second trans­former (Figure 8) should be placed in series with the single-ended-to-differential conversion transformer. This transformer reduces the increase of even-order harmonics at high frequencies.
Single-Ended, AC-Coupled Analog Inputs
Although not recommended, the MAX1213 can be used in single-ended mode (Figure 9). Analog signals can be AC-coupled to the positive input INP through a 0.1µF capacitor and terminated with a 49.9resistor to AGND. The negative input should be reverse terminated with
24.9resistors and AC-grounded with a 0.1µF capacitor.
Grounding, Bypassing, and
Board Layout Considerations
The MAX1213 requires board layout design techniques suitable for high-speed data converters. This ADC pro­vides separate analog and digital power supplies. The analog and digital supply voltage pins accept input voltage ranges of 1.7V to 1.9V. Although both supply types can be combined and supplied from one source, it is recommended to use separate sources to cut down on performance degradation caused by digital switch­ing currents, which can couple into the analog supply network. Isolate analog and digital supplies (AVCCand OVCC) where they enter the PC board with separate networks of ferrite beads and capacitors to their corre­sponding grounds (AGND, OGND).
Figure 8. Analog Input Configuration with Back-to-Back Transformers and Secondary-Side Termination
Figure 9. Single-Ended AC-Coupled Analog Input Configuration
SINGLE-ENDED
INPUT TERMINAL
0.1µF ADT1-1WT
ADT1-1WT
25
25
0.1µF
AV
OV
CC
CC
10
INP
D0P/N–D11P/N
MAX1213
INN
10
12
AGND
OGND
OV
AV
CC
CC
SINGLE-ENDED
INPUT TERMINAL
50
25
0.1µF
0.1µF
INP
INN
MAX1213
AGND
D0P/N–D11P/N
12
OGND
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
______________________________________________________________________________________ 17
To achieve optimum performance, provide each supply with a separate network of a 47µF tantalum capacitor and parallel combinations of 10µF and 1µF ceramic capacitors. Additionally, the ADC requires each supply pin to be bypassed with separate 0.1µF ceramic capacitors (Figure 10). Locate these capacitors directly at the ADC supply pins or as close as possible to the MAX1213. Choose surface-mount capacitors, whose preferred location should be on the same side as the converter to save space and minimize the inductance. If close placement on the same side is not possible, these bypassing capacitors may be routed through vias to the bottom side of the PC board.
Multilayer boards with separated ground and power planes produce the highest level of signal integrity. Consider the use of a split ground plane arranged to match the physical location of analog and digital ground on the ADC’s package. The two ground planes should be joined at a single point such that the noisy digital ground currents do not interfere with the analog ground plane. The dynamic currents that may need to travel long distances before they are recombined at a common-source ground, resulting in large and undesir­able ground loops, are a major concern with this approach. Ground loops can degrade the input noise by coupling back to the analog front end of the convert­er, resulting in increased spurious activity, leading to decreased noise performance.
Alternatively, all ground pins could share the same ground plane, if the ground plane is sufficiently isolated from any noisy, digital systems ground. To minimize the coupling of the digital output signals from the analog input, segregate the digital output bus carefully from the
analog input circuitry. To further minimize the effects of digital noise coupling, ground return vias can be posi­tioned throughout the layout to divert digital switching currents away from the sensitive analog sections of the ADC. This approach does not require split ground planes, but can be accomplished by placing substantial ground connections between the analog front end and the digital outputs.
The MAX1213 is packaged in a 68-pin QFN-EP pack­age (package code: G6800-4), providing greater design flexibility, increased thermal dissipation, and optimized AC performance of the ADC. The exposed paddle (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 board with standard infrared (IR) flow soldering techniques.
Thermal efficiency is one of the factors for selecting a package with an exposed pad for the MAX1213. The exposed pad improves thermal and ensures a solid ground connection between the DAC and the PC board’s analog ground layer.
Considerable care must be taken when routing the digi­tal output traces for a high-speed, high-resolution data converter. It is essential to keep trace lengths at a mini­mum and place minimal capacitive loading—less than 5pF—on any digital trace to prevent coupling to sensi­tive analog sections of the ADC. It is recommended running the LVDS output traces as differential lines with 100characteristic impedance from the ADC to the LVDS load device.
Figure 10. Grounding, Bypassing, and Decoupling Recommendations for MAX1213
BYPASSING-ADC LEVEL
AV
CC
OV
CC
BYPASSING-BOARD LEVEL
AV
CC
0.1µF0.1µF
AGND
MAX1213
AGND
OGND
OGND
D0P/N–D11P/N
12
NOTE: EACH POWER-SUPPLY PIN (ANALOG AND DIGITAL) SHOULD BE DECOUPLED WITH AN INDIVIDUAL 0.1µF CAPACITOR AS CLOSE AS POSSIBLE TO THE ADC.
1µF
1µF
10µF
OV
CC
10µF47µF
47µF
ANALOG POWER­SUPPLY SOURCE
DIGITAL/OUTPUT DRIVER POWER­SUPPLY SOURCE
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
18 ______________________________________________________________________________________
Static Parameter Definitions
Integral Nonlinearity (INL)
Integral nonlinearity is the deviation of the values on an actual transfer function from a straight line. This straight line can be either a best straight-line fit or a line drawn between the end points of the transfer function, once offset and gain errors have been nullified. However, the static linearity parameters for the MAX1213 are mea­sured using the histogram method with an input fre­quency of 10MHz.
Differential Nonlinearity (DNL)
Differential nonlinearity is the difference between an actual step width and the ideal value of 1LSB. A DNL error specification of less than 1LSB guarantees no missing codes and a monotonic transfer function. The MAX1213’s DNL specification is measured with the his­togram method based on a 10MHz input tone.
Dynamic Parameter Definitions
Aperture Jitter
Figure 11 depicts the aperture jitter (tAJ), which is the
sample-to-sample variation in the aperture delay.
Aperture Delay
Aperture delay (tAD) is the time defined between the rising edge of the sampling clock and the instant when an actual sample is taken (Figure 11).
Signal-to-Noise Ratio (SNR)
For a waveform perfectly reconstructed from digital samples, the theoretical maximum SNR is the ratio of the full-scale analog input (RMS value) to the RMS quantization error (residual error). The ideal, theoretical minimum analog-to-digital noise is caused by quantiza-
tion error only and results directly from the ADC’s reso­lution (N bits):
SNR
[max]
= 6.02 x N + 1.76
In reality, other noise sources such as thermal noise, clock jitter, signal phase noise, and transfer function nonlinearities are also contributing to the SNR calcula­tion and should be considered when determining the signal-to-noise ratio in ADC.
Signal-to-Noise Plus Distortion (SINAD)
SINAD is computed by taking the ratio of the RMS sig­nal to all spectral components excluding the fundamen­tal and the DC offset. In the case of the MAX1213, SINAD is computed from a curve fit.
Spurious-Free Dynamic Range (SFDR)
SFDR is the ratio of RMS amplitude of the carrier fre­quency (maximum signal component) to the RMS value of the next-largest noise or harmonic distortion compo­nent. SFDR is usually measured in dBc with respect to the carrier frequency amplitude or in dBFS with respect to the ADC’s full-scale range.
Intermodulation Distortion (IMD)
IMD is the ratio of the RMS sum of the intermodulation products to the RMS sum of the two fundamental input tones. This is expressed as:
The fundamental input tone amplitudes (V1and V2) are at
-7dBFS. The intermodulation products are the amplitudes of the output spectrum at the following frequencies:
• Second-order intermodulation products: f
IN1
+ f
IN2
,
f
IN2
- f
IN1
• Third-order intermodulation products: 2 x f
IN1
- f
IN2
,
2 x f
IN2
- f
IN1
, 2 x f
IN1
+ f
IN2
, 2 x f
IN2
+ f
IN1
• Fourth-order intermodulation products: 3 x f
IN1
- f
IN2
,
3 x f
IN2
- f
IN1
, 3 x f
IN1
+ f
IN2
, 3 x f
IN2
+ f
IN1
•Fifth-order intermodulation products: 3 x f
IN1
- 2 x f
IN2
,
3 x f
IN2
-2 x f
IN1
, 3 x f
IN1
+2 x f
IN2
, 3 x f
IN2
+ 2 x f
IN1
Full-Power Bandwidth
A large -1dBFS analog input signal is applied to an ADC and the input frequency is swept up to the point where the amplitude of the digitized conversion result has decreased by 3dB. The -3dB-point is defined as full-power input bandwidth frequency of the ADC.
Figure11. Aperture Jitter/Delay Specifications
CLKP CLKN
IMD
log
20
2
VV V V
IM IM IM IMn
1
 
2
++++
......
2
VV
+
122
22
3
2
 
 
ANALOG
INPUT
SAMPLED
DATA (T/H)
T/H
t
AD
TRACK TRACK
t
AJ
HOLD
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
______________________________________________________________________________________ 19
Noise Power Ratio (NPR)
NPR is commonly used to characterize the return path of cable systems where the signals are typically individual quadrature amplitude-modulated (QAM) carriers with a frequency spectrum similar to noise. Numerous such carriers are operated in a continuous spectrum, generat­ing a noise-like signal, which covers a relatively broad bandwidth. To test the MAX1213 for NPR, a “noise-like” signal is passed through a high-order bandpass filter to produce an approximately square spectral pedestal of noise with about the same bandwidth as the signals being simulated. Following the bandpass filter, the signal is passed through a narrow band-reject filter to produce a deep notch at the center of the noise pedestal. Finally, this signal is applied to the MAX1213 and its digitized results analyzed. The RMS noise power of the signal inside the notch is compared with the RMS noise level outside the notch using an FFT. Note that the NPR test requires sufficiently long data records to guarantee a suitable number of samples inside the notch. NPR for the MAX1213 was determined for 35MHz and 50MHz noise bandwidth signals, simulating a typical cable signal envi­ronment (see the Typical Operating Characteristics for test details and results).
Pin-Compatible Lower
Speed/Resolution Versions
Applications that require lower resolution and/or higher speed can refer to other family members of the MAX1213. Adjusting an application to a lower resolution has been simplified by maintaining an identical pinout for all members of this high-speed family. See Table 2 for a selection of different resolution and speed grades.
Table 2. Selection of Lower Resolution/
Higher Speed Versions of the MAX1213
PART
MAX1121 8 250 MAX1122 10 170 MAX1123 10 210 MAX1124 10 250
RESOLUTION
(BITS)
SPEED GRADE
(Msps)
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
20 ______________________________________________________________________________________
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
21-0122
1
C
2
MAX1213
1.8V, 12-Bit, 170Msps ADC for Broadband Applications
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 21
© 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Package Information (continued)
(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
.)
PACKAGE OUTLINE, 68L QFN, 10x10x0.9 MM
21-0122
1
C
2
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