Rainbow Electronics MAX1449 User Manual
General Description
The MAX1449 +3.3V, 10-bit analog-to-digital converter
(ADC) features a fully differential input, a pipelined 10stage ADC architecture with wideband track-and-hold
(T/H), and digital error correction incorporating a fully
differential signal path. The ADC is optimized for lowpower, high-dynamic performance in imaging and digital communications applications. The converter
operates from a single +2.7V to +3.6V supply, consuming only 186mW while delivering a 58.5dB (typ) signalto-noise ratio (SNR) at a 20MHz input frequency. The
fully differential input stage has a -3dB 400MHz bandwidth and may be operated with single-ended inputs. In
addition to low operating power, the MAX1449 features
a 5µA power-down mode for idle periods.
An internal +2.048V precision bandgap reference is
used to set the ADC’s full-scale range. A flexible reference structure allow’s the user to supply a buffered,
direct, or externally derived reference for applications
requiring increased accuracy or a different input voltage range.
Lower speed, pin-compatible versions of the MAX1449
are also available. Refer to the MAX1444 data sheet for
a 40Msps version, the MAX1446 data sheet for a
60Msps version, and the MAX1448 data sheet for 80Msps.
The MAX1449 has parallel, offset binary, CMOS-compatible, three-state outputs that can be operated from
+1.7V to +3.6V to allow flexible interfacing. The device
is available in a 5mm x 5mm 32-pin TQFP package and
is specified over the extended industrial (-40°C to
+85°C) temperature range.
________________________Applications
Ultrasound Imaging
CCD Imaging
Baseband and IF Digitization
Digital Set-Top Boxes
Video Digitizing Applications
Features
♦ Single +3.3V Operation
♦ Excellent Dynamic Performance
58.5dB SNR at f
IN
= 20MHz
72dBc SFDR at f
IN
= 20MHz
♦ Low Power
62mA (Normal Operation)
5µA (Shutdown Mode)
♦ Fully Differential Analog Input
♦ Wide 2Vp-p Differential Input Voltage Range
♦ 400MHz -3dB Input Bandwidth
♦ On-Chip +2.048V Precision Bandgap Reference
♦ CMOS-Compatible Three-State Outputs
♦ 32-Pin TQFP Package
♦ Evaluation Kit Available
MAX1449
10-Bit, 105Msps, Single +3.3V, Low-Power
ADC with Internal Reference
________________________________________________________________ Maxim Integrated Products 1
Functional Diagram
19-4802; Rev 0; 10/00
EVALUATION KIT AVAILABLE
Ordering Information
Pin Configuration appears at end of data sheet.
Pin-Compatible, Lower Speed
Selection Table
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
PART TEMP. RANGE PIN-PACKAGE
MAX1449EHJ -40°C to +85°C 32 TQFP
PART NUMBER SAMPLING SPEED
MAX1444 40Msps
MAX1446 60Msps
MAX1448 80Msps
CLK
IN+
T/H
IN-
PD
REF
REFINREFOUT REFP COM REFN OE
MAX1449
CONTROL
10
D
OUTPUT
PIPELINE ADC
REF SYSTEM +
BIAS
E
DRIVERS
C
V
DD
GND
D9–D0
OV
DD
OGND
MAX1449
10-Bit, 105Msps, Single +3.3V, Low-Power
ADC with Internal Reference
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VDD= +3.3V, OVDD= +2.0V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; V
REFIN
= +2.048V, REFOUT
connected to REFIN through a 10kΩ resistor, V
IN
= 2Vp-p (differential with respect to COM), CL ≈ 10pF at digital outputs, f
CLK
=
105MHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. 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.
VDD, OVDDto GND ...............................................-0.3V to +3.6V
OGND to GND.......................................................-0.3V to +0.3V
IN+, IN- to GND........................................................-0.3V to V
DD
REFIN, REFOUT, REFP,
REFN, and COM to GND..........................-0.3V to (V
DD
+ 0.3V)
OE, PD, CLK to GND..................................-0.3V to (V
DD
+ 0.3V)
D9–D0 to GND.........................................-0.3V to (OV
DD
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
32-Pin TQFP (derate 11.1mW/°C above +70°C)...........889mW
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
DC ACCURACY
Resolution 10 Bits
Integral Nonlinearity INL fIN = 7.5MHz ±0.75 ±2.4 LSB
Differential Nonlinearity DNL fIN = 7.5MHz, no missing codes guaranteed ±0.5 ±1.0 LSB
Offset Error < ±1 ±1.7 % FS
Gain Error 0 ±2% FS
ANALOG INPUT
Input Differential Range V
Common-Mode
Voltage Range
Input Resistance R
Input Capacitance C
CONVERSION RATE
Maximum Clock Frequency f
Data Latency 5.5 Cycles
DYNAMIC CHARACTERISTICS (f
Signal-To-Noise Ratio
(Note 1)
Signal-To-Noise And Distortion
(Up to 5
Spurious-Free Dynamic
Range (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
th
Harmonic) (Note 1)
DIFF
V
COM
IN
IN
CLK
= 105.26MHz, 4096-point FFT)
CLK
SNR
SINAD
SFDR
Differential or single-ended inputs ±1.0 V
Switched capacitor load 20 kΩ
f
= 7.5MHz 56.3 58.5
IN
fIN = 20MHz 55.8 58.5 dB
f
= 50MHz 58
IN
fIN = 7.5MHz 55.3 58.2
fIN = 20MHz 55.1 58.1 dB
f
= 50MHz 57.6
IN
fIN = 7.5MHz 61 72
fIN = 20MHz, TA = +25°C 63 72 dBc
f
= 50MHz 70
IN
105 MHz
VDD/2
± 0.5
5pF
V
MAX1449
10-Bit, 105Msps, Single +3.3V, Low-Power
ADC with Internal Reference
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VDD= +3.3V, OVDD= +2.0V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; V
REFIN
= +2.048V, REFOUT
connected to REFIN through a 10kΩ resistor, V
IN
= 2Vp-p (differential with respect to COM), CL≈ 10pF at digital outputs, f
CLK
=
105MHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
=
+25°C.)
Third-Harmonic Distortion
(Note 1)
Intermodulation Distortion (First 5
Odd-Order IMDs) (Note 2)
Third-Order Intermodulation
Distortion (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
HD3
IMD
IM3
Total Harmonic Distortion
(First 5 Harmonics)
THD
(Note 1)
fIN = 7.5MHz -72
fIN = 20MHz -72
f
= 50MHz -70
IN
f
= 38MHz at -6.5dB FS
1
= 42MHz at -6.5dB FS
f
2
f
= 38MHz at -6.5dB FS
1
f
= 42MHz at -6.5dB FS
2
fIN = 7.5MHz, TA = +25°C -70 -61.5
fIN = 20MHz, TA = +25°C -70 -61.5 dBc
= 50MHz -70
f
IN
Small-Signal Bandwidth Input at -20dB FS, differential inputs 500 MHz
Full-Power Bandwidth FPBW Input at -0.5dB FS, differential inputs 400 MHz
Aperture Delay t
Aperture Jitter t
AD
AJ
Overdrive Recovery Time For 1.5 x full-scale input 2 ns
Differential Gain ±1%
Differential Phase ±0.25 degree
Output Noise IN+ = IN- = COM 0.2 LS B
INTERNAL REFERENCE
Reference Output Voltage REFOUT
Reference Temperature
Coefficient
TC
REF
Load Regulation 1.25 mV/mA
EXTERNAL REFERENCE
Positive Reference REFP V
Negative Reference REFN V
Differential Reference Voltage ∆V
REFIN Resistance R
REF
REFIN
= +2.048V 2.162 V
REFIN
= +2.048V 1.138 V
REFIN
V
-V
, V
REFP
REFN
= +2.048V 0.98 1.024 1.07 V
REFIN
DIGITAL INPUTS (CLK, PD, OE)
0.8 x
V
DD
0.8 x
V
DD
Input High Threshold V
CLK
IH
PD, OE
CLK
Input Low Threshold V
IL
PD, OE
dBc
-76 dBc
-76 dBc
1ns
2ps
2.048
±1%
RMS
RM S
V
60 ppm/°C
>50 MΩ
V
0.2 x
V
DD
0.2 x
V
DD
V
Note 1: SNR, SINAD, THD, SFDR and HD3 are based on an analog input voltage of -0.5dB FS referenced to a +1.024V full-scale
input voltage range.
Note 2: Intermodulation distortion is the total power of the intermodulation products relative to the individual carrier. This number is
6dB better if referenced to the two-tone envelope.
Note 3: Digital outputs settle to V
IH,VIL
.
Note 4: With REFIN driven externally, REFP, COM, and REFN are left floating while powered down.
MAX1449
10-Bit, 105Msps, Single +3.3V, Low-Power
ADC with Internal Reference
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(VDD= +3.3V, OVDD= +2.0V; 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND; V
REFIN
= +2.048V, REFOUT
connected to REFIN through a 10kΩ resistor, V
IN
= 2Vp-p (differential with respect to COM), CL≈ 10pF at digital outputs,
f
CLK
= 105MHz, TA= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
=
+25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Hysteresis V
Input Leakage
Input Capacitance C
HYST
I
I
IH
IL
IN
VIH = VDD = OV
DD
VIL = 0 ±5
DIGITAL OUTPUTS (D9–D0)
Output Voltage Low V
Output Voltage High V
Three-State Leakage Current I
Three-State Output Capacitance C
LEAK
OUT
OL
OH
I
= 200µA 0.2 V
SINK
I
OE = OV
OE = OV
SOURCE
= 200µA
DD
DD
POWER REQUIREMENTS
Analog Supply Voltage V
Output Supply Voltage OV
Analog Supply Current I
DD
DD
VDD
Operating, fIN = 20MHz at -0.5dB FS 58 74 mA
Shutdown, clock idle, PD = OE = OV
DD
Operating, CL = 15pF , fIN = 20MHz at
Output Supply Current I
OVDD
Power Supply Rejection PSRR
-0.5dB FS
Shutdown, clock idle, PD = OE = OV
DD
Offset ±0.1 mV/V
Gain ±0.1 %/V
TIMING CHARACTERISTICS
CLK Rise-to-Output Data Valid t
OE Fall-to-Output Enable t
OE Rise-to-Output Disable t
ENABLE
DISABLE
CLK Pulse Width High t
CLK Pulse Width Low t
Wake-Up Time t
DO
CH
WAKE
Figure 6 (Note 3) 5 8 ns
Figure 5 10 ns
Figure 5 15 ns
Figure 6, clock period 9.52ns
Figure 6, clock period 9.52ns
CL
(Note 4) 1.5 µs
OV
DD
- 0.2
2.7 3.3 3.6 V
1.7 3.3 3.6 V
0.1 V
±5 µA
5pF
V
±10 µA
5pF
415µA
10 mA
110µA
4.76
±0.47
4.76
±0.47
ns
ns
MAX1449
10-Bit, 105Msps, Single +3.3V, Low-Power
ADC with Internal Reference
_______________________________________________________________________________________ 5
Typical Operating Characteristics
(VDD= +3.3V, OVDD= +2.0V, internal reference, differential input at -0.5dB FS, f
CLK
= 106.2345MHz, CL≈ 10pF, TA= +25°C,
unless otherwise noted.)
FFT PLOT (fIN = 7.5MHz,
8192-POINT FFT, DIFFERENTIAL INPUT)
0
-10
-20
-30
-40
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
02010 30 40 50 60
2ND HARMONIC
3RD HARMONIC
ANALOG INPUT FREQUENCY (MHz)
FFT PLOT (fIN = 7.5MHz,
8192-POINT FFT, SINGLE-ENDED INPUT)
0
-10
-20
-30
-40
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
02010 30 40 50 60
2ND HARMONIC
3RD HARMONIC
ANALOG INPUT FREQUENCY (MHz)
SNR = 58.6dB
SINAD = 58.4dB
THD = -72.7dBc
SFDR = 73.6dBc
SNR = 57.7dB
SINAD = 57.5dB
THD = -71.8dBc
SFDR = 74.4dBc
MAX1449 toc01
MAX1449 toc04
-10
-20
-30
-40
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
-10
-20
-30
-40
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
FFT PLOT (fIN = 19.99MHz,
8192-POINT FFT, DIFFERENTIAL INPUT)
0
2ND HARMONIC
02010 30 40 50 60
ANALOG INPUT FREQUENCY (MHz)
SNR = 58.5dB
SINAD = 58.4dB
THD = -73.7dBc
SFDR = 75.9dBc
3RD HARMONIC
FFT PLOT (fIN = 19.99MHz,
8192-POINT FFT, SINGLE-ENDED INPUT)
0
2ND HARMONIC
02010 30 40 50 60
ANALOG INPUT FREQUENCY (MHz)
SNR = 57.7dB
SINAD = 57.2dB
THD = -67dBc
SFDR = 67.7dBc
3RD HARMONIC
UNDERSAMPLING FFT PLOT (fIN = 50.12MHz,
8192-POINT FFT, DIFFERENTIAL INPUT)
0
SNR = 57.9dB
-10
SINAD = 56.7dB
MAX1449 toc02
THD = -71.3dBc
-20
SFDR = 71.1dBc
-30
-40
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
2ND HARMONIC
3RD HARMONIC
02010 30 40 50 60
ANALOG INPUT FREQUENCY (MHz)
TWO-TONE INTERMODULATION
(8192-POINT IMD, DIFFERENTIAL INPUT)
0
f1 = 38MHz AT -6.5dB FS
-10
= 42MHz AT -6.5dB FS
f
MAX1449 toc05
2
-20
-30
-40
-50
-60
AMPLITUDE (dB)
-70
-80
-90
-100
2ND ORDER IMD
02010 30 40 50 60
ANALOG INPUT FREQUENCY (MHz)
f
3RD ORDER IMD
MAX1449 toc03
f
2
1
MAX1449 toc06
SPURIOUS-FREE DYNAMIC RANGE
vs. ANALOG INPUT FREQUENCY
80
DIFFERENTIAL
74
68
SFDR (dBc)
62
56
50
SINGLE-ENDED
110100
ANALOG INPUT FREQUENCY (MHz)
MAX1449 toc07
SIGNAL-TO-NOISE RATIO
vs. ANALOG INPUT FREQUENCY
60
DIFFERENTIAL
58
SINGLE-ENDED
56
SNR (dB)
54
52
50
110100
ANALOG INPUT FREQUENCY (MHz)
MAX1449 toc08
TOTAL HARMONIC DISTORTION
vs. ANALOG INPUT FREQUENCY
-50
-56
-62
THD (dBc)
-68
-74
-80
SINGLE-ENDED
DIFFERENTIAL
1 10 100
ANALOG INPUT FREQUENCY (MHz)
MAX1449 toc09
MAX1449
10-Bit, 105Msps, Single +3.3V, Low-Power
ADC with Internal Reference
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VDD= +3.3V, OVDD= +2.0V, internal reference, differential input at -0.5dB FS, f
CLK
= 106.2345MHz, CL≈ 10pF, TA= +25°C,
unless otherwise noted.)
SIGNAL-T0-NOISE PLUS DISTORTION
vs. ANALOG INPUT FREQUENCY
60
DIFFERENTIAL
58
56
SINAD (dB)
54
52
50
SINGLE-ENDED
1 10 100
ANALOG INPUT FREQUENCY (MHz)
MAX1449 toc10
FULL-POWER INPUT BANDWIDTH vs.
ANALOG INPUT FREQUENCY, SINGLE-ENDED
6
4
2
0
-2
AMPLITUDE (dB)
-4
-6
-8
1 100010010
ANALOG INPUT FREQUENCY (MHz)
SMALL-SIGNAL INPUT BANDWIDTH vs.
ANALOG INPUT FREQUENCY, SINGLE-ENDED
6
VIN = 100mVp-p
4
MAX1449 toc11
2
0
-2
AMPLITUDE (dB)
-4
-6
-8
1 100010010
ANALOG INPUT FREQUENCY (MHz)
MAX1449 toc12
SPURIOUS-FREE DYNAMIC RANGE
vs. INPUT POWER (f
80
75
70
65
SFDR (dBc)
60
55
50
-12 -6-9 -3 0
INPUT POWER (dB FS)
= 19MHz)
IN
SIGNAL-TO-NOISE + DISTORTION vs.
= 19MHz)
IN
65
60
55
SINAD (dB)
50
INPUT POWER (f
MAX1449 toc13
MAX1449 toc16
SIGNAL-TO-NOISE RATIO vs.
INPUT POWER (f
65
60
55
SNR (dB)
50
45
40
-12 -6-9 -3 0
INPUT POWER (dB FS)
= 19MHz)
IN
SPURIOUS-FREE DYNAMIC RANGE
vs. TEMPERATURE
84
fIN = 26.1696MHz
80
76
SFDR (dBc)
72
MAX1449 toc14
MAX1449 toc17
TOTAL HARMONIC DISTORTION
vs. INPUT POWER (f
-50
-55
-60
-65
THD (dBc)
-70
-75
-80
-12 -6-9 -3 0
INPUT POWER (dB FS)
= 19MHz)
IN
SIGNAL-TO-NOISE vs. TEMPERATURE
70
fIN = 26.1696MHz
66
62
SNR (dB)
58
MAX1449 toc15
MAX1449 toc18
45
40
-12 -6-9 -3 0
INPUT POWER (dB FS)
68
64
-40 10-15 35 60 85
TEMPERATURE (°C)
54
50
-40 10-15 35 60 85
TEMPERATURE (°C)
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