MAXIM MAX1183

19-2173; Rev 0; 9/01
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
Functional Diagram appears at end of data sheet.
♦ On-Chip +2.048V Precision Bandgap Reference
♦ User-Selectable Output Format—Two’s
Complement or Offset Binary
♦ 48-Pin TQFP Package with Exposed Paddle for
Improved Thermal Dissipation
Ordering Information
PART
MAX1183ECM
TEMP. RANGE
PIN-PACKAGE
-40°C to +85°C
48 TQFP-EP
37
38
39
40
41
42
43
44
45
46
47
48
REFN
REFP
REFIN
REFOUT
D9A
D8A
D7A
D6A
D5A
D4A
D3A
D2A
Pin Configuration
COM
1
36
D1A
VDD
GND
INA+
INA-
2
35
3
34
4
33
D0A
OGND
OVDD
5
32
VDD
GND
INBINB+
6
31
GND
VDD
CLK
MAX1183
7
30
OVDD
OGND
D0B
D1B
D2B
D3B
D4B
D5B
24
25
23
26
12
22
11
21
27
20
28
10
19
29
9
18
8
17
Ultrasound
♦ 400MHz -3dB Input Bandwidth
16
Video Application
♦ Wide ±1Vp-p Differential Analog Input Voltage
Range
15
Instrumentation
♦ 0.02dB Gain and 0.25° Phase Matching
14
Multichannel IF Sampling
♦ Low Power
40mA (Normal Operation)
2.8mA (Sleep Mode)
1µA (Shutdown Mode)
13
I/Q Channel Digitization
♦ Excellent Dynamic Performance
59.6dB SNR at fIN = 20MHz
73dB SFDR at fIN = 20MHz
VDD
VDD
GND
T/B
SLEEP
PD
OE
D9B
D8B
D7B
D6B
High-Resolution Imaging
♦ Single +3V Operation
GND
Applications
Features
48 TQFP-EP
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX1183
General Description
The MAX1183 is a +3V, dual 10-bit analog-to-digital
converter (ADC) featuring fully differential wideband
track-and-hold (T/H) inputs, driving two pipelined, ninestage ADCs. The MAX1183 is optimized for low-power,
high dynamic performance applications in imaging,
instrumentation, and digital communication applications. This ADC operates from a single +2.7V to +3.6V
supply, consuming only 120mW while delivering a typical signal-to-noise ratio (SNR) of 59.6dB at an input frequency of 20MHz and a sampling rate of 40Msps. The
T/H driven input stages incorporate 400MHz (-3dB)
input amplifiers. The converters may also be operated
with single-ended inputs. In addition to low operating
power, the MAX1183 features a 2.8mA sleep mode as
well as a 1µA power-down mode to conserve power
during idle periods.
An internal +2.048V precision bandgap reference sets
the full-scale range of the ADC. A flexible reference
structure allows the use of this internal or an externally
derived reference, if desired for applications requiring
increased accuracy or a different input voltage range.
The MAX1183 features parallel, CMOS-compatible
three-state outputs. The digital output format can be set
to two’s complement or straight offset binary through a
single control pin. The device provides for a separate
output power supply of +1.7V to +3.6V for flexible interfacing. The MAX1183 is available in a 7mm ✕ 7mm, 48pin TQFP package, and is specified for the extended
industrial (-40°C to +85°C) temperature range.
Pin-compatible lower and higher speed versions of the
MAX1183 are also available. Refer to the MAX1180
data sheet for 105Msps, the MAX1181 data sheet for
80Msps, the MAX1182 data sheet for 65Msps, and the
MAX1184 data sheet for 20Msps. In addition to these
speed grades, this family includes a multiplexed output
version, for which digital data is presented time-interleaved and on a single, parallel 10-bit output port.
MAX1183
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
ABSOLUTE MAXIMUM RATINGS
VDD, OVDD to GND .............................................. -0.3V to +3.6V
OGND to GND.......................................................-0.3V to +0.3V
INA+, INA-, INB+, INB- to GND ...............................-0.3V to VDD
REFIN, REFOUT, REFP, REFN,
COM, CLK to GND .................................-0.3V to (VDD + 0.3V)
OE, PD, SLEEP, T/B
D9A–D0A, D9B–D0B to OGND ...........-0.3V to (OVDD + 0.3V)
Continuous Power Dissipation (TA = +70°C)
48-Pin TQFP (derate 12.5mW/°C above +70°C)........1000mW
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
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
(VDD = +3V, OVDD = +2.5V, 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND, REFOUT connected to REFIN through
a 10kΩ resistor, VIN = 2Vp-p (differential with respect to COM), CL = 10pF at digital outputs (Note 5), fCLK = 40MHz, TA = TMIN to
TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC ACCURACY
Resolution
10
Bits
Integral Nonlinearity
INL
fIN = 7.51MHz
±0.5
±1.5
LSB
Differential Nonlinearity
DNL
fIN = 7.51MHz, no missing codes guaranteed
±0.25
±1.0
LSB
Offset Error
<±1
±1.7
% FS
Gain Error
0
±2
% FS
ANALOG INPUT
Differential Input Voltage Range
VDIFF
Common-Mode Input Voltage
Range
VCM
Input Resistance
RIN
Input Capacitance
CIN
Differential or single-ended inputs
Switched capacitor load
±1.0
V
VDD/2
±0.5
V
50
kΩ
5
pF
5
Clock
Cycles
CONVERSION RATE
Maximum Clock Frequency
fCLK
40
Data Latency
MHz
DYNAMIC CHARACTERISTICS (fCLK = 40MHz, 4096-point FFT)
Signal-to-Noise Ratio
SNR
Signal-to-Noise and Distortion
SINAD
Spurious-Free Dynamic Range
SFDR
Third-Harmonic Distortion
HD3
Intermodulation Distortion
IMD
Total Harmonic Distortion
(First 4 Harmonics)
THD
2
fINA or B = 7.51MHz, TA = +25°C
57.3
59.6
fINA or B = 20MHz, TA = +25°C
56.8
59.6
fINA or B = 7.51MHz, TA = +25°C
57
59.4
56.5
59
fINA or B = 7.51MHz, TA = +25°C
65
76
fINA or B = 20MHz, TA = +25°C
65
73
fINA or B = 20MHz, TA = +25°C
dB
dB
dBc
fINA or B = 7.51MHz
-76
fINA or B = 20MHz
-73
fINA or B = 11.6066MHz at -6.5dB FS,
fINA or B = 13.3839MHz at -6.5dB FS
(Note 2)
-78
fINA or B = 7.51MHz, TA = +25°C
-73
-64
fINA or B = 20MHz, TA = +25°C
-73
-63
_______________________________________________________________________________________
dB
dBc
dBc
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
(VDD = +3V, OVDD = +2.5V, 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND, REFOUT connected to REFIN through
a 10kΩ resistor, VIN = 2Vp-p (differential with respect to COM), CL = 10pF at digital outputs (Note 5), fCLK = 40MHz, TA = TMIN to
TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
Small-Signal Bandwidth
Full-Power Bandwidth
FPBW
CONDITIONS
MIN
TYP
MAX
UNITS
Input at -20dB FS, differential inputs
500
MHz
Input at -0.5dB FS, differential inputs
400
MHz
Aperture Delay
tAD
1
ns
Aperture Jitter
tAJ
2
psRMS
2
ns
Overdrive Recovery Time
For 1.5 x full-scale input
Differential Gain
±1
%
±0.25
Degrees
0.2
LSBRMS
REFOUT
2.048
±3%
V
TCREF
60
ppm/
°C
1.25
mV/mA
Differential Phase
Output Noise
INA+ = INA- = INB+ = INB- = COM
INTERNAL REFERENCE
Reference Output Voltage
Reference Temperature
Coefficient
Load Regulation
BUFFERED EXTERNAL REFERENCE (VREFIN = +2.048V)
REFIN Input Voltage
VREFIN
2.048
V
Positive Reference Output
Voltage
VREFP
2.012
V
Negative Reference Output
Voltage
VREFN
0.988
V
Differential Reference Output
Voltage Range
∆VREF
REFIN Resistance
RREFIN
>50
MΩ
Maximum REFP, COM
Source Current
ISOURCE
5
mA
Maximum REFP, COM
Sink Current
ISINK
-250
µA
ISOURCE
250
µA
ISINK
-5
mA
Maximum REFN Source Current
Maximum REFN Sink Current
∆VREF = VREFP - VREFN
0.98
1.024
1.07
V
UNBUFFERED EXTERNAL REFERENCE (VREFIN = AGND, reference voltage applied to REFP, REFN, and COM)
REFP, REFN Input Resistance
RREFP,
RREFN
Measured between REFP and COM and
REFN and COM
Differential Reference Input
Voltage Range
∆VREF
∆VREF = VREFP - VREFN
COM Input Voltage Range
4
kΩ
1.024
±10%
V
VCOM
VDD/2
±10%
V
REFP Input Voltage
VREFP
VCOM +
∆VREF/2
V
REFN Input Voltage
VREFN
VCOM ∆VREF/2
V
_______________________________________________________________________________________
3
MAX1183
ELECTRICAL CHARACTERISTICS (continued)
MAX1183
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
ELECTRICAL CHARACTERISTICS (continued)
(VDD = +3V, OVDD = +2.5V, 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND, REFOUT connected to REFIN through
a 10kΩ resistor, VIN = 2Vp-p (differential with respect to COM), CL = 10pF at digital outputs (Note 5), fCLK = 40MHz, TA = TMIN to
TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DIGITAL INPUTS (CLK, PD, OE, SLEEP, T/B)
Input High Threshold
Input Low Threshold
Input Hysteresis
Input Leakage
Input Capacitance
CLK
0.8 x
VDD
PD, OE, SLEEP, T/B
0.8 x
OVDD
VIH
V
CLK
0.2 x
VDD
PD, OE, SLEEP, T/B
0.2 x
OVDD
VIL
VHYST
0.1
V
IIH
VIH = OVDD or VDD (CLK)
±5
IIL
VIL = 0
±5
CIN
V
5
µA
pF
DIGITAL OUTPUTS (D9A–D0A, D9B–D0B)
Output Voltage Low
VOL
ISINK = -200µA
Output Voltage High
VOH
ISOURCE = 200µA
Three-State Leakage Current
ILEAK
OE = OVDD
Three-State Leakage
Capacitance
COUT
OE = OVDD
0.2
OVDD
- 0.2
V
V
±10
5
µA
pF
POWER REQUIREMENTS
Analog Supply Voltage Range
VDD
Output Supply Voltage Range
OVDD
Analog Supply Current
IVDD
IOVDD
PDISS
PSRR
V
1.7
V
3.6
40
60
Sleep mode
2.8
1
Operating, CL = 15pF,
fINA or B = 20MHz at -0.5dB FS
5.8
Sleep mode
100
15
10
Operating, fINA or B = 20MHz at -0.5dB FS
120
180
Sleep mode
8.4
3
mA
µA
mA
2
Shutdown, clock idle, PD = OE = OVDD
Power-Supply Rejection
3.6
2.5
Shutdown, clock idle, PD = OE = OVDD
Power Dissipation
3
Operating, fINA or B = 20MHz at -0.5dB FS
Shutdown, clock idle, PD = OE = OVDD
Output Supply Current
2.7
45
µA
mW
µW
Offset
±0.2
mV/V
Gain
±0.1
%V
TIMING CHARACTERISTICS
CLK Rise to Output Data Valid
Figure 3 (Note 3)
5
Output Enable Time
tENABLE
Figure 4
10
ns
Output Disable Time
tDISABLE
Figure 4
1.5
ns
4
tDO
_______________________________________________________________________________________
8
ns
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
(VDD = +3V, OVDD = +2.5V, 0.1µF and 1.0µF capacitors from REFP, REFN, and COM to GND, REFOUT connected to REFIN through
a 10kΩ resistor, VIN = 2Vp-p (differential with respect to COM), CL = 10pF at digital outputs (Note 5), fCLK = 40MHz, TA = TMIN to
TMAX, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
CLK Pulse Width High
tCH
Figure 3, clock period: 25ns
12.5
±3.8
ns
CLK Pulse Width Low
tCL
Figure 3, clock period: 25ns
12.5
±3.8
ns
Wake up from sleep mode (Note 4)
0.41
Wake up from shutdown (Note 4)
1.5
fINA or B = 20MHz at -0.5dB FS
-70
Wake-Up Time
tWAKE
µs
CHANNEL-TO-CHANNEL MATCHING
Crosstalk
Gain Matching
fINA or B = 20MHz at -0.5dB FS
0.02
Phase Matching
fINA or B = 20MHz at -0.5dB FS
0.25
dB
±0.2
dB
Degrees
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 VIH, VIL. Parameter guaranteed by design.
Note 4: With REFIN driven externally, REFP, COM, and REFN are left floating while powered down.
Note 5: Equivalent dynamic performance is obtainable over full OVDD range with reduced CL.
Typical Operating Characteristics
(VDD = +3V, OVDD = +2.5V, VREFIN = +2.048V, differential input at -0.5dB FS, fCLK = 40.0006MHz, CL ≈ 10pF, TA = +25°C, unless
otherwise noted.)
FFT PLOT CHB (DIFFERENTIAL INPUT,
8192-POINT DATA RECORD)
AMPLITUDE (dB)
-30
-40
-50
-60
HD3
-70
HD2
-80
CHB
fCLK = 40.0005678MHz
fINB = 6.1475482MHz
fINA = 7.524866MHz
AINB = -0.534dB FS
-20
-30
-40
-50
-60
HD3
HD2
-70
0
-80
-20
-40
-50
-70
-90
-90
-100
4
6
8
10 12 14 16 18 20
HD2
-80
-100
ANALOG INPUT FREQUENCY (MHz)
HD3
-60
-90
2
CHA
-30
-100
0
fCLK = 40.0005678MHz
fINA = 24.9661747MHz
fINB = 19.8879776MHz
AINA = -0.552dB FS
-10
MAX1183 toc03
-20
0
-10
AMPLITUDE (dB)
fCLK = 40.0005678MHz
fINA = 7.5342866MHz
fINB = 6.1475482MHz
AINA = -0.498dB FS
AMPLITUDE (dB)
CHA
MAX1183 toc01
0
-10
FFT PLOT CHA (DIFFERENTIAL INPUT,
8192-POINT DATA RECORD)
MAX1183 toc02
FFT PLOT CHA (DIFFERENTIAL INPUT,
8192-POINT DATA RECORD)
0
2
4
6
8
10 12 14 16 18 20
ANALOG INPUT FREQUENCY (MHz)
0
2
4
6
8
10 12 14 16 18 20
ANALOG INPUT FREQUENCY (MHz)
_______________________________________________________________________________________
5
MAX1183
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(VDD = +3V, OVDD = +2.5V, VREFIN = +2.048V, differential input at -0.5dB FS, fCLK = 40.0006MHz, CL ≈ 10pF, TA = +25°C, unless
otherwise noted.)
-40
HD3
-60
-70
-20
-40
-80
-90
-90
IMD2
4
6
8
10 12 14 16 18 20
CHB
58
57
IMD3 IMD2
IMD3
56
55
-100
2
CHA
60
59
fIN1
-60
61
fIN2
-50
-80
0
2
4
6
8
1
10 12 14 16 18 20
10
100
ANALOG INPUT FREQUENCY (MHz)
ANALOG INPUT FREQUENCY (MHz)
ANALOG INPUT FREQUENCY (MHz)
SIGNAL-TO-NOISE + DISTORTION vs.
ANALOG INPUT FREQUENCY
TOTAL HARMONIC DISTORTION vs.
ANALOG INPUT FREQUENCY
SPURIOUS-FREE DYNAMIC RANGE vs.
ANALOG INPUT FREQUENCY
60
80
-68
MAX1183 toc09
-65
MAX1183 toc07
62
MAX1183 toc08
0
CHA
76
CHA
58
CHB
CHB
-71
SFDR (dBc)
THD (dBc)
-74
72
CHB
68
CHA
56
64
-77
60
-80
54
1
10
1
100
10
1
100
10
100
ANALOG INPUT FREQUENCY (MHz)
ANALOG INPUT FREQUENCY (MHz)
FULL-POWER INPUT BANDWIDTH vs.
ANALOG INPUT FREQUENCY, SINGLE-ENDED
SMALL-SIGNAL INPUT BANDWIDTH vs.
ANALOG INPUT FREQUENCY, SINGLE-ENDED
SIGNAL-TO-NOISE RATIO vs.
INPUT POWER (fIN = 19.8879776MHz)
6
6
4
VIN = 100mVp-p
4
60
2
0
-2
0
-2
-4
-4
-6
-6
-8
55
SNR (dB)
GAIN (dB)
2
65
10
100
ANALOG INPUT FREQUENCY (MHz)
1000
50
45
40
-8
1
MAX1183 toc12
MAX1183 toc10
ANALOG INPUT FREQUENCY (MHz)
MAX1183 toc11
SINAD (dB)
-30
-70
HD2
-100
6
fCLK = 40.0005678MHz
fIN1 = 11.606610MHz
fIN2 = 13.383979MHz
AIN = -6.5dB FS
TWO-TONE ENVELOPE =
-0.525dB FS
SNR (dB)
-30
-50
0
-10
AMPLITUDE (dB)
AMPLITUDE (dB)
-20
CHB
SIGNAL-TO-NOISE RATIO vs.
ANALOG INPUT FREQUENCY
MAX1183 toc05
fCLK = 40.0005678MHz
fINA = 24.9661747MHz
fINB = 19.8879776MHz
AINB = -0.525dB FS
MAX1183 toc04
0
-10
TWO-TONE IMD PLOT (DIFFERENTIAL INPUT,
8192-POINT DATA RECORD)
MAX1183 toc06
FFT PLOT CHB (DIFFERENTIAL INPUT,
8192-POINT DATA RECORD)
GAIN (dB)
MAX1183
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
35
1
10
100
ANALOG INPUT FREQUENCY (MHz)
1000
-20
-16
-12
-8
INPUT POWER (dB FS)
_______________________________________________________________________________________
-4
0
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
TOTAL HARMONIC DISTORTION vs.
INPUT POWER (fIN = 19.8879776MHz)
60
80
MAX1183 toc14
-55
MAX1183 toc13
65
SPURIOUS-FREE DYNAMIC RANGE vs.
INPUT POWER (fIN = 19.8879776MHz)
-60
MAX1183 toc15
SIGNAL-TO-NOISE + DISTORTION vs.
INPUT POWER (fIN = 19.8879776MHz)
76
50
SFDR (dBc)
THD (dBc)
SINAD (dB)
55
-65
-70
72
68
45
-75
40
35
64
-80
-12
-8
-4
0
60
-20
-16
INPUT POWER (dB FS)
-4
0
-20
DIFFERENTIAL NONLINEARITY
DNL (LSB)
0.1
0
0
-0.1
-0.1
-0.2
-0.2
-0.3
-4
0.4
0.3
0.2
0.1
CHA
-0.1
0
128 256 384 512 640 768 896 1024
-40
-15
10
35
60
DIGITAL OUTPUT CODE
DIGITAL OUTPUT CODE
TEMPERATURE (°C)
OFFSET ERROR vs. TEMPERATURE
ANALOG SUPPLY CURRENT vs.
ANALOG SUPPLY VOLTAGE
ANALOG SUPPLY CURRENT vs.
TEMPERATURE
0.1
50
MAX1183 toc20
50
MAX1183 toc19
0.2
0
CHB
0
-0.3
128 256 384 512 640 768 896 1024
-8
GAIN ERROR vs. TEMPERATURE
GAIN ERROR (% FS)
0.2
0.1
-12
0.5
MAX1183 toc17
0.2
0
-16
INPUT POWER (dB FS)
0.3
MAX1183 toc16
0.3
46
46
85
-0.1
IVDD (mA)
0
CHB
42
IVDD (mA)
INL (LSB)
-8
INPUT POWER (dB FS)
INTEGRAL NONLINEARITY
(BEST END-POINT FIT)
OFFSET ERROR (% FS)
-12
MAX1183 toc18
-16
MAX1183 toc21
-20
38
42
38
-0.2
34
34
-0.3
CHA
-0.4
30
30
-40
-15
10
35
TEMPERATURE (°C)
60
85
2.70
2.85
3.00
3.15
VDD (V)
3.30
3.45
3.60
-40
-15
10
35
60
85
TEMPERATURE (°C)
_______________________________________________________________________________________
7
MAX1183
Typical Operating Characteristics (continued)
(VDD = +3V, OVDD = +2.5V, VREFIN = +2.048V, differential input at -0.5dB FS, fCLK = 40.0006MHz, CL ≈ 10pF, TA = +25°C, unless
otherwise noted.)
Typical Operating Characteristics (continued)
(VDD = +3V, OVDD = +2.5V, VREFIN = +2.048V, differential input at -0.5dB FS, fCLK = 40.0006MHz, CL ≈ 10pF, TA = +25°C, unless
otherwise noted.)
SFDR, SNR, THD, SINAD vs.
CLOCK DUTY CTCLE
0.3
0.2
fIN = 7.5342866MHz
SFDR
0.1
80
70
THD
SNR
2.0020
60
2.0014
3.00
3.15
3.30
3.45
3.60
1.9990
25
VDD (V)
35
45
55
65
3.00
2.005
3.15
OUTPUT NOISE HISTOGRAM (DC INPUT)
64,515
63,000
56,000
49,000
COUNTS
2.000
1.995
42,000
35,000
28,000
1.990
21,000
14,000
1.985
7,000
1.980
0
-40
-15
10
35
TEMPERATURE (°C)
60
3.30
VDD (V)
70,000
MAX1183 toc25
2.010
8
2.85
CLOCK DUTY CYCLE (%)
INTERNAL REFERENCE VOLTAGE vs.
TEMPERATURE
VREFOUT (V)
2.70
75
MAX1183 toc26
2.85
2.0002
1.9996
40
2.70
2.0008
SINAD
50
0
MAX1183 toc24
0.4
90
VREFOUT (V)
OE = PD = OVDD
SFDR, SNR, THD, SINAD (dB)
MAX1183 toc22
0.5
INTERNAL REFERENCE VOLTAGE vs.
ANALOG SUPPLY VOLTAGE
MAX1183 toc23
ANALOG POWER-DOWN CURRENT vs.
ANALOG POWER SUPPLY
IVDD (µA)
MAX1183
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
85
0
869
N-2
N-1
N
152
0
N+1
N+2
DIGITAL OUTPUT CODE
_______________________________________________________________________________________
3.45
3.60
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
PIN
NAME
1
COM
Common-Mode Voltage Input/Output. Bypass to GND with a ≥0.1µF capacitor.
FUNCTION
2, 6, 11,
14, 15
VDD
Analog Supply Voltage. Bypass to GND with a capacitor combination of 2.2µF in parallel with 0.1µF.
3, 7, 10,
13, 16
GND
Analog Ground
4
INA+
Channel A Positive Analog Input. For single-ended operation connect signal source to INA+.
5
INA-
Channel A Negative Analog Input. For single-ended operation connect INA- to COM.
8
INB-
Channel B Negative Analog Input. For single-ended operation connect INB- to COM.
9
INB+
Channel B Positive Analog Input. For single-ended operation connect signal source to INB+.
12
CLK
Converter Clock Input
17
T/B
T/B Selects the ADC Digital Output Format.
High: Two’s complement.
Low: Straight offset binary.
18
SLEEP
19
PD
Power Down Input.
High: Power-down mode.
Low: Normal operation.
20
OE
Output Enable Input.
High: Digital outputs disabled.
Low: Digital outputs enabled.
21
D9B
Three-State Digital Output, Bit 9 (MSB), Channel B
22
D8B
Three-State Digital Output, Bit 8, Channel B
23
D7B
Three-State Digital Output, Bit 7, Channel B
24
D6B
Three-State Digital Output, Bit 6, Channel B
25
D5B
Three-State Digital Output, Bit 5, Channel B
26
D4B
Three-State Digital Output, Bit 4, Channel B
27
D3B
Three-State Digital Output, Bit 3, Channel B
28
D2B
Three-State Digital Output, Bit 2, Channel B
29
D1B
Three-State Digital Output, Bit 1, Channel B
30
D0B
Three-State Digital Output, Bit 0 (LSB), Channel B
31, 34
OGND
Output Driver Ground.
32, 33
OVDD
Output Driver Supply Voltage. Bypass to OGND with a capacitor combination of 2.2µF in parallel with
0.1µF.
35
D0A
Three-State Digital Output, Bit 0 (LSB), Channel A
36
D1A
Three-State Digital Output, Bit 1, Channel A
37
D2A
Three-State Digital Output, Bit 2, Channel A
38
D3A
Three-State Digital Output, Bit 3, Channel A
39
D4A
Three-State Digital Output, Bit 4, Channel A
40
D5A
Three-State Digital Output, Bit 5, Channel A
Sleep Mode Input.
High: Deactivates the two ADCs, but leaves the reference bias circuit active.
Low: Normal operation.
_______________________________________________________________________________________
9
MAX1183
Pin Description
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
MAX1183
Pin Description (continued)
PIN
NAME
FUNCTION
41
D6A
Three-State Digital Output, Bit 6, Channel A
42
D7A
Three-State Digital Output, Bit 7, Channel A
43
D8A
Three-State Digital Output, Bit 8, Channel A
44
D9A
Three-State Digital Output, Bit 9 (MSB), Channel A
Internal Reference Voltage Output. May be connected to REFIN through a resistor or a resistor
divider.
45
REFOUT
46
REFIN
Reference Input. VREFIN = 2 ✕ (VREFP - VREFN). Bypass to GND with a >1nF capacitor.
47
REFP
Positive Reference Input/Output. Conversion range is ±(VREFP - VREFN).
Bypass to GND with a > 0.1µF capacitor.
48
REFN
Negative Reference Input/Output. Conversion range is ±(VREFP - VREFN).
Bypass to GND with a > 0.1µF capacitor.
Detailed Description
The MAX1183 uses a nine-stage, fully differential,
pipelined architecture (Figure 1) that allows for highspeed conversion while minimizing power consumption. Samples taken at the inputs move progressively
through the pipeline stages every half-clock cycle.
Including the delay through the output latch, the total
clock-cycle latency is five clock cycles.
One-and-a-half bit (2-comparator) flash ADCs convert
the held-input voltages into a digital code. The digitalVIN
Σ
T/H
FLASH
ADC
x2
to-analog converters (DACs) convert the digitized
results back into analog voltages, which are then subtracted from the original held-input signals. The resulting error signals are then multiplied by two, and the
residues are passed along to the next pipeline stages
where the process is repeated until the signals have
been processed by all nine stages. Digital error correction compensates for ADC comparator offsets in each
of these pipeline stages and ensures no missing
codes.
VIN
VOUT
Σ
T/H
FLASH
ADC
DAC
1.5 BITS
x2
VOUT
DAC
1.5 BITS
2-BIT FLASH
ADC
STAGE 1
STAGE 2
STAGE 8
2-BIT FLASH
ADC
STAGE 9
STAGE 1
DIGITAL CORRECTION LOGIC
T/H
VINA
10
D9A–D0A
STAGE 2
STAGE 8
DIGITAL CORRECTION LOGIC
T/H
VINB
10
D9B–D0B
VINA = INPUT VOLTAGE BETWEEN INA+ AND INA- (DIFFERENTIAL OR SINGLE ENDED)
VINB = INPUT VOLTAGE BETWEEN INB+ AND INB- (DIFFERENTIAL OR SINGLE ENDED)
Figure 1. Pipelined Architecture—Stage Blocks
10
______________________________________________________________________________________
STAGE 9
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
COM
S5a
S2a
C1a
S3a
S4a
INA+
OUT
C2a
S1
OUT
INAS4b
C2b
C1b
S3b
S5b
S2b
INTERNAL
BIAS
COM
HOLD
INTERNAL
BIAS
CLK
HOLD
TRACK
COM
TRACK
S5a
S2a
C1a
S3a
S4a
INB+
OUT
S1
OUT
INBS4b
MAX1183
C2b
C1b
S3b
S2b
INTERNAL
BIAS
The full-scale range of the MAX1183 is determined by
the internally generated voltage difference between
REFP (V DD /2 + V REFIN /4) and REFN (V DD /2 VREFIN/4). The full-scale range for both on-chip ADCs is
adjustable through the REFIN pin, which is provided for
this purpose. REFOUT, REFP, COM (VDD/2), and REFN
are internally buffered low-impedance outputs. The
MAX1183 provides three modes of reference operation:
• Internal reference mode
S5b
COM
INTERNAL
NONOVERLAPPING
CLOCK SIGNALS
In internal reference mode, connect the internal reference output REFOUT to REFIN through a resistor (e.g.,
10kΩ) or resistor divider, if an application requires a
reduced full-scale range. For stability and noise filtering
purposes, bypass REFIN with a >10nF capacitor to
GND. In internal reference mode, REFOUT, COM, REFP,
and REFN become low-impedance outputs.
In buffered external reference mode, adjust the reference voltage levels externally by applying a stable and
accurate voltage at REFIN. In this mode, COM, REFP,
and REFN become outputs. REFOUT may be left open
or connected to REFIN through a >10kΩ resistor.
In unbuffered external reference mode, connect REFIN
to GND. This deactivates the on-chip reference buffers
for REFP, COM, and REFN. With their buffers shut
down, these nodes become high impedance and may
be driven through separate, external reference
sources.
Clock Input (CLK)
C2a
S4c
Analog Inputs and Reference
Configurations
• Buffered external reference mode
• Unbuffered external reference mode
INTERNAL
BIAS
S4c
bandwidth T/H amplifiers allow the MAX1183 to track
and sample/hold analog inputs of high frequencies (>
Nyquist). Both ADC inputs (INA+, INB+, INA- and INB-)
can be driven either differentially or single ended.
Match the impedance of INA+ and INA-, as well as
INB+ and INB- and set the common-mode voltage to
midsupply (VDD/2) for optimum performance.
The MAX1183’s CLK input accepts CMOS-compatible
clock signals. Since the interstage conversion of the
device depends on the repeatability of the rising and
falling edges of the external clock, use a clock with low
jitter and fast rise and fall times (<2ns). In particular,
sampling occurs on the rising edge of the clock signal,
requiring this edge to provide lowest possible jitter. Any
significant aperture jitter would limit the SNR performance of the on-chip ADCs as follows:
Figure 2. MAX1183 T/H Amplifiers
______________________________________________________________________________________
11
MAX1183
Input Track-and-Hold (T/H) Circuits
Figure 2 displays a simplified functional diagram of the
input track-and-hold (T/H) circuits in both track-andhold mode. In track mode, switches S1, S2a, S2b, S4a,
S4b, S5a, and S5b are closed. The fully differential circuits sample the input signals onto the two capacitors
(C2a and C2b) through switches S4a and S4b. S2a and
S2b set the common mode for the amplifier input, and
open simultaneously with S1, sampling the input waveform. Switches S4a and S4b are then opened before
switches S3a and S3b connect capacitors C1a and
C1b to the output of the amplifier and switch S4c is
closed. The resulting differential voltages are held on
capacitors C2a and C2b. The amplifiers are used to
charge capacitors C1a and C1b to the same values
originally held on C2a and C2b. These values are then
presented to the first stage quantizers and isolate the
pipelines from the fast-changing inputs. The wide input
MAX1183
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
Digital Output Data, Output Data Format
Selection (T/B), Output Enable (OE)
SNRdB = 20 ✕ log10 (1 / [2π ✕ fIN ✕ tAJ])
where fIN represents the analog input frequency and
tAJ is the time of the aperture jitter.
Clock jitter is especially critical for undersampling
applications. The clock input should always be considered as an analog input and routed away from any analog input or other digital signal lines.
The MAX1183 clock input operates with a voltage threshold set to VDD/2. Clock inputs with a duty cycle other
than 50% must meet the specifications for high and low
periods as stated in the Electrical Characteristics.
All digital outputs, D0A–D9A (Channel A) and
D0B–D9B (Channel B) are TTL/CMOS-logic compatible. There is a five-clock-cycle latency between any
particular sample and its corresponding output data.
The output coding can be chosen to be either straight
offset binary or two’s complement (Table 1) controlled
by a single pin (T/B). Pull T/B low to select offset binary
and high to activate two’s complement output coding.
The capacitive load on the digital outputs D0A–D9A
and D0B–D9B should be kept as low as possible
(<15pF) to avoid large digital currents that could feed
back into the analog portion of the MAX1183, thereby
degrading its dynamic performance. Using buffers on
the digital outputs of the ADCs can further isolate the
digital outputs from heavy capacitive loads. To further
improve the dynamic performance of the MAX1183
small series resistors (e.g., 100Ω) may be added to the
digital output paths, close to the MAX1183.
System Timing Requirements
Figure 3 depicts the relationship between the clock
input, analog input, and data output. The MAX1183
samples at the rising edge of the input clock. Output
data for channels A and B is valid on the next rising
edge of the input clock. The output data has an internal
latency of five clock cycles. Figure 4 also determines
the relationship between the input clock parameters
and the valid output data on channels A and B.
5-CLOCK-CYCLE LATENCY
N
N+1
N+2
N+3
N+4
N+5
N+6
ANALOG INPUT
CLOCK INPUT
tDO
tCH
tCL
DATA OUTPUT
D9A–D0A
N-6
N-5
N-4
N-3
N-2
N-1
N
N+1
DATA OUTPUT
D9B–D0B
N-6
N-5
N-4
N-3
N-2
N-1
N
N+1
Figure 3. System Timing Diagram
12
______________________________________________________________________________________
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
application. For the application in Figure 5, a RISO of
50Ω is placed before the capacitive load to prevent
ringing and oscillation. The 22pF CIN capacitor acts as
a small bypassing capacitor.
Using Transformer Coupling
OE
tENABLE
OUTPUT
D9A–D0A
HIGH-Z
OUTPUT
D9B–D0B
HIGH-Z
tDISABLE
HIGH-Z
VALID DATA
HIGH-Z
VALID DATA
Figure 4. Output Timing Diagram
Power-Down (PD) and Sleep
(SLEEP) Modes
The MAX1183 offers two power-save modes—sleep
and full power-down modes. In sleep mode (SLEEP =
1), only the reference bias circuit is active (both ADCs
are disabled), and current consumption is reduced to
2.8mA. To enter full power-down mode, pull PD high.
With OE simultaneously low, all outputs are latched at
the last value prior to the power-down. Pulling OE high
forces the digital outputs into a high-impedance state.
An RF transformer (Figure 6) provides an excellent
solution to convert a single-ended source signal to a
fully differential signal, required by the MAX1183 for
optimum performance. Connecting the center tap of the
transformer to COM provides a VDD/2 DC level shift to
the input. Although a 1:1 transformer is shown, a stepup transformer may be selected to reduce the drive
requirements. A reduced signal swing from the input
driver, such as an op amp, may also improve the overall distortion.
In general, the MAX1183 provides better SFDR and
THD with fully differential input signals than singleended drive, especially for very high input frequencies.
In differential input mode, even-order harmonics are
lower as both inputs (INA+, INA- and/or INB+, INB-) are
balanced, and each of the ADC inputs only requires
half the signal swing compared to single-ended mode.
Single-Ended AC-Coupled Input Signal
Figure 7 shows an AC-coupled, single-ended application. Amplifiers like the MAX4108 provide high speed,
high bandwidth, low noise, and low distortion to maintain the integrity of the input signal.
Applications Information
Typical QAM Demodulation Application
Figure 5 depicts a typical application circuit containing
two single-ended to differential converters. The internal
reference provides a VDD/2 output voltage for levelshifting purposes. The input is buffered and then split
to a voltage follower and inverter. One lowpass filter per
ADC suppresses some of the wideband noise associated with high-speed operational amplifiers, follows the
amplifiers. The user may select the RISO and CIN values to optimize the filter performance to suit a particular
The most frequently used modulation technique for digital communications applications is probably the quadrature amplitude modulation (QAM). Typically found in
spread-spectrum-based systems, a QAM signal represents a carrier frequency modulated in both amplitude
and phase. At the transmitter, modulating the baseband signal with quadrature outputs, a local oscillator
followed by subsequent up conversion can generate
the QAM signal. The result is an in-phase (I) and a
Table 1. MAX1183 Output Codes for Differential Inputs
DIFFERENTIAL INPUT
VOLTAGE*
DIFFERENTIAL INPUT
STRAIGHT OFFSET BINARY
T/B = 0
TWO'S COMPLEMENT
T/B = 1
VREF x 511/512
+FULL SCALE - 1LSB
11 1111 1111
01 1111 1111
VREF x 1/512
+ 1LSB
10 0000 0001
00 0000 0001
00 0000 0000
0
Bipolar Zero
10 0000 0000
- VREF x 1/512
- 1LSB
01 1111 1111
11 1111 1111
-VREF x 512/512
-FULL SCALE +1LSB
00 0000 0001
10 0000 0001
-VREF x 512/512
-FULL SCALE
00 0000 0000
10 0000 0000
*VREF = VREFP - VREFN
______________________________________________________________________________________
13
MAX1183
Figure 4 displays the timing relationship between output enable and data output valid, as well as powerdown/wake-up and data output valid.
MAX1183
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
+5V
0.1µF
LOWPASS FILTER
INA+
MAX4108
RIS0
50Ω
0.1µF
300Ω
CIN
22pF
0.1µF
-5V
600Ω
600Ω
300Ω
COM
0.1µF
+5V
+5V
0.1µF
600Ω
INPUT
0.1µF
LOWPASS FILTER
MAX4108
300Ω
-5V
0.1µF
INA-
MAX4108
RIS0
50Ω
300Ω
CIN
22pF
0.1µF
-5V
300Ω
300Ω
+5V
600Ω
MAX1183
0.1µF
LOWPASS FILTER
INB+
MAX4108
RIS0
50Ω
0.1µF
300Ω
CIN
22pF
0.1µF
-5V
600Ω
600Ω
300Ω
0.1µF
+5V
+5V
0.1µF
600Ω
INPUT
0.1µF
LOWPASS FILTER
MAX4108
300Ω
-5V
0.1µF
INB-
MAX4108
RIS0
50Ω
300Ω
-5V
CIN
22pF
0.1µF
300Ω
300Ω
600Ω
Figure 5. Typical Application for Single-Ended to Differential Conversion
14
______________________________________________________________________________________
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
MAX1183
REFP
25Ω
INA+
22pF
VIN
0.1µF
1
VIN
N.C.
T1
3
1kΩ RISO
50Ω
INA+
MAX4108
6
100Ω
5
2
0.1µF
CIN
22pF
1kΩ
COM
2.2µF
4
COM
REFN
0.1µF
MINICIRCUITS
TT1–6
0.1µF
RISO
50Ω
INA-
100Ω
CIN
22pF
25Ω
INAREFP
22pF
MAX1183
25Ω
VIN
0.1µF
MAX1183
1kΩ RISO
50Ω
INB+
INB+
MAX4108
22pF
100Ω
CIN
22pF
1kΩ
0.1µF
1
VIN
N.C.
T1
6
REFN
2
5
3
4
2.2µF
100Ω
0.1µF
0.1µF
RISO
50Ω
INBCIN
22pF
MINICIRCUITS
TT1–6
25Ω
INB22pF
Figure 6. Transformer-Coupled Input Drive
quadrature (Q) carrier component, where the Q component is 90-degree phase-shifted with respect to the inphase component. At the receiver, the QAM signal is
divided down into its I and Q components, essentially
representing the modulation process reversed. Figure 8
displays the demodulation process performed in the
analog domain, using the dual matched +3V, 10-bit
ADC MAX1183 and the MAX2451 quadrature demodulator to recover and digitize the I and Q baseband signals. Before being digitized by the MAX1183, the
mixed-down signal components may be filtered by
matched analog filters, such as Nyquist or pulse-shaping filters, which remove any unwanted images from the
mixing process, thereby enhancing the overall SNR
performance and minimizing intersymbol interference.
Figure 7. Using an Op Amp for Single-Ended, AC-Coupled
Input Drive
Grounding, Bypassing, and
Board Layout
The MAX1183 requires high-speed board layout design
techniques. Locate all bypass capacitors as close to
the device as possible, preferably on the same side as
the ADC, using surface-mount devices for minimum
inductance. Bypass VDD, REFP, REFN, and COM with
two parallel 0.1µF ceramic capacitors and a 2.2µF
bipolar capacitor to GND. Follow the same rules to
bypass the digital supply (OVDD) to OGND. 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 the analog ground (GND) and the
digital output driver ground (OGND) 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 ideal
location of this connection can be determined experimentally at a point along the gap between the two
ground planes, which produces optimum results. Make
this connection with a low-value, surface-mount resistor
______________________________________________________________________________________
15
MAX1183
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
MAX2451
INA+
INA0°
90°
DSP
POSTPROCESSING
MAX1183
INB+
INB-
DOWNCONVERTER
÷8
Figure 8. Typical QAM Application, Using the MAX1183
(1Ω to 5Ω), a ferrite bead, or a direct short.
Alternatively, all ground pins could share the same
ground plane, if the ground plane is sufficiently isolated
from any noisy, digital systems ground plane (e.g.
downstream output buffer or DSP ground plane). Route
high-speed digital signal traces away from the sensitive
analog traces of either channel. Make sure to isolate
the analog input lines to each respective converter to
minimize channel-to-channel crosstalk. Keep all signal
lines short and free of 90 degree turns.
CLK
ANALOG
INPUT
tAD
tAJ
SAMPLED
DATA (T/H)
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 endpoints of the transfer function, once
offset and gain errors have been nullified. The static linearity parameters for the MAX1183 are measured using
the best straight-line fit method.
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.
Dynamic Parameter
Definitions
Aperture Jitter
Figure 9 depicts the aperture jitter (tAJ), which is the
sample-to-sample variation in the aperture delay.
16
T/H
TRACK
HOLD
TRACK
Figure 9. T/H Aperture Timing
Aperture Delay
Aperture delay (tAD) is the time defined between the
falling edge of the sampling clock and the instant when
an actual sample is taken (Figure 9).
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 quantization
error only and results directly from the ADCs resolution
(N-Bits):
SNRdB[max] = 6.02dB ✕ N + 1.76dB
In reality, there are other noise sources besides quantization noise: thermal noise, reference noise, clock jitter,
etc. SNR is computed by taking the ratio of the rms signal to the rms noise, which includes all spectral compo-
______________________________________________________________________________________
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
Signal-to-Noise Plus Distortion (SINAD)
SINAD is computed by taking the ratio of the RMS signal to all spectral components minus the fundamental
and the DC offset.
Effective Number of Bits (ENOB)
ENOB specifies the dynamic performance of an ADC at
a specific input frequency and sampling rate. An ideal
ADC’s error consists of quantization noise only. ENOB
is computed from:
(SINADdB − 1.76dB )
ENOB =
6.02dB
where V1 is the fundamental amplitude, and V2 through
V5 are the amplitudes of the 2nd- through 5th-order
harmonics.
Spurious-Free Dynamic Range (SFDR)
SFDR is the ratio expressed in decibels of the RMS
amplitude of the fundamental (maximum signal component) to the RMS value of the next-largest spurious
component, excluding DC offset.
Intermodulation Distortion (IMD)
The two-tone IMD is the ratio expressed in decibels of
either input tone to the worst 3rd-order (or higher) intermodulation products. The individual input tone levels
are at -6.5dB full scale and their envelope is at -0.5dB
full scale.
Chip Information
Total Harmonic Distortion (THD)
THD is typically the ratio of the RMS sum of the first four
harmonics of the input signal to the fundamental itself.
This is expressed as:
  2
2
2
2
  V2 + V3 + V4 + V5 
THD = 20 × log10 
V1



TRANSISTOR COUNT: 10,811
PROCESS: CMOS






Functional Diagram
VDD
OGND
OVDD
GND
INA+
PIPELINE
ADC
T/H
10
DEC
OUTPUT
DRIVERS
10
D9A–D0A
INA-
CONTROL
CLK
OE
INB+
T/H
PIPELINE
ADC
10
DEC
OUTPUT
DRIVERS
10
D9B–D0B
INB-
REFERENCE
MAX1183
T/B
PD
SLEEP
REFOUT
REFN COM REFP
REFIN
______________________________________________________________________________________
17
MAX1183
nents minus the fundamental, the first five harmonics,
and the DC offset.
Dual 10-Bit, 40Msps, +3V, Low-Power ADC with
Internal Reference and Parallel Outputs
48L,TQFP.EPS
MAX1183
Package Information
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.
18 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.