MAXIM MAX1181 User Manual

General Description

The MAX1181 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 MAX1181 is optimized for low-power,
high-dynamic performance applications in imaging,
instrumentation, and digital communication applica­tions. The MAX1181 operates from a single 2.7V to 3.6V
supply, consuming only 246mW, while delivering a typi­cal signal-to-noise ratio (SNR) of 59dB at an input fre­quency of 20MHz and a sampling rate of 80Msps. 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 MAX1181 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 the internal or external
reference, if desired for applications requiring
increased accuracy or a different input voltage range.

The MAX1181 features parallel, CMOS-compatible
three-state outputs. The digital output format is 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 MAX1181 is available in a 7mm ✕ 7mm, 48-pin
TQFP package, and is specified for the extended
industrial (-40°C to +85°C) temperature range.

Pin-compatible higher and lower speed versions of the
MAX1181 are also available. Please refer to the
MAX1180 datasheet for 105Msps, the MAX1182
datasheet for 65Msps, the MAX1183 datasheet for
40Msps, and the MAX1184 datasheet for 20Msps. In
addition to these speed grades, this family includes a
20Msps multiplexed output version (MAX1185), for
which digital data is presented time-interleaved on a
single, parallel 10-bit output port.

Applications

High-Resolution Imaging

I/Q Channel Digitization

Multichannel IF Undersampling

Instrumentation

Video Application

Features

♦ Single 3V Operation

♦ Excellent Dynamic Performance

59dB SNR at fIN= 20MHz
73dB SFDR at fIN= 20MHz

♦ Low Power

82mA (Normal Operation)

2.8mA (Sleep Mode)
1µA (Shutdown Mode)

♦ 0.02dB Gain and 0.25° Phase Matching (typ)

♦ Wide ±1V

P-P

Differential Analog Input Voltage

Range

♦ 400MHz, -3dB Input Bandwidth

♦ On-Chip 2.048V Precision Bandgap Reference

♦ User-Selectable Output Format—Two’s

Complement or Offset Binary

♦ 48-Pin TQFP Package with Exposed Pad for

Improved Thermal Dissipation

♦ Evaluation Kit Available

MAX1181

Dual 10-Bit, 80Msps, 3V, Low-Power ADC

with Internal Reference and Parallel Outputs

________________________________________________________________ Maxim Integrated Products 1

D1A
D0A
OGND
OV

DD

OV

DD

OGND
D0B
D1B
D2B
D3B
D4B
D5B

COM

V

DD

GND
INA+
INA-

V

DD

GND
INB­INB+
GND

V

DD

CLK

1

2

3

4

5

6

7

8

9

10

11

12

36

35

34

33

32

31

30

29

28

27

26

25

48 TQFP-EP

MAX1181

GND

V

DD

GND

V

DD

T/B

SLEEP

PD

OE

D9B

D8B

D7B

D6B

1314151617181920212223

24

4847464544434241403938

37

REFN

REFP

REFIN

REFOUT

D9A

D8A

D7A

D6A

D5A

D4A

D3A

D2A

EP*

NOTE: THE PIN 1 INDICATOR FOR LEAD-FREE PACKAGES IS REPLACED
BY A "+" SIGN.

Pin Configuration

Ordering Information

19-2093; Rev 1; 2/07

EVALUATION KIT

AVAILABLE

PART TEMP RANGE PIN-PACKAGE

MAX1181ECM -40°C to +85°C 48 TQFP-EP*

-40°C to +85°C 48 TQFP-EP*

Functional Diagram appears at end of data sheet.

*EP = Exposed paddle.
+Denotes a lead-free package.

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim's website at www.maxim-ic.com.

MAX1181ECM+

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, V

IN

= 2V

P-P

(differential with respect to COM), CL= 10pF at digital outputs (Note 1), f

CLK

= 83.333MHz, TA= T

MIN

to

T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

MAX1181

Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

VDD, OVDDto GND ...............................................-0.3V to +3.6V

OGND to GND.......................................................-0.3V to +0.3V

INA+, INA-, INB+, INB- to GND ...............................-0.3V to V

DD

REFIN, REFOUT, REFP, REFN, CLK,

COM to GND ...........................................-0.3V to (V

DD

+ 0.3V)

OE, PD, SLEEP, T/B, D9A–D0A,

D9B–D0B to OGND ..............................-0.3V to (OV

DD

+ 0.3V)

Continuous Power Dissipation (T

A

= +70°C)

48-Pin TQFP-EP (derate 30.4mW/°C above +70°C) ...2430mW

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

PARAMETER

CONDITIONS

UNITS

DC ACCURACY

Resolution 10 Bits

Integral Nonlinearity INL fIN = 7.47MHz

LSB

Differential Nonlinearity DNL

LSB

Offset Error -2 +2

% FS

Gain Error 0 ±2

% FS

ANALOG INPUT

Differential Input Voltage Range

V

DIFF

Differential or single-ended inputs

V

Common-Mode Input Voltage
Range

V

CM

VDD/2

V

Input Resistance R

IN

Switched capacitor load 25 kΩ

Input Capacitance C

IN

5pF

CONVERSION RATE

Maximum Clock Frequency f

CLK

80

MHz

Data Latency 5

Clock

Cycles

DYNAMIC CHARACTERISTICS

f

INA or B

= 7.47MHz, TA = +25°C

f

INA or B

= 20MHz, TA = +25°C5659

Signal-to-Noise Ratio
(Note 3)

SNR

f

INA or B

= 39.9MHz 59

dB

f

INA or B

= 7.47MHz, TA = +25°C5659

f

INA or B

= 20MHz, TA = +25°C

Signal-to-Noise And Distortion
(Note 3)

f

INA or B

= 39.9MHz

dB

f

INA or B

= 7.47MHz, TA = +25°C6575

f

INA or B

= 20MHz, TA = +25°C6473

Spurious-Free Dynamic
Range (Note 3)

SFDR

fINA or B

= 39.9MHz 71

dBc

f

INA or B

= 7.47MHz -76

f

INA or B

= 20MHz -76

Third-Harmonic Distortion
(Note 3)

HD3

f

INA or B

= 39.9MHz -75

dBc

SYMBOL

fIN = 7.47MHz, no missing codes guaranteed ±0.4 ±1.0

MIN TYP MAX

±0.6 ±2.2

SINAD

±1.0

± 0.5

56.5 59.5

55.3 58.5

58.5

MAX1181

Dual 10-Bit, 80Msps, 3V, Low-Power ADC

with Internal Reference and Parallel Outputs

_______________________________________________________________________________________ 3

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, V

IN

= 2V

P-P

(differential with respect to COM), CL= 10pF at digital outputs (Note 1), f

CLK

= 83.333MHz, TA= T

MIN

to

T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

PARAMETER

CONDITIONS

UNITS

f

INA or B

= 7.47MHz, TA = +25°C

f

INA or B

= 20MHz, TA = +25°C

Total Harmonic Distortion
(First Four Harmonics) (Note 3)

THD

f

INA or B

= 39.9MHz

dBc

Intermodulation Distortion
(First Five Odd-Order IMDs)

IMD

f

INA or B

= 38.1546MHz at -6.5dBFS

f

INA or B

= 41.9532MHz at -6.5dBFS

(Note 4)

dBc

Small-Signal Bandwidth Input at -20dBFS, differential inputs

MHz

Full-Power Bandwidth FPBW Input at -0.5dBFS, differential inputs

MHz

Aperture Delay t

AD

1ns

Aperture Jitter t

AJ

2ps

RMS

Overdrive Recovery Time For 1.5 x full-scale input 2 ns

Differential Gain

%

Differential Phase

degrees

Output Noise INA+ = INA- = INB+ = INB- = COM

LSB

RMS

INTERNAL REFERENCE

Reference Output Voltage

V

Reference Temperature
Coefficient

ppm/°C

Load Regulation

mV/mA

BUFFERED EXTERNAL REFERENCE (V

REFIN

= 2.048V)

REFIN Input Voltage

V

Positive Reference Output
Voltage

V

REFP

V

Negative Reference Output
Voltage

V

Differential Reference Output
Voltage Range

ΔV

REF

= V

REFP

- V

REFN

V

REFIN Resistance

MΩ

Maximum REFP, COM Source
Current

mA

Maximum REFP, COM Sink
Current

I

SINK

µA

Maximum REFN Source Current

µA

Maximum REFN Sink Current I

SINK

mA

UNBUFFERED EXTERNAL REFERENCE (V

REFIN

= AGND, reference voltage applied to REFP, REFN and COM )

REFP, REFN Input Resistance

,

Measured between REFP and COM and
REFN and COM

4kΩ

SYMBOL

REFOUT

TC

REF

V

REFIN

MIN TYP MAX

-73 -64

-70 -63

-70

-73.5

500

400

±1

±0.25

0.2

2.048
±3%

60

1.25

2.048

V

REFN

ΔV

REF

R

REFIN

I

SOURCE

I

SOURCE

R

REFP

R

REFN

2.012

0.988

0.95 1.024 1.10

> 50

> 5

250

250

> 5

MAX1181

Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs

4 _______________________________________________________________________________________

PARAMETER

CONDITIONS

UNITS

Differential Reference Input
Voltage

ΔV

REF

= V

REFP

- V

REFN

1.024

± 10%

V

COM Input Voltage V

COM

V

DD

/ 2

± 10%

V

REFP Input Voltage V

REFP

V

COM

+ ΔV

REF

/ 2

V

REFN Input Voltage

V

COM

- ΔV

REF

/ 2

V

DIGITAL INPUTS (CLK, PD, OE, SLEEP, T/B)

CLK

0.8 x

Input High Threshold V

IH

PD, OE, SLEEP, T/B

0.8 x

V

CLK

0.2 x

Input Low Threshold V

IL

PD, OE, SLEEP, T/B

0.2 x

V

Input Hysteresis V

HYST

0.1 V

I

IH

V

IH

= OV

DD

or V

DD

(CLK) ±5

Input Leakage

I

IL

VIL = 0 ±5

µA

Input Capacitance C

IN

5pF

DIGITAL OUTPUTS (D9A–D0A, D9B–D0B)

Output-Voltage Low V

OL

I

SINK

= 200µA 0.2 V

Output-Voltage High V

OH

I

SOURCE

= 200µA

OV

DD

V

Three-State Leakage Current I

LEAK

OE = OV

DD

µA

C

OUT

OE = OV

DD

5pF

POWER REQUIREMENTS

Analog Supply Voltage Range V

DD

2.7 3.0 3.6 V

Output Supply Voltage Range OV

DD

1.7 2.5 3.6 V

Operating, f

INA or B

= 20MHz at -0.5dBFS 82 97

Sleep mode 2.8

mA

Analog Supply Current I

VDD

Shutdown, clock idle, PD = OE = OV

DD

115µA

-0.5dBFS

13 mA

Sleep mode 100

Output Supply Current I

OVDD

Shutdown, clock idle, PD = OE = OV

DD

210

µA

Operating, f

INA or B

= 20MHz at -0.5dBFS 246

mW

Sleep mode 8.4Power Dissipation
Shutdown, clock idle, PD = OE = OV

DD

345

µW

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, V

IN

= 2V

P-P

(differential with respect to COM), CL= 10pF at digital outputs (Note 1), f

CLK

= 83.333MHz, TA= T

MIN

to

T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

SYMBOL

ΔV

REF

MIN TYP MAX

Three-State Output Capacitance

OV

- 0.2

V

DD

DD

V

REFN

V

DD

OV

DD

±10

Operating, CL = 15pF , f

INA or B

= 20MHz at

PDISS

291

MAX1181

Dual 10-Bit, 80Msps, 3V, Low-Power ADC

with Internal Reference and Parallel Outputs

_______________________________________________________________________________________ 5

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0

010155 2025303540

FFT PLOT CHA (8192-POINT RECORD,

DIFFERENTIAL INPUT)

MAX1181 toc01

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

f

INA

= 6.0449MHz

f

INB

= 7.5099MHz

f

CLK

= 80.0006MHz

A

INA

= -0.46dBFS

CHA

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0

010155 2025303540

FFT PLOT CHB (8192-POINT RECORD,

DIFFERENTIAL INPUT)

MAX1181 toc02

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

f

INA

= 6.0449MHz

f

INB

= 7.5099MHz

f

CLK

= 80.0006MHz

A

INB

= -0.52dBFS

CHB

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0

010155 2025303540

FFT PLOT CHA (8192-POINT RECORD,

DIFFERENTIAL INPUT)

MAX1181 toc03

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

f

INA

= 19.9123MHz

f

INB

= 24.9123MHz

f

CLK

= 80.0006MHz

A

INA

= -0.52dBFS

CHA

Typical Operating Characteristics

(VDD= 3V, OVDD= 2.5V, internal reference, differential input at -0.5dBFS, f

CLK

= 80.0006MHz, CL≈ 10pF. TA= +25°C, unless other-

wise noted.)

PARAMETER

CONDITIONS

UNITS

Offset

mV/V

Power Supply Rejection PSRR

Gain

%/V

TIMING CHARACTERISTICS

CLK Rise to Output Data Valid t

DO

Figure 3 (Note 5) 5 8 ns

Output Enable Time

Figure 4

ns

Output Disable Time

Figure 4

ns

CLK Pulse-Width High t

CH

Figure 3 clock period: 12ns

ns

CLK Pulse-Width Low t

CL

Figure 3 clock period: 12ns

ns

Wakeup from sleep mode

Wake-Up Time (Note 6) t

WAKE

Wakeup from shutdown

µs

CHANNEL-TO-CHANNEL MATCHING

Crosstalk f

INA or B

= 20MHz at -0.5dBFS

dB

Gain Matching f

INA or B

= 20MHz at -0.5dBFS

dB

Phase Matching f

INA or B

= 20MHz at -0.5dBFS

degrees

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, V

IN

= 2V

P-P

(differential with respect to COM), CL= 10pF at digital outputs (Note 1), f

CLK

= 83.333MHz, TA= T

MIN

to

T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Note 2)

Note 1: Equivalent dynamic performance is obtainable over full OVDDrange with reduced CL.
Note 2: Specifications at ≥ +25°C are guaranteed by production test and < +25°C are guaranteed by design and characterization.
Note 3: SNR, SINAD, THD, SFDR, and HD3 are based on an analog input voltage of -0.5dBFS, referenced to a +1.024V full-scale

input voltage range.

Note 4: Intermodulation distortion is the total power of the intermodulation products relative to the individual carrier. This number is

6dB or better, if referenced to the two-tone envelope.

Note 5: Digital outputs settle to V

IH

, VIL. Parameter guaranteed by design.

Note 6: With REFIN driven externally, REFP, COM, and REFN are left floating while powered down.

SYMBOL

t

ENABLE

t

DISABLE

MIN TYP MAX

±0.2

±0.1

10

1.5

6 ±1

6 ±1

0.28

1.5

-70

0.02 ±0.2

0.25

MAX1181

Dual 10-Bit, 80Msps, 3V, Low-Power ADC
with Internal Reference and Parallel Outputs

6 _______________________________________________________________________________________

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0

010155 2025303540

FFT PLOT CHB (8192-POINT RECORD,

DIFFERENTIAL INPUT)

MAX1181 toc04

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

f

INA

= 19.9123MHz

f

INB

= 24.9123MHz

f

CLK

= 80.0006MHz

A

INB

= -0.53dBFS

CHB

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0

010155 2025303540

FFT PLOT CHA (8192-POINT RECORD,

DIFFERENTIAL INPUT)

MAX1181 toc05

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

f

INA

= 40.4202MHz

f

INB

= 47.0413MHz

f

CLK

= 80.0006MHz

A

INA

= -0.52dBFS

CHA

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0

010155 2025303540

FFT PLOT CHB (8192-POINT RECORD,

DIFFERENTIAL INPUT)

MAX1181 toc06

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

f

INA

= 40.4202MHz

f

INB

= 47.0413MHz

f

CLK

= 80.0006MHz

A

INB

= -0.53dBFS

CHB

-100

-80

-90

-60

-70

-40

-50

-30

-10

-20

0

010155 2025303540

TWO-TONE IMD PLOT (8192-POINT RECORD,

COHERENT SAMPLING)

MAX1181 toc07

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

f

IN1

= 38.1546MHz

f

IN2

= 41.9632MHz

f

CLK

= 80.0006MHz

A

IN1

= A

IN2

= -6dBFS

2nd ORDER IMD

f

IN1

f

IN2

55

58

57

56

59

60

61

0403010 20 50 60 70 80 90 100

SIGNAL-TO-NOISE RATIO

vs. ANALOG INPUT FREQUENCY

MAX1181 toc08

ANALOG INPUT FREQUENCY (MHz)

SNR (dB)

CHA

CHB

55

58

57

56

59

60

61

0403010 20 50 60 70 80 90 100

SIGNAL-TO-NOISE AND DISTORTION

vs. ANALOG INPUT FREQUENCY

MAX1181 toc09

ANALOG INPUT FREQUENCY (MHz)

SINAD (dB)

CHA

CHB

-80

-77

-74

-71

-68

-65

0405020 3010 60 70 80 90 100

TOTAL HARMONIC DISTORTION

vs. ANALOG INPUT FREQUENCY

MAX1181 toc10

ANALOG INPUT FREQUENCY (MHz)

THD (dBc)

CHA

CHB

65

68

71

74

77

80

0405020 3010 60 70 80 90 100

SPURIOUS-FREE DYNAMIC RANGE

vs. ANALOG INPUT FREQUENCY

MAX1181 toc11

ANALOG INPUT FREQUENCY (MHz)

SFDR (dBc)

CHA

CHB

1 10 100 1000

FULL-POWER INPUT BANDWIDTH

vs. ANALOG INPUT FREQUENCY

(SINGLE-ENDED)

MAX1181 toc12

ANALOG INPUT FREQUENCY (MHz)

GAIN (dB)

6

-8

-6

-2

0

2

4

-4

Typical Operating Characteristics (continued)

(VDD= 3V, OVDD= 2.5V, internal reference, differential input at -0.5dBFS, f

CLK

= 80.0006MHz, CL≈ 10pF. TA= +25°C, unless other-

wise noted.)