MAXIM MAX1446 Technical data

General Description

The MAX1446 10-bit, 3V analog-to-digital converter
(ADC) features a fully differential input, a pipelined 10­stage ADC architecture with digital error correction and
wideband track and hold (T/H) incorporating a fully dif­ferential signal path. This ADC is optimized for low­power, high dynamic performance applications in
imaging and digital communications. The MAX1446
operates from a single 2.7V to 3.6V supply, consuming
only 90mW while delivering a 59.5dB signal-to-noise
ratio (SNR) at a 20MHz input frequency. The fully differ­ential input stage has a 400MHz, -3dB bandwidth and
may be operated with single-ended inputs. In addition
to low operating power, the MAX1446 features a 5µA
power-down mode for idle periods.

An internal 2.048V precision bandgap reference is used
to set the ADC full-scale range. A flexible reference
structure allows the user to supply a buffered, direct or
externally derived reference for applications requiring
increased accuracy or a different input voltage range.

Lower and higher speed, pin-compatible versions of
the MAX1446 are also available. Refer to the MAX1444
data sheet for a 40Msps version, the MAX1448 data
sheet for an 80Msps version, and the MAX1449 data
sheet for a 105Msps version.

The MAX1446 has parallel, offset binary, three-state
outputs that can be operated from 1.7V to 3.3V 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) and automotive
(-40°C to +105°C) temperature ranges.

________________________Applications

Ultrasound Imaging

CCD Imaging

Baseband and IF Digitization

Digital Set-Top Boxes

Video Digitizing Applications

Features

o Single 3.0V Operation

o Excellent Dynamic Performance

59.5dB SNR at f

IN

= 20MHz

73dB SFDR at fIN= 20MHz

o Low Power:

30mA (Normal Operation)

5µA (Shutdown Mode)

o Fully Differential Analog Input

o Wide 2V

P-P

Differential Input Voltage Range

o 400MHz -3dB Input Bandwidth

o On-Chip 2.048V Precision Bandgap Reference

o CMOS-Compatible Three-State Outputs

o 32-Pin TQFP Package

o Evaluation Kit Available (MAX1448 EV Kit)

MAX1446

10-Bit, 60Msps, 3.0V, Low-Power

ADC with Internal Reference

________________________________________________________________

Maxim Integrated Products

1

Functional Diagram

19-1729; Rev 4; 11/08

EVALUATION KIT

AVAILABLE

Ordering Information

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.

Pin-Compatible,

Lower/Higher Speed Versions

+

Denotes a lead(Pb)-free/RoHS-compliant package.

PART TEMP RANGE

MAX1446EHJ+ -40°C to +85°C 32 TQFP

MAX1446GHJ+ -40°C to +105°C 32 TQFP

PIN­PACKAGE

PART SAMPLING SPEED (Msps)

MAX1444 40

MAX1448 80

MAX1449 105

CLK

IN+

MAX1446

CONTROL

10

D

T/H

IN-

PD

REF

PIPELINE ADC

REF SYSTEM +

BIAS

REFINREFOUT REFP COM REFN OE

E
C

OUTPUT
DRIVERS

V

DD

GND

D9–D0

OV

DD

OGND

MAX1446

10-Bit, 60Msps, 3.0V, Low-Power
ADC with Internal Reference

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= 3.0V, OVDD= 2.7V; 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

= 2V

P-P

(differential with respect to COM), CL≈ 10pF at digital outputs, f

CLK

= 62.5MHz

(50% duty cycle), T

A

= 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.

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 18.7mW/°C above +70°C)......1495.3mW

Operating Temperature Ranges:

MAX1446EHJ+ .................................................-40°C to +85°C

MAX1446GHJ+...............................................-40°C to +105°C

Storage Temperature Range ............................-60°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DC ACCURACY

Resolution 10 Bits

Integral Nonlinearity INL f

Differential Nonlinearity DNL No missing codes, f
Offset Error -1.6 < ±0.1 ±1.9 % FS

Gain Error TA ≥ +25°C 0 ±2.0 % FS

ANALOG INPUT

Input Differential Range V

Common-Mode Voltage Range V

Input Resistance R

Input Capacitance C

CONVERSION RATE

Maximum Clock Frequency f

Data Latency 5.5 Cycles

DYNAMIC CHARACTERISTICS

Signal-to-Noise + Distortion
(Up to 5th Harmonic)

Spurious-Free Dynamic
Range

DIFF

COM

CLK

SINAD

SFDR

= 7.492MHz, TA ≥ +25°C ±0.6 ±1.9 LSB

IN

= 7.492MHz ±0.4 ±1.0 LSB

IN

Differential or single-ended inputs ±1.0 V

Switched capacitor load 33 kΩ

IN

IN

fIN = 7.492MHz 57 59.5

fIN = 19.943MHz 56.5 59.5Signal-to-Noise Ratio SNR

= 39.9MHz (Note 1) 59

f

IN

fIN = 7.492MHz 56.6 59.4

fIN = 19.943MHz 56.2 59

f

= 39.9MHz (Note 1) 58.5

IN

fIN = 7.492MHz 65 74

fIN = 19.943MHz 63 73

f

= 39.9MHz (Note 1) 71

IN

VDD/2

± 0.5

5pF

60 MHz

V

dB

dB

dBc

MAX1446

10-Bit, 60Msps, 3.0V, Low-Power

ADC with Internal Reference

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 3.0V, OVDD= 2.7V; 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

= 2V

P-P

(differential with respect to COM), CL≈ 10pF at digital outputs, f

CLK

= 62.5MHz

(50% duty cycle), T

A

= 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.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

fIN = 7.492MHz -74

dBc

Two-Tone Intermodulation
Distortion

Third-Order Intermodulation
Distortion

IMD

IM3

TT

fIN = 19.943MHz -73Third-Harmonic Distortion HD3

= 39.9MHz (Note 1) -71

f

IN

f

= 19MHz at -6.5dBFS,

1

f

= 21MHz at -6.5dBFS (Note 2)

2

f

= 19MHz at -6.5dBFS

1

= 21MHz at -6.5dBFS (Note 2)

f

2

-75 dBc

-75 dBc

fIN = 7.492MHz -70 -64

Total Harmonic Distortion
(First 5 Harmonics)

THD

fIN = 19.943MHz -70 -63

f

= 39.9MHz (Note 1) -69

IN

dBc

Small-Signal Bandwidth Input at -20dBFS, differential inputs 500 MHz

Full-Power Bandwidth FPBW Input at -0.5dBFS, differential inputs 400 MHz

Aperture Delay t

Aperture Jitter t

AD

AJ

1ns

2 psrms

Overdrive Recovery Time For 1.5 × full-scale input 2 ns
Differential Gain ±1%
Differential Phase ±0.25 °

Output Noise IN+ = IN- = COM 0.2 LSBrms

INTERNAL REFERENCE

Reference Output Voltage REFOUT

Reference Temperature
Coefficient

TC

REF

2.048

±1%

60 ppm/°C

V

Load Regulation 1.25 mV/mA

BUFFERED EXTERNAL REFERENCE (V

REFIN Input Voltage V

P osi ti ve Refer ence Outp ut V ol tag eV

N eg ati ve Refer ence Outp ut
V ol tag e

Common-Mode Level V

Differential Reference Output
Voltage Range

REFIN Resistance R

Maximum REFP, COM Source
Current

Maximum REFP, COM Sink
Current

REFIN

REFP

V

REFN

COM

ΔV

REFIN

I

SOURCE

I

SINK

REFIN

REF

= 2.048V)

ΔV

= V

REF

REFP

- V

2.048

2.012 V

0.988 V

VDD/2 V

, TA ≥ +25°C 0.98 1.024 1.07 V

REFN

> 50 MΩ

5mA

-250 µA

MAX1446

10-Bit, 60Msps, 3.0V, Low-Power
ADC with Internal Reference

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 3.0V, OVDD= 2.7V; 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

= 2V

P-P

(differential with respect to COM), CL≈ 10pF at digital outputs, f

CLK

= 62.5MHz

(50% duty cycle), T

A

= 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.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Maximum REFN Source Current I

Maximum REFN Sink Current I

UNBUFFERED EXTERNAL REFERENCE (V

REFP, REFN Input Resistance

REFP, REFN, COM Input
Capacitance

Differential Reference Input
Voltage Range

COM Input Voltage Range V

REFP Input Voltage V

REFN Input Voltage V

DIGITAL OUTPUTS (CLK, PD, OE)

Input High Threshold V

Input Low Threshold V

Input Hysteresis V

Input Leakage

Input Capacitance C

DIGITAL OUTPUTS (D9–D0)

Output Voltage Low V

Output Voltage High V

Three-State Leakage Current I

SOURCE

SINK

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

REFIN

R

,

Measured between REFP and COM and
REFN and COM

IN

ΔV

REF

REF

= V

REFP

- V

REFN

R

ΔV

REFP

REFN

C

COM

REFP

REFN

CLK

IH

PD, OE

CLK

IL

PD, OE

HYST

I

IH

I

IL

OL

OH

LEAK

VIH = V

DD

= OV

DD

VIL = 0 ±5

IN

I

= 200µA 0.2 V

SINK

I

OE = OV

SOURCE

= 200µA

DD

250 µA

-5 mA

4KΩ

15 pF

1.024
±10%

VDD/2
±10%

V

+

COM

/2

ΔV

REF

V

-

COM

/2

ΔV

REF

0.8 x
V

DD

0.8 x

OV

D D

0.2 x
V

0.2 x

OV

0.1 V

±5

5pF

OV

-

DD

0.2

±10 µA

DD

D D

V

V

V

V

V

V

µA

V

Three-State Output Capacitance C

OUT

OE = OV

DD

5pF

MAX1446

Note 1: 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 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: Wake-up time is defined as the time from complete reference power-down until the ADC performs within 0.3 ENOB of the

final performance for f

IN

= 10MHz at -0.5dBFS input amplitude. V

REFIN

= 2.048V, REFP, REFN, and CML decoupled with

2.3µF.

Note 5: Dynamic characteristics guaranteed at f

IN

= 19.943MHz for the specified duty-cycle range.

Note 6: Guaranteed by design and engineering characterization.

10-Bit, 60Msps, 3.0V, Low-Power

ADC with Internal Reference

_______________________________________________________________________________________ 5

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 3.0V, OVDD= 2.7V; 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

= 2V

P-P

(differential with respect to COM), CL≈ 10pF at digital outputs, f

CLK

= 62.5MHz

(50% duty cycle), T

A

= 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.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER REQUIREMENTS

Analog Supply Voltage V

Output Supply Voltage OV

Analog Supply Current I

Output Supply Current I

Power-Supply Rejection PSRR

TIMING CHARACTERISTICS

CLK Rise to Output Data Valid t

OE Fall to Output Enable t
OE Rise to Output Disable t

Clock Duty Cycle Figure 6, clock period 16ns (Notes 5, 6) 45 55 %

Wake-Up Time t

DD

VDD

OVDD

DO

ENABLE

DISABLE

WAKE

CL = 10pF 1.7 3.0 3.6 V

DD

Operating, fIN = 19.943MHz at -0.5dBFS 30 37 mA
Shutdown, clock idle, PD = OE = OV

Operating, CL = 15pF, fIN = 19.943MHz at

-0.5dBFS
Shutdown, clock idle, PD = OE = OV

Offset ± 0.1 mV/V
Gain ± 0.1 %/V

Figure 5 (Notes 3, 6) 2 5 8 ns

Figure 5 10 ns

Figure 5 1.5 ns

(Notes 4, 6) 366 520 µs

DD

DD

2.7 3.0 3.6 V

415µA

7mA

120µA

MAX1446

10-Bit, 60Msps, 3.0V, Low-Power
ADC with Internal Reference

6 _______________________________________________________________________________________

Typical Operating Characteristics

(VDD= 3.0V, OVDD= 2.7V, internal reference, differential input at -0.5dBFS, f

CLK

= 62.35MHz, CL≈ 10pF, TA= +25°C, unless

otherwise noted.)

MAX1446 toc01

-100

-70

-80

-90

-50

-60

-10

-20

-30

-40

0

0 5 10 15 20 25 30 35

FFT PLOT

(f

IN

= 7.5MHz, 8192-POINT FFT,

DIFFERENTIAL INPUT)

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

SFDR = 72.2dBc
SNR = 60.1dB
THD = -71.5dBc
SINAD = 59.8dB

HD2

HD3

-100

-70

-80

-90

-50

-60

-10

-20

-30

-40

0

0 5 10 15 20 25 30 35

FFT PLOT

(f

IN

= 13.3MHz, 8192-POINT FFT,

DIFFERENTIAL INPUT)

MAX1446 toc02

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

SINAD = 59.3dB
SNR = 59.5dB
THD = -72.9dBc
SFDR = 74.3dBc

HD2

HD3

-100

-70

-80

-90

-50

-60

-10

-20

-30

-40

0

0 5 10 15 20 25 30 35

FFT PLOT

(f

IN

= 20MHz, 8192-POINT FFT,

DIFFERENTIAL INPUT)

MAX1446 toc03

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

SINAD = 59.3dB
SNR = 59.6dB
THD = -70.7dBc
SFDR = 72.2dBc

HD2

HD3

-100

-70

-80

-90

-50

-60

-10

-20

-30

-40

0

0 5 10 15 20 25 30 35

FFT PLOT

(f

IN

= 26.8MHz, 8192-POINT FFT,

DIFFERENTIAL INPUT)

MAX1446 toc04

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

SINAD = 59.0dB
SNR = 59.4dB
THD = -70.5dBc
SFDR = 72.9dBc

HD2

HD3

-100

-70

-80

-90

-50

-60

-10

-20

-30

-40

0

0 5 10 15 20 25 30 35

FFT PLOT

(f

IN

= 50MHz, 8192-POINT FFT,

DIFFERENTIAL INPUT)

MAX1446 toc05

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

SFDR = 70dBc
SNR = 59.1dB
THD = -67.1dBc
SINAD = 58.5dB

HD2

HD3

-100

-70

-80

-90

-50

-60

-10

-20

-30

-40

0

0 5 10 15 20 25 30 35

FFT PLOT

(f

IN

= 7.5MHz, 8192-POINT FFT,

SINGLE-ENDED INPUT)

MAX1446 toc06

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

SINAD = 59.5dB
SNR = 59.7dB
THD = -73.0dBc
SFDR = 73.6dBc

HD2

HD3

-100

-70

-80

-90

-50

-60

-10

-20

-30

-40

0

0 5 10 15 20 25 30 35

FFT PLOT

(f

IN

= 20MHz, 8192-POINT FFT,

SINGLE-ENDED INPUT)

MAX1446 toc07

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

SINAD = 59.2dB
SNR = 59.5dB
THD = -70.7dBc
SFDR = 71.1dBc

HD2

HD3

-100

-70

-80

-90

-50

-60

-10

-20

-30

-40

0

0 5 10 15 20 25 30 35

TWO-TONE INTERMODULATION

(8192-POINT IMD,

DIFFERENTIAL INPUT)

MAX1446 toc08

ANALOG INPUT FREQUENCY (MHz)

AMPLITUDE (dB)

f1 = 19MHz AT -6.5dBFS
f2 = 21MHz AT -6.5dBFS
3RD IMD = -76dBc

SPURIOUS-FREE DYNAMIC RANGE

vs. ANALOG INPUT FREQUENCY

(A

IN

= -0.5dBFS)

ANALOG INPUT FREQUENCY (MHz)

SFDR (dBc)

MAX1446 toc09

0 102030405060708090

50

55

60

65

70

75

80

DIFFERENTIAL

SINGLE-ENDED