ELECTRICAL CHARACTERISTICS

ADS5270

SBAS293F – JANUARY 2004 – REVISED JANUARY 2009............................................................................................................................................... www.ti.com

TMIN = –40°C and TMAX = +85°C. Typical values are at TA = +25°C, clock frequency = maximum specified, 50% clock duty

cycle, AVDD = 3.3V, LVDD = 3.3V, –1dBFS, ISET = 56.2kΩ, internal voltage reference, and LVDS buffer current at 3.5mA per

channel, unless otherwise noted.

ADS5270

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNITS

DC ACCURACY

No Missing Codes

Tested

DNL Differential Nonlinearity

fIN = 5MHz

–0.9

±0.5

+0.9

LSB

INL Integral Nonlinearity

fIN = 5MHz

–2.0

±0.6

+2.0

LSB

Offset Error(1)

–0.75

+0.75

%FS

Offset Temperature Coefficient

±6

ppm/°C

Fixed Attenuation in Channel(2)

1.5

%FS

Fixed Attenuation Matching Across Channels

0.01

0.2

dB

Gain Error/Reference Error(3)

VREFT – VREFB

–2.5

±1.0

+2.5

%FS

Gain Error Temperature Coefficient

±20

ppm/°C

POWER REQUIREMENTS(4)

Internal Reference

Power Dissipation

Analog Only (AVDD)

716

760

mW

Output Driver (LVDD)

172

188

mW

Total Power Dissipation

888

948

mW

External Reference

Power Dissipation

Analog Only (AVDD)

650

mW

Output Driver (LVDD)

172

mW

Total Power Dissipation

822

mW

Power-Down

Clock Running

90

mW

REFERENCE VOLTAGES

VREFT Reference Top (internal)

1.9

1.95

2.0

V

VREFB Reference Bottom (internal)

0.9

0.95

1.0

V

VCM Common-Mode Voltage

1.4

1.45

1.5

V

VCM Output Current

(5)

±50mV Change in Voltage

±2.0

mA

VREFT Reference Top (external)

1.825

1.95

2.0

V

VREFB Reference Bottom (external)

0.9

0.95

1.075

V

External Reference Common-Mode

VCM ± 50mV

V

External Reference Input Current(6)

1.0

mA

(1)

Offset error is the deviation of the average code from mid-code with –1dBFS sinusoid from ideal mid-code (2048). Offset error is

expressed in terms of % of full-scale.

(2)

Fixed attenuation in the channel arises due to a fixed attenuation in the sample-and-hold amplifier. When the differential voltage at the

analog input pins are changed from –VREF to +VREF, the swing of the output code is expected to deviate from the full-scale code

(4096LSB) by the extent of this fixed attenuation. NOTE: VREF is defined as (REFT – REFB).

(3)

The reference voltages are trimmed at production so that (VREFT – VREFB) is within ± 25mV of the ideal value of 1V. This specification

does not include fixed attenuation.

(4)

Supply current can be calculated from dividing the power dissipation by the supply voltage of 3.3V.

(5)

VCM provides the common-mode current for the inputs of all eight channels when the inputs are ac-coupled. The VCM output current

specified is the additional drive of the VCM buffer if loaded externally.

(6)

Average current drawn from the reference pins in the external reference mode.

4

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