ADS7891

SLAS410 − DECEMBER 2003

www.ti.com

3

SPECIFICATIONS

TA = −40°C to 85°C, +VA = 5 V, +VBD = 5 V or 3.3 V, Vref = 2.5 V, fsample = 3 MHz (unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

ANALOG INPUT

Full-scale input span(1)

+IN – (−IN)

0

Vref

V

Absolute input range

+IN

−0.2

Vref + 0.2

V

Absolute input range

−IN

−0.2

+0.2

V

Input capacitance

27

pF

Input leakage current

500

pA

SYSTEM PERFORMANCE

Resolution

14

Bits

No missing codes

14

Bits

Integral linearity(2)

−1.5

±0.75

1.5

LSB(3)

Differential linearity

−1

±0.75

1.5

LSB(3)

Offset error(4)

External reference

−1.5

±0.2

1.5

mV

Gain error(4)

External reference

−1

±0.2

1

mV

Common-mode rejection ratio

With common mode input signal = 200

mVp−p at 1 MHz

60

dB

Power supply rejection

At 3FF0H output code,

+VA = 4.75 V to 5.25 V , Vref = 2.50 V

80

dB

SAMPLING DYNAMICS

Conversion time

+VDB = 5 V

255

273

nsec

Conversion time

+VDB = 3 V

273

nsec

Acquisition time

+VDB = 5 V

60

78

nsec

Acquisition time

+VDB = 3 V

60

nsec

Maximum throughput rate

3

MHz

Aperture delay

2

nsec

Aperture jitter

20

psec

Step response

50

nsec

Over voltage recovery

50

nsec

DYNAMIC CHARACTERISTICS

(5)

VIN = 2.496 Vp−p at 100 kHz/2.5 Vref

−93

Total harmonic distortion(5)

VIN = 2.496 Vp−p at 1 MHz/2.5 Vref

−88.5

−87

dB

Total harmonic distortion(5)

VIN = 2.496 Vp−p at 1.4 MHz/2.5 Vref

−79.5

dB

VIN = 2.496 Vp−p at 100 kHz/2.5 Vref

78.5

SNR

VIN = 2.496 Vp−p at 1 MHz/2.5 Vref

78

dB

SNR

VIN = 2.496 Vp−p at 1.4 MHz/2.5 Vref

75

dB

VIN = 2.496 Vp−p at 100 kHz/2.5 Vref

78

SINAD

VIN = 2.496 Vp−p at 1 MHz/2.5 Vref

77

dB

SINAD

VIN = 2.496 Vp−p at 1.4 MHz/2.5 Vref

73.8

dB

SFDR

VIN = 2.496 Vp−p at 1 MHz/2.5 Vref

88

90

dB

−3 dB Small signal bandwidth

50

MHz

EXTERNAL REFERENCE INPUT

Input VREF range

2.4

2.5

2.6

V

Resistance(6)

500

k

Ω

(1) Ideal input span; does not include gain or offset error.

(2) This is endpoint INL, not best fit.

(3) LSB means least significant bit.

(4) Measured relative to actual measured reference.

(5) Calculated on the first nine harmonics of the input frequency.

(6) Can vary ±20%.