Data Sheet

AD1938

Rev. E | Page 3 of 32

SPECIFICATIONS

TEST CONDITIONS

Performance of all channels is identical, exclusive of the interchannel gain mismatch and interchannel phase deviation specifications.

Supply voltages (AVDD, DVDD)

3.3 V

Temperature range1

as specified in Table 1 and Table 2

Master clock

Input sample rate

48 kHz

Measurement bandwidth

20 Hz to 20 kHz

Word width

24 bits

Load capacitance (digital output)

20 pF

Load current (digital output)

±1 mA or 1.5 kΩ to ½ DVDD supply

Input voltage high

2.0 V

Input voltage low

0.8 V

ANALOG PERFORMANCE SPECIFICATIONS

Specifications guaranteed at an ambient temperature of 25°C.

Table 1.

Parameter

Conditions

Min

Typ

Max

Unit

ANALOG-TO-DIGITAL CONVERTERS

ADC Resolution

All ADCs

24

Bits

Dynamic Range

20 Hz to 20 kHz, −60 dB input

No Filter (RMS)

98

102

dB

With A-Weighted Filter (RMS)

100

105

dB

Total Harmonic Distortion + Noise

−1 dBFS

−96

−87

dB

Full-Scale Input Voltage (Differential)

1.9

V rms

Gain Error

−10

+10

%

Interchannel Gain Mismatch

−0.25

+0.25

dB

Offset Error

−10

0

+10

mV

Gain Drift

100

ppm/°C

Interchannel Isolation

−110

dB

CMRR

100 mV rms, 1 kHz

55

dB

100 mV rms, 20 kHz

55

dB

Input Resistance

14

kΩ

Input Capacitance

10

pF

Input Common-Mode Bias Voltage

1.5

V

DIGITAL-TO-ANALOG CONVERTERS

Dynamic Range

20 Hz to 20 kHz, −60 dB input

No Filter (RMS)

98

104

dB

With A-Weighted Filter (RMS)

100

106

dB

With A-Weighted Filter (Average)

108

dB

Total Harmonic Distortion + Noise

0 dBFS

Single-Ended Version

Two channels running

−92

dB

Single-Ended Version

Eight channels running

−86

−75

dB

Full-Scale Output Voltage

0.88 (2.48)

V rms (V p-p)

Gain Error

−10

+10

%

Interchannel Gain Mismatch

−0.2

+0.2

dB

Offset Error

−25

−4

+25

mV

Gain Drift

−30

+30

ppm/°C