AD28MSP01 Ver la hoja de datos (PDF) - Analog Devices

Número de pieza

componentes Descripción

Fabricante

AD28MSP01

PSTN Signal Port

Analog Devices 

AD28msp01

+12V

0.1µF

AD28msp01

VOUT

GNDA

7

5

SSSSMM-2141

1

4

GNDA

0.1µF

VOUTP

VOUTN

–12V

GNDA

Figure 15. Example Circuit for Single-Ended Output

Single Power Supply Operation

Use of a single +5 V power supply is possible with the

AD28msp01. If a single supply is used, the analog power supply

input to the device must be properly filtered. The proper filter is

dependent on the noise present in your system.

PC Board Layout Considerations

Separate analog and digital ground planes should be provided

for the AD28msp01 in order to assure the characteristics of the

device’s ADC and DAC. The two ground planes should be con-

nected only at a single point. The point of connection may be at

the system power supply, at the PC board power connection, or

at any other appropriate location. Multiple connections between

the analog and digital ground planes should be avoided.

The ground planes should be designed such that all noise-

sensitive areas are isolated from one another and critical signal

traces (such as digital clocks and analog signals) are as short as

possible.

Each +5 V supply pin of the AD28msp01 should be bypassed to

ground with a 0.1 µF capacitor. These capacitors should be low

inductance, monolithic, ceramic, and surface-mount. The ca-

pacitor leads and PC board traces should be as short as possible

to minimize inductive effects. In addition, a 10 µF capacitor

should be connected between VDD and ground, near the PC

board power connection.

MCLK Frequency

The sigma-delta converters and digital filters of the AD28msp01

are specifically designed to operate at a master clock (MCLK)

frequency of 13.824 MHz. MCLK must equal 13.824 MHz to

guarantee the filter characteristics and sample rate of the ADC

and DAC. The AD28msp01 is not tested or characterized at

any other clock frequency.

DEFINITION OF SPECIFICATIONS

Typical (Typ) specifications represent nominal performance at

+25°C with VCC and VDD set to +5 V.

Minimum (Min) and Maximum (Max) specifications are guar-

anteed across the full operating range, however, devices are

tested only at the indicated test conditions.

Absolute Gain

Absolute gain is a measure of converter gain for a known signal.

Absolute gain is measured with a 1.0 kHz sine wave at 0 dBm0.

The absolute gain specification is used as a reference for gain

tracking error specification.

Gain Tracking Error

Gain tracking error measures changes in converter output for

different signal levels relative to an absolute signal level. The ab-

solute signal level is 1 kHz at 0 dBm0 (equal to absolute gain).

Gain tracking error at 0 dBm0 is 0 dB by definition.

SNR

Signal-to-noise ratio is defined to be the ratio of the rms value of

the measured input signal to the rms sum of all the spectral

components in the specified passband, excluding dc and har-

monic components.

THD

Total harmonic distortion is defined to be the ratio of the rms

value of the measured input signal to the rms sum of the har-

monic components in the specified passband.

Intermodulation Distortion

With inputs consisting of sine waves at two frequencies, fa and

fb, any active device with nonlinearities will create distortion

products at sum and difference frequencies of mfa ± nfb where

m, n = 0, 1, 2, 3, etc. Intermodulation terms are those for which

neither m nor n are equal to zero. This specification contains

the second order terms include (fa + fb) and (fa – fb), and the

third order terms include (2fa + fb), (2fa – fb), (fa + 2fb), and

(fa – 2fb).

Idle Channel Noise

Idle channel noise is defined as the total signal energy measured

at the output of the device when the input is grounded (mea-

sured in the specified passband).

Crosstalk

Crosstalk is defined as the ratio of the amplitude of a 0 dB sig-

nal appearing on one channel to the amplitude of the same sig-

nal coupled onto the other, idle channel. Crosstalk is expressed

in dB.

Power Supply Rejection

Power supply rejection measures the susceptibility of a device to

noise on the power supply. Power supply rejection is measured

by modulating the power supply with a 1 kHz, 100 mV p-p sine

wave and measuring the relative level at the output.

Group Delay

Group delay is defined as the derivative of radian phase with re-

spect to radian frequency, ∂φ(ω)/∂ω. Group delay is a measure

of the linearity of the phase response of a linear system. A linear

system with a constant group delay has a linear phase response.

The deviation of the group delay away from a constant indicates

the degree of nonlinear phase response of the system.

REV. A

–17–

Share Link: