T7507 参数 Datasheet PDF下载

Data Sheet

August 1999

T7507 Quad PCM Codec with Filters,

Termination Impedance, and Hybrid Balance

Transmission Characteristics

(continued)

ac Transmission Characteristics

Unless otherwise noted, the analog input is a –26 dBm (at 813

Ω),

1020 Hz sine wave. The digital input is a PCM

bit stream equivalent to that obtained by passing a 0 dBm0, 1020 Hz sine wave through an ideal encoder. The out-

put level is sin(x)/x-corrected.

Table 11. Absolute Gain

Parameter

†

Encoder Milliwatt

Response (transmit gain

tolerance)

Decoder Milliwatt

Response (receive gain

tolerance)

Relative Gain Variation

Referenced to DmW

Symbol

†

EmW

Test Conditions

†

Signal input of 0.0452 Vrms

(–26 dBm at 813

Ω

at 1020 Hz)

Measured differential relative to

0.902 Vrms,

PCM input of 0 dBm0 1020 Hz

RL = 10 kΩ, receive gain in –7.0 dB mode

Decoder gain = –3.5 dB mode

Min*

†

Typ

†

—

–0.20

Max*

†

Unit

†

—

dBm0

DmW

—

–7.20

—

dBm0

RGR

—

3.5

—

dB

* Combination test results are translated into system-level characteristics guaranteed by Table 21, Figure 8, and Figure 9.

† Overall system-level tolerances are +0.3 dB to –0.7 dB in both directions. Therefore, nominal analog levels are shifted by –0.2 dB.

Table 12. Gain Tracking

Parameter

Transmit Gain Tracking Error

Sinusoidal Input A-law

Receive Gain Tracking Error

Sinusoidal Input A-law

Table 13. Distortion

Parameter

Transmit Signal to Distortion

Symbol

SD

X

Test Conditions

3 dBm0

≥

VF

X

I

≥

–30 dBm0

–30 dBm0

≥

VF

X

I

≥

–40 dBm0

–40 dBm0

≥

VFxI

≥

–45 dBm0

3 dBm0

≥

VF

R

O

≥

–30 dBm0

–30 dBm0

≥

VF

R

O

≥

–40 dBm0

–40 dBm0

≥

VF

R

O

≥

–45 dBm0

200 Hz—3400 Hz, 0 dBm0 input,

output any other single

frequency

≤

3400 Hz

200 Hz—3400 Hz, 0 dBm0 input,

output any other single

frequency

≤

3400 Hz

Transmit or receive, two frequencies

in the range (300 Hz—3400 Hz)

at –6 dBm0

Min

35

29

25

35

29

25

—

Typ

—

—

—

—

—

—

—

Max Unit

—

dB

—

dB

—

dB

—

dB

—

dB

—

dB

–38 dBm0

Symbol

GT

X

GT

R

Test Conditions

+3 dBm0 to –37 dBm0

–37 dBm0 to –50 dBm0

+3 dBm0 to –37 dBm0

–37 dBm0 to –50 dBm0

Min

–0.25

–0.50

–0.25

–0.50

Typ

—

—

—

—

Max

0.25

0.50

0.25

0.50

Unit

dB

dB

dB

dB

Receive Signal to Distortion

SD

R

Single-frequency Distortion,

Transmit

Single-frequency Distortion,

Receive

Intermodulation Distortion

SFD

X

SFD

R

—

—

–40

dBm0

IMD

—

—

–42

dBm0

Lucent Technologies Inc.

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