TCM29C13, TCM29C14, TCM29C16, TCM29C17,

TCM129C13, TCM129C14, TCM129C16, TCM129C17

COMBINED SINGLE-CHIP PCM CODEC AND FILTER

SCTS011H – APRIL 1986 – REVISED JULY 1996

23

POST OFFICE BOX 655303

PRINCIPLES OF OPERATION

receive output power amplifiers

A balanced-output amplifier is provided to allow maximum flexibility in output configuration. Either of the two

outputs can be used single ended (i.e., referenced to ANLG GND) to drive single-ended loads. Alternatively,

the differential output directly drives a bridged load. The output stage is capable of driving loads as low as 300-

Ω

single-ended to a level of 12 dBm or 600

Ω differentially to a level of 15 dBm.

The receive channel transmission level may be adjusted between specified limits by manipulation of the GSR

input. GSR is internally connected to an analog gain-setting network. When GSR is connected to PWRO –, the

receive level is maximum. When GSR is connected to PWRO+, the level is minimum. The output transmission

level is adjusted between 0 and –12 dB as GSR is adjusted (with an adjustable resistor) between PWRO+ and

PWRO–.

Transmission levels are specified relative to the receive channel output under digital milliwatt conditions

(i.e., when the digital input at PCM IN is the eight-code sequence specified in CCITT recommendation G.711).