TCM38C17IDL Datasheet, PDF (19/22 Pages) Texas Instruments – QComboE FOUR-CHANNEL QUAD PCM COMBO

TCM38C17IDL
QCombo™ FOUR-CHANNEL (QUAD) PCM COMBO
SLWS040C – JUNE 1996 – REVISED OCTOBER 1999
APPLICATION INFORMATION
differential configuration (continued)
Maximum output (A = 1) can be obtained by maximizing R1 and minimizing R2. This can be done by letting
R1 = infinity and R2 = 0 Ω (connect GSR to PWRO –), as shown in Figure 10. Referring to the transmit and
receive gain and dynamic range specifications, a maximum output of approximately 8 Vpp can be expected in
this configuration with a load ≥ 600 Ω. See the maximum analog output section for more detail on the digital input
required for maximum analog output.
PWRO +
VO ₊
GSR
RL
PWRO –
VO _–
Figure 10. Fully Differential Maximum Gain-Setting Configuration (A = 1)
Figure 11 illustrates the QCombo with the resistor gain-control setting for an attenuation of A = 0.625.
PWRO +
GSR
PWRO –
10 kΩ
2.5 kΩ
VO ₊
RL
VO _–
Figure 11. Fully Differential Mid-Gain-Setting Configuration (A = 0.625)
Shown in Figure 12, a minimum output (A = 0.25 dB) can be obtained by letting R1 = 0 Ω (connect GSR to
PWRO+), and R2 = infinity.
PWRO+
VO ₊
GSR
RL
PWRO–
VO _–
Figure 12. Fully Differential Minimum-Gain-Setting Configuration (A = 0.25)
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