TCM38C17IDL

QCombo

™ FOUR-CHANNEL (QUAD) PCM COMBO

SLWS040C – JUNE 1996 – REVISED OCTOBER 1999

19

POST OFFICE BOX 655303

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 +

PWRO –

GSR

RL

VO+

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 +

PWRO –

GSR

10 k

Ω

RL

VO+

VO–

2.5 k

Ω

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+

PWRO–

GSR

RL

VO+

VO–

Figure 12. Fully Differential Minimum-Gain-Setting Configuration (A = 0.25)