Assume that the output of the DAC in Figure 11-7(a) is connected to the op-amp of Figure 11-7(b).

(a) With V_REF = 5 V, R = 20 kΩ, and R_F = 10 k, determine the step size and the full-scale voltage at V_OUT.

(b) Change the value of R_F so that the full-scale voltage at V_OUT is –2 V.

(c) Use this new value of R_F, and determine the proportionality factor, K, in the relationship V_OUT = K(V_REF × B). (B is the binary input value.)

Figure 11-7

Transcribed Image Text:

+VREF switch closed when input bit = 1 R MSB B3 lOUT N15 → OV 2 R 814 → + B₂ B₁ Binary inputs (0 or 1) (a) www. RF IF = OUT 4 R (b) 0100 → www Bo 8 R LSB OUT=B3 xlo + B₂x2 lo lo +B₁X + Box where lo = OUT w 111 VREE R RL VOUT = -loUTXRF