The output current equation for MC1408 digital to analog converter would be
(a) Io= -(Vref/R1)×[(D7/2)+(D6/4)+(D5/8)+(D4/16)+(D3/32)+(D2/64)+(D1/128)+(D0/256)].
(b) Io= (Vref/2R1)×[(D7/2)+(D6/4)+(D5/8)+(D4/16)+(D3/32)+(D2/64)+(D1/128)+(D0/256)].
(c) Io= (Vref/R1)×[(D7/2)+(D6/4)+(D5/8)+(D4/16)+(D3/32)+(D2/64)+(D1/128)+(D0/256)].
(d) Io= -(Vref/2R1)×[(D7/2)+(D6/4)+(D5/8)+(D4/16)+(D3/32)+(D2/64)+(D1/128)+(D0/256)].
I got this question in a job interview.
Question is from Current to Voltage Converter in portion Operational Amplifier Applications of Linear Integrated Circuits