ADC Ch 10 - Exam with complete solutions
2025
Steps .of .Analog .to .Digital .Converter .- .AD/C .(3) .- .CORRECT .ANSWER✔✔1. .Tranducer
2. .Signal .Conditioning
3. .Accuracy
Tranducer .- .CORRECT .ANSWER✔✔Non-electrical .quantity .converted .to .electrical .voltage
Signal .Conditioning .- .CORRECT .ANSWER✔✔Tranducer's .output .voltage .shifted/scaled .to
.match .AD/C .input .specs
Accuracy .- .CORRECT .ANSWER✔✔# .of .bits .used .to .represent .digital .value
How .accurate .are .most .68HC12? .- .CORRECT .ANSWER✔✔they .implement .a .10-bit .A/D
.convert .voltage
What .is .the .successive .approximation .algorithm? .- .CORRECT .ANSWER✔✔where .the
.converter .guesses .the .analog .signals .in .an .n-bit .value .in .n .steps
What .are .the .steps .to .the .Successive .Approximation .Method? .- .CORRECT .ANSWER✔✔1.
.Initialize .SAR .register .to .0 .and .start .at .the .MSB
2. .Always .start .by .guessing .the .bit .to .be .1
, 3. .Convert .value .of .SAR .to .analog .voltage
4. .Comapare .D/A .output .with .the .analog .input
5. .Clear .the .bit .to .0 .if .D/A .ouput .is .larger
Most .A/D .Converters .are .ratiometric. .What .does .that .mean? .- .CORRECT .ANSWER✔✔A/DC
.compares .input .voltage .against .low/high .reference .voltage
AD/C .equation? .- .CORRECT .ANSWER✔✔Vx .= .Vlref .+ .(range .* .x) ./ .(2^n .- .1) .where .n .is .the
.number .of .bits
How .many .ratiometric .A/D .converters .does .the .68HC12DP256 .have .and .what .are .their
.names? .- .CORRECT .ANSWER✔✔two .8-channel .converters .- .AD0 .and .AD1
What .do .the .channels .do? .- .CORRECT .ANSWER✔✔correspond .to .one .analog .input, .equal
.to .one .input .pin .on .the .AD .port
What .is .associated .with .each .pin? .- .CORRECT .ANSWER✔✔an .internal .channel .unit .which
.has .the .results .register
What .is .the .range .of .their .clock .signals? .- .CORRECT .ANSWER✔✔2MHz .to .500KHz
Since .it .uses .channels, .what .issue .is .there? .- .CORRECT .ANSWER✔✔only .one .converter .can
.convert .at .a .time
ADC .works .on .sequences. .What .are .the .2 .major .types .of .sequences? .- .CORRECT
.ANSWER✔✔1. .sequence .of .conversions .on .the .same .channel
2. .sequence .of .conversions .over .a .set .of .channels
2025
Steps .of .Analog .to .Digital .Converter .- .AD/C .(3) .- .CORRECT .ANSWER✔✔1. .Tranducer
2. .Signal .Conditioning
3. .Accuracy
Tranducer .- .CORRECT .ANSWER✔✔Non-electrical .quantity .converted .to .electrical .voltage
Signal .Conditioning .- .CORRECT .ANSWER✔✔Tranducer's .output .voltage .shifted/scaled .to
.match .AD/C .input .specs
Accuracy .- .CORRECT .ANSWER✔✔# .of .bits .used .to .represent .digital .value
How .accurate .are .most .68HC12? .- .CORRECT .ANSWER✔✔they .implement .a .10-bit .A/D
.convert .voltage
What .is .the .successive .approximation .algorithm? .- .CORRECT .ANSWER✔✔where .the
.converter .guesses .the .analog .signals .in .an .n-bit .value .in .n .steps
What .are .the .steps .to .the .Successive .Approximation .Method? .- .CORRECT .ANSWER✔✔1.
.Initialize .SAR .register .to .0 .and .start .at .the .MSB
2. .Always .start .by .guessing .the .bit .to .be .1
, 3. .Convert .value .of .SAR .to .analog .voltage
4. .Comapare .D/A .output .with .the .analog .input
5. .Clear .the .bit .to .0 .if .D/A .ouput .is .larger
Most .A/D .Converters .are .ratiometric. .What .does .that .mean? .- .CORRECT .ANSWER✔✔A/DC
.compares .input .voltage .against .low/high .reference .voltage
AD/C .equation? .- .CORRECT .ANSWER✔✔Vx .= .Vlref .+ .(range .* .x) ./ .(2^n .- .1) .where .n .is .the
.number .of .bits
How .many .ratiometric .A/D .converters .does .the .68HC12DP256 .have .and .what .are .their
.names? .- .CORRECT .ANSWER✔✔two .8-channel .converters .- .AD0 .and .AD1
What .do .the .channels .do? .- .CORRECT .ANSWER✔✔correspond .to .one .analog .input, .equal
.to .one .input .pin .on .the .AD .port
What .is .associated .with .each .pin? .- .CORRECT .ANSWER✔✔an .internal .channel .unit .which
.has .the .results .register
What .is .the .range .of .their .clock .signals? .- .CORRECT .ANSWER✔✔2MHz .to .500KHz
Since .it .uses .channels, .what .issue .is .there? .- .CORRECT .ANSWER✔✔only .one .converter .can
.convert .at .a .time
ADC .works .on .sequences. .What .are .the .2 .major .types .of .sequences? .- .CORRECT
.ANSWER✔✔1. .sequence .of .conversions .on .the .same .channel
2. .sequence .of .conversions .over .a .set .of .channels
