1. An electronics design engineer is tasked with building the analog
front end (highlighted green) of an ECG system shown below:
Real
World
Supply Voltages
Power Management
ADC
Digital Signal Processing
Clock & Timers
a. If the sensor interface looks the circuits below, convert it into a
Thevenin source.
300
80?
+
3v$_s$
60?
100?
$V_o$
-
b. Use the Thevenin source derived in a), to source the voltage
amplifier model below. Assuming the filter has an input
resistance of $R_L$ (10k?), what is the expression for the amplifier
gain ($v_o/v_i$)? What should $R_{in}$ and $R_f$ be for maximum gain?
from (a)
Source
+
$V_{in}$
$R_{in}$
$A_{vin}$
+
$R_f$
Resistance
Filter Input