On
page 1146 in the third paragraph you indicate that you can't use
the topology seen in Fig. 31.19 for
the TIA because it's not inverting.
However,
if the input current goes up the output voltage goes down so
isn't it inverting?
Yes,
you are right and this is a good question. The reason you can't use
this topology is
that the reset device, M5 in Fig. 31.51, must be connected
between a
high-impedance node and a low-impedance node for the reset to
work properly. This
means that the reset device can't be connected back to
the input in Fig. 31.19.
The
key thing is that M5 can't have a DC current flowing in it if the reset
is to work correctly. If M5 does
pass a current then the biasing will be
corrupted when M5 shuts
off causing the amplifier's output to move towards
either vdd or gnd.