chopper stabilized amplifier design

[tiger99]

Hi All
I am trying to simulate a cmos chopper amplifier circuit shown in Figure7 of the attached document.

Does anyone know what type of transistors are used in the input and output modulators? There are no arrows in the circuit diagram, so I can't tell whether it's a nmos or pmos

Also, in the same figure, figure7, there are some circles below Vdd and above Vss. Does anyone know what they are?

If someone has resource(i.e. schematic files or detail schematics) related to implementing chopper stabilized amplifier using Multisim or LTspice. Could you please send me a copy?

I really appreciate all the inputs

Thanks in advance

 

[xusoso]

PMOS or NMOS depends on the input signal.if the input signal is below VDD-Vth,the fours devices befor input shoud be nmos
circles is the current source

 

[sudheerkm]

see the attached doc may help