AD524 pin and internal circuit function block diagram

AD524 has low drift (voltage drift 0.5mV, maximum temperature drift 25 mV gate C), low noise (0.3mVp_p,
0.1-10Hz), good linearity (=0.0030/0, when the gain is l), and high CMRR (120dB) It is a precision instrument amplifier with a gain bandwidth
of 25MHz, adjustable gain steps (gain 1, 10, 100, 1000) and an output conversion rate of 5V/ms
. The working power supply range is ±(6 ~18V). Its pins and internal circuit functional block diagram are shown in Figure 10-10.
    AD524 is internally composed of input protection, input amplification, differential
instrument amplification and gain setting circuits. After the signal is input from
pins ② and ③, it is first pre-amplified, and then
amplified by the differential instrument and then output from pin ⑨. When pins ⑧, ⑩ and ⑩
are connected to pin ③ respectively, accurately set the gain of the internal amplifier
to 10, 100 and 1000. When pin ③ is not connected, the gain is
1. In addition, when a resistor is connected in series between these pins
or a resistor is connected to the feedback input terminals of pins ⑥ and ⑩,
the gain of the amplifier can be adjusted. Therefore, the AD 524 is
an instrument amplifier with very easy gain adjustment.