It is on the body of the desk charger of green laser

Regardless of the gain range, the AD603 gain additional 1.07dB in the basis of theoretical gain limit, lower limit of the additional-1.07dB, such as the bandwidth is 90MHz. Theoretically gain range: 10dB to 30dB, the actual gain:-11.07dB 31.07dB; bandwidth 9MHz between pin 5 and ground with a resistor, it is possible to get higher gain the upper limit, but the gain no more than 60dB; of AD603 drive the load impedance of about 100 minimal distortion; the magnitude of the output voltage and load resistance: If an external load 500, the amplitude of the output voltage: ± 25V; AD603 input resistance of 100. The charger of  green laser pointer  is high and strict in performance.
Signal input corresponding to consider impedance matching; output pin is 7 feet, positive and negative power supply is 8 feet, 6 feet. Measuring the output must be careful, but the output-side and supply-side short-circuit, the chip will cause permanent damage. 3, the user can use the connection of the feedback network (VOUT FDBK side) design of AD603, the gain can be set to three modes [15]: Mode 1: VOUT FDBK short circuit is wideband mode (90MHz bandwidth) of AD603 gain-11.07dB to +31.07 dB,; mode: VOUT FDBK between an external resistor, the amplifier gain relationship, select the appropriate resistor. No training is needed to teach the user how to use the desk charge of  green laser pointer .
Between mode 1 and mode available by the need to gain value. This design selection mode; mode: VOUT FDBK between open and a 18pF capacitor the FDBK on COMM connection for extended frequency response, the pattern for high gain mode, the gain range of +8.93 ~ +51.07 dB bandwidth of 9MHz. Figure 3.12 of AD603 gain control voltage curve in the above three modes, the gain G (dB) and control voltage VG curve shown in Figure 3.12. VG in linear-500mV ~ +500 at mV range of 40dB / V (both 25mV/dB). AGC circuit analysis and design of the laser from the transmitter to the receiver process, subject to the emission power of semiconductor lasers, send and receive distance and other factors. It indicates the polarity of the battery of  green laser pointer .
Receiving circuit to receive the laser signal strength range. Need to design automatic gain control circuit so that the gain of the receiver circuit with the received signal strength automatically change. Two AD603 cascade mode, the capacitive coupling between the level, the total gain up to 84.28dB. 37 Shandong University of Science and Technology bachelor's degree thesis phase-shift laser rangefinder receiver circuit design in cascade applications, there are two gain control connection: sequential control mode and parallel control mode [16]. Sequence control: optimization of signal to noise ratio, two the AD603 cascade of sequential control mode will be two two AD603 gain control input GPOS driven by a positive voltage VG (GPOS-to-ground voltage) in parallel form. It is the durable and sturdy case of  green laser pointer .
While two of the negative gain control input (GNEG), respectively, plus a stable voltage VG1 and VG2 meet the 2 * 0.526V potential difference, the first gain maximum, the second level gain from the minimum to begin to improve. Parallel control mode: two the AD603 cascade of parallel control mode will be two positive gain control input (GPOS) by a positive voltage VG-driven, while the two negative gain control input (GNEG) parallel to the parallel form of ground in the form or add a stable voltage, and of VG1 = VG2, so the two gain synchronous changes in the control capability within the linear range of the parallel control mode is 80dB / V, that the smaller the control voltage can be obtained higher gain. It is on the body of the desk charger of  green laser   .