The VCA8617 is an 8-channel variable gain amplifier ideally suited to portable ultrasound applications. Excellent dynamic performance enables use in low-power, high-performance portable applications. Each channel consists of a 20dB gain Low-Noise pre-Amplifier (LNA) and a Variable Gain Amplifier (VGA). The differential outputs of the LNA can be switched through the 8x10 cross-point switch, which is programmable through the serial interface input port. The output of the LNA is fed directly into the VGA stage. The VGA consists of two parts, a Voltage-Controlled Attenuator (VCA) and a Programmable Gain Amplifier (PGA). The gain and gain range of the PGA can be digitally configured separately. The gain of the PGA can vary between four discrete settings of 25dB, 30dB, 35dB, and 40dB. The VCA has four programmable maximum attenuation settings: 29dB, 33dB, 36.5dB, and 40dB. Also, the VCA can be continuously varied by a control voltage from 0dB to a maximum of 29dB, 33dB, 36.5dB, and 40dB. The output of the PGA feeds directly into an integrated low-pass filter. The VCA8617 is an 8-channel variable gain amplifier ideally suited to portable ultrasound applications. Excellent dynamic performance enables use in low-power, high-performance portable applications. Each channel consists of a 20dB gain Low-Noise pre-Amplifier (LNA) and a Variable Gain Amplifier (VGA). The differential outputs of the LNA can be switched through the 8x10 cross-point switch, which is programmable through the serial interface input port. The output of the LNA is fed directly into the VGA stage. The VGA consists of two parts, a Voltage-Controlled Attenuator (VCA) and a Programmable Gain Amplifier (PGA). The gain and gain range of the PGA can be digitally configured separately. The gain of the PGA can vary between four discrete settings of 25dB, 30dB, 35dB, and 40dB. The VCA has four programmable maximum attenuation settings: 29dB, 33dB, 36.5dB, and 40dB. Also, the VCA can be continuously varied by a control voltage from 0dB to a maximum of 29dB, 33dB, 36.5dB, and 40dB. The output of the PGA feeds directly into an integrated low-pass filter.

The VFC110 voltage-to-frequency converter is a third-generation VFC offering improved features and performance. These include higher frequency operation, an on-board precision 5V reference and a Disable function. The precision 5V reference can be used for offsetting the VFC transfer function, as well as exciting transducers or bridges. The Enable pin allows several VFCs' outputs to be paralleled, multiplexed, or simply to shut off the VFC. The open-collector frequency output is TTL/CMOS-compatible. The output may be isolated by using an opto-coupler or transformer. Internal input resistor, one-shot and integrator capacitors simplify applications circuits. These components are trimmed for a full-scale output frequency of 4MHz at 10V input. No additional components are required for many applications. The VFC110 is packaged in plastic and ceramic 14-pin DIPs. Industrial and military temperature range gradeouts are available. The VFC110 voltage-to-frequency converter is a third-generation VFC offering improved features and performance. These include higher frequency operation, an on-board precision 5V reference and a Disable function. The precision 5V reference can be used for offsetting the VFC transfer function, as well as exciting transducers or bridges. The Enable pin allows several VFCs' outputs to be paralleled, multiplexed, or simply to shut off the VFC. The open-collector frequency output is TTL/CMOS-compatible. The output may be isolated by using an opto-coupler or transformer. Internal input resistor, one-shot and integrator capacitors simplify applications circuits. These components are trimmed for a full-scale output frequency of 4MHz at 10V input. No additional components are required for many applications. The VFC110 is packaged in plastic and ceramic 14-pin DIPs. Industrial and military temperature range gradeouts are available.

The VFC320 monolithic voltage-to-frequency and frequency-to-voltage converter provides a simple low cost method of converting analog signals into digital pulses. The digital output is an open collector and the digital pulse train repetition rate is proportional to the amplitude of the analog input voltage. Output pulses are compatible with TTL, and CMOS logic families. High linearity (0.005%, max at 10kHz FS) is achieved with relatively few external components. Two external resistors and two external capacitors are required to operate. Full scale frequency and input voltage are determined by a resistor in series with—In and two capacitors (one-shot timing and input amplifier integration). The other resistor is a non-critical open collector pull-up (fOUTto +VCC). The VFC320 is available in two performance grades. The VFC320 is specified for the –25°C to +85°C, range. The VFC320 monolithic voltage-to-frequency and frequency-to-voltage converter provides a simple low cost method of converting analog signals into digital pulses. The digital output is an open collector and the digital pulse train repetition rate is proportional to the amplitude of the analog input voltage. Output pulses are compatible with TTL, and CMOS logic families. High linearity (0.005%, max at 10kHz FS) is achieved with relatively few external components. Two external resistors and two external capacitors are required to operate. Full scale frequency and input voltage are determined by a resistor in series with—In and two capacitors (one-shot timing and input amplifier integration). The other resistor is a non-critical open collector pull-up (fOUTto +VCC). The VFC320 is available in two performance grades. The VFC320 is specified for the –25°C to +85°C, range.