AD7742

a Single and Multichannel, Synchronous Voltage-to-Frequency Converters AD7741/AD7742 FUNCTIONAL BLOCK DIAGRAMS VDD REFIN/OUT PD +2.5V REFERENCE FEATURES AD7741: One Single-Ended Input Channel AD7742: Two Differential or Three Pseudo-Differential Input Channels Integral Nonlinearity of 0.012% at fOUT(Max) = 2.75 MHz (AD7742) and at fOUT(Max) = 1.35 MHz (AD7741) Single +5 V Supply Operation Buffered Inputs Programmable Gain Analog Front-End On-Chip +2.5 V Reference Internal/External Reference Option Power Down to 35 ␮ A Max Minimal External Components Required 8-Lead and 16-Lead DIP and SOIC Packages APPLICATIONS Low Cost Analog-to-Digital Conversion Signal Isolation GAIN VIN1 VIN2 VIN3 POWER-DOWN LOGIC VIN X1 VOLTAGE-TOFREQUENCY MODULATOR fOUT CLOCK GENERATION AD7741 CLKIN CLKOUT GND VDD UNI/BIP PD AD7742 POWER-DOWN LOGIC INPUT MUX X1/X2 VOLTAGE-TOFREQUENCY MODULATOR fOUT GENERAL DESCRIPTION VIN4 A1 A0 CLOCK GENERATION +2.5V REFERENCE The AD7741/AD7742 are a new generation of synchronous voltage-to-frequency converters (VFCs). The AD7741 is a single-channel version in an 8-lead package (SOIC/DIP) and the AD7742 is a multichannel version in a 16-lead package (SOIC/ DIP). No user trimming is required to achieve the specified performance. The AD7741 has a single buffered input whereas the AD7742 has four buffered inputs that may be configured as two fullydifferential inputs or three pseudo-differential inputs. Both parts include an on-chip +2.5 V bandgap r...