Datasheet AD7741, AD7742 (Analog Devices)

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Single and Multichannel, Synchronous Voltage-to-Frequency Converters AD7741/AD7742 FEATURES FUNCTIONAL BLOCK DIAGRAMS AD7741: One Single-Ended Input Channel V AD7742: Two Differential or Three Pseudo-Differential DD REFIN/OUT PD Input Channels Integral Nonlinearity of 0.012% at f +2.5V OUT(Max) = 2.75 MHz REFERENCE POWER-DOWN (AD7742) and at fOUT(Max) = 1.35 MHz (AD7741) LOGIC Single +5 V Supply Operation VOLTAGE-TO- Buffered Inputs V X1 FREQUENCY f IN OUT MODULATOR Programmable Gain Analog Front-End On-Chip +2.5 V Reference Internal/External Reference Option AD7741 CLOCK Power Down to 35
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A Max GENERATION Minimal External Components Required 8-Lead and 16-Lead DIP and SOIC Packages CLKIN CLKOUT GND APPLICATIONS Low Cost Analog-to-Digital Conversion Signal Isolation VDD UNI/BIP PD GAIN AD7742 POWER-DOWN V LOGIC IN1 V VOLTAGE-TO- IN2 INPUT X1/X2 FREQUENCY f MUX OUT MODULATOR VIN3 VIN4 GENERAL DESCRIPTION +2.5V CLOCK
The AD7741/AD7742 are a new generation of synchronous
A1 REFERENCE GENERATION
voltage-to-frequency converters (VFCs). The AD7741 is a
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single-channel version in an 8-lead package (SOIC/DIP) and the AD7742 is a multichannel version in a 16-lead package (SOIC/
GND CLKIN CLKOUT REFIN REFOUT
DIP). No user trimming is required to achieve the specified performance. The AD7741 has a single buffered input whereas the AD7742 The AD7741 has a single-ended voltage input range from 0 V has four buffered inputs that may be configured as two fully- to REFIN. The AD7742 has a differential voltage input range differential inputs or three pseudo-differential inputs. Both parts from –VREF to +VREF. Both parts operate from a single +5 V include an on-chip +2.5 V bandgap reference that provides the supply consuming typically 6 mA, and also contain a power- user with the option of using this internal reference or an exter- down feature that reduces the current consumption to less than nal reference. 35 µA. REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties
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