Overview
The AD7740KRM-REEL7, produced by Analog Devices Inc., is a low-cost, ultrasmall synchronous Voltage-to-Frequency Converter (VFC). This device is designed to operate from a single supply voltage ranging from 3.0 V to 3.6 V or 4.75 V to 5.25 V, making it versatile for various applications. The AD7740 is available in 8-lead SOT-23 and 8-lead MSOP packages, emphasizing small size, low cost, and ease of use. It includes an on-chip 2.5 V bandgap reference, which can be overdriven by an external reference if needed.
Key Specifications
| Parameter | Value | Conditions |
|---|---|---|
| Supply Voltage (VDD) | 3.0 V to 3.6 V or 4.75 V to 5.25 V | |
| Current Consumption (IDD) | 0.9 mA to 1.25 mA | Normal Mode |
| Input Frequency Range | 0 to 1 MHz | |
| Input Voltage Range (VIN) | 0 V to VREF (buffered mode), -0.15 V to VDD + 0.15 V (unbuffered mode) | |
| Reference Voltage (VREF) | 2.5 V (internal), can be overdriven by an external reference up to VDD | |
| Output Frequency Range | 10% to 90% of fCLKIN | |
| Input High Voltage (VIH) | 2.1 V (VDD = 3.3 V), 2.4 V (VDD = 5 V) | |
| Input Low Voltage (VIL) | 0.4 V (VDD = 3.3 V), 0.8 V (VDD = 5 V) | |
| Output High Voltage (VOH) | 2.1 V (VDD = 3.3 V), 4.0 V (VDD = 5 V) | |
| Output Low Voltage (VOL) | 0.1 V to 0.4 V |
Key Features
- Synchronous operation with the system clock.
- Full-scale frequency set by the external system clock.
- Available in 8-lead SOT-23 and 8-lead MSOP packages.
- Low power consumption: 3 mW (typical) at 3.3 V supply.
- Internal 2.5 V reference voltage, which can be overdriven by an external reference.
- Selectable high impedance buffered input.
- Minimal external components required.
- High input impedance in buffered mode.
Applications
- Isolation of high common-mode voltages.
- Low-cost analog-to-digital conversion.
- Battery monitoring.
- Automotive sensing.
- Isolated analog signal transmission applications.
Q & A
- What is the supply voltage range for the AD7740?
The AD7740 operates from a single supply voltage ranging from 3.0 V to 3.6 V or 4.75 V to 5.25 V.
- What are the package options for the AD7740?
The AD7740 is available in 8-lead SOT-23 and 8-lead MSOP packages.
- What is the maximum input frequency for the AD7740?
The maximum input frequency for the AD7740 is 1 MHz.
- Can the internal reference voltage be overdriven by an external reference?
- What are the typical applications of the AD7740?
The AD7740 is used in applications such as isolation of high common-mode voltages, low-cost analog-to-digital conversion, battery monitoring, automotive sensing, and isolated analog signal transmission.
- How does the AD7740 handle input voltage ranges?
The AD7740 can handle input voltages from 0 V to VREF in buffered mode and from -0.15 V to VDD + 0.15 V in unbuffered mode.
- What is the power consumption of the AD7740?
The AD7740 consumes approximately 3 mW of power at a 3.3 V supply.
- Can the AD7740 be used for high-resolution ADC applications?
- How does the AD7740 reject interfering signals?
The AD7740 can reject interfering signals by counting for an integer number of periods of the interfering signal, which is achieved by setting an appropriate gate interval.
- Is the AD7740 suitable for isolated analog signal transmission?
