Overview
The AD7740KRMZ, 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 of either 3.0 V to 3.6 V or 4.75 V to 5.25 V, consuming a typical current of 0.9 mA. It is available in 8-lead SOT-23 and 8-lead MSOP packages, making it ideal for space-constrained and cost-sensitive applications. The AD7740 features an internal 2.5 V bandgap reference, which can be overdriven by an external reference if needed. The device is known for its ease of use, low power consumption, and minimal requirement for external components.
Key Specifications
| Parameter | Specification |
|---|---|
| Supply Voltage | 3.0 V to 3.6 V or 4.75 V to 5.25 V |
| Current Consumption | 0.9 mA (typical) |
| Package Type | 8-lead SOT-23, 8-lead MSOP |
| Input Frequency Range | 0 to 1 MHz |
| Output Frequency Range | 10% to 90% of fCLKIN |
| Input Range (Buffered Mode) | 0.1 V to VDD - 0.2 V |
| Input Range (Unbuffered Mode) | -0.15 V to VDD + 0.15 V |
| Voltage Reference Range | 2.5 V to VDD |
| Operating Temperature Range | -40°C to +105°C (Y Grade), 0°C to +85°C (K Grade) |
Key Features
- Synchronous operation with the clock signal on the CLKIN pin
- Full-scale output frequency set by the external system clock
- Low power consumption: 3 mW (typical)
- Internal 2.5 V bandgap reference, which can be overdriven by an external reference
- Selectable high impedance buffered input
- Minimal external components required
- Automatic power-down function when CLKIN is inactive low for 1 ms (typical)
- True -150 mV capability without charge pump
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 AD7740KRMZ?
The AD7740KRMZ operates from a single supply voltage of either 3.0 V to 3.6 V or 4.75 V to 5.25 V.
- What are the available package types for the AD7740KRMZ?
The device is available in 8-lead SOT-23 and 8-lead MSOP packages.
- What is the maximum input frequency for the AD7740KRMZ?
The maximum input frequency is 1 MHz.
- How does the output frequency range relate to the clock input frequency?
The output frequency ranges from 10% to 90% of the clock input frequency (fCLKIN).
- What is the input range for the buffered and unbuffered modes?
In buffered mode, the input range is 0.1 V to VDD - 0.2 V. In unbuffered mode, the input range is -0.15 V to VDD + 0.15 V.
- Can the internal voltage reference be overdriven by an external reference?
Yes, the internal 2.5 V bandgap reference can be overdriven by an external reference.
- What is the typical current consumption of the AD7740KRMZ?
The typical current consumption is 0.9 mA.
- Does the AD7740KRMZ have an automatic power-down feature?
Yes, the device automatically enters power-down when CLKIN is inactive low for 1 ms (typical).
- What are some common applications of the AD7740KRMZ?
Common applications include isolation of high common-mode voltages, low-cost analog-to-digital conversion, battery monitoring, and automotive sensing.
- What is the operating temperature range for the AD7740KRMZ?
The operating temperature range is -40°C to +105°C for the Y Grade and 0°C to +85°C for the K Grade.
