**ADM207EAR: A Comprehensive Technical Overview and Application Note**

The **ADM207EAR** is a robust, high-performance integrated circuit from Analog Devices, specifically designed as a **±15 kV ESD-protected, RS-232 compliant transceiver**. This device is engineered to facilitate full-duplex serial communication in electrically noisy environments where voltage spikes and electrostatic discharge (ESD) pose a significant risk to system integrity. Its combination of durability, low power consumption, and compliance with the EIA-232E standards makes it a cornerstone component in a wide array of data communication interfaces.

Housed in a compact 16-pin SOIC package, the ADM207EAR integrates both a driver and a receiver channel. A key feature of this IC is its **on-board, dual charge-pump circuitry**, which requires only a single +5V power supply to generate the necessary ±5.5V output voltages for RS-232 compliance. This eliminates the need for costly and bulky dual external power supplies, simplifying board design and reducing overall system cost.

The device's most critical attribute is its exceptional **robustness against ESD events**. All transmitter outputs and receiver inputs are protected to **±15 kV using the Human Body Model (HBM)**. This high level of protection is crucial for applications where connectors are exposed and accessible to users, such as on industrial control panels, point-of-sale (POS) terminals, and communication ports, effectively preventing costly field failures and enhancing product reliability.

From a performance standpoint, the ADM207EAR guarantees a **minimum data rate of 120 kbps**, making it suitable for a broad spectrum of applications, from slower industrial sensor networks to standard modem and computer serial port communications. It also features a low-power shutdown mode that reduces the supply current to a mere 5 µA, a vital characteristic for battery-powered and portable equipment.

**Application Notes and Circuit Implementation**

Implementing the ADM207EAR in a design is straightforward. A typical application circuit for a full-duplex point-to-point connection requires minimal external components: only four small **0.1 µF charge-pump capacitors** are needed for the voltage converter to function. The following design considerations are paramount:

1. **PCB Layout:** The four capacitors (**C1, C2, C3, C4**) must be placed as close as possible to their designated pins on the IC to minimize parasitic inductance and ensure efficient charge-pump operation.

2. **Bypassing:** A **0.1 µF ceramic bypass capacitor** between the VCC and GND pins is essential to decouple the internal logic and suppress noise on the power supply line.

3. **Interface Connection:** The driver output (T1OUT) is connected to the remote device's receiver input (RIN), while the local receiver input (R1IN) is connected to the remote device's driver output (TOUT). The GND connection establishes a common ground reference between the two systems.

A common application is in industrial programmable logic controller (PLC) systems, where the ADM207EAR is used to create a reliable serial data link (e.g., for programming, configuration, or data logging) that is immune to the harsh electrical noise typically found on factory floors.

**ICGOODFIND**

The ADM207EAR stands out as an **industry-standard solution for robust serial communication**. Its integrated ESD protection, single-supply operation, and low-power shutdown mode make it an exceptionally reliable and efficient choice for designers. It effectively bridges the gap between legacy RS-232 interfaces and modern low-voltage logic, ensuring data integrity in the most challenging environments.

**Keywords:**

RS-232 Transceiver

ESD Protection

Charge-Pump Circuitry

Single 5V Power Supply

Data Communication