Analog Devices Inc. ADM3307EARU

ADM3307EARU RS-232 Transceiver Product Summary from Analog Devices

The ADM3307EARU, part of Analog Devices’ robust serial port transceiver family, is engineered to meet full RS-232 compliance while operating from a single supply voltage between 2.7 V and 3.6 V. Integrating five drivers and three receivers into a 28-TSSOP package, the ADM3307EARU simplifies the requirements for RS-232-level translation in space-constrained and portable electronic systems. Its built-in charge pump eliminates dual-supply needs, offering practical energy savings and design flexibility for battery-powered equipment such as mobile data cables, laptops, and personal devices. The device is suitable for industrial applications given its extended operating temperature range (-40°C to +85°C) and advanced protection features.

ADM3307EARU Main Characteristics and Performance Advantages

The ADM3307EARU stands out by offering full RS-232 compliance with advanced performance characteristics. Among its signature features, it utilizes “Green Idle” power-saving mode, efficiently gating the charge pump oscillator to maintain output voltages (±7.25 V) while minimizing current draw. Data rates reach up to 920 kbps at 3 V supply, making it suitable for high-speed communication links. An integrated shutdown mode draws as little as 20 nA, preserving battery life during idle periods. Importantly, the device retains one receiver in active state during shutdown, enabling peripheral monitoring without fully powering the system. Exceptional ESD protection (≥15 kV, IEC 1000-4-2 standard) on all input/output lines further ensures reliability in rugged or plug-intensive environments.

Operating Principles of the ADM3307EARU RS-232 Transceiver

At the heart of the ADM3307EARU’s function is a CMOS-based architecture that couples line-level transmitters and receivers with an onboard charge pump voltage converter. The charge pump features a tripler and inverter, generating both positive and negative RS-232 voltage levels from the single logic supply. The block diagram reveals five transmitter (driver) channels and three receiver channels, each protected by internal resistors for optimized input and output impedance. An active receiver in shutdown mode is realized through dedicated circuit design, permitting peripheral signal detection. Control pins (EN and SD) offer host system management of power modes and enable robust power gating strategies for mobile or standby operation.

Electrical Parameters of the ADM3307EARU Series

Engineers evaluating the ADM3307EARU will find its supply and signal characteristics align with modern low-power requirements. The transceiver operates across a supply voltage of 2.7–3.6 V, with quiescent supply current ranging from 0.75 to 1.5 mA (nominal, no load), and a maximum shutdown supply current of just 1 μA. Its EIA-232 input voltage range spans ±25 V, with receiver input thresholds set for reliable logic state discrimination. RS-232 output swings are guaranteed between ±5.0 V and ±6.4 V, loaded at 3 kΩ, with transmitter output resistance at 300 Ω. Maximum data rates of up to 920 kbps (3 V operation) support rapid data exchanges in portable devices and industrial equipment. Signal propagation delays, output enable/disable times, and input/output leakage currents are minimized for efficient real-time operation.

Temperature and Environmental Limits for ADM3307EARU

Robustness is paramount in the ADM3307EARU design. Thermal impedance values for the 28-TSSOP package stand at 68.0°C/W, supporting operation in densely populated assemblies. Absolute maximum ratings allow Vcc up to +4 V and I/O voltage swings to ±15 V for RS-232 outputs, with input pins accommodating up to ±30 V. The storage temperature range extends from −65°C to +150°C, and the device withstands soldering temperatures of up to 300°C for brief intervals. The industrial temperature rating (-40°C to +85°C) assures the ADM3307EARU’s suitability for field-deployed systems in demanding climates.

ADM3307EARU Application ESD Resistance and Reliability

A key differentiator of the ADM3307EARU is its enhanced ESD protection. The device features robust circuitry shielding all I/O lines, including RS-232, CMOS, EN, and SD pins, against discharges up to ±15 kV (human body model and IEC air discharge) and ±8 kV (contact discharge). This compliance with IEC 1000-4-2 standards is essential for mission-critical applications where cables are frequently connected and disconnected, including in mobile, industrial, and medical designs. Analog Devices’ patented protection ensures minimal risk of latch-up or logic upset even in harsh electromagnetic environments.

ADM3307EARU Packaging Types and Pinout Details

The ADM3307EARU is exclusively offered in a compact 28-TSSOP (4.4 mm width) surface-mount package, supporting automated, high-density PCB layouts. The pin configuration includes dedicated lines for the five RS-232 transmitters and three receivers, along with necessary support for charge pump capacitors, supply voltage (Vcc), ground, enable (EN), and shutdown (SD) control. Each CMOS input features a built-in 400 kΩ pull-up resistor, while all outputs are arranged to minimize crosstalk and facilitate clear signal routing. The exposed pad is internally connected to ground, aiding thermal management.

Typical Applications and Deployment Examples of ADM3307EARU

The ADM3307EARU’s electrical and environmental robustness makes it ideal for portable and stationary serial communications. Prime use cases include mobile phone data cables, notebook/laptop computers, printers, modems, PDAs, hand-held computing devices, and automotive systems. The device’s high data rates, low-power shutdown, and active receiver enable uninterrupted monitoring and efficient wake-up protocols in battery-operated designs. Compliance with EIA/TIA-232 and intrinsic ESD suppression further enhance its reliability in office and industrial networking environments where cable wear and static events are frequent concerns.

Alternative and Substitute Models for ADM3307EARU

With the ADM3307EARU designated as obsolete, engineers and procurement specialists are advised to assess direct analogs within the Analog Devices series. Notable alternatives include the ADM3310E, ADM3311E, ADM3312E, and ADM3315E. These variants share the single-supply, charge pump-powered RS-232 interface with full compliance, ESD protection, and varying driver/receiver channel counts. Depending on system pinout needs, operating current, and shutdown receiver activity, a suitable replacement can be selected. For instance, ADM3311E and ADM3310E offer five receivers (versus three in the ADM3307EARU), while the ADM3312E and ADM3315E feature tailored input resistances for optimized current draw in portable electronics.

Conclusion

: Selecting the ADM3307EARU for RS-232 Connectivity

For engineers and buyers evaluating RS-232 connectivity solutions, the ADM3307EARU integrates high data rate capability, exceptional ESD robustness, and advanced power management in a single-supply CMOS architecture. Its thoughtful shutdown and receiver-active features are especially advantageous for battery-operated and standby systems. Although the ADM3307EARU is now obsolete, its design strengths persist in closely related Analog Devices models, ensuring continued support for high-performance serial data interfaces in portable, automotive, and industrial applications. Careful review of system requirements and the ADM3307EARU’s comprehensive specification table enables informed device selection and successful circuit integration.