ADM101EARM

Overview

The ADM101EARM is a single-channel RS-232 transceiver from the Analog Devices Craft Port series, designed for portable applications. It operates from a single 5 V supply and utilizes an internal charge-pump DC-DC converter to generate the required negative voltage, eliminating the need for external negative rails. The device supports data rates up to 460 kbit/s with ±4.2 V output swing. Key electrical parameters include a typical supply current of 1 mA in active mode and 1 μA in shutdown mode. It features Schmitt trigger inputs with 0.2 V hysteresis and provides ESD protection exceeding 15 kV on all I/O pins. The component is housed in a 10-lead MSOP package.

Feature Summary

• Integrates a highly efficient charge-pump DC-DC converter to generate internal negative supply voltages from a single positive source.
• Features ultralow power consumption with a dedicated shutdown mode that disables the charge pump while keeping the receiver active.
• Includes overvoltage protection on receiver inputs capable of withstanding continuous voltages beyond ±30 V.
• Provides robust electrostatic discharge (ESD) protection on all input and output pins.

Applications

• Mobile telephones
• Palmtop computers
• Personal digital assistants (PDAs)
• Portable instrumentation
• GPS receivers

Procurement Notes

Verify the specific ordering suffix to confirm packaging format and compliance status. The base model designation indicates the functional variant, while suffixes such as Z denote RoHS compliance. Ensure the selected package option matches the required manufacturing process. Confirm temperature range specifications align with the intended operational environment before finalizing procurement orders.

Selection Notes

Select this component when space constraints and low power consumption are critical design factors. The integrated charge pump simplifies circuit design by removing the need for dual-rail power supplies. Verify that the 460 kbit/s transmission rate meets system requirements. Consider the automotive-grade variants if the application demands higher reliability standards or specific quality certifications defined by the manufacturer.

Part Context

The ADM101E belongs to the Analog Devices Craft Port series, which focuses on miniaturized interface solutions for battery-powered devices. This series emphasizes compact footprints and energy efficiency. The ARMZ suffix variants indicate lead-free construction compliant with environmental directives. The family includes reel and tape options for automated assembly processes.

Replacement Considerations

Direct replacements within the same series include the ADM101EARM-REEL and ADM101EARM-REEL7, which share identical electrical characteristics but differ in packaging quantities. Automotive qualified versions are designated with the W suffix, such as ADM101EWARMZ-REEL7. Designers must verify pin compatibility and thermal performance when substituting these variants.

FAQ

How does the ADM101E generate the negative voltage required for RS-232 signaling?

The device uses an internal charge-pump DC-DC converter driven by a 200 kHz oscillator. This circuit utilizes two external capacitors to invert the positive 5 V supply, creating the necessary negative rail without requiring an external negative power source.

What is the behavior of the receiver during shutdown mode?

When the shutdown input is set to Logic 1, the charge pump and transmitter are disabled to minimize power consumption. However, the receiver remains functional and active during this state.

What type of input protection is provided on the receiver pins?

The receiver inputs feature internal pull-down resistors and are protected against overvoltages up to ±30 V. Additionally, all I/O pins provide electrostatic discharge (ESD) protection rated at greater than 15 kV.