Texas Instruments MAX3318EIPWR

Overview

MAX3318EIPWR from Texas Instruments is a dual-driver/dual-receiver RS-232 transceiver operating from a single 2.25-V to 3-V supply, delivering ±4 V RS-232 output swing, 460-kbps data rate, and ±15-kV IEC 61000-4-2 air-gap ESD protection. It serves as a low-power interface bridge between 2.5-V logic systems and legacy RS-232 peripherals in portable industrial terminals.

For engineers reviewing the MAX3318EIPWR datasheet, MAX3318EIPWR pinout, MAX3318EIPWR application, or MAX3318EIPWR equivalent, key selection considerations include its auto-power-down plus mode (1-μA standby), TSSOP-20 package compatibility with space-constrained PCBs, dual-channel independent control via FORCEON/FORCEOFF, and INVALID/READY status signaling for system-level power management.

Technical Context

The MAX3318EIPWR integrates a dual charge-pump architecture generating ±2×VCC rails (V+ and V−) using four 0.1-μF capacitors, enabling true RS-232 voltage levels from sub-3-V logic supplies. Its proprietary low-dropout driver stage achieves ±3.7 V minimum output swing into 3-kΩ loads at 2.5 V VCC.

Auto-power-down plus operates when FORCEON = low and FORCEOFF = high, entering 1-μA standby after ~30 s of inactivity on all RIN/DIN inputs; wake-up occurs within 100 μs upon valid edge detection. The INVALID output asserts high when any RIN exceeds ±2.7 V or transitions through the indeterminate zone (<30 μs), directly supporting cable-detect and link-status monitoring.

Key Specifications

Pinout & Package

TSSOP-20 package (PW), 6.4 mm × 4.4 mm × 1.2 mm height, RoHS-compliant NIPDAU lead finish, MSL Level-1, 2000-piece tape-and-reel (Q1 pin orientation).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RS-232 transceiver applications.

Compared with MAX3232ECPWR and SP3232EEN-L, the MAX3318EIPWR uniquely delivers 2.25-V operation, 460-kbps speed, and hardware INVALID/READY signaling in a 6.4-mm × 4.4-mm TSSOP, making it the only option meeting simultaneous low-voltage, high-speed, and system-aware power requirements.

Availability

MAX3318EIPWR is available at Aetrix Electronics and suitable for battery-powered systems, handheld medical devices, and industrial data loggers requiring stable component supply across extended product lifecycles.

Supply support for MAX3318EIPWR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies with over 50 years of industrial-grade reliability validation.

The MAX3318EIPWR belongs to TI's RS-232 transceiver product line, engineered specifically for ultra-low-power, single-supply interfacing in portable and energy-sensitive applications.

FAQ

What is the minimum supply voltage required for reliable operation of the MAX3318EIPWR?

The MAX3318EIPWR operates reliably from 2.25 V to 3 V. At 2.25 V, it maintains ±3.7 V RS-232 output swing into 3-kΩ loads and sustains 460-kbps data rates per the datasheet's recommended operating conditions. Below 2.25 V, V− may fail to reach −3.5 V, causing READY to remain low and disabling transmitter operation. The MAX3318EIPWR must not be operated below 2.25 V in production systems.

How does the INVALID output function in the MAX3318EIPWR, and what design value does it provide?

The INVALID output of the MAX3318EIPWR is an open-drain signal that goes high when any RIN input exceeds ±2.7 V or transitions through the ±0.3 V indeterminate window in under 30 μs. It stays low only when all RIN inputs remain within ±0.3 V for >30 μs-indicating cable disconnection or invalid signal. This eliminates software polling and external comparators, enabling hardware-triggered sleep/wake in battery-powered systems using the MAX3318EIPWR.

Can the MAX3318EIPWR be used with a 3.3-V microcontroller I/O interface?

No-the MAX3318EIPWR is not rated for 3.3-V logic interfaces. Its DIN, FORCEON, and FORCEOFF inputs specify VIH ≥ 0.7×VCC and VIL ≤ 0.3×VCC, meaning at VCC = 3 V, VIH = 2.1 V max and VIL = 0.9 V min. A 3.3-V MCU output may exceed absolute maximum ratings (6 V) or cause undefined logic states. The MAX3318EIPWR must be driven by 2.5-V logic or level-shifted 3.3-V signals; direct connection to 3.3-V GPIO violates its input voltage specifications.

What is the purpose of the FORCEON and FORCEOFF pins on the MAX3318EIPWR, and how do they interact?

FORCEOFF (pin 20) is an active-low manual shutdown that immediately disables drivers and the charge pump, overriding all other controls. FORCEON (pin 14) is active-high and only takes effect when FORCEOFF is high; it forces drivers active and disables auto-power-down plus. When both are high, normal operation occurs; when FORCEON = low and FORCEOFF = high, auto-power-down plus engages. This dual-control scheme gives designers precise, hardware-based power-state management for the MAX3318EIPWR.

Does the MAX3318EIPWR require external capacitors, and if so, what values and types are specified?

Yes-the MAX3318EIPWR requires four external 0.1-μF ceramic capacitors: C1+ (pin 2), C1− (pin 4), C2+ (pin 5), and C2− (pin 6). These must be X7R or better dielectric, rated ≥10 V, placed within 5 mm of the device per TI layout guidelines. No bypass capacitor is needed on VCC beyond standard PCB decoupling, as the internal regulation is optimized for this exact capacitor set. Omitting or substituting values degrades RS-232 output swing and stability of the MAX3318EIPWR.