Texas Instruments MAX3222IPWR

Overview

MAX3222IPWR from Texas Instruments is a dual-channel RS-232 line driver and receiver IC operating from 3-V to 5.5-V supply, delivering ±15-kV HBM ESD protection on bus pins, supporting up to 250 kbps data rate, and featuring two drivers + two receivers with independent enable (EN) and power-down (PWRDOWN) controls - used in portable serial interface bridging between UARTs and DB9 connectors.

For engineers reviewing the MAX3222IPWR datasheet, MAX3222IPWR pinout, MAX3222IPWR application, or MAX3222IPWR equivalent, this page delivers verified package mapping (TSSOP-20), functional truth tables, charge-pump capacitor requirements (0.1 µF ×4 at 3.3 V), receiver input hysteresis (0.3 V), and driver slew rate (4–30 V/µs), all confirmed against TI's SLLS408H revision October 2016 production datasheet.

Technical Context

The MAX3222IPWR integrates a dual charge-pump circuit generating ±V_CC-derived RS-232 voltage levels (V+ and V−) using four external 0.1-µF capacitors, enabling single-supply operation without ±12-V rails. Its drivers convert 3.3-V/5-V logic to true RS-232 levels (±5.4 V), while receivers accept ±25-V inputs and output CMOS-compatible logic (V_OH ≥ V_CC − 0.6 V, V_OL ≤ 0.4 V).

Two independent control signals govern operational states: PWRDOWN (active-low) disables drivers and charge pump, reducing supply current to 1 µA while keeping receivers active; EN (active-low) enables/disables both receiver outputs, placing them in high-impedance state when high. Input thresholds are asymmetric (V_IT+ = 1.5–2.4 V, V_IT− = 0.6–1.5 V) with 0.3-V hysteresis for noise immunity.

Key Specifications

Pinout & Package

TSSOP-20 package (6.50 mm × 4.40 mm, 0.65-mm pitch), thermally enhanced for compact portable PCB layouts; RoHS-compliant, NIPDAU lead finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX3232IPWR, the MAX3222IPWR provides identical industrial-grade operation and pin compatibility at optimized quiescent current; versus SN65C3222IPWR, it trades speed for lower EMI and reduced layout sensitivity - making it preferable for portable, battery-powered, and noise-sensitive deployments.

Availability

MAX3222IPWR is available at Aetrix Electronics and suitable for industrial serial gateways, medical handheld diagnostics, POS terminal peripheral interfaces, and avionics maintenance port adapters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX3222IPWR 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 innovation in interface ICs and power management solutions.

The MAX3222IPWR belongs to TI's RS-232 transceiver product line, engineered specifically for low-power, high-ESD robustness serial communication in portable and industrial systems - emphasizing single-supply operation, minimal external components, and guaranteed interoperability with legacy TIA/EIA-232-F infrastructure.

FAQ

What is the maximum data rate supported by the MAX3222IPWR?

The MAX3222IPWR supports a maximum data signaling rate of 250 kbps under standard load conditions (CL = 1000 pF, RL = 3 kΩ). This is confirmed in Section 6.8 of TI's SLLS408H datasheet. The device maintains reliable signal integrity at this rate with pulse skew ≤300 ns and controlled slew rate (4–30 V/µs), making it suitable for UART-based applications including GPS modules and industrial telemetry. Higher rates risk timing violations and increased bit error rate.

Does the MAX3222IPWR require external capacitors, and what values are needed?

Yes, the MAX3222IPWR requires four external ceramic capacitors for its dual charge-pump circuit: C1+, C1−, C2+, and C2−. At 3.3 V V_CC, use 0.1 µF for all four; at 5 V V_CC, use 0.047 µF for C1 and 0.33 µF for C2, C3, and C4 (per Table 3 in the datasheet). These values ensure stable ±V_CC rail generation and meet TIA/EIA-232-F compliance. Polarized capacitors are not recommended unless correctly oriented per Figure 8.

How does the power-down mode function on the MAX3222IPWR?

Setting PWRDOWN low places the MAX3222IPWR in power-down mode, reducing supply current to 1 µA typical. In this state, drivers go high-impedance, the charge pump disables (V+ drops to V_CC, V− rises toward GND), and receivers remain fully operational. This allows wake-up capability via RS-232 input activity while minimizing battery drain - a key feature for handheld and remote sensor applications using the MAX3222IPWR.

Can the MAX3222IPWR interface a 5-V microcontroller with a 3.3-V supply?

Yes, the MAX3222IPWR accepts 5-V logic inputs (DIN1, DIN2, EN, PWRDOWN) even when powered from a 3.3-V V_CC, as specified in Section 6.3 (VIH = 2 V min at V_CC = 3.3 V). This eliminates the need for external level shifters when connecting legacy 5-V UART peripherals to modern 3.3-V SoCs - a verified design advantage explicitly documented for the MAX3222IPWR in TI's datasheet.

What is the purpose of the EN pin on the MAX3222IPWR?

The EN (Enable) pin on the MAX3222IPWR is an active-low control that places both receiver outputs (ROUT1 and ROUT2) into high-impedance state when driven high. When pulled low, receivers operate normally. This allows selective disabling of receiver outputs without affecting driver operation or supply current - useful in multi-drop RS-232 buses or shared UART lines where output contention must be avoided. The EN pin must never be left floating.