Texas Instruments SN65C3243PWR

Overview

SN65C3243PWR from Texas Instruments is a 3-V to 5.5-V RS-232 line driver and receiver IC with three drivers, five receivers, ±15-kV HBM ESD protection on bus pins, 1 μA standby current, and support for data rates up to 1 Mbit/s. It integrates a dual charge-pump circuit requiring only four 0.1-μF external capacitors and features an always-active noninverting receiver output (ROUT2B) for ring-indicator functionality during power-down.

For engineers reviewing the SN65C3243PWR datasheet, SN65C3243PWR pinout, SN65C3243PWR application, or SN65C3243PWR equivalent, key selection considerations include its TSSOP-28 package, auto-powerdown control via FORCEON/FORCEOFF inputs, INVALID status output, slew rate range of 24–150 V/μs, and compatibility with 3.3-V logic while operating from a 5-V supply.

Technical Context

The SN65C3243PWR implements a dual-stage charge-pump architecture generating ±15-V RS-232 compliant outputs from a single 3.3-V or 5-V supply, using four 0.1-μF external capacitors. Its auto-powerdown mode activates when FORCEON = GND and FORCEOFF = VCC, disabling drivers and most receivers while maintaining ROUT2B activity and reducing ICC to ≤10 μA.

Receiver input thresholds are VIT+ = 1.6–2.4 V and VIT− = 0.6–1.4 V (dependent on VCC), with 0.5-V hysteresis; the INVALID output asserts high when any RIN exceeds ±2.7 V or remains within −0.3 V to +0.3 V for <30 μs, and low when all RIN stay in that indeterminate band for >30 μs.

Key Specifications

Pinout & Package

TSSOP-28 package (9.70 mm × 4.40 mm body size), lead-free, RoHS-compliant, moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN65C3238PWR and MAX3232EUP+, the SN65C3243PWR uniquely delivers 3 drivers + 5 receivers in TSSOP-28 with ROUT2B and INVALID outputs-enabling full RS-232 modem control and autonomous wake-up in battery-sensitive portable systems without layout redesign.

Availability

SN65C3243PWR is available at Aetrix Electronics and suitable for portable computing interfaces, industrial serial gateways, medical handheld diagnostics, and point-of-sale terminals requiring stable component supply and long-term production continuity.

Supply support for SN65C3243PWR 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 company specializing in analog and embedded processing technologies, with leadership in interface, power management, and signal chain solutions.

The SN65C3243PWR belongs to TI's RS-232 transceiver product line, designed specifically for low-power, multi-channel serial communication in battery-operated and space-constrained embedded systems.

FAQ

What is the maximum data rate supported by the SN65C3243PWR?

The SN65C3243PWR supports data rates up to 1 Mbit/s under specified load and capacitance conditions (CL = 250 pF, RL = 3 kΩ). At higher capacitance (CL = 1000 pF), the maximum rate is 250 kbit/s for VCC = 3 V–4.5 V and 1000 kbit/s for VCC = 4.5 V–5.5 V. These values are measured per TIA/EIA-232-F timing compliance.

Does the SN65C3243PWR require external charge-pump capacitors?

Yes, the SN65C3243PWR requires four external 0.1-μF capacitors (C1–C4) for charge-pump operation when powered from 3.3 V. At 5 V, C1 is 0.047 μF and C2–C4 are 0.33 μF. These capacitors enable generation of ±15-V RS-232 compliant outputs from a single supply.

How does the INVALID output function on the SN65C3243PWR?

The INVALID output on the SN65C3243PWR goes high when any receiver input (RIN1–RIN5) exceeds ±2.7 V or remains within −0.3 V to +0.3 V for less than 30 μs. It goes low only when all RIN inputs stay within that indeterminate band for more than 30 μs - indicating loss of valid RS-232 signal presence.

Can the SN65C3243PWR operate with a 3.3-V supply while interfacing with 5-V logic inputs?

Yes, the SN65C3243PWR accepts 5-V logic inputs (e.g., on DIN1–DIN3, FORCEON, FORCEOFF) while operating from a 3.3-V VCC supply. This eliminates the need for external level-shifting circuitry when connecting to legacy 5-V UARTs or control signals.

What is the purpose of the ROUT2B pin on the SN65C3243PWR?

The ROUT2B pin on the SN65C3243PWR is an always-active noninverting receiver output tied to RIN2. It remains functional even when the device is powered down (FORCEOFF = GND), enabling continuous ring indicator (RI) monitoring in laptop or modem applications without host processor intervention.