NXP Semiconductors MC33290D

Overview

MC33290D from Freescale Semiconductor is an ISO 9141-compliant K-line serial bus interface IC designed for automotive on-board diagnostics (OBD) communication between vehicle microcontrollers and external diagnostic tools. It operates over 8.0–18 V supply, supports -40°C to +125°C ambient temperature, features thermal shutdown with hysteresis, and delivers robust short-circuit protection on the ISO pin. Its role is signal-level translation and bus driver conditioning in OBD-II compliant diagnostic gateways.

For engineers reviewing the MC33290D datasheet, MC33290D pinout, MC33290D application, or MC33290D equivalent, this page provides verified electrical parameters, validated SOIC-8 package mapping, confirmed ISO K-line timing behavior (≤2.0 µs fall time), thermal shutdown threshold (150–170°C), and real-world diagnostic interface design constraints including 10 nF parasitic capacitance tolerance and 510 Ω external pull-up compatibility.

Technical Context

The MC33290D implements a bi-directional half-duplex K-line physical layer transceiver using SMARTMOS process technology, integrating CMOS logic, bipolar/MOS analog circuitry, and DMOS power FETs. It performs level-shifting between 5.0 V CMOS microcontroller logic (VDD) and battery-referenced ISO bus signals (VBB), with internal active pull-down and passive pull-up on the ISO line.

Its control architecture includes a chip-enable (CEN) input with internal pull-down (2–40 µA), TX input with internal pull-up (-40 to -2.0 µA), and RX output compatible with standard CMOS thresholds. Propagation delay is ≤2.0 µs (high-to-low and low-to-high), and ISO output voltage swing is guaranteed at 0.95×VBB (high) and ≤0.1×VBB (low) under 510 Ω load conditions.

Key Specifications

Pinout & Package

The MC33290D is housed in an 8-pin SOICN (Small Outline Integrated Circuit, Narrow) plastic surface-mount package (suffix D), RoHS-compliant and Pb-free capable (EF suffix variant available).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar K-line transceiver applications.

Compared with MC33291D and TLE6250G, the MC33290D offers the most cost-effective, drop-in solution for single-wire ISO 9141 K-line interfaces - delivering identical timing, protection, and temperature performance in the same SOIC-8 footprint without requiring L-line capability or external 5 V regulation.

Availability

MC33290D is available at Aetrix Electronics and suitable for automotive diagnostic tools, ECU reprogramming ports, telematics gateways, and test bench interfaces requiring stable component supply across extended product lifecycles.

Supply support for MC33290D 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

Freescale Semiconductor (now part of NXP Semiconductors since 2015) was a leading designer of automotive and industrial analog/mixed-signal ICs, known for robust process technologies like SMARTMOS.

The MC33290D belongs to Freescale's ISO 9141 K-line interface product line, engineered specifically for automotive OBD-II diagnostic communication with emphasis on transient resilience, wide supply tolerance, and seamless integration with 5 V microcontrollers.

FAQ

What is the maximum data rate supported by the MC33290D?

The MC33290D supports a maximum data rate of 150 kbps, determined by its guaranteed ISO fall time of ≤2.0 µs and compatibility with up to 10 nF of bus parasitic capacitance. This meets ISO 9141-2 timing requirements for K-line diagnostic communication, enabling reliable transmission of diagnostic trouble codes (DTCs) and live parameter data in automotive applications. The MC33290D achieves this without external timing components due to its internally optimized driver stage.

Does the MC33290D require external components for basic ISO 9141 operation?

Yes, the MC33290D requires an external 510 Ω pull-up resistor from ISO to VBB and a reverse-battery blocking diode on the VBB line for full ISO 9141-2 compliance and fault protection. While it integrates internal pull-up and active pull-down on the ISO pin, the external 510 Ω resistor sets the bus termination impedance and enables proper voltage level definition per specification. The MC33290D datasheet Figure 1 explicitly shows these mandatory components in the simplified application diagram.

Is the MC33290D pin-compatible with the MC33291D?

Yes, the MC33290D and MC33291D share identical pinout, package (SOIC-8), and electrical specifications for all shared pins (VBB, GND, ISO, TX, RX, VDD, CEN). The MC33291D adds an L-line driver on Pin 2 (NC on MC33290D), but this does not affect routing or layout compatibility. Therefore, MC33290D can be used as a direct replacement in K-line-only systems, and MC33291D serves as a functional upgrade path when L-line support is later required - both use the same PCB footprint.

What is the purpose of the NC pin (Pin 2) on the MC33290D?

Pin 2 on the MC33290D is designated NC (No Connect) and must remain unconnected - it is not internally bonded and is not guaranteed to be an open circuit. This differs from the MC33291D, where Pin 2 functions as the L-line output. Leaving Pin 2 floating on the MC33290D avoids unintended coupling or leakage paths; soldering or routing to this pin violates the datasheet requirement and may compromise device reliability. The MC33290D's NC pin status is explicitly defined in Table 1 of the Rev 8.0 datasheet.

How does the MC33290D handle battery voltage transients such as load dump?

The MC33290D is rated for 45 V peak load dump on the VBB pin and 40 V on the ISO pin, meeting automotive transient immunity requirements per ISO 7637-2. Its SMARTMOS process and internal clamp structures allow survival of double-battery jump-start conditions (10 minutes duration) without permanent damage, though parametric performance is not guaranteed during the event. The MC33290D achieves this robustness without requiring external TVS diodes on VBB when paired with the recommended 500 Ω series resistor and 45 V zener - reducing BOM count and board space.