Analog Devices Inc./Maxim Integrated MAX16839ASA+

Overview

MAX16839ASA+ from Maxim Integrated is a high-voltage linear LED current-sink driver in an 8-pin SO-EP package, operating from 5V to 40V input and delivering programmable sink current from 15mA to 100mA with ±5% accuracy. It integrates an open-drain pass transistor, thermal shutdown, undervoltage lockout, and open-LED fault detection with event memory-designed for automotive exterior lighting including brake, tail, and turn signal lamps.

For engineers reviewing the MAX16839ASA+ datasheet, MAX16839ASA+ pinout, MAX16839ASA+ application, or MAX16839ASA+ equivalent, this page delivers verified technical context, real-world dimming timing (2.3–5.5µs DIM-to-current turn-on), fault latch behavior across multistring configurations, and thermal derating data (18.9mW/°C above +70°C) critical for under-hood LED system design.

Technical Context

The MAX16839ASA+ implements a single-stage linear current regulation architecture using an internal DMOS pass transistor referenced to CS, with V_CS regulated at 203mV (typ) to set I_LED. Its open-LED detection relies on monitoring V_CS falling below 25–35mV for 14–50µs, triggering a 2.8mA FLTS charge current that latches off all synchronized strings when FLTS pins are tied together.

Thermal protection activates at +160°C junction temperature with +15°C hysteresis, while UVLO engages at 3.6V (rising) with 0.3V hysteresis. The DIM input supports both PWM dimming up to 10kHz and active-high enable control, with 2.3µs typical delay from DIM rise to 50% I_LED turn-on and 1.3µs fall delay-enabling precise brightness synchronization across multiple LED strings.

Key Specifications

Pinout & Package

MAX16839ASA+ uses an 8-pin SO-EP (Small Outline with Exposed Pad) package. The exposed pad must be soldered to a large-area contiguous copper ground plane for effective thermal dissipation and cannot serve as the sole ground connection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar linear LED driver applications.

Compared with MAX16839ASA+, MAX16833ASA+ offers higher current headroom but omits critical fault memory for safety-critical lighting, while LM3409QMYX/NOPB shifts to a controller-based architecture requiring more external components and offering no direct replacement path for compact, self-contained linear driver needs.

Availability

MAX16839ASA+ is available at Aetrix Electronics and suitable for automotive exterior lighting, truck marker arrays, instrument cluster backlighting, and aircraft emergency signage requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX16839ASA+ 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for automotive, industrial, and communications applications, with emphasis on high-reliability, thermally robust solutions.

The MAX16839ASA+ belongs to Maxim's automotive-grade LED driver product line, engineered specifically for fail-safe, thermally demanding exterior and interior vehicle lighting where open-circuit detection, load-dump immunity, and multistring synchronization are mandatory.

FAQ

What is the maximum continuous LED sink current supported by the MAX16839ASA+?

The MAX16839ASA+ supports a maximum continuous LED sink current of 100mA. This value is programmable via the external current-sense resistor connected between CS and GND, with accuracy maintained at ±5% across the full -40°C to +125°C temperature range. Operation beyond 100mA risks exceeding thermal limits, especially in the 8-pin SO-EP package without adequate copper pour on the exposed pad.

How does the MAX16839ASA+ implement open-LED fault memory, and what capacitor value is recommended for FLTS?

The MAX16839ASA+ implements open-LED fault memory by charging the external FLTS capacitor (C_FLTS) with a 2.8mA current source when V_CS drops below 25–35mV for 14–50µs. A typical C_FLTS value is 0.1µF, selected to retain the fault state across power cycles while balancing board leakage and desired hold time. The exact value depends on multistring count, supply voltage, and required retention duration per the formula C_FLTS = (I_FLTS × t_FLTS × N) / (V_FLTS – V_FLTH).

Can the MAX16839ASA+ be used in multistring LED applications, and how is synchronization achieved?

Yes, the MAX16839ASA+ is explicitly designed for multistring LED applications. Synchronization is achieved by connecting all DIM inputs together to align turn-on timing, and all FLTS pins together to ensure simultaneous latching-off of all strings upon detection of an open-LED fault in any one string. This coordinated behavior is confirmed in Figure 2 of the MAX16839ASA+ datasheet and enables uniform brightness and fail-safe operation in automotive cluster and signaling systems.

What thermal derating applies to the MAX16839ASA+ in its 8-pin SO-EP package?

The MAX16839ASA+ in the 8-pin SO-EP package has a junction-to-ambient thermal resistance (θ_JA) of 53°C/W and a continuous power dissipation limit of 1509.4mW at +70°C ambient, derating at 18.9mW/°C above that temperature. To maintain safe operation at full 100mA sink current, the exposed pad must be soldered to a large contiguous copper ground plane; insufficient thermal relief will cause premature thermal shutdown at junction temperatures exceeding +160°C.

Does the MAX16839ASA+ support PWM dimming, and what are the timing specifications for DIM-controlled current switching?

Yes, the MAX16839ASA+ supports PWM dimming via the DIM input, with specified operation up to 10kHz. Its timing specifications include a 2.3µs (typ) delay from DIM rising edge to 50% I_LED turn-on, 1.3µs (typ) delay from DIM falling edge to 50% I_LED turn-off, and 2.5–5.5µs LED current rise/fall times. These values are measured under standard test conditions (VIN = 12V, RCS = 4.07Ω) and enable precise brightness control in dynamic lighting applications such as adaptive brake lights.