Microchip Technology AT9919K7-G

Overview

AT9919K7-G from Microchip Technology is a hysteretic buck PWM controller IC designed to drive high-brightness LEDs with high-side current sensing. It operates from 4.5V to 40V input, delivers >90% efficiency, maintains ±5% LED current accuracy, supports up to 2 MHz switching frequency, and enables analog or PWM dimming-used in automotive exterior lighting and industrial signage.

For engineers reviewing the AT9919K7-G datasheet, AT9919K7-G pinout, AT9919K7-G application, or AT9919K7-G equivalent, key selection criteria include high-side current sense architecture, 125°C operating temperature, 8-lead DFN thermal performance, and dual-dimming interface compatibility (DIM + ADIM/RAMP).

Technical Context

The AT9919K7-G implements hysteretic control using a high-side current sense resistor to regulate constant LED current without external compensation. Its comparator-based architecture sustains accuracy across wide input voltage (4.5–40V) and temperature (–40°C to +125°C) ranges while enabling fast transient response and stable operation at up to 2 MHz.

Dimming is implemented via two independent paths: logic-level PWM on DIM pin (VIH ≥ 2.2V, VIL ≤ 0.7V), and analog-controlled PWM via ADIM (0–2.0V input) synchronized to a programmable ramp generated at RAMP pin using an external capacitor-enabling true constant-color dimming over wide duty cycles.

Key Specifications

Pinout & Package

AT9919K7-G is housed in an 8-lead DFN package (3 mm × 3 mm, 0.5 mm pitch) with exposed thermal pad (TAB) tied to GND for enhanced power dissipation (θJA = 37°C/W). The package is RoHS-compliant and lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ4425AGL-Z and LM3409HVMM/NOPB, the AT9919K7-G uniquely integrates both high-side current sensing and a programmable analog PWM dimming ramp - enabling compact, thermally robust, and color-stable LED drivers without external signal conditioning.

Availability

AT9919K7-G is available at Aetrix Electronics and suitable for automotive exterior lighting, industrial signage, architectural lighting, and commercial downlighting requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AT9919K7-G 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

Microchip Technology is a global semiconductor company specializing in microcontrollers, analog devices, and timing solutions, with ISO/TS-16949 certified manufacturing facilities.

The AT9919K7-G belongs to Microchip's high-brightness LED driver controller product line, engineered specifically for efficient, thermally resilient, and dimming-flexible constant-current LED power stages in harsh-environment applications.

FAQ

What is the maximum input voltage supported by the AT9919K7-G?

The AT9919K7-G supports a DC input voltage range of 4.5V to 40V, with an absolute maximum rating of +45V on the VIN and CS pins. Operation beyond 40V is not guaranteed and may trigger overvoltage stress conditions. For designs requiring >40V input, consider the LM3409HVMM/NOPB alternative, which supports up to 75V.

How does the AT9919K7-G achieve constant LED current accuracy?

The AT9919K7-G achieves ±5% typical LED current accuracy using a precision hysteretic comparator with tightly controlled sense voltage thresholds (VCS(HI) = 230 mV ±27 mV, VCS(LO) = 170 mV ±23 mV) and low propagation delay (70 ns). Accuracy depends on external RSENSE tolerance and temperature drift; a 1% resistor yields best results.

Can the AT9919K7-G be used with both PWM and analog dimming simultaneously?

Yes - the AT9919K7-G supports concurrent DIM (digital PWM) and ADIM (analog) inputs. When both are active, the resulting GATE signal reflects the smaller dimming duty cycle. This enables hybrid control schemes, such as microcontroller PWM override with analog thermal derating via an NTC on ADIM.

What package type and thermal characteristics does the AT9919K7-G have?

The AT9919K7-G uses an 8-lead DFN package (3 mm × 3 mm, 0.5 mm pitch) with exposed thermal pad (TAB) connected to GND. Its junction-to-ambient thermal resistance is θJA = 37°C/W, enabling reliable operation at full load in ambient temperatures up to +125°C when mounted on ≥2 cm² copper area.

Does the AT9919K7-G include built-in protection features?

Yes - the AT9919K7-G integrates overtemperature protection (trip at 140°C ±12°C with 60°C hysteresis), undervoltage lockout (UVLO rising threshold = 4.5V on VDD), and absolute maximum ratings for all pins. It does not include open-LED or short-circuit protection - those must be implemented externally using monitoring circuits or MOSFET current limiting.