Monolithic Power Systems Inc. MP4068GN-Z

Overview

MP4068GN-Z from Monolithic Power Systems is a non-isolated, TRIAC-dimmable LED driver IC optimized for 120VAC input and up to 10W LED loads. It integrates a 500V MOSFET, achieves >0.7 power factor, delivers ±5% LED current accuracy via internal averaging feedback, and supports buck/buck-boost topologies in residential A19/GU10 lamps.

For engineers reviewing the MP4068GN-Z datasheet, MP4068GN-Z pinout, MP4068GN-Z application, or MP4068GN-Z equivalent, key selection criteria include its hybrid CCM/DCM operation mode for flicker-free dimming, thermal foldback at 145°C, programmable OVP, and SOIC-8 EP package with 2.6W power dissipation rating.

Technical Context

The MP4068GN-Z implements MPS' proprietary hybrid operation mode that dynamically switches between continuous conduction mode (CCM) and discontinuous conduction mode (DCM) across the AC half-cycle to maintain TRIAC latching/holding current and sustain high power factor (>0.7). Its internal 500V MOSFET eliminates need for external MOV/TVS in 500V surge tests.

Constant-current regulation uses an internal sample-and-hold circuit comparing VFB to a 0.195V reference; output current is set by I_OUT = 0.195V / R_SENSE. Thermal protection initiates de-rating at 145°C and triggers shutdown at 160°C with 50°C hysteresis, ensuring flicker-free operation under high ambient temperatures.

Key Specifications

Pinout & Package

MP4068GN-Z is housed in an SOIC-8 EP (exposed pad) package with 2.6W power dissipation capability and 48°C/W θ_JA on a 4-layer PCB. Pin functions are validated per MPS datasheet Rev. 1.01.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TRIAC-dimmable LED driver applications.

Compared with MP4068GN-Z, MP4067GN-Z increases component count and reduces surge robustness, while BP5758D sacrifices dimming smoothness and thermal foldback precision-making MP4068GN-Z optimal for cost-constrained, high-reliability 120VAC TRIAC-dimmable lamps.

Availability

MP4068GN-Z is available at Aetrix Electronics and suitable for residential LED retrofits, commercial spotlight installations, and PAR lamp designs requiring stable component supply with full RoHS/lead-free compliance.

Supply support for MP4068GN-Z 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with design centers in the US, China, and Taiwan.

The MP4068 product line targets cost-sensitive, non-isolated LED lighting applications requiring TRIAC dimmer compatibility, high power factor, and thermal resilience in compact form factors.

FAQ

What is the maximum allowable junction temperature before thermal shutdown activates?

The MP4068GN-Z initiates thermal shutdown at a junction temperature of 160°C, with automatic restart once the die cools to 110°C due to 50°C hysteresis. This threshold is guaranteed by characterization and ensures reliable operation in enclosed luminaires without external thermal sensors.

Can MP4068GN-Z operate with 230VAC input?

No-MP4068GN-Z is specifically designed for 108–132VAC (low-line) operation. Its integrated 500V MOSFET and internal HV regulator are characterized only for 120VAC applications; using it with 230VAC risks exceeding absolute maximum ratings and invalidates all performance guarantees.

How is LED current accuracy maintained across temperature and line variations?

LED current accuracy is maintained via an internal averaging current feedback loop with a 0.195V reference and peak current limit of 0.46V at CS. The design achieves ±5% output current tolerance over -40°C to +125°C and 108–132VAC input range, verified by characterization data in the datasheet.

What is the purpose of the Leading Edge Blanking (LEB) function?

The 200ns LEB window disables the current comparator during MOSFET turn-on to prevent false triggering from parasitic current spikes caused by circuit capacitance. This ensures consistent on-time duration and stable constant-current regulation, especially critical in high-frequency buck-boost topologies.

Does MP4068GN-Z require an external VCC charging circuit in TRIAC-dimming applications?

Yes-an external VCC charging circuit (e.g., resistor + diode + capacitor) is recommended because the internal HV regulator only supplies power when the TRIAC is conducting. Without it, VCC may collapse during dimmer off-cycles, causing intermittent operation or startup failure.

What is the minimum off-time limitation during normal operation?

The minimum off-time is 7μs during normal operation, increasing to 12μs and 24μs during soft-start phases. This constraint ensures stable switching frequency control and prevents sub-harmonic oscillation, particularly important for maintaining dimming linearity at low brightness levels.

How does the hybrid operation mode improve TRIAC dimming performance?

The hybrid mode dynamically transitions between CCM and DCM across the AC half-cycle to sustain sufficient latching and holding current for leading-edge TRIACs. This eliminates dropout and pop-on artifacts while preserving >0.7 power factor-unachievable with fixed-mode controllers in low-power non-isolated designs.