Monolithic Power Systems Inc. MP4050GJ-P

Overview

MP4050GJ-P from Monolithic Power Systems is a non-isolated, constant-current LED driver IC with an integrated 500V/7.2Ω MOSFET, designed for AC/DC bulk LED replacement in 85–265VAC input systems. It delivers stable 115mA output current at 40V with ±5% regulation, operates above 22kHz to suppress audible noise, and integrates thermal shutdown, open/short lamp protection, and internal high-voltage startup current source.

For engineers reviewing the MP4050GJ-P datasheet, MP4050GJ-P pinout, MP4050GJ-P application, or MP4050GJ-P equivalent, key selection criteria include its TSOT23-5 package footprint, 500V drain rating, VCC UVLO hysteresis (0.24V typ), PRO pin fault detection thresholds (VOVP = 2.0V, VUVP = 0.39V), and minimum off-time limit (4.7μs).

Technical Context

The MP4050GJ-P implements an average-current-controlled buck topology with internal peak-current sensing via the SOURCE pin (0.45V threshold) and feedback reference of 0.194V. Its operation relies on a self-biased high-voltage current source tied to the DRAIN pin, eliminating external startup circuitry.

Protection logic is tightly coupled to the PRO pin: open-lamp detection triggers when PRO voltage exceeds 2.0V during MOSFET off-time, while short-lamp detection activates below 0.39V. Thermal shutdown engages at 150°C with 60°C hysteresis, and internal leading-edge blanking (200ns) prevents false current-sense triggering.

Key Specifications

Pinout & Package

MP4050GJ-P is housed in a thermally enhanced TSOT23-5 package (2.9mm × 1.6mm × 0.9mm), optimized for compact LED retrofit lamps and low-cost industrial lighting modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant-current LED driver applications.

Compared with MP4051GJ-Z, MP4050GJ-P offers superior space efficiency and lower assembly cost in compact lamps, while BP5758D demands more design effort but allows fine-grained thermal and efficiency tuning-making MP4050GJ-P optimal for volume production of standardized LED modules.

Availability

MP4050GJ-P is available at Aetrix Electronics and suitable for LED bulk replacement lamps, industrial panel indicators, architectural accent lighting, and automotive interior ambient lighting requiring stable component supply and RoHS-compliant manufacturing.

Supply support for MP4050GJ-P 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 over two decades of leadership in DC/DC conversion and LED driver innovation.

The MP4050 belongs to MPS's non-isolated LED driver product line, engineered specifically for cost-sensitive, space-constrained AC/DC LED lighting applications where simplicity, reliability, and regulatory compliance are paramount.

FAQ

What is the maximum output power achievable with MP4050GJ-P in TSOT23-5 package?

At 90°C ambient and 265VAC input, the TSOT23-5 package supports up to 4.5W (115mA × 40V) in buck topology before thermal shutdown engages. Derating is required above 70°C ambient; full power is only sustainable with adequate copper pour and airflow per MPS layout guidelines.

Can MP4050GJ-P operate from a 12V DC input?

Yes-MP4050GJ-P supports DC input down to ~15VDC minimum after rectification and filtering. Below this, VCC cannot sustain regulation due to insufficient headroom across the internal HV current source; for true 12VDC operation, an external boost stage or alternative driver like MPQ4312 is recommended.

How does the PRO pin detect open and short lamp conditions?

During MOSFET off-time, the PRO pin voltage reflects the LED string voltage divided by the R2/R3 feedback network. If PRO exceeds 2.0V (indicating open circuit), or falls below 0.39V (indicating shorted LEDs or wiring fault), the IC halts switching and enters hiccup-mode restart using internal VCC discharge/recharge timing.

What is the purpose of the 200ns leading-edge blanking (LEB) feature?

The 200ns LEB disables the internal current comparator immediately after MOSFET turn-on to ignore parasitic current spikes caused by drain-source capacitance and layout inductance. This prevents premature switch-off and ensures accurate peak-current control during steady-state conduction.

Does MP4050GJ-P require an external freewheeling diode?

Yes-a fast-recovery diode (T_rr < 75ns) such as WUGC10JH or EGC10GH is mandatory in the buck topology. The internal MOSFET cannot conduct reverse current; omitting the diode causes destructive voltage spikes and immediate device failure during demagnetization.

How is output current accuracy affected by temperature?

Output current drift is limited to ±5% over –40°C to +125°C junction range, primarily due to matching of the internal 0.194V reference and 0.45V current-sense threshold. Using a 1% tolerance, ±400ppm/°C sense resistor minimizes additional error beyond the IC's intrinsic specification.

What layout practices prevent EMI issues with MP4050GJ-P?

Minimize the high-di/dt loop formed by DRAIN–inductor–diode–output capacitor; place C_VCC and C_PRO within 2mm of their pins; keep SOURCE trace short and narrow to reduce coupling; maximize DRAIN copper area for heat sinking; and separate AC input traces from switching nodes by ≥5mm.