Monolithic Power Systems Inc. MP4057AGS-Z

Overview

MP4057AGS-Z from Monolithic Power Systems is a single-chip, single-stage primary-side regulated (PSR) LED driver IC with integrated 3.3V LDO output for MCU/wireless modules, supporting both constant-current (CC) and constant-voltage (CV) operation modes, achieving >0.9 power factor, 5% deep dimming, and ultra-low 30mW no-load standby loss in smart Zigbee/Bluetooth lighting systems.

For engineers reviewing the MP4057AGS-Z datasheet, MP4057AGS-Z pinout, MP4057AGS-Z application, or MP4057AGS-Z equivalent, this device delivers verified PSR-based LED current regulation without secondary-side feedback, real-current control from primary sensing, valley-switching efficiency optimization, and seamless CC/CV transition without flicker or VO voltage drop-key selection criteria for cost-sensitive, compact smart LED drivers.

Technical Context

The MP4057AGS-Z implements proprietary real-current control using primary-side sensing at the S pin to regulate LED current without optocoupler or secondary shunt regulator. It employs valley-switching mode in CC operation to minimize MOSFET turn-on loss and EMI, while dynamically modulating switching frequency down to ~400Hz in CV standby to achieve <30mW no-load loss.

Its dual-supply architecture allows VDD or VCC (whichever is higher) to power internal circuitry and the 3.3V VO LDO; DIM pin controls mode selection (low = CV, floating/high = CC) and enables PWM dimming with linear current scaling and 10mV minimum reference clamp for 5% dim depth. Protection includes primary-side OCP, ZCD-based OVP/SCP/brown-out, UVLO, and auto-restart OTP at 160°C.

Key Specifications

Pinout & Package

MP4057AGS-Z is housed in a 14-pin SOIC package with exposed pad for thermal enhancement. Pin functions are validated per MPS datasheet Rev. 1.01 (2018), with NC pins (3, 7, 8, 13) electrically isolated and not bonded.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP4056AGS-Z, MP4057AGS-Z reduces component count by integrating VO and simplifies layout; versus BP5778E, it delivers 62% lower standby loss, 2× deeper dimming, and eliminates flicker during mode transitions-critical for premium smart lighting.

Availability

MP4057AGS-Z is available at Aetrix Electronics and suitable for Zigbee/Bluetooth smart bulbs, DALI-compatible drivers, commercial downlights, and outdoor streetlight nodes requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MP4057AGS-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, and global manufacturing partnerships.

The MP4057A product line targets cost-sensitive, compact smart LED lighting systems requiring integrated MCU power, ultra-low standby, and flicker-free dimming-designed specifically for IoT-connected luminaires with stringent energy and reliability requirements.

FAQ

What is the function of the NLP pin on MP4057AGS-Z?

The NLP pin drives an external depletion-mode N-FET gate to disable the high-voltage startup current path during standby mode. This reduces no-load power consumption by cutting off the initial charging current to VDD, contributing directly to the 30mW typical standby loss specification. It is not used during normal CC or CV operation.

How does MP4057AGS-Z achieve flicker-free transition between CC and CV modes?

Flicker-free transition is achieved through synchronized control of VO voltage and LED current paths: during CC→CV, VO remains powered by VDD while LED current drops to zero via controlled COMP clamp; during CV→CC, VO is sustained by VCC before LED current ramps up. The DIM pin state change triggers immediate mode reconfiguration without interrupting VO regulation or causing current discontinuity.

Can MP4057AGS-Z operate without an external high-side MOSFET?

No. MP4057AGS-Z contains only an internal low-side MOSFET (drain D, source S). An external high-side MOSFET is mandatory for flyback or buck-boost topologies. The D pin connects to the source of that external MOSFET, and the S pin senses current through a resistor to ground-this configuration is fundamental to its primary-side regulation architecture.

What is the maximum allowable output power for MP4057AGS-Z in SOIC-14 package?

At TA = 25°C, the SOIC-14 package supports 1.45W continuous power dissipation (θJA = 86°C/W). With TJ(max) = 150°C, maximum ambient operating temperature is 115°C at full rated power. For 230VAC input and 370mA LED load, typical board-level thermal design achieves ≤110°C junction temperature, confirming safe operation within spec.

Does MP4057AGS-Z support analog dimming via DC voltage on DIM pin?

No. The DIM pin accepts only digital PWM signals or static logic levels. A low-level signal (<0.3V) forces CV mode; floating or high-level (>1.13V) enables CC mode with PWM dimming. Analog dimming is not supported-the datasheet specifies t_{dim_detect} = 9.5ms for PWM frequency recognition, confirming digital-only interface.

What is the purpose of the ZCD pin's blanking time (t_{LEB_ZCD})?

t_{LEB_ZCD} (0.5–2μs) prevents false zero-current detection during MOSFET turn-off due to ringing or parasitic coupling. In CC mode, blanking starts after turn-off when Vs_peak exceeds 0.15V; in CV mode, it applies regardless. This ensures accurate valley detection for switching and reliable OVP triggering only after valid blanking expires.

How is the 5% dimming depth implemented in MP4057AGS-Z?

5% dimming is achieved by clamping the COMP voltage to a minimum of 10mV during PWM dimming in CC mode, which scales the LED current reference proportionally. Combined with t_{min_OFF_CC} control (2.4–4.2μs) and t_{max_OFF_CC} extension (30–57μs), this maintains stable regulation even at lowest duty cycles without current dropout or audible noise.