Monolithic Power Systems Inc. MP023GS-P

Overview

MP023GS-P from Monolithic Power Systems is a primary-side constant-current/constant-voltage (CC/CV) flyback controller for offline AC/DC adapters and battery chargers. It delivers optocoupler-free regulation with 700V integrated high-voltage start-up current source, programmable cable compensation via CP pin, and variable off-time peak current control enabling DCM operation. Typical use includes 5–20W USB wall adapters requiring <30mW no-load power and ±5% output regulation.

For engineers reviewing the MP023GS-P datasheet, MP023GS-P pinout, MP023GS-P application, or MP023GS-P equivalent, key selection criteria include its SOIC8-7A package compatibility, 464–496mV current limit threshold, 3.96V FB reference voltage, 140°C thermal shutdown threshold, and support for programmable secondary duty cycle and FB sampling timing.

Technical Context

The MP023GS-P implements primary-side regulation using auxiliary winding voltage sensing at the FB pin, with programmable sampling windows (180–330ns duration) synchronized to ZCD detection to avoid conduction-phase errors. Its variable off-time control modulates switching frequency between 72Hz and 105kHz to maintain CV or CC regulation without secondary feedback.

Internal protection logic includes open-loop protection triggered after 128 consecutive low-FB samples (<1.38V), OVP activation at 5.96V on FB, and thermal shutdown at 140°C with 40°C hysteresis. The HV pin sustains 700V breakdown while sourcing 2.2mA typical start-up current, and the DRV pin drives external MOSFETs with 7.8V high-level output and 50mV low-level clamp.

Key Specifications

Pinout & Package

MP023GS-P is housed in a SOIC8-7A package - an industry-standard 8-lead small-outline IC with one pin omitted (Pin 7 not bonded), optimized for thermal performance in compact adapter designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar primary-side CC/CV flyback controller applications.

Compared with MP023GS-P, MP022GS-P trades cable compensation and adjustable duty cycle for lower unit cost, while INN2214K replaces discrete MOSFET drive with monolithic integration-making MP023GS-P optimal for designs needing precise cable-drop correction, DCM stability across wide load ranges, and EMI spectrum shaping via variable frequency.

Availability

MP023GS-P is available at Aetrix Electronics and suitable for USB wall adapters, smartphone fast chargers, appliance auxiliary supplies, and IoT device power modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP023GS-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 design centers in the US, China, and Taiwan, and manufacturing partners across Asia.

The MP023 belongs to MPS's primary-side flyback controller product line, engineered specifically for cost-sensitive, low-power AC/DC applications where optocoupler elimination, ultra-low standby power, and robust protection are mandatory.

FAQ

What is the purpose of the CP pin on MP023GS-P?

The CP pin serves two mutually exclusive functions: (1) output cable compensation when connected to a 1µF ceramic capacitor, generating a DC voltage proportional to output current for voltage-drop correction; or (2) programming maximum secondary duty cycle (DS-Max) via resistor values (0.3–0.5 range). Connecting both resistor and capacitor disables cable compensation.

How does MP023GS-P achieve optocoupler-free regulation?

It samples the transformer's auxiliary winding voltage at the FB pin during secondary diode conduction, using programmable timing (180–330ns) and internal 3.96V reference to infer output voltage. Peak current on the primary side (via CS pin) controls output current, eliminating need for secondary-side feedback components.

What protection features are integrated into MP023GS-P?

MP023GS-P integrates VCC under-voltage lockout (UVLO), over-voltage protection (OVP at 5.96V on FB), open-circuit protection (OCkP), overload protection (OLP triggered after 128 low-FB cycles), over-temperature protection (OTP at 140°C), and leading-edge blanking (280ns typical) to reject current-sense noise.

Can MP023GS-P operate in continuous conduction mode (CCM)?

No-it is designed exclusively for discontinuous conduction mode (DCM) operation. Internal zero-current detection (ZCD) with 100mV threshold prevents next switching cycle until demagnetization completes, ensuring DCM across all load and input conditions.

What is the minimum recommended input capacitance for universal AC input?

For universal 85–265VAC input, use 2–3µF per watt of output power (e.g., 10–15µF for a 5W adapter). This ensures sufficient hold-up time and maintains V_DC(min) above the level required to sustain maximum secondary duty cycle under low-line conditions.

How is no-load power minimized in MP023GS-P?

Through integrated high-voltage start-up current source (reducing auxiliary winding dependency), variable-frequency control that lowers switching rate at light loads, and deep sleep modes that disable non-essential blocks-achieving <30mW no-load consumption per DOE Level VI and CoC Tier 2 standards.

Does MP023GS-P require an external X-capacitor discharge circuit?

No-MP023GS-P does not integrate X-capacitor discharge functionality. An external bleeder circuit (e.g., series 1MΩ + 100kΩ resistors across X-cap) remains necessary for safety compliance with IEC 62368-1 touch-current limits after AC removal.