Monolithic Power Systems Inc. MP163CGS-33-Z

Overview

MP163CGS-33-Z from Monolithic Power Systems is a 700V non-isolated offline primary-side regulator with integrated 700V MOSFET and 3.3V LDO, supporting buck/boost/flyback topologies for dual-output CV regulation without optocoupler. It delivers up to 4W output power, achieves <30mW no-load consumption, and features green-mode operation with frequency foldback and peak-current compression for high light-load efficiency in home appliance standby supplies.

For engineers reviewing the MP163CGS-33-Z datasheet, MP163CGS-33-Z pinout, MP163CGS-33-Z application, or MP163CGS-33-Z equivalent, key selection criteria include its 660mA peak current limit, 13.5Ω R_DS(on), SOIC8-7B package thermal resistance (θ_JA = 86°C/W), 3.3V ±2% LDO output, and primary-side CV control architecture enabling compact, low-BOM offline AC/DC designs.

Technical Context

The MP163CGS-33-Z implements primary-side constant voltage regulation using feedback sampling via an external capacitor (C3) charged during freewheeling diode conduction, eliminating optocoupler dependency. Its internal error amplifier compares sampled FB voltage against a 2.55V reference with 6µs delay after MOSFET turn-off.

Green-mode operation dynamically reduces both switching frequency and peak current under light load: minimum off-time τ_minoff = 9.5–12 µs and maximum on-time τ_maxon = 19–24 µs are programmable per load condition, while ramp compensation scales exponentially with decreasing peak current to maintain stability across CCM/DCM transitions.

Key Specifications

Pinout & Package

MP163CGS-33-Z uses the SOIC8-7B package: 8-pin surface-mount with exposed thermal pad, optimized for high-voltage isolation and thermal performance in compact offline regulators.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar offline primary-side regulator applications.

Compared with MP163BGSE-33, MP163CGS-33-Z offers 57% higher peak current in the same SOIC8-7B footprint, enabling higher output power density; versus MP163AGS-33, it provides 214% more current capacity and 16% lower R_DS(on), making it optimal for 3–4 W dual-rail designs where space is constrained but power demand exceeds entry-level variants.

Availability

MP163CGS-33-Z is available at Aetrix Electronics and suitable for home appliance standby power, IoT sensor hub auxiliary supplies, and white goods control board auxiliary rails requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for MP163CGS-33-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 over two decades of leadership in DC/DC converters, LED drivers, and offline AC/DC regulators.

The MP163 product line targets cost-sensitive, space-constrained offline power applications requiring primary-side regulation-designed specifically to replace optocoupler-based feedback in home appliances, industrial controls, and consumer electronics standby supplies.

FAQ

What is the maximum continuous output power achievable with MP163CGS-33-Z in buck topology?

The MP163CGS-33-Z supports up to 4 W of continuous output power in buck configuration when paired with appropriate magnetics, heatsinking, and layout. This is determined by its 660 mA peak current limit, 13.5 Ω R_DS(on), and SOIC8-7B thermal resistance (θ_JA = 86 °C/W). Derating is required above 70°C ambient temperature per the absolute maximum ratings table.

Does MP163CGS-33-Z require an external optocoupler for regulation?

No. The MP163CGS-33-Z implements primary-side constant voltage regulation using a sample-and-hold capacitor (C3) charged during freewheeling diode conduction. This eliminates the need for optocouplers, secondary-side error amplifiers, or TL431 references-reducing BOM count, cost, and long-term reliability risks in consumer applications.

How does the integrated LDO interact with the main switching regulator output?

The LDO (pin IN → OUT) accepts its input from the main switching output (e.g., 12 V buck rail) and regulates it to 3.3 V. Its dropout voltage is 1.1 V at 150 mA, so the main rail must exceed 4.4 V under all load conditions. An external series resistor on IN can reduce LDO power dissipation when the main rail is significantly higher than 4.4 V.

What protection mechanisms prevent latch-up during short-circuit events?

MP163CGS-33-Z employs multi-layer protection: short-circuit protection (SCP) triggers at 900 mA peak current, forcing immediate MOSFET shutdown; if SCP repeats, VCC discharges to 2.8 V (V_CCpro) and the internal HV regulator remains disabled until VCC falls below that threshold, enforcing a controlled restart cycle rather than latching.

Can MP163CGS-33-Z operate with universal AC input (90–264 VAC)?

Yes. Its 700 V integrated MOSFET and internal HV startup circuit support universal AC input ranges. Input capacitor selection must follow MPS recommendations: 1.5–2 µF/W for full-wave rectification or 3 µF/W for half-wave, depending on target output power and ripple requirements per the Application Information section.

Is the SOIC8-7B package lead-free and RoHS-compliant?

Yes. MP163CGS-33-Z is lead-free, halogen-free, and fully compliant with the EU RoHS directive. All MPS products adhere to strict environmental standards, and green status verification is available on the Monolithic Power Systems website under Quality Assurance documentation.

What is the recommended minimum off-time setting for stable operation at full load?

The MP163CGS-33-Z has a fixed minimum off-time of 9.5–12 µs (typical 12 µs). This value is internally trimmed and not user-adjustable. It ensures sufficient time for energy transfer in discontinuous conduction mode and prevents subharmonic oscillation; external compensation is not required for standard buck implementations.