Monolithic Power Systems Inc. MP163BGS-5-Z

Overview

MP163BGS-5-Z from Monolithic Power Systems is a 700V non-isolated offline primary-side regulator with integrated 700V MOSFET and 5V LDO, delivering up to 4W output power in buck/boost/flyback topologies. It features 420mA peak current limit, 14Ω typical R_DS(on), <30mW no-load consumption, and green-mode frequency foldback for home appliance standby power and white goods auxiliary supplies.

For engineers reviewing the MP163BGS-5-Z datasheet, MP163BGS-5-Z pinout, MP163BGS-5-Z application, or MP163BGS-5-Z equivalent, this device serves as a self-biased, optocoupler-free CV controller optimized for low-component-count AC/DC conversion in cost-sensitive, space-constrained embedded power rails.

Technical Context

The MP163BGS-5-Z implements primary-side constant voltage regulation using sampled feedback from a secondary-side capacitor, eliminating optocouplers and TL431 references. Its internal 700V MOSFET operates in discontinuous conduction mode (DCM) with programmable minimum off-time (12μs typ) and peak-current compression to maintain regulation down to near-zero load.

It integrates an LDO with 5V ±2% output, 270mA peak current capability, and 1.1V dropout at 150mA - designed specifically to power microcontrollers or sensors from the same high-voltage rail it regulates. Protection includes thermal shutdown (150°C), OLP (220ms delay), SCP (600mA threshold), and open-loop detection (0.5V FB threshold).

Key Specifications

Pinout & Package

MP163BGS-5-Z is housed in a SOIC-8-7B package - a thermally optimized 8-pin surface-mount variant with 7 functional terminals and one dummy pin (Pin 3). The exposed pad improves thermal performance but is not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP163AGS-5-Z, MP163BGS-5-Z delivers 100% higher peak current and 12.5% lower R_DS(on) in the same footprint - enabling 4W operation with smaller magnetics and cooler thermal performance. Versus MP163CGS-5-Z, it trades 57% higher current capability for lower cost and adequate margin in mid-power (2–4W) applications.

Availability

MP163BGS-5-Z is available at Aetrix Electronics and suitable for home appliance control boards, white goods auxiliary power supplies, and industrial sensor hubs requiring stable component supply across multi-year production cycles.

Supply support for MP163BGS-5-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 MP163 product line targets cost-sensitive, space-constrained offline AC/DC conversion - delivering integrated HV regulation and LDO functionality for consumer, appliance, and industrial standby power where simplicity, reliability, and regulatory compliance are critical.

FAQ

What is the minimum recommended input capacitor value for MP163BGS-5-Z in universal AC applications?

For universal AC input (85–265VAC) with full-wave rectification, a minimum 3.3μF input capacitor is recommended - calculated as 1.5μF/W for a 4W output. This ensures sufficient hold-up time and limits peak inrush current. Lower values risk VCC droop during low-line conditions and may trigger UVLO.

Can MP163BGS-5-Z operate in flyback topology without optocoupler feedback?

Yes - MP163BGS-5-Z supports flyback topology using primary-side regulation. It samples output voltage via a resistive divider and capacitor network on the secondary side, then reflects that information to the FB pin through transformer coupling. No optocoupler or secondary-side reference is required.

How does the integrated LDO handle input voltage variations above 6V?

The LDO input (IN pin) must remain ≤6V to avoid excessive power dissipation. If the upstream HV rail exceeds 6V, a series resistor must be added between the rail and IN to drop excess voltage. Thermal derating applies: at 150mA load and 10V input, >500mW dissipation occurs - requiring careful thermal design or external LDO substitution.

What causes the MP163BGS-5-Z to enter open-loop protection, and how does it recover?

Open-loop protection activates when FB voltage drops below 0.5V for >100μs - indicating loss of feedback signal due to open feedback resistor, broken trace, or missing sampling capacitor. The IC stops switching and discharges VCC to VCC_pro (2.8V); recovery begins only after VCC recharges to VCC_OFF (5.6V) and soft-start completes.

Is MP163BGS-5-Z RoHS-compliant and halogen-free?

Yes - MP163BGS-5-Z is lead-free, halogen-free, and fully compliant with the EU RoHS Directive 2011/65/EU. All packaging materials and die attach compounds meet MPS's green status requirements, verified per JEDEC J-STD-709A and IEC 61249-2-21 standards.

What is the purpose of the EN pin on MP163BGS-5-Z, and is it used in the SOIC-8-7B package?

The EN pin enables external control of the integrated LDO. However, in the SOIC-8-7B package (including MP163BGS-5-Z), EN is not bonded out - it is internally tied high. Therefore, the LDO operates continuously when VCC is valid; external enable functionality is only available in the SOIC-16 variant (e.g., MP163BGSE-5-Z).

How does the MP163BGS-5-Z achieve <30mW no-load consumption?

It combines three techniques: (1) frequency foldback - switching frequency drops below 10kHz at light load; (2) peak-current compression - MOSFET on-time shrinks to limit energy per cycle; and (3) low ICC (720μA active, 24μA latch-off) - minimizing quiescent draw from VCC capacitor during idle periods.