Monolithic Power Systems Inc. HF920AGSE-P

Overview

HF920AGSE-P from Monolithic Power Systems is a monolithic 900V flyback switching regulator IC integrating a high-voltage power MOSFET (R_DS(ON) = 15 Ω @ 25°C), peak-current-mode control, programmable switching frequency up to 150 kHz, and active burst mode enabling <30 mW no-load consumption. It delivers up to 9.5 W at 230 VAC ±15% in SOIC8-7A package and targets AC/DC power supplies for smart meters, industrial controls, and large appliances operating on poor or wide-range AC grids.

For engineers reviewing the HF920AGSE-P datasheet, HF920AGSE-P pinout, HF920AGSE-P application, or HF920AGSE-P equivalent, key selection criteria include its integrated 900V MOSFET breakdown voltage, VCC UVLO hysteresis (4 V), PRO-pin programmable UVP/OVP thresholds, thermal shutdown at 150°C with 30°C recovery hysteresis, and frequency jittering (±3.5%) for PLC-friendly EMI reduction.

Technical Context

The HF920AGSE-P implements peak-current-mode control with internal slope compensation and leading-edge blanking (t_LEB1 = 385 ns, t_LEB2 = 350 ns) to ensure stable operation across CCM/BCM transitions. Its proprietary 900V monolithic process integrates the power switch and temperature sensor on-die, enabling precise junction-based OTP activation without external thermistors.

Switching frequency is resistor-programmed via FSET (1.25 V reference), supporting fixed-frequency design with ±3.5% jittering over 256-cycle carrier for EMI spread-spectrum compliance. Protection logic includes time-based OLP (8192-cycle counter), auto-recovery SCP (V_SCP = 1.5 V), and dual-threshold PRO pin (UVP: 0.25 V, OVP: 3.1 V) for flexible system-level fault management.

Key Specifications

Pinout & Package

HF920AGSE-P is housed in an SOIC8-7A package with exposed GND pad (3 cm² copper area) for thermal performance. Pin 5 is internally connected to GND; pins 1–4 and 6–8 are functional as listed below.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP101GSE-Z and LNK364PG, HF920AGSE-P uniquely supports 900V input operation, PRO-pin programmable protection, and frequency jittering-making it the only option among the three suitable for 420 VAC smart meter front-ends and PLC-coexistence applications.

Availability

HF920AGSE-P is available at Aetrix Electronics and suitable for smart meter power supplies, industrial PLC modules, and large appliance control boards requiring stable component supply across extended product lifecycles and global manufacturing sites.

Supply support for HF920AGSE-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 a focus on energy-efficient power management solutions for industrial, automotive, and consumer markets.

The HF920A product line is designed specifically for high-reliability, wide-input-voltage offline flyback converters in utility-grade equipment-emphasizing integration (900V MOSFET + controller), low standby power, and robust protection for harsh grid environments.

FAQ

What is the maximum continuous input voltage the HF920AGSE-P can handle?

The HF920AGSE-P features a monolithic 900 V MOSFET with guaranteed breakdown voltage (V_(BR)DSS = 900 V), enabling safe operation with DC bus voltages up to 850 V. In AC/DC applications, this supports universal input ranges up to 420 VAC after full-wave rectification and bulk capacitance, provided proper snubber design limits voltage spikes to <810 V (90% of rating).

How does the PRO pin function in under-voltage protection schemes?

The PRO pin provides a dual-threshold comparator: it triggers shutdown when pulled below 0.25 V (UVP) or above 3.1 V (OVP). For input UVP, PRO is connected to a resistive divider from the rectified AC bus; when input drops to ~54 VDC, PRO falls below threshold and disables switching until voltage recovers to ~59 VDC, preventing brownout-induced instability.

Can the HF920AGSE-P operate in discontinuous conduction mode (DCM)?

Yes-the HF920AGSE-P supports DCM, boundary conduction mode (BCM), and continuous conduction mode (CCM) via its peak-current-mode architecture and internal slope compensation. At light loads, it automatically enters burst mode; at heavier loads, duty cycle and inductance selection determine conduction mode, with stable operation confirmed up to 87% maximum duty cycle.

What thermal derating applies to the SOIC8-7A package at elevated ambient temperatures?

With θ_JA = 96°C/W and T_J(MAX) = 150°C, the SOIC8-7A package delivers 1.3 W maximum continuous power at 25°C ambient. At 50°C ambient, allowable power drops to ~1.04 W (PD_MAX = (150 − 50)/96). Derating is linear; PCB copper area (3 cm² GND pad) and airflow must be maintained per datasheet layout guidelines to sustain rated output power.

Is frequency jittering enabled by default, and can it be disabled?

Frequency jittering is always active and cannot be disabled-it is a hardwired feature of the HF920AGSE-P oscillator. The ±3.5% deviation around the programmed center frequency occurs over a 256-cycle carrier period and requires no external components or configuration. This fixed implementation ensures consistent EMI reduction without design overhead.

How does the internal soft-start sequence interact with burst mode during startup?

Soft-start (6.7 ms) operates independently of burst mode: during initial power-up, the IC ramps peak current threshold and increases switching frequency from 20% to 100% of programmed value before feedback loop engagement. Burst mode only activates after soft-start completes and load conditions drop below VBURL (0.5 V on FB), ensuring controlled startup even under no-load conditions.

What is the recommended minimum bulk capacitor value for 230 VAC ±15% input operation?

For 230 VAC ±15% (195–265 VAC), the datasheet recommends 1 μF/W of output power. For a 9.5 W SOIC14-11 design, ≥9.5 μF is required; for SOIC8-7A (6.5 W), ≥6.5 μF is advised. Capacitors must be rated for ≥450 VDC and stacked with balancing resistors if bus voltage exceeds individual capacitor ratings, as typical peak DC bus reaches ~375 V.