Monolithic Power Systems Inc. EVHFC0100HS-00A

Overview

EVHFC0100HS-00A from Monolithic Power Systems is a peak current mode quasi-resonant controller for offline flyback SMPS, featuring integrated 700V HV start-up current source, valley-switching detection (VVSD = 55mV typ), burst-mode operation (VBURL = 0.5V, VBURH = 0.7V), and comprehensive protection including OVP (6V), OLP (3.7V), UVLO (8V/11.8V), and thermal shutdown (150°C). It targets universal-input (85–265VAC) AC/DC adapters for consumer electronics.

For engineers reviewing the EVHFC0100HS-00A datasheet, EVHFC0100HS-00A pinout, EVHFC0100HS-00A application, or EVHFC0100HS-00A equivalent, key selection criteria include valley-switching propagation delay (tVSD = 160ns typ), minimum off-time limit (tMIN = 7.8μs), internal soft-start time (tSS = 2.4ms), and SOIC-8 package compatibility with creepage-enhanced NC pin.

Technical Context

The HFC0100 operates in discontinuous conduction mode (DCM) with valley detection to enable zero-voltage switching of the primary MOSFET, minimizing turn-on loss and EMI. Its VSD pin monitors auxiliary winding voltage to trigger switching at drain-source voltage minima, with fixed 10mV hysteresis and 3.5μs OVP sampling blanking.

Control logic enforces a 7.8μs minimum off-time to cap frequency below 150kHz (EN55022 limit), while burst mode modulates switching on/off based on FB voltage thresholds (0.5V entry, 0.7V exit) to achieve sub-75mW standby power. Protection states-UVLO, OLP, OVP, and TSD-are independently latched or auto-retrying per fault type.

Key Specifications

Pinout & Package

EVHFC0100HS-00A is housed in a standard SOIC-8 package with creepage-optimized layout, including an isolated NC pin (Pin 3) for enhanced isolation between HV and signal domains.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quasi-resonant controller applications.

Compared with NCP1342DR2G and ICE2QS03G, EVHFC0100HS-00A delivers superior light-load efficiency via integrated burst mode and eliminates external HV components, while its valley-switching architecture reduces EMI without requiring complex snubbers or frequency dithering.

Availability

EVHFC0100HS-00A is available at Aetrix Electronics and suitable for smartphone adapters, LCD TV standby supplies, inkjet printer SMPS, and HVAC control board power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for EVHFC0100HS-00A 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 HFC0100 product line targets cost-sensitive, high-efficiency offline QR flyback converters for consumer and industrial power supplies, emphasizing integration, reliability, and regulatory compliance (DOE VI, CoC Tier 2, RoHS).

FAQ

What is the purpose of the NC pin (Pin 3) on EVHFC0100HS-00A?

Pin 3 is a no-connect terminal physically implemented to increase creepage distance between the HV pin (Pin 4) and VCC pin (Pin 2), enhancing isolation safety in high-voltage AC/DC designs. It must remain unconnected on the PCB and serves no electrical function.

How does the HFC0100 implement over-voltage protection without direct output sensing?

OVP is derived from the auxiliary winding voltage on the VSD pin, which scales proportionally with output voltage. When VSD exceeds 6.0V, the controller latches off permanently until VCC drops below 3V-requiring a full AC cycle reset to recover.

Can EVHFC0100HS-00A operate without an external VCC capacitor?

No. A minimum 4.7μF bulk capacitor plus 0.1μF ceramic capacitor on VCC is mandatory. The internal HV current source charges VCC only during startup; sustained operation relies on auxiliary winding-derived VCC, and insufficient capacitance causes premature UVLO shutdown.

What determines the burst mode frequency in light-load operation?

Burst frequency depends on output capacitance, load current, and transformer turns ratio. As VFB falls below 0.5V, switching stops; VOUT droop raises VFB until it crosses 0.7V, restarting a burst cycle. Typical burst rates range from 100Hz to 1kHz depending on design parameters.

Is the 700V HV rating absolute maximum or operational rating?

The 700V rating is the absolute maximum breakdown voltage of the HV pin-exceeding this voltage risks permanent damage. Operational use must maintain margin: typical designs limit peak HV pin voltage to ≤650V, accounting for line surges and ringing.

How does leading-edge blanking (250ns) improve current-sense reliability?

The 250ns LEB disables the CS comparator immediately after DRIVE turn-on, blocking high dv/dt-induced noise from parasitic capacitance. This prevents false triggering during MOSFET turn-on spikes, ensuring accurate peak current limiting across all operating conditions.

Does EVHFC0100HS-00A support synchronous rectification?

No. The HFC0100 is designed for primary-side regulation in diode-rectified flyback topologies. It lacks secondary-side timing signals or dedicated SR control outputs; synchronous rectification requires a separate SR controller or QR+SR combo IC.