ML4800ISX PFC Controller - Equivalent & Substitute Parts

Part Overview

The ML4800ISX is an average current mode Power Factor Correction (PFC) controller manufactured by onsemi, designed for power management applications requiring active power factor correction at 76kHz switching frequency. This device is classified as obsolete, making equivalent and substitute parts necessary for new designs, production continuity, and system upgrades. The ML4800ISX operates across a 11V to 16.5V supply range and is housed in a 16-SOIC surface mount package suitable for industrial and consumer power supply applications.

Substiute Parts

ML4800ISX

onsemiIn Stock: 8170ML4800ISX Datasheet

Current PartRFQ

FAN4800AUM

onsemiIn Stock: 17747FAN4800AUM Datasheet

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UCC3819AD

Texas InstrumentsIn Stock: 1448UCC3819AD Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution for the ML4800ISX is determined by the following critical parameters:

• Functional Mode: Average current PFC control architecture
• Package Compatibility: 16-SOIC surface mount form factor with identical 0.154" (3.90mm) width
• Supply Voltage Range: Overlap or compatibility with 11V ~ 16.5V operating window
• Switching Frequency: Operation in the power factor correction frequency band (76kHz to 268kHz)
• Thermal Operating Range: Minimum coverage of -40°C to 85°C

Two substitute parts meet these criteria: the FAN4800AUM (onsemi) and UCC3819AD (Texas Instruments). Both devices maintain the same 16-SOIC package, average current control mode, and surface mount configuration. The FAN4800AUM operates at higher switching frequencies (240kHz ~ 268kHz) with extended supply voltage range (11V ~ 22V) and wider temperature range (-40°C ~ 105°C). The UCC3819AD operates at 250kHz with a narrower supply range (10.8V ~ 17V) and limited temperature range (0°C ~ 70°C).

Parameter Comparison

Engineering Selection Recommendations

FAN4800AUM is the primary substitute for new designs and production continuity. This device maintains onsemi manufacturer consistency, carries Active product status ensuring long-term availability, and provides ROHS3 compliance. The FAN4800AUM offers superior specifications including extended supply voltage range (11V ~ 22V), wider operating temperature range (-40°C ~ 105°C), and lower startup current (30 µA). The higher switching frequency (240kHz ~ 268kHz) enables smaller passive component sizing in PFC stage design. Inventory availability is substantial at 17,700 pieces.

UCC3819AD serves as a secondary substitute option for applications with specific Texas Instruments ecosystem requirements. This device carries Last Time Buy status, indicating limited future availability. The UCC3819AD provides ROHS3 compliance and unlimited moisture sensitivity rating. However, the narrower operating temperature range (0°C ~ 70°C) restricts deployment in extended temperature environments. Supply voltage compatibility (10.8V ~ 17V) overlaps the ML4800ISX range but does not extend to higher voltages. Current inventory is 1,400 pieces.

For applications requiring the original 76kHz switching frequency, neither substitute maintains this exact specification. Design modifications to accommodate higher switching frequencies (240kHz ~ 268kHz for FAN4800AUM or 250kHz for UCC3819AD) may be necessary, including passive component recalculation and EMI filter redesign.

Frequently Asked Questions (FAQ)

Q: Can FAN4800AUM directly replace ML4800ISX without circuit modifications?

A: Both devices share identical 16-SOIC packaging and average current control architecture, enabling direct socket replacement. However, the FAN4800AUM operates at 240kHz ~ 268kHz versus the ML4800ISX at 76kHz. This frequency difference requires recalculation of PFC inductor and output capacitor values to maintain equivalent power factor correction performance and harmonic compliance.

Q: What are the supply voltage compatibility constraints?

A: The ML4800ISX operates within 11V ~ 16.5V. The FAN4800AUM extends this to 11V ~ 22V, providing broader input range compatibility. The UCC3819AD operates within 10.8V ~ 17V, covering the ML4800ISX range with minimal margin at the lower end. Verify your application's actual supply voltage window against each substitute's specification.

Q: How does switching frequency affect component selection?

A: Higher switching frequencies reduce passive component size but increase switching losses and EMI generation. The ML4800ISX at 76kHz uses larger inductors and capacitors compared to the FAN4800AUM at 240kHz ~ 268kHz. Frequency change necessitates complete PFC stage redesign including inductor core selection, capacitor voltage ratings, and EMI filter topology.

Q: Are there thermal operating range limitations?

A: The ML4800ISX operates from -40°C to 85°C. The FAN4800AUM extends to 105°C, suitable for high-ambient or high-power applications. The UCC3819AD is limited to 0°C ~ 70°C, restricting use in cold environments or high-temperature industrial settings. Select based on your application's actual thermal requirements.

Q: What is the significance of product status (Obsolete, Active, Last Time Buy)?

A: Obsolete status (ML4800ISX) indicates no further manufacturing or support. Active status (FAN4800AUM) ensures continued production and long-term availability. Last Time Buy status (UCC3819AD) signals final production run with limited future supply. For new designs, Active status products are preferred for supply chain stability.

Q: Do moisture sensitivity levels affect handling and storage?

A: MSL 1 (Unlimited) devices like ML4800ISX and UCC3819AD have no moisture-related storage restrictions. MSL 3 (168 Hours) devices like FAN4800AUM require controlled humidity storage and have a 168-hour floor life after moisture exposure. Verify your manufacturing environment's moisture control capabilities before selecting MSL 3 components.

Q: Is the 16-SOIC package identical across all three devices?

A: Yes. All three devices use 16-SOIC (0.154", 3.90mm Width) surface mount packaging with identical pin pitch and footprint. PCB layout and reflow profiles remain unchanged during substitution. Verify datasheet pin assignments for control signal connections, as internal architecture may differ.