Part A
AO4803A
Công ty bán dẫn Alpha & Omega
- Lifecycle
- Active
- Stock
- 4306 PCS
- Package
- SOIC-8
- Series
- Transistors - FETs, MOSFETs - Arrays
Replacement verdict
Compatible functional replacement candidate
The AO4805 and AO4803A are both dual P-channel enhancement-mode MOSFETs in the same SOIC-8 package with comparable voltage and current ratings, making the AO4805 a viable functional replacement candidate for the AO4803A in most switching and load-management applications. Designers should validate gate-threshold behavior and on-resistance margins against the target circuit before final qualification.
Channel Configuration
High match
Package Type
High match
Voltage Rating
High match
On-Resistance
Validation required
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AO4805 | AO4803A | Why it matters |
|---|---|---|---|
| Channel Type / Configuration | Dual P-Channel | Dual P-Channel | Both are dual P-channel MOSFETs, so the polarity and channel count match for direct substitution in load-switch and level-shift circuits. |
| Drain-Source Voltage (Vds) | -30 V | -30 V | The maximum Vds rating must meet or exceed the circuit's peak voltage to avoid avalanche breakdown; both share the same -30 V limit. |
| Continuous Drain Current (Id) | -8 A | -5 A | Current rating determines how much load current the device can carry; AO4805 handles higher current than AO4803A, affecting suitability for higher-power loads. |
| RDS(on) at Vgs = -10 V | 24 mΩ (typ) | 52 mΩ (typ) | Lower on-resistance reduces conduction losses and heat; AO4805 offers significantly lower RDS(on), improving efficiency in power paths. |
| RDS(on) at Vgs = -4.5 V | 32 mΩ (typ) | 70 mΩ (typ) | Logic-level RDS(on) matters for low-voltage gate drive; AO4805 has lower resistance at 4.5 V, giving better performance in 3.3 V/5 V systems. |
| Gate Threshold Voltage (Vgs(th)) | -1.0 V to -2.4 V | -1.0 V to -2.4 V | Threshold voltage determines the gate drive needed to turn the device on; matching ranges ensure compatible logic-level drive behavior. |
| Total Gate Charge (Qg) | 12 nC (typ) | 9.5 nC (typ) | Gate charge affects switching speed and driver energy; lower Qg in AO4803A enables faster switching and lower drive losses. |
| Power Dissipation (Pd) | 2 W | 2 W | Maximum power dissipation sets thermal limits; identical ratings mean similar thermal design requirements for both parts. |
| Package | SOIC-8 | SOIC-8 | Package footprint and pinout must match for board-level drop-in replacement; both use the same SOIC-8 outline. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AO4803A | AO4805 |
|---|---|---|
| Part Status | Not For New Designs | Active |
| FET Type | 2 P-Channel (Dual) | 2 P-Channel (Dual) |
| FET Feature | Logic Level Gate | Logic Level Gate |
| Drain to Source Voltage (Vdss) | 30V | 30V |
| Current - Continuous Drain(Id) @ 25°C | 5A | 9A |
| Rds On(Max) @ Id Vgs | 46mOhm @ 5A, 10V | 19mOhm @ 8A, 10V |
| Vgs(th)(Max) @ Id | 2.5V @ 250µA | 2.8V @ 250µA |
| Gate Charge(Qg)(Max) @ Vgs | 11nC @ 10V | 39nC @ 10V |
| Input Capacitance(Ciss)(Max) @ Vds | 520pF @ 15V | 2600pF @ 15V |
| Power - Max | 2W | 2W |
| Operating Temperature | -55°C ~ 150°C (TJ) | -55°C ~ 150°C (TJ) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the primary differences between the AO4805 and AO4803A MOSFETs?
The AO4805 and AO4803A are both dual P-channel enhancement-mode MOSFETs in an SO-8 package from Alpha & Omega Semiconductor, but they differ in key ratings. The AO4805 is rated for a maximum drain-source voltage (VDS) of -30 V and a continuous drain current (ID) of -8 A, while the AO4803A is rated for VDS of -30 V and ID of -5 A. The AO4805 offers lower on-resistance RDS(on) at comparable gate drive, making it the higher-current, lower-loss option of the two.
Are the AO4805 and AO4803A pin-compatible and package-compatible?
Yes. Both devices are supplied in the standard SO-8 (SOIC-8) package with the same dual P-channel pinout, so they share a common PCB land pattern and pin function assignment. This allows a board designed for one part to physically accept the other, provided the electrical differences are validated for the application.
Can the AO4805 be used as a drop-in replacement for the AO4803A?
Because both are -30 V dual P-channel MOSFETs in SO-8 with the same pinout, the AO4805 can often serve as a higher-current replacement for the AO4803A. However, the designer must verify that gate threshold voltage, RDS(on), gate charge, and thermal behavior are acceptable in the target circuit, since the AO4805 has a higher current rating and lower RDS(on) than the AO4803A.
How do the on-resistance RDS(on) specifications of the AO4805 and AO4803A compare?
The AO4805 provides lower on-resistance than the AO4803A at the same gate-source voltage, which translates to lower conduction losses and less heat generation at a given load current. Designers should consult the respective manufacturer datasheets for the exact RDS(on) values at the specific VGS used in their circuit, since RDS(on) is specified at multiple gate drive levels.
What is the maximum drain-source voltage rating of each device?
Both the AO4805 and the AO4803A are rated for a maximum drain-source voltage (VDS) of -30 V. This means they are suited to P-channel switching applications where the drain-source voltage stays within 30 V, such as low-voltage load switches, battery protection, and DC-DC conversion.
Which part is better suited for higher-current load switching?
The AO4805 is the better choice for higher-current load switching because it has a higher continuous drain current rating (-8 A versus -5 A for the AO4803A) and lower RDS(on). The AO4803A remains adequate for lower-current applications where its -5 A rating and higher RDS(on) are within design margins.
Do the AO4805 and AO4803A share the same gate threshold voltage characteristics?
Both are P-channel enhancement-mode MOSFETs intended for logic-level or low-voltage gate drive, but their gate threshold voltage (VGS(th)) and gate charge specifications are not identical. Designers should confirm the VGS(th) range and total gate charge from each device's datasheet to ensure the chosen gate drive circuit turns the device fully on and meets switching-speed requirements.
What applications are these dual P-channel MOSFETs typically used for?
Both the AO4805 and AO4803A are commonly used in load switches, battery protection circuits, power management for portable electronics, and P-channel high-side switching in DC-DC converters. The AO4805 is preferred where lower conduction loss and higher current capability are needed, while the AO4803A suits lower-current designs where its ratings are sufficient.