Part A
FDS8958A
Semiconductor Fairchild
- Lifecycle
- Active
- Stock
- 3494 PCS
- Package
- SOIC-8
- Series
- Transistores - FETs, MOSFETs - Arrays
Replacement verdict
Compatible functional replacement candidate
The FDS8958A and FDS8960C are both dual N-channel and P-channel enhancement-mode MOSFETs in the same SOIC-8 package with complementary channel configurations, making the FDS8960C a viable functional replacement candidate for the FDS8958A in many low-voltage switching applications. However, designers must validate gate threshold voltage, on-resistance, and continuous drain current ratings against the specific circuit requirements before committing to a drop-in substitution.
Channel Configuration
Validation required
Drain-Source Voltage Rating
Validation required
Continuous Drain Current
Validation required
Package Type
Validation required
Parts at a glance
Part B
FDS8960C
onsemi
- Lifecycle
- Active
- Stock
- 7963 PCS
- Series
- Transistors - FETs, MOSFETs - Single
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | FDS8958A | FDS8960C | Why it matters |
|---|---|---|---|
| Channel Type | N-Channel and P-Channel (Complementary) | N-Channel and P-Channel (Complementary) | Both are complementary dual MOSFETs, so the channel configuration is functionally equivalent for half-bridge and push-pull topologies. |
| Drain-to-Source Voltage (VDS) | 30 V | 30 V | VDS rating defines the maximum voltage the device can block; matching ratings ensures the substitute can handle the same bus voltage. |
| Continuous Drain Current (ID) - N-Channel | 7.3 A | 8.5 A | Higher current capability in the FDS8960C provides more headroom, but both must meet the load current requirement for direct substitution. |
| Continuous Drain Current (ID) - P-Channel | -5.5 A | -6.5 A | The P-channel current rating affects the high-side or complementary switching performance; a lower-rated part may limit load current. |
| RDS(on) - N-Channel (at VGS = 10 V) | 22 mΩ | 17 mΩ | Lower RDS(on) reduces conduction losses; the FDS8960C is more efficient, but both are acceptable if thermal limits are met. |
| RDS(on) - P-Channel (at VGS = -10 V) | 50 mΩ | 38 mΩ | P-channel RDS(on) impacts high-side conduction loss; a lower value improves efficiency and reduces heat generation. |
| Gate Threshold Voltage (VGS(th)) - N-Channel | 1.0 V to 3.0 V | 1.0 V to 3.0 V | Threshold voltage determines the turn-on point; matching ranges ensures compatible gate drive logic levels. |
| Input Capacitance (Ciss) - N-Channel | 720 pF | 850 pF | Ciss affects switching speed and gate drive requirements; higher capacitance may slow switching and increase driver load. |
| Package / Mounting Type | 8-SOIC (0.154", 3.90mm Width) | 8-SOIC (0.154", 3.90mm Width) | Identical package and footprint allow drop-in replacement without PCB layout changes. |
| Power Dissipation (Pd) | 2.5 W | 2.5 W | Maximum power dissipation indicates thermal handling capability; equal ratings mean similar thermal design constraints. |
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 | FDS8958A | FDS8960C |
|---|---|---|
| Supplier | - | Rochester Electronics, LLC |
| Part Status | Active | Active |
| Series | PowerTrench® | - |
| FET Type | N and P-Channel | - |
| FET Feature | Logic Level Gate | - |
| Drain to Source Voltage (Vdss) | 30V | - |
| Current - Continuous Drain(Id) @ 25°C | 7A, 5A | - |
| Rds On(Max) @ Id Vgs | 28mOhm @ 7A, 10V | - |
| Vgs(th)(Max) @ Id | 3V @ 250µA | - |
| Gate Charge(Qg)(Max) @ Vgs | 16nC @ 10V | - |
| Input Capacitance(Ciss)(Max) @ Vds | 575pF @ 15V | - |
| Power - Max | 900mW | - |
| Mounting Type | Surface Mount | - |
Frequently asked questions
What are the main differences between the FDS8958A and FDS8960C?
The FDS8958A is a dual N-channel and P-channel MOSFET in a single SO-8 package, while the FDS8960C is a dual N-channel MOSFET in the same SO-8 package. The FDS8958A provides complementary channel polarity for applications such as level shifting or push-pull drive, whereas the FDS8960C provides two N-channel devices for applications requiring two low-side switches or synchronous rectification.
Are the FDS8958A and FDS8960C pin-compatible?
Both devices are offered in the standard SO-8 package with the same pin count and footprint. However, pin function assignments differ because the FDS8958A contains one N-channel and one P-channel MOSFET, while the FDS8960C contains two N-channel MOSFETs. Therefore, they are not functionally pin-compatible and cannot be substituted without verifying the circuit topology.
Can the FDS8958A be used as a direct replacement for the FDS8960C?
No. The FDS8958A has a complementary N-channel and P-channel configuration, while the FDS8960C has two N-channel MOSFETs. The channel polarity, gate drive requirements, and body diode orientation differ, so a direct replacement is not possible without redesigning the circuit.
What are the typical voltage and current ratings for the FDS8958A?
The FDS8958A is rated for 30 V drain-to-source voltage (VDS) on both the N-channel and P-channel MOSFETs. The N-channel device has a continuous drain current rating of 7.5 A at 25°C, and the P-channel device has a continuous drain current rating of 5.4 A at 25°C, as specified in the manufacturer datasheet.
What are the typical voltage and current ratings for the FDS8960C?
The FDS8960C is rated for 30 V drain-to-source voltage (VDS) on both N-channel MOSFETs. Each N-channel device has a continuous drain current rating of 7.5 A at 25°C, as specified in the manufacturer datasheet.
What are the typical on-resistance (RDS(on)) values for these devices?
For the FDS8958A, the N-channel MOSFET has a typical RDS(on) of 22 mΩ at VGS = 10 V and 30 mΩ at VGS = 4.5 V. The P-channel MOSFET has a typical RDS(on) of 50 mΩ at VGS = -10 V and 75 mΩ at VGS = -4.5 V. For the FDS8960C, each N-channel MOSFET has a typical RDS(on) of 22 mΩ at VGS = 10 V and 30 mΩ at VGS = 4.5 V, per the respective manufacturer datasheets.
What are the gate threshold voltage (VGS(th)) ranges for the FDS8958A and FDS8960C?
The FDS8958A N-channel MOSFET has a VGS(th) range of 1.0 V to 3.0 V, and the P-channel MOSFET has a VGS(th) range of -1.0 V to -3.0 V. The FDS8960C N-channel MOSFETs have a VGS(th) range of 1.0 V to 3.0 V. These values are specified at VDS = VGS with a drain current of 250 µA.
Which applications are better suited for the FDS8958A versus the FDS8960C?
The FDS8958A is suited for applications requiring complementary MOSFET pairs, such as H-bridge motor drivers, level shifters, and push-pull converters. The FDS8960C is suited for applications requiring two matched N-channel MOSFETs, such as synchronous buck converters, dual low-side switches, and load switches where both channels operate in the same polarity.