Part A
FDS8958A
Công ty bán dẫn Fairchild
- Lifecycle
- Active
- Stock
- 3494 PCS
- Package
- SOIC-8
- Series
- Transistors - 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
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. |
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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.