Doris Lee
| Picture | Part Number | Manufacturer | Stock | Action |
|---|---|---|---|---|
 | TC4424AVOA713 | Microchip | 6,410 | |
 | TC4423AVOA | Microchip | 9,500 |
Forward voltage covers conduction loss only. Reverse leakage during blocking intervals and the actual heat-removal path also contribute. Leakage changes with temperature, so a room-temperature forward-loss estimate cannot by itself establish a stable operating junction temperature.
Table 7 gives 0.17 mA typical and 0.6 mA maximum at 10 V, and 0.32 mA typical and 1.5 mA maximum at 20 V. These are pulsed tests with duration ≤300 µs and duty ≤0.02; they are not guaranteed continuous hot-leakage values.
Only if the cathode is ground in the actual circuit. The thermal solder-point reference is the cathode tab, but its copper and vias must remain on the cathode electrical net. Otherwise a ground connection can short or alter the circuit.
No. The datasheet’s 1 A forward-current limit requires cathode solder-point temperature no higher than 55°C. Board copper, thermal environment, waveform and reverse loss determine whether an application meets that condition. A nominal current label does not replace thermal validation.
By Doris Lee | YG GROUP
The TC4424AVOA713 is a dual non-inverting MOSFET driver in an eight-lead SOIC. Its channels share a supply and ground connection, so gate-current transients can disturb both output drive and input references. Local decoupling and compact returns reduce that coupling, but do not guarantee its elimination.
A dual gate driver can reproduce a clean logic signal on one channel while disturbing the other through its supply and return network. The useful design question is where the gate charge flows during each transition. The TC4424AVOA713 has two non-inverting outputs and one ground pin in its eight-lead SOIC. Compact gate loops, local supply charge and a controlled signal reference reduce common impedance; none of those choices alone guarantees zero ground bounce.
The Microchip DS21998B datasheet specifies a 4.5–18 V operating supply. It describes a 3 A driver family and lists a 4.5 A typical characterized peak output current at 10–18 V in its electrical table. This is transient drive capability, not a continuous load rating or a promise that two outputs can be paralleled for twice the headline current.
Table 1. Eight-lead SOIC pin functions | Source: manufacturer documents in References; assumptions and operating conditions are stated in the table or adjacent text. Compiled / calculated by: YG GROUP.
| Pin | Eight-lead SOIC function | Layout consequence |
|---|---|---|
| 1, 8 | NC | Do not treat either as an output or thermal pad |
| 2 | IN A | Reference control voltage to driver ground |
| 3 | GND | Shared return for both output channels |
| 4 | IN B | Keep away from high-current gate paths |
| 5 | OUT B | Route to channel B gate network |
| 6 | VDD | Place local bypassing between VDD and GND |
| 7 | OUT A | Route to channel A gate network |
The source also shows a 16-pin wide SOIC with duplicate pins. Its requirement to connect duplicate pins does not authorize tying OUT A and OUT B together on the eight-pin version. Nor does the electrically isolated exposed pad of the DFN option appear on this SOIC. Selecting the correct package symbol before discussing placement avoids both errors.
On a rising output edge, the bypass network supplies current through the driver’s high-side output stage into the MOSFET gate. On a falling edge, charge leaves the gate through the low-side output stage and the driver’s ground return. The MOSFET source reference and the bypass return therefore matter as much as the gate trace. A long shared return segment can couple one channel’s changing current into the other channel or its input reference.
For a low-side MOSFET application, place the driver near the gate networks and route the returns to minimize common impedance. Keep input routing referenced to the same ground system, with distance from the high-current loops. Figure 1 shows connectivity and current paths rather than a production footprint. Its two gate resistors are selection variables, not universal values or guarantees of stable switching.
Figure 1. Illustrative low-side gate-drive connections based on DS21998B §§3.3–3.4. Gate-current returns share the driver GND node; compact local loops reduce coupling. Resistors and gate loads represented by Cgate are application-selected, and the drawing is not a qualified PCB layout. Source: manufacturer documents in References; calculation / diagram: YG GROUP.
The manufacturer’s switching-test circuit uses a 0.1 µF ceramic capacitor in parallel with a 1 µF film capacitor. That is a useful source-supported test configuration, not proof that those values suit every board. Real selection depends on gate charge, switching frequency, supply impedance, capacitor bias dependence and placement. A remotely located bulk capacitor cannot replace a low-inductance local high-frequency path.
An inductive return contribution follows V = L dI/dt. As a purely illustrative calculation, 5 nH carrying a 1 A change in 10 ns gives 0.5 V. This value is not a measured property of a trace length, package or recommended board. The actual inductance and current waveform must be established for the assembled circuit; gate charge and a nominal driver peak rating are not enough to reconstruct them.
The voltage sensed at an input is Vcontroller minus Vdriver-ground when both are measured against a common reference. Positive driver-ground movement reduces a controller-high voltage at the input. Negative driver-ground movement raises a controller-low voltage. This sign distinction prevents an incorrect claim that every positive ground pulse makes a low input appear high.
Figure 2. Calculated reference-shift example: Vinput,effective = Vcontroller − Vground, with a 0 V controller input. DS21998B specifies VIL ≤ 0.8 V and VIH ≥ 2.4 V. The intermediate region is indeterminate; exceeding VIL alone does not prove a high logic state. Source: manufacturer documents in References; calculation / diagram: YG GROUP.
For example, −1.225 V driver-ground displacement makes a 0 V controller input appear as +1.225 V locally. That exceeds the guaranteed-low ceiling but remains below the guaranteed-high threshold. It demonstrates lost margin, not proof of a high transition. Built-in hysteresis does not turn an unspecified voltage into a guaranteed logic state. Check the input waveform directly between its input pin and pin 3.
Gate resistance changes charging current, transition time and damping. Increasing it can reduce ringing and instantaneous return-current slope, but it can also increase MOSFET switching loss. Evaluate both turn-on and turn-off behavior under the application’s voltage, current and temperature conditions. If separate charge and discharge paths are used, account for diode orientation and driver output-stage loading rather than assuming symmetric behavior.
The 12 ns typical rise and fall times are specified with a 1,800 pF test load at VDD = 18 V and room temperature, using the datasheet’s switching circuit. They are not guaranteed MOSFET switching times. A real MOSFET has voltage-dependent capacitance and Miller behavior, so its gate-charge curve and operating drain voltage are needed for an application estimate. The full-temperature limits also differ from the room-temperature typical values.
Table 2. Same-family driver polarity comparison | Source: manufacturer documents in References; assumptions and operating conditions are stated in the table or adjacent text. Compiled / calculated by: YG GROUP.
| Model | Verified polarity and package | Replacement boundary |
|---|---|---|
| TC4424AVOA713 | Dual non-inverting, eight-lead SOIC, tape and reel | Primary device |
| TC4423AVOA | Dual inverting, eight-lead SOIC example in the same datasheet | Changes both channels' control polarity; cannot be substituted without logic review |
The comparison establishes a real adjacent family member, not an interchangeable-driver list. Supply range and package resemblance do not replace checks of polarity, timing, current, thermal loading and sourcing requirements.
During bring-up, observe VDD-to-GND at the driver pins, each gate-to-source voltage and each input-to-driver-ground voltage. Exercise simultaneous and staggered channel transitions, including the application’s worst gate load. Use a probing arrangement whose loop does not dominate the apparent ringing. Record test conditions before drawing a before-and-after conclusion. If the disturbance remains, trace the shared impedance through the bypass return, MOSFET source network and controller reference instead of relying on an unsupported millimeter-based layout rule.