The AMBRB3045CT is a 30 A, 45 V common-cathode Schottky dual diode in a D2PAK package from Good-Ark, with 0.64 V typical forward drop per die at 15 A and a 200 A per-die surge rating. It targets dashboard power, SMPS output stages, and OR-ing roles where 30 A of board-level rectification needs a low drop and a working thermal path.
AMBRB3045CT at a Glance
All values below come from the official Good-Ark datasheet:
| Parameter | Symbol | Value |
|---|---|---|
| Maximum repetitive peak reverse voltage | VRRM | 45 V |
| Maximum RMS / DC blocking voltage | VRMS / VDC | 32 / 45 V |
| Average forward current | IF(AV) | 30 A |
| Peak forward surge current (8.3 ms, per die) | IFSM | 200 A |
| Forward voltage, IF = 15 A, TJ = 25 °C | VF | 0.64 typ / 0.65 max V |
| Forward voltage, IF = 15 A, TJ = 125 °C | VF | 0.60 max V |
| Reverse leakage, TJ = 25 °C / 100 °C | IR | 50 µA max / 10 mA max |
| Thermal resistance | RθJC / RθJA | 2.0 / 62.5 °C/W |
| Package | — | TO-263 (D2PAK), dual common cathode |
The part is a dual diode in one package: two die with a shared cathode, each rated for the current it carries, in a D2PAK body that conducts heat through the exposed pad into the board.
The dual construction changes how the current is read: the 30 A rating is the package total, and each die carries its share—typically 15 A per die when the two paths are balanced. The per-die VF figures at 15 A match that sharing, so the loss budget is built per die and summed for the package.
The CT (Common Cathode) Configuration Explained
The CT suffix means common cathode: both die share the cathode connection, and the two anodes are independent. That configuration suits circuits where two outputs or two phases need to feed a shared positive rail—OR-ing, half-bridge secondaries, and center-tapped transformer outputs. The value of the dual package is the same as any dual: matched die, one heat path, one footprint; the configuration detail belongs to the common-cathode guide.
The shared cathode also simplifies the thermal story: both die sit on the same lead frame, so their heat joins in one path to the exposed pad, and the board sees one thermal load instead of two separate ones. The mechanical layout for a center-tapped secondary is a single D2PAK footprint instead of two single-diode placements.
Target Uses: Dashboard Power, SMPS Output, OR-ing
Three roles fit the 45 V class and 30 A current. Dashboard power in a vehicle runs at 12 V with transients; the 45 V class covers the peaks with margin, and the low drop keeps the loss small in a sealed module. SMPS output stages at 5–24 V use the dual rectifier for the two halves of the output; the 200 A per-die surge absorbs the power-on inrush as a survival margin checked against the real waveform. OR-ing diodes combine redundant supplies to a shared bus; the common-cathode package and low drop make the sharing efficient.
In the OR-ing role the low drop does double duty: each redundant rail loses only its own forward drop to the shared bus, and the common-cathode package keeps the two paths on one footprint. The 45 V class also covers the 12 V rail’s worst transients with room to spare.
D2PAK Thermal and Mounting Notes
The D2PAK’s exposed pad is the thermal exit, and the board completes the path: a copper area matching the pad, thermal vias into inner planes, and a void-controlled solder joint decide whether the 30 A rating is real. The current is valid at a stated case temperature with a defined mounting, so the board design follows the D2PAK design guide and the thermal result is confirmed on the prototype.
The per-die sharing sets the thermal expectation: at 15 A per die with the 0.64 V typical drop, each die dissipates roughly 9.6 W as a first pass, and the 2.0 °C/W junction-to-case resistance turns that into about 19 °C of rise per die. The final budget uses the maximum VF at the hot condition and walks the full board path before the case temperature is accepted.
Availability and Sample Requests
The AMBRB3045CT product page hosts the datasheet, and the Schottky rectifier diodes category shows where the part sits in the family. Contact Good-Ark with your output current, voltage, and board design to confirm availability and request samples.
The D2PAK body also suits automated SMT assembly, and the supply format—tube or reel—is confirmed with the supplier for the production line.
Frequently Asked Questions
What does the CT suffix mean?
Common cathode—both die share the cathode, with independent anodes. The configuration suits OR-ing, half-bridge secondaries, and center-tapped outputs feeding a shared positive rail.
What is the forward drop at the rated current?
0.64 V typical and 0.65 V maximum per die at 15 A and 25 °C, with 0.60 V maximum at 125 °C. Read VF at the working current and temperature for the loss budget.
How much surge can the AMBRB3045CT survive?
200 A per die at 8.3 ms half-sine—a single-pulse survival margin checked against the real inrush waveform, not a repetitive capability.
What package is it in?
TO-263 (D2PAK), a board-mount package with an exposed pad for heat conduction. The pad and via design decide the thermal performance.
Is the 30 A rating usable continuously?
At a stated case temperature with a defined mounting. The board copper and vias set the real limit; confirm with a case-temperature measurement at the load.
Specifications, Applications, Ordering
Specifications:
30 A / 45 V common-cathode Schottky in D2PAK; VF 0.64 typ / 0.65 max V at 15 A; IFSM 200 A per die; IR 50 µA max at 25 °C; RθJC 2.0 °C/W.
Applications:
dashboard power, SMPS output rectification, OR-ing and redundant-rail combining at 5–24 V.
Ordering:
the datasheet is on the AMBRB3045CT product page; request samples and documentation through Good-Ark sales with your load and board design.