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Product Overview
DSEK40S06P is a 600V common-cathode dual soft-recovery rectifier in TO-247AD. Each diode is rated at 20A, giving a total device current rating of 40A for center-tapped outputs and common-cathode current paths.
The 40A total device rating comprises two 20A diode paths. Evaluate each branch at its own current waveform and operating temperature when calculating conduction loss and the required cooling.
Key Features
● 600V repetitive peak reverse voltage and two 20A diode paths.
● 35ns maximum reverse-recovery time under the specified 0.5A test condition.
● 1.6V maximum forward voltage at 20A and 25°C.
● 250A non-repetitive surge current per diode for a 8.3ms pulse.
Key Specifications
| Parameter | Value and conditions |
| Configuration / package | Dual common cathode / TO-247AD |
| Forward current | 40A per device; 20A per diode |
| Repetitive peak reverse voltage | 600V |
| Forward voltage | 1.12V typ at IF = 20A, Tj = 125°C 1.6V max at IF = 20A, Tj = 25°C |
| Reverse recovery time | 35ns max; Tj = 25°C, IF = 0.5A, IR = 1.0A, Irr = 0.25A |
| Surge current | 250A per diode; non-repetitive, t = 8.3ms |
| Junction to case thermal resistance | 1.0°C/W |
| Junction temperature range | −55°C to +175°C |
Current capability depends on case temperature and cooling. Use the datasheet derating curve when determining operating current.
Electrical Configuration and Pinout
Two separate anodes connect to a shared cathode. With the marking face toward you and the leads pointing down, the lead functions are A1, K and A2 from left to right. The exposed metal tab is also connected to K.
Figure 1. Circuit and connection detail from the DSEK40S06P datasheet, page 1. A = anode; K = cathode.
| Connection | Function |
| Left lead | A1 — first diode anode |
| Center lead | K — common cathode |
| Right lead | A2 — second diode anode |
| Metal tab | K — electrically connected to the common cathode |
Typical Applications
● Positive center-tapped industrial rectifiers.
● Modular power-conversion supplies.
● Common-cathode freewheel circuits.
Two 20A Paths for Positive Rectification
This device suits two-branch rectifier designs built around a 20A per-diode current class. Its 1.12V typical forward-voltage point at 20A and 125°C supports hot conduction-loss estimates for each branch.
Design Notes
Evaluate each diode at its own current waveform and duty cycle. The 40A total device rating does not mean one junction can carry 40A. Check reverse-voltage peaks, including switching transients, against the 600V rating.
The metal tab carries the common cathode potential. If the heatsink must remain at a different potential, use an appropriate insulating mounting interface and include its thermal resistance.
The 35ns recovery limit uses the low-current test condition in the parameter table. Evaluate recovery at the application current and temperature. The 250A surge specification is non-repetitive and must not be used as a repetitive overload rating.
FAQ
It is a 40 A dual device rated at 20 A per internal diode.
It is typical at 20 A and 125°C. The 25°C maximum is 1.6 V at 20 A; these values have different temperature and statistical bases.
Only after current-sharing, layout, and thermal analysis. The common-cathode package does not guarantee equal parallel current in every connection.
