Spark Logic

BAT54A Schottky diode connection guide

BAT54A Schottky diode (BAT54A · SOT-23) connection guide. Verify polarity with a meter.

BAT54A · SOT-23

3 contacts Current package
BAT54 · SOT-23 3 contacts
BAT54C · SOT-23 3 contacts
BAT54S · SOT-23 3 contacts
BAT54AW · SOT-323 3 contacts
BAT54W · SOT-323 3 contacts
BAT54CW · SOT-323 3 contacts
BAT54SW · SOT-323 3 contacts

onsemi / Diodes Incorporated / PANJIT · Common anode; onsemi top code L42.

Verify polarity with a meter

Required

With board power disconnected, isolate the part if other paths can affect the reading. For each branch put the red diode-test probe on its anode and the black probe on its cathode.

Verify polarity with a meterPin 3 · anodePin 1 · cathodePin 3 · anodePin 2 · cathode
  • Pin 1
    • D1 cathode
  • Pin 2
    • D2 cathode
  • Pin 3
    • D1 anode
    • D2 anode

Bench checks

  • D1: forward from pin 3 to pin 1; reverse the probes to check blocking.
  • D2: forward from pin 3 to pin 2; reverse the probes to check blocking.

onsemi BAT54/D Rev. 3, p. 1 Connection Diagram; meter reading depends on the test current.

BAT54A · SOT-23 wiring map

External wiring example · Verify polarity with a meter

Highlighted contacts are used in the required step or selected circuit. Select a contact to highlight its wiring nets.

BAT54A · SOT-23
Top view, single lead at the top. Pin 1 is lower left, pin 2 lower right and pin 3 at the top.
Selected pin details

1 · K1

Terminal · Bidirectional

Cathode of D1.

onsemi BAT54/D Rev. 3, p. 1 Connection Diagram

Electrical limits · Pin in the reference

Models and documents

L42 is documented for onsemi BAT54A and Diodes BAT54ATA in SOT-23, and PANJIT BAT54AW in SOT-323. All three have a 1+2 lead pattern. Check the package body size and confirm forward conduction from pin 3 to both pins 1 and 2. The N 8 characters do not establish the manufacturer or date.

BAT54A
onsemi order code for the common anode configuration.
BAT54ATA
Diodes Incorporated SOT-23. Marking: L42.