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BLF driver DDm-20 [rev01][tried and tested]

author: DEL
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2 layer board of 0.82 x 0.82 inches (20.7 x 20.8 mm)
Uploaded: March 04, 2017
Shared: March 04, 2017
Total Price: $3.30

BLF flashlight driver, 20 mm, DD+m

Features

  • 20 mm direct drive + 350 mA regulator LED driver
  • No OTC - Intended for e-switch, memory-decay or no-memory firmware.
  • R5 to eliminate unintentional Vcc boosting during PWM.
  • R3, R4 for stable drive of FET.
  • Oversized heat plane for the 7135 with good thermal link to the ground ring.
  • Generous 0603 pad sizes that will accept 0805 parts as well.
  • Universal package size for MCU. Tiny13-85 fits.

Revision changes

  • 01 Slight spring-side changes to adapt to a specific light.

Suggested parts list

  • U1: Atmel Attiny25, SSU or SSN package
  • U2: 7135 350 mA LED driver
  • Q1: Vishay SiR800DP
  • C1: 10 uF, X5R or better, 0805
  • D1: Schottky diode, 200 mA 20 V or better, 0805 or SOD323
  • R1: 22 / 330 kohm, 1%, 0603 (R1, R2 larger values for e-switch lights)
  • R2: 4.7 / 100 kohm, 1%, 0603
  • R3: 100 kohm, 5%, 0603
  • R4: 47 ohm, 5%, 0603
  • R5: 4.7 ohm, 5%, 0603

BLF flashlight driver, 20 mm, DD+m

Features

  • 20 mm direct drive + 350 mA regulator LED driver
  • No OTC - Intended for e-switch, memory-decay or no-memory firmware.
  • R5 to eliminate unintentional Vcc boosting during PWM.
  • R3, R4 for stable drive of FET.
  • Oversized heat plane for the 7135 with good thermal link to the ground ring.
  • Generous 0603 pad sizes that will accept 0805 parts as well.
  • Universal package size for MCU. Tiny13-85 fits.

Revision changes

  • 01 Slight spring-side changes to adapt to a specific light.

Suggested parts list

  • U1: Atmel Attiny25, SSU or SSN package
  • U2: 7135 350 mA LED driver
  • Q1: Vishay SiR800DP
  • C1: 10 uF, X5R or better, 0805
  • D1: Schottky diode, 200 mA 20 V or better, 0805 or SOD323
  • R1: 22 / 330 kohm, 1%, 0603 (R1, R2 larger values for e-switch lights)
  • R2: 4.7 / 100 kohm, 1%, 0603
  • R3: 100 kohm, 5%, 0603
  • R4: 47 ohm, 5%, 0603
  • R5: 4.7 ohm, 5%, 0603
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      Since this is a project designed by a community member, it may contain design errors that prevent it from working as intended. OSH Park cannot place any guarantees about the functionality or correctness of the design.
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