2 layer board of 1.82 x 1.82 inches (46.2 x 46.2 mm)
Uploaded:
September 26th 2017
Shared:
December 8th 2017
Total Price:
$16.50
This is the driver used in the production version of the BLF GT light.
[Bunny logo is the property of Lumintop…
This is the driver used in the production version of the BLF GT light.
[Bunny logo is the property of Lumintop, manufacturer of the GT]
Features
2.5 A buck regulator with constant current output
Attiny85 MCU, supported by NarsilM 1.2 and up firmware
Most BLF ‘1-channel’ and ‘2-channel’ firmware can be made to work with a few simple changes
0.4 V dropout voltage, <150 μA parasitic drain
Support for button indicator light
Revision changes
00 - driver prototype
01 - cosmetic changes
02 - adapted to the prototype 1 hosts and cell cradles (dedicated ground ring)
03 - copper added back to retaining ring area
04 - adapted to the production version hosts and cell cradles (retaining ring for ground)
Suggested parts list
Part no.
Value
Type
Package
C1
1u
X7R, 25 V
C0603
C2
3.3u - 10u
X5R, 16 V
C0805
C4
1u
X7R, 25 V
C0603
C11
4u7
X7R, 50 V
C1206
C12
4u7
X7R, 50 V
C1206
C13
4u7
X7R, 50 V
C1206
C14
4u7
X7R, 50 V
C1206
C15
470p
C0G, 50 V
C0603
C16
1u
X7R, 25 V
C0603
C17
4u7
X7R, 50 V
C1206
D1
SS34
Schottky, 40 V, 3 A
SMC/DO-214AB
L1
10u
Bourns SRR1208-100ML
12x12x8 mm
Q1
AOD417
P-chan <50 mohm <20 nC
TO252 / DPAK
R1
1M
1%
R0603
R2
47k
1%
R0603
R3
10R
1%
R0603
R4
10k
1%
R0603
R5
3k3
1%
R0603
R6
n/p
R7
1k
1%
R0603
R8
33k
1%
R0603
R11
0R091
1%, <300 ppm/C, 1-3 W
R2512
R12
47k
1%
R0603
R13
n/p
R14
4k7
1%
R0603
U1
ATTINY85-20SU
SOIC-8
U2
MIC5235-5
5 V LDO regulator
SOT23-5
U3
LM3409
Buck controller
HVSSOP-10
Output current range is determined by the R4/R5 ratio and the sense resistor (R11) value. R4/R5 could be used to lower the current, but to increase the current R11 should be adjusted:
Iout = 0.248 / R11 - 0.15
or R11 = 0.248 / (Iout + 0.15)
(the 0.15 offset is determined by the inductor ripple current and will change if the inductor value or switching frequency is modified)
This is the driver used in the production version of the BLF GT light.
[Bunny logo is the property of Lumintop…
This is the driver used in the production version of the BLF GT light.
[Bunny logo is the property of Lumintop, manufacturer of the GT]
Features
2.5 A buck regulator with constant current output
Attiny85 MCU, supported by NarsilM 1.2 and up firmware
Most BLF ‘1-channel’ and ‘2-channel’ firmware can be made to work with a few simple changes
0.4 V dropout voltage, <150 μA parasitic drain
Support for button indicator light
Revision changes
00 - driver prototype
01 - cosmetic changes
02 - adapted to the prototype 1 hosts and cell cradles (dedicated ground ring)
03 - copper added back to retaining ring area
04 - adapted to the production version hosts and cell cradles (retaining ring for ground)
Suggested parts list
Part no.
Value
Type
Package
C1
1u
X7R, 25 V
C0603
C2
3.3u - 10u
X5R, 16 V
C0805
C4
1u
X7R, 25 V
C0603
C11
4u7
X7R, 50 V
C1206
C12
4u7
X7R, 50 V
C1206
C13
4u7
X7R, 50 V
C1206
C14
4u7
X7R, 50 V
C1206
C15
470p
C0G, 50 V
C0603
C16
1u
X7R, 25 V
C0603
C17
4u7
X7R, 50 V
C1206
D1
SS34
Schottky, 40 V, 3 A
SMC/DO-214AB
L1
10u
Bourns SRR1208-100ML
12x12x8 mm
Q1
AOD417
P-chan <50 mohm <20 nC
TO252 / DPAK
R1
1M
1%
R0603
R2
47k
1%
R0603
R3
10R
1%
R0603
R4
10k
1%
R0603
R5
3k3
1%
R0603
R6
n/p
R7
1k
1%
R0603
R8
33k
1%
R0603
R11
0R091
1%, <300 ppm/C, 1-3 W
R2512
R12
47k
1%
R0603
R13
n/p
R14
4k7
1%
R0603
U1
ATTINY85-20SU
SOIC-8
U2
MIC5235-5
5 V LDO regulator
SOT23-5
U3
LM3409
Buck controller
HVSSOP-10
Output current range is determined by the R4/R5 ratio and the sense resistor (R11) value. R4/R5 could be used to lower the current, but to increase the current R11 should be adjusted:
Iout = 0.248 / R11 - 0.15
or R11 = 0.248 / (Iout + 0.15)
(the 0.15 offset is determined by the inductor ripple current and will change if the inductor value or switching frequency is modified)
The switch is a NO SMD 6.2x6.2x3.1 mm tactile type.
The LEDs have 0805 footprints.
Normally R1 is not populated. A jumper or small-value resistor here wires the two LEDs to be driven in parallel.
The switch is a NO SMD 6.2x6.2x3.1 mm tactile type.
The LEDs have 0805 footprints.
Normally R1 is not populated. A jumper or small-value resistor here wires the two LEDs to be driven in parallel.
R1 and R2 are populated if MCU pin 7 is used for cell voltage monitoring. This could, however, be done using the software-only method of Vcc vs. the internal 1.1 V reference.
R7 is populated when re-purposing pin 7 to drive a second indicator LED, as per the stock driver.
There is an R1 on the back of the switch board. A jumper here rewires the two indicator LEDs in parallel, both to be driven from MCU pin 3.
C3 = 10 uF is optional
C4 = 100 nF is optional
5+1 7135 driver for Solarstorm/Fandyfire K2 lights.
Revision changes
New
Needs the DDm-K2-SW daughter boa…
5+1 7135 driver for Solarstorm/Fandyfire K2 lights.
Revision changes
New
Needs the DDm-K2-SW daughter board for the tactile switch and indicator LEDs:
R1 and R2 are populated if MCU pin 7 is used for cell voltage monitoring. This could, however, be done using the software-only method of Vcc vs. the internal 1.1 V reference.
R7 is populated when re-purposing pin 7 to drive a second indicator LED, as per the stock driver.
There is an R1 on the back of the switch board. A jumper here rewires the two indicator LEDs in parallel, both to be driven from MCU pin 3.
