SHEET: OF 6
AD25FPE01A.sch
9-40-0505-E
9-79-0505-E-0
1/6/2009M. Stith
AKAI
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LTR
C
B
A
C
D
6 5 4 3 2 1
DATE:
D
B
A
RELEASED: DATED:
DATED:
ECO NO: APPROVED:
REVISION RECORD
SCALE:
COMPANY:
AD25 FRONT PANEL PCB
TO LCD
I/O
TO
MAIN
PCB *
* Pin order reversed vs. main board connector.
TO
MAIN
PCB *
Ensure large area of copper is used as heatsink for drive transistor
Datasheet recommends 1. 6" x 1. 6" PCB area for 350mW at 25 deg. C
Max di ssipation will be about 130mW:
6V (DC input) - 0.3V (Schottky Diode) - 0.6V (Resistor on Emitter) - 2.75V (white LED backlight) = 2.35V
2.35V * 55mA = 130mW
R = (Vbe / I) = (0.66V / 55mA) = 12 Ohms
(Vbe was measured in a VC0 sample to be .66V, so that volt age will be assumed to be nominal)
(Backlight current in AD24 measured to be 55mA the goal is t o keep backlight brightness consistent across product line
Dissipation at accidental 9VDC input will be about 300mW
B
Copyright (c) 2008 Akai Professional
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J4
GFP-231221-21802G
R18
100k
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J1
GFP-231221-22602G
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J3
GFP-231221-12202G
Q1
MBT4401
R7
470 ohm
Q2
MBT4401
R8
12 ohm
Q3
MBT4403
C33
0.1uF
C23
1000pF
D10
SMAJ10A
C110.1uF
C130.1uF
C140.1uF
+5VUNREG
LCD_E
LCD_RW
LCD_RS
+3V3
+5VUNREG
+3V3_FULL
LCD_CONTRAST_DC
LCD_RS
LCD_RW
LCD_E
LCD_CONTRAST_DC
+3V3_FULL
DATA[0:7]
DATA0
DATA1
DATA2
DATA3
DATA4
DATA5
DATA6
DATA7
BTN_SCAN[0:3]
BTN_SCAN0
BTN_SCAN1
BTN_SCAN2
BTN_SCAN3
ANALOG_TOP
PITCH
MOD
+3V3
PAD_SCAN[0:3]
PAD_SCAN0
PAD_SCAN1
PAD_SCAN2
PAD_SCAN3
ANALOG[0:1]
ANALOG1
ANALOG0
PAD_RETURN[0:2]
PAD_RETURN0
PAD_RETURN1
PAD_RETURN2
ENC_A
ENC_B
LED_LATCH2
LED_LATCH1
DATA[0:7]
DATA0
DATA1
DATA2
DATA3
DATA4
DATA5
DATA6
DATA7
ANALOG_SELECT[0:3]
ANALOG_SELECT3
ANALOG_SELECT2
ANALOG_SELECT1
ANALOG_SELECT0
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