Complete Schematics
STK525 Hardware User Guide
6-31
7608A–AVR–04/06
Figure 6-1 . Schematics, 1 of 5
C7
1uF
VBU
S
SW
2
E
xt Re
se
t
PE3
AVC
C
P
D[7
..0
]
P
D
[7
..0
]
NC
K
A
D1
BAT
54/
SOT
INT
0
/2
PA0
U
C
AP C
apac
it
or
C
los
ed t
o
t
he M
C
U
VC
C
PA1
R4
0
PF7
SP2
PA3
UGND
VC
C
PA[
7
..
0
]
PA[
7
..
0
]
PA[
7
..
0
]
PA2
PE7
RESET
PA4
Reset Circuit
Force Bootloader Execution
VC
C
R3
47k
C8
220nF
PE2
UV
CO
N
VBU
S
Important Note:
U1 is mounted through a TQFP64 ZIF socket
PA5
PA6
C1
100nF
UCA
P
PA7
C
los
e Solder Pad
T
o
us
e parallel prog m
ode
(1
2
V
o
n
Re
se
t P
in
)
SW
1
HWB
PE2
P
F[7
..0
]
PC
7
UG
ND
R7
0
AGN
D
R6
0
1
TP
1
D+
D-
D+
1
TP
2
D-
1
TP
3
AR
EF
AR
EF
R
ESI
ST
OR
S
C
L
OSED
T
O
T
H
E D
EVI
C
E
VC
C
PE4
PB[
7.
.0
]
PB[
7
..
0
]
PB[
7
..
0
]
PE5
PC
6
VC
C
AVC
C
L1
B
L
M
-21A
102S
SP1
C2
100nF
Ti
tl
e
Siz
e
D
oc
um
ent
N
u
m
ber
R
e
v
D
a
te
:
S
heet
of
11
.0
CP
U
A4
14
W
ednes
day
, F
ebruary
15,
2006
PC
5
PC
4
VC
C
PB0
VC
C
F
e
rrit
e & c
apac
it
ors
c
los
ed t
o
t
he M
C
U
PB1
1-V_BU
S
3-D
+
2-D
-
4-I
D
5-GN
D
S
HIE
L
D
S
HIE
L
D
S
HIE
L
D
S
HIE
L
D
U
SB_M
iniABF
J1
PB2
PC
3
R5
47k
PE7
2
UV
cc
3
D-
4
D+
5
UG
ND
6
UCA
P
7
VBU
S
8
PE3
9
PB0
10
PB1
11
PB2
12
PB3
13
PB4
14
PB5
15
PB6
16
PB7
17
PD0
25
PD1
26
PD2
27
PD3
28
PD4
29
PD5
30
PD6
31
PD7
32
PE4
18
PE5
19
AREF
62
RESET
20
GND
53
GND
63
GND
22
XTAL2
23
XTAL1
24
PE0
33
PE1
34
PE6
1
PE2
43
PC
0
35
PC
1
36
PC
2
37
PC
3
38
PC
4
39
PC
5
40
PC
6
41
PC
7
42
PA7
44
PA6
45
PA5
46
PA4
47
PA3
48
PA2
49
PA1
50
PA0
51
PF7
54
PF6
55
PF5
56
PF4
57
PF3
58
PF2
59
PF1
60
PF0
61
VCC
52
VCC
21
AVCC
64
AT
90U
SB128
U1
PB3
UV
CO
N
P
E
7
C5
100nF
VC
C
DE
CO
UP
L
ING
CA
P
A
CIT
O
R
S
C
L
OSED
T
O
T
H
E D
EVI
C
E
M
C
U
Pin3
VBU
S
PC
2
PB4
Y1
8M
H
z
C1
1
15pF
C1
0
15pF
PC
1
PB5
VBU
S
AR
EF
PC
0
PB6
PE[
7.
.0
]
PE1
PB7
PF0
PE0
S
T
K
525 M
E
Z
Z
A
N
IN
E
F
O
R
S
T
K
500
C9
220nF
UG
ND
UG
ND
UG
ND
UG
ND
UG
ND
P
C[7
..0
]
P
C
[7
..0
]
C3
100nF
PF1
R2
2
2
R1
2
2
R
ESET
D+
C4
100nF
D-
UID
P
E
3
PF2
PD0
XTAL2
PD1
PD2
PF3
PD3
AGN
D
CR1
PGB0010603
PA[
7
..
0
]
PA[
7
..
0
]
PA[
7
..
0
]
CR2
PGB0010603
PE0
PD4
XTAL1
PD5
PD6
DE
CO
UP
L
ING
CA
P
A
CIT
O
R
S
C
L
OSED
T
O
T
H
E D
EVI
C
E
M
CU P
in
5
2
PE1
PD7
PF4
X
T
AL2
UCA
P
NRS
T
UV
CC
D
+
D
- R
ESI
ST
OR
S
C
los
ed t
o
t
he M
C
U
PE2
PF5
R
ESET
C6
100nF
VC
C
PA[
7.
.0
]
AR
EF
DE
CO
UP
L
ING
CA
P
A
CIT
O
R
S
C
L
OSED
T
O
T
H
E D
EVI
C
E
M
CU P
in
2
1
PF6
X
T
AL1
