ISSI IS31IO7326 User manual

IS31IO7326 Debounced 8x8 Key-Scan Controller Evaluation Board Guide
Integrated Silicon Solution, Inc. – www.issi.com 1
R1.0, 08/23/2012
Description
IS31IO7326 is a 64 key, key-scan controller. It offloads
the burden of keyboard scanning from the host
processor. The IS31IO7326 supports keypad matrix of
up to 8×8. Key press and release events are encoded
into a byte format and loaded into a key event register
for retrieval by the host processor.
To minimize power, the IS31IO7326 automatically
enters a low power standby mode when there is no
keypad, I/O, or host activity.
Features
•Supply voltage range from 3.0V to 5.5V
•400kHz I
2
C serial interface
•Available for multi-key press detect
•Low 0.3µA (typ.) standby current
•Operate in -40°C to +125°C
•Pb-free 4mm × 4mm QFN-24 package
Quick Start
Recommended Equipment
•5.0V, 2A power supply
Absolute Maximum Ratings
•≤5.5V power supply
Caution: Do not exceed the conditions listed above, otherwise
the board will be damaged.
Procedure
The IS31FL7326 evaluation board is fully assembled
and tested. Follow the steps listed below to verify
board operation.
Caution: Do not turn on the power supply until all connections
are completed.
1) Connect the ground terminal of the power supply
to the GND and the positive terminal to the VCC.
Or connect the DC power to the connector (DC
IN).
2) Turn on the power supply and pay attention to the
supply current. If the current exceeds 200mA,
please check for circuit fault.
Figure 1: Photo of IS31IO7326 Evaluation Board
Evaluation Board Ordering Information
Part No. IC Package
IS31IO7326-QFLS4-EB QFN-24, Lead-free
Table1: Ordering Information
For pricing, delivery, and ordering information, please contacts ISSI’s analog marketing
team at [e-mail] or [phone].

IS31IO7326 Debounced 8x8 Key-Scan Controller Evaluation Board Guide
Integrated Silicon Solution, Inc. – www.issi.com 2
R1.0, 08/23/2012
Evaluation Board Operation
K0 to K63 are push buttons on the demo
board. When each of the button is pressed
briefly, a number corresponding to the key will
be displayed. When the button is pressed
and held for a few seconds, the period dot will
also be displayed. If two buttons are
pressed at the same time, the corresponding
key numbers will be displayed.
Note:
IS31IO7326 solely controls the Key-Scan function on the
evaluation board.
Software support
Note:
JP1 is set to close circuit by default. If it is set to open, the
on-board MCU will stop working. The pins driving the I2C pin
from MCU will be set to High Impedance. External control
signals can be connected to TP3 port to control the IS31IO7326.
Refer to the datasheet to get more information about
IS31IO7326.
f10
g5
e1
d2
H4
6
c4
DP 3
b7
a11
DIG1
K0 K8 K16 K24 K32 K40 K48 K56
K1 K9 K17 K25 K33 K41 K49 K57
K2 K10 K18 K26 K34 K42 K50 K58
K3 K11 K19 K27 K35 K43 K51 K59
K4 K12 K20 K28 K36 K44 K52 K60
K5 K13 K21 K29 K37 K45 K53 K61
K6 K14 K22 K30 K38 K46 K54 K62
K7 K15 K23 K31 K39 K47 K55 K63
100K
R5 100K R6 100K R7 100K R8 100K R9 100K R10 100K R11 100K R12
VCC
1uF
C2
SDA
SCL
VCC
4.7K
R1
4.7K
R2
H3
8
H2
9
H1
12
10nF
C5
VDD
1
GND
2
SD
3
BP 4
VOUT 5
U2
PAM3101
1uF
C6
3VVCC
CON1
DCIN
10uF
C1 1uF C4
TP1
TP2
PP0 1
PP1 2
PP2 3
PP3 4
OD0 5
OD1 6
OD2 7
OD3 8
GND
9
OD4 10
OD5 11
OD6 12
OD7 13
PP4 14
PP5 15
PP6 16
PP7 17
AD0
18
SCL
19
SDA
20
VCC
21
INT
22
RST
23
AD1
24
U1
IS31IO7326
100K
R3
4.7K
R4
3V
INT
RST
DP
g
f
e
d
c
b
a
C1C2C3C4
PP0
PP1
PP2
PP3
PP4
PP5
PP6
PP7
OD0
OD1
OD2
OD3
OD4
OD5
OD6
OD7
PP0
PP1
PP2
PP3
PP4
PP5
PP6
PP7
OD0 OD1 OD2 OD3 OD4 OD5 OD6 OD7
P0.0/CMP2/KBI0
1
P1.7
2P1.6
3
P1.5/RST 4
VSS 5
P3.1/XTAL1 6
P3.0XTAL2/CLKOUT 7
P1.4/INT1
8
P1.3/INT0/SDA 9
P1.2/T0/SCL
10
P1.1/RXD 11
P1.0/TXD 12
P0.7/T1/KBI7 13
P0.6/CMP1/KBI6
14
VDD 15
P0.5/CMPREF/KBI5 16
P0.4/CIN1A/KBI4 17
P0.3/CIN1B/KBI3
18 P0.2/CIN2A/KBI2
19 P0.1/CIN2B/KBI1
20
U3
LPC922
3V
JP1
OPEN=EXT CTRL
RST
SDA
SCL
1
2
3
4
5
TP4 3V
P0.5
P0.4
RESET
GND
P0.5
P0.4
RESET
INT
1
2
3
4
5
TP3
INT
RST
SDA
SCL
GND
1uF
C3
VCC
SDA
SCL
SDA
1
SCL
2
SDB
3
IN
4
C_FILT
5
AD
6
C6 18
C5 19
C4 21
C3 22
VDD
11
C2 23
C1 24
R1 7
R2 8
R3 9
R4 10
R5 12
R6/C11 13
GND
20
R7/C10 14
R8/C9 15
C7 17
C8 16
U4
IS31FL3728
C1
C2
C3
C4
a
b
c
d
e
f
g
DP
Figure 2:IS31IO7326 Application Schematic

IS31IO7326 Debounced 8x8 Key-Scan Controller Evaluation Board Guide
Integrated Silicon Solution, Inc. – www.issi.com 3
R1.0, 08/23/2012
Bill of Materials
Name Symbol Description Qty Supplier Part No.
I/O IC U1 16 I/O ports.Expander 1 ISSI IS31IO7326
LDO U2 Low-dropout Regulator 1 PAM PAM3101
MCU U3 Microcontroller 1 NXP LPC922
LED Driver U4 Array FxLED Driver 1 ISSI IS31FL3728
Displayer DIG1 4 Digit Display, Common
Kathode 1 ZSO 3461AS
Resistors R1,R2,R4 RES,4.7k,1/16W,±5%,SMD 3
Resistor R3 RES,100k,1/16W,±5%,SMD 1
Resistors R5~R12 RES,100k,1/16W,±5%,SMD 8
Capacitor C1 CAP,10µF,16V,±20%,SMD 1
Capacitors C2,C3,C4,C6 CAP, 1µF,16V,±20%,SMD 4
Capacitor C5 CAP,10nF,16V,±20%,SMD 1
Buttons K0~K63 Button SMD 64
Table 2: Bill of Materials, refer to Figure 2 above.

IS31IO7326 Debounced 8x8 Key-Scan Controller Evaluation Board Guide
Integrated Silicon Solution, Inc. – www.issi.com 4
R1.0, 08/23/2012
14
12
11
10
9
8
7
6
5
43
2
10
1312
11
9
10 11 12
13
14
1516
17
18
19
20
21
22
0
00
0
2
2
2
1
2
3
4
5
2
1
000000
000000
1
2
1
2
Figure 3: Board Component Placement Guide -Top Layer
Figure 4: Board PCB Layout- Top Layer

IS31IO7326 Debounced 8x8 Key-Scan Controller Evaluation Board Guide
Integrated Silicon Solution, Inc. – www.issi.com 5
R1.0, 08/23/2012
14
12
11
10
9
8
7
6
5
43
2
10
1312
11
9
10 11 12
13
14
1516
17
18
19
20
21
22
0
00
0
2
2
2
1
2
3
4
5
2
1
000000
000000
1
2
1
2
Figure 5: Board Component Placement Guide -Bottom Layer
Figure 6: Board PCB Layout-Bottom Layer

IS31IO7326 Debounced 8x8 Key-Scan Controller Evaluation Board Guide
Integrated Silicon Solution, Inc. – www.issi.com 6
R1.0, 08/23/2012
Copyright © 201
2
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and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information,
products or services described herein. Customers are advised to obtain the latest version of this device specification before relying
on any published information and before placing orders for products.
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malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety
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