ETC MAX7360

19-4566; Rev 0; 4/09
估板
可提供评
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
按键控制器进行按键去抖，并将按下和弹起事件保存在
FIFO 中( 如果使能，还提供自动重复功能)。中断输出(INTK)
特性
S 集成ESD 保护
±8kV IEC 61000-4-2 接触放电
±15kV IEC 61000-4-2 气隙放电
S 能够承受 +14V电压的漏极开路I/O 端口，可用作恒流 LED
驱动
S 旋转开关输入对(PORT6、PORT7)
S 独立的 256 级 PWM LED亮度控制
S 独立的LED闪烁速率及 256ms至4096ms LED渐明/ 渐暗
速率控制
S FIFO 队列可保存多达16 个去抖按键事件
可配置成在按键按下时报警或以最大速率报警。
S 用户可配置按键去抖时间(9ms至40ms)
器件具有 8 个漏极开路I/O 端口，用于驱动 LED。每个漏极
开路端口的最大固定输出电流为 20mA。每个漏极开路端口
的 LED 亮度可通过 256 级 PWM 控制信号独立调节。输入端
口对 (PORT6、PORT7)可配置成接受旋转开关的 2 位格雷
码输入。此外，如果没有用作按键开关控制，最多 6 列引脚
可作为通用漏极开路输出(GPO)，用于 LED 驱动或逻辑控制。
S 按键扫描采用静态矩阵监测，实现低 EMI 操作
MAX7360 提供带裸焊盘的 40 引脚 (5mmx5mm) 薄型
QFN 封装和小尺寸 36 焊球晶片级封装 (WLP)，适合蜂窝电
话、掌上电脑及其它便携式消费类电子应用。MAX7360工
作于 -40 °C至+85°C 扩展级温度范围。
应用
蜂窝电话
PDA
手持式游戏机
便携式消费类电子
S +1.62V至+3.6V供电
S 最多可监测 64个按键
S 每个去抖事件 /FIFO 级或预设时间周期结束时，产生按键
开关中断(INTK)
S 输入端口中断(INTI)，用作特殊按键功能
S 400kbps、+5.5V 耐压、2 线串口，可选择总线超时
S 4个I2C 地址选择
定购信息
PART
TEMP RANGE
MAX7360ETL+
-40°C to +85°C
MAX7360EWX+**
-40°C to +85°C
+表示无铅(Pb)/ 符合 RoHS 标准的封装。
*EP= 裸焊盘。
**未来产品—供货状况请与工厂联系。
PIN-PACKAGE
40 TQFN-EP*
36 WLP
打印机
仪表
简化框图
+1.8V
TO
FC
SCL
SDA
INTI
INTK
PORT7
PORT6
MAX7360
AD0
ROTARY
SWITCH
+14V
PORT0
ROW_(8x)
COL_(8x)
8x8
引脚配置在数据资料的最后给出。
________________________________________________________________ Maxim Integrated Products 1
本文是英文数据资料的译文，文中可能存在翻译上的不准确或错误。如需进一步确认，请在您的设计中参考英文资料。
有关价格、供货及订购信息，请联络Maxim亚洲销售中心：10800 852 1249 (北中国区)，10800 152 1249 (南中国区)，
或访问Maxim的中文网站：china.maxim-ic.com。
MAX7360
概述
2
MAX7360I C 接口外设能够为微处理器管理多达 64 个
按键开关，附加的 8 路 LED 驱动器 /GPIO 具有固定电流、
PWM 亮度调节及旋转开关控制选项。
按键开关驱动器能够与金属开关或导通电阻高达 5kΩ 的阻性
开关连接。以静态 (而非动态扫描) 方式监测按键输入，确
保低 EMI工作。MAX7360 具有自动休眠和自动唤醒模式，
使器件功耗最低。经过1个休眠超时周期后，自动休眠功能
可以将器件置于低功耗状态 ( 典型值为1µA)。检测到按键动
作时，自动唤醒功能使 MAX7360 返回正常工作模式。
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
ABSOLUTE MAXIMUM RATINGS
VCC to GND.............................................................. -0.3V to +4V
COL0–COL7, ROW0–ROW7 to GND....................... -0.3V to +4V
SDA, SCL, AD0, INTI, INTK to GND......................... -0.3V to +6V
PORT0–PORT7 to GND.......................................... -0.3V to +16V
All Other Pins to GND.................................-0.3V to (VCC + 0.3V)
DC Current on PORT0–PORT7, COL2–COL7.....................25mA
GND Current........................................................................80mA
Continuous Power Dissipation (TA = +70NC)
40-Pin TQFN (derate 22.2mW/NC above +70NC).......1777mW
36-Bump WLP (derate 21.7mW/NC above +70NC).....1739mW
Junction-to-Case Thermal Resistance (BJC) (Note 1)
40-Pin TQFN...................................................................2NC/W
36-Bump WLP.................................................................... N/A
Junction-to-Ambient Thermal Resistance (BJA) (Note 1)
40-Pin TQFN.................................................................45NC/W
36-Bump WLP..............................................................46NC/W
Operating Temperature Range........................... -40NC to +85NC
Junction Temperature......................................................+150NC
Storage Temperature Range............................. -65NC to +150NC
ESD Protection
Human Body Model (RD = 1.5kI, CS = 100pF)
All Pins..............................................................................Q2kV
IEC 61000-4-2 (RD = 330I, CS = 150pF)
Contact Discharge
ROW0–ROW7, COL0–COL7, PORT0–PORT7 to GND.....Q8kV
Air-Gap Discharge
ROW0–ROW7, COL0–COL7, PORT0–PORT7 to GND...Q15kV
Lead Temperature (soldering, 10s)
40-Pin TQFN.................................................................+300NC
36-Bump WLP............................................................ (Note 2)
Note 1:Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a single-
.layer board. For detailed information on package thermal considerations, refer to china.maxim-ic.com/thermal-tutorial.
Note 2:Refer to Pb-free solder-reflow requirements described in J-STD-020, Rev D.1, or any other paste supplier specification.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may
affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 3, 4)
PARAMETER
Operating Supply Voltage
External Supply Voltage
PORT0–PORT7
Operating Supply Current
SYMBOL
CONDITIONS
VCC
MIN
TYP
MAX
UNITS
1.62
3.3
3.6
V
14
V
VPORT_
ICC
All key switches open, oscillator running,
COL2–COL7 configured as key switches,
VPORT_ = VCC
34
50
FA
34 +
20 x N
N keys pressed
Sleep-Mode Supply Current
ISL
1.3
3
FA
Key-Switch Source Current
IKEY
20
35
FA
Key-Switch Source Voltage
VKEY
0.43
0.5
V
5
kI
2
2.4
ms
0.5
V
Key-Switch Resistance
Startup Time from Shutdown
RKEY
Output Low Voltage
COL2–COL7
VOL
Oscillator Frequency (PWM
Clock)
fOSC
Oscillator Frequency Variation
Key-Scan Frequency
(Note 5)
tSTART
DfOSC
fKEY
ISINK = 10mA
TA = +25NC, VCC = +2.61V
125
TA = TMIN to TMAX, VCC P 3.6V
102
164
-6
+8.5
TA = +25NC
Derived from oscillator clock
128
64
2 _______________________________________________________________________________________
131
kHz
%
kHz
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 3, 4)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
GPIO SPECIFICATIONS
Input High Voltage
PORT0–PORT7
VIH
Input Low Voltage
PORT0–PORT7
VIL
Input Leakage Current
PORT0–PORT7
IIN
Output Low Voltage
PORT0–PORT7
VOL
0.7 x
VCC
V
0.3 x
VCC
VIN P VCC
-0.25
+0.25
VCC < VIN
-1
+5
ISINK < 20mA
0.6
Input Capacitance
PORT0–PORT7
20
10mA Port Sinking Current
PORT0–PORT7
VCC = +1.62V to +3.6V, TA = +25NC
8.55
VCC = +3.3V, VOL = +1V
8.67
20mA Port Sinking Current
PORT0–PORT7
VCC = +1.62V to +3.6V, TA = +25NC
19.40
VCC = +3.3V, VOL = +1V
19.55
Port Sink Current Variation
VCC = +3.3V, VOL = +1V, TA = +25NC,
20mA output mode
Output Logic-Low Voltage
INTI, INTK
ISINK = 10mA
PWM Frequency
fPWM
Derived from oscillator clock
FA
V
pF
11.52
9.76
V
10.51
21.33
mA
mA
20
20.69
+Q1.5
+Q2.4
%
0.6
V
500
Hz
SERIAL-INTERFACE SPECIFICATIONS
Input High Voltage
SDA, SCL, AD0
VIH
Input Low Voltage
SDA, SCL, AD0
VIL
Input Leakage Current
SDA, SCL, AD0
IIN
Output Low Voltage
SDA
VOL
Input Capacitance
SDA, SCL, AD0
CIN
I2C TIMING SPECIFICATIONS
SCL Serial-Clock Frequency
Bus Free Time Between a STOP
and START Condition
fSCL
0.7 x
VCC
V
0.3 x
VCC
VIN P VCC
-0.25
+0.25
VIN > VCC
-0.5
+0.5
ISINK = 6mA
0.6
10
Bus timeout disabled
0
V
FA
V
pF
400
kHz
tBUF
1.3
Fs
Hold Time (Repeated) START
Condition
tHD, STA
0.6
Fs
Repeated START Condition
Setup Time
tSU, STA
0.6
Fs
STOP Condition Setup Time
tSU, STO
0.6
Fs
_______________________________________________________________________________________ 3
MAX7360
ELECTRICAL CHARACTERISTICS (continued)
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 3, 4)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Data Hold Time
tHD, DAT
Data Setup Time
tSU, DAT
100
ns
SCL Clock Low Period
tLOW
1.3
Fs
SCL Clock High Period
tHIGH
0.7
Fs
(Note 6)
0.9
Fs
Rise Time of Both SDA and SCL
Signals, Receiving
tR
(Notes 5, 7)
20 +
0.1Cb
300
ns
Fall Time of Both SDA and SCL
Signals, Receiving
tF
(Notes 5, 7)
20 +
0.1Cb
300
ns
tF, TX
(Notes 5, 8)
20 +
0.1Cb
250
ns
Pulse Width of Spike Suppressed
tSP
(Notes 5, 9)
50
Capacitive Load for Each Bus
Line
Cb
(Note 5)
Fall Time of SDA Signal,
Transmitting
ns
400
pF
Note 3: All parameters are tested at TA = +25NC. Specifications over temperature are guaranteed by design.
Note 4: All digital inputs at VCC or GND.
Note 5: Guaranteed by design.
Note 6: A master device must provide a hold time of at least 300ns for the SDA signal (referred to VIL of the SCL signal) to bridge
the undefined region of SCL’s falling edge.
Note 7: Cb = total capacitance of one bus line in pF. tR and tF measured between +0.8V and +2.1V.
Note 8: ISINK P 6mA. Cb = total capacitance of one bus line in pF. tR and tF measured between +0.8V and +2.1V.
Note 9: Input filters on the SDA, SCL, and AD0 inputs suppress noise spikes less than 50ns.
4 _______________________________________________________________________________________
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
(VCC = +2.5V, TA = +25NC, unless otherwise noted.)
TA = -40NC
50
100
TA = -40°C
50
0
5
15
0
5
0
20
18.3
TA = -40NC, +85NC
18.2
18.1
18.0
TA = +25NC
TA = +85NC
17.9
17.8
TA = -40NC
17.7
17.6
15
20
3.2
25
2.0
2.4
3.2
2.8
SUPPLY VOLTAGE (V)
TA = +25NC
TA = +85NC
5
VCC = 3.0V
20
SINK CURRENT (mA)
TA = -40NC
0
2.0
OUTPUT VOLTAGE (V)
2.5
TA = +85NC
0.5
1.6
TA = +25NC
TA = +85NC
10
3.0
2.8
2.4
3.2
3.6
CONSTANT-CURRENT GPIO OUTPUT
SINK CURRENT vs. OUTPUT VOLTAGE
TA = -40NC
15
2.0
SUPPLY VOLTAGE (V)
25
VCC = 3.6V
20
TA = -40NC
15
TA = +25NC
TA = +85NC
10
5
0
1.5
TA = +25NC
1.0
3.6
5
1.0
1.5
CONSTANT-CURRENT GPIO OUTPUT
SINK CURRENT vs. OUTPUT VOLTAGE
MAX7360 toc07
20
2.0
0
CONSTANT-CURRENT GPIO OUTPUT
SINK CURRENT vs. OUTPUT VOLTAGE
VCC = 2.4V
TA = -40NC
TA = -40NC, +25NC
1.6
3.6
2.5
MAX7360 toc09
2.8
3.0
17.4
SUPPLY VOLTAGE (V)
0.5
10
MAX7360 toc06
VCOL0 = O
SINK CURRENT (mA)
2.4
2.0
MAX7360 toc05
18.4
17.5
0
5
0
SHUTDOWN SUPPLY CURRENT (A)
TA = -40NC
20
SINK CURRENT (mA)
15
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
25
10
10
KEY-SWITCH SOURCE CURRENT
vs. SUPPLY VOLTAGE
TA = +25NC
15
TA = -40°C
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
35
25
100
SINK CURRENT (mA)
TA = +85NC
1.6
TA = +25°C
SINK CURRENT (mA)
40
15
150
SINK CURRENT (mA)
AUTOSLEEP = OFF
30
TA = +85°C
50
0
20
KEY-SWITCH SOURCE CURRENT (A)
45
10
MAX7360 toc04
0
SUPPLY CURRENT (A)
TA = +25°C
VCC = 3.6V
200
OUTPUT VOLTAGE (mV)
100
TA = +85°C
150
250
MAX7360 toc08
OUTPUT VOLTAGE (mV)
TA = +25NC
150
VCC = 3.0V
200
OUTPUT VOLTAGE (mV)
TA = +85NC
GPO OUTPUT LOW VOLTAGE
vs. SINK CURRENT (COL2–COL7)
MAX7360 toc02
VCC = 2.4V
200
250
MAX7360 toc01
250
GPO OUTPUT LOW VOLTAGE
vs. SINK CURRENT (COL2–COL7)
MAX7360 toc03
GPO OUTPUT LOW VOLTAGE
vs. SINK CURRENT (COL2–COL7)
0
0
0.5
1.0
1.5
2.0
OUTPUT VOLTAGE (V)
2.5
3.0
0
0.5
1.0
1.5
2.0
2.5
3.0
OUTPUT VOLTAGE (V)
_______________________________________________________________________________________ 5
MAX7360
典型工作特性
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
引脚说明
引脚
TQFN
WLP
1
A6
名称
功能
ROW0
按键矩阵的行输入，不用时将 ROW0 浮空或连接至GND。
ROW1
按键矩阵的行输入，不用时将 ROW1浮空或连接至GND。
2
B6
3
C4
ROW2
按键矩阵的行输入，不用时将 ROW2 浮空或连接至GND。
4
C6
ROW3
按键矩阵的行输入，不用时将 ROW3 浮空或连接至GND。
5, 15, 25,
35
B4, C5, D2,
E4
GND
地。
6
D6
ROW4
按键矩阵的行输入，不用时将 ROW4浮空或连接至GND。
7
D5
ROW5
按键矩阵的行输入，不用时将 ROW5浮空或连接至GND。
8
E6
ROW6
按键矩阵的行输入，不用时将 ROW6浮空或连接至GND。
9
D4
ROW7
按键矩阵的行输入，不用时将 ROW7浮空或连接至GND。
10, 20, 27,
30, 40
C2
N.C.
11
F6
COL0
按键矩阵的列输出，不用时将 COL0 浮空。
12
E5
COL1
按键矩阵的列输出，不用时将 COL1浮空。
13
F5
COL2
按键矩阵的列输出，不用时将 COL2 浮空。COL2 还可配置为 GPO(参见寄存器表中的表 9)。
14
F4
COL3
按键矩阵的列输出，不用时将 COL3 浮空。COL3 还可配置为 GPO(参见寄存器表中的表 9)。
16
F3
COL4
按键矩阵的列输出，不用时将 COL4浮空。COL4还可配置为 GPO(参见寄存器表中的表 9)。
17
E3
COL5
按键矩阵的列输出，不用时将 COL5浮空。COL5 还可配置为 GPO(参见寄存器表中的表 9)。
18
F2
COL6
按键矩阵的列输出，不用时将 COL6浮空。COL6还可配置为 GPO(参见寄存器表中的表 9)。
无连接，内部没有连接，浮空。
按键矩阵的列输出，不用时将 COL7浮空。COL7还可配置为 GPO(参见寄存器表中的表 9)。
19
F1
COL7
21
E2
SDA
22
E1
SCL
I2C兼容，串行数据I/O。
I2C兼容，串行时钟输入。
23
D3
INTK
低电平有效按键开关中断输出，INTK为漏极开路输出，需要一个上拉电阻。
6 _______________________________________________________________________________________
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
引脚
名称
功能
TQFN
WLP
24
D1
INTI
低电平有效 GPI中断输出，INTI为漏极开路输出，需要一个上拉电阻。
26
C1
VCC
正电源电压，用一个大于等于 0.1µF 的陶瓷电容将VCC 旁路至GND。
28
B1
AD0
地址输入，AD0可以选择4个器件从地址 (表3)。
29
A1
I.C.
内部连接，正常工作时连接至 GND。
31
B2
PORT0
32
A2
PORT1
33
B3
PORT2
34
A3
PORT3
36
A4
PORT4
37
C3
PORT5
38
A5
PORT6
39
B5
PORT7
—
—
EP
GPIO 端口。漏极开路I/O，可承受 +14V 额定电压。PORT0可配置为恒流输出。
GPIO 端口。漏极开路I/O，可承受 +14V 额定电压。PORT1可配置为恒流输出。
GPIO 端口。漏极开路I/O，可承受 +14V 额定电压。PORT2可配置为恒流输出。
GPIO 端口。漏极开路I/O，可承受 +14V 额定电压。PORT3可配置为恒流输出。
GPIO 端口。漏极开路I/O，可承受 +14V 额定电压。PORT4可配置为恒流输出。
GPIO 端口。漏极开路I/O，可承受 +14V 额定电压。PORT5 可配置为恒流输出。
GPIO 端口。漏极开路I/O，可承受 +14V 额定电压。PORT6可配置为恒流输出或旋转开关输入。
GPIO 端口。漏极开路I/O，可承受 +14V 额定电压。PORT7 可配置为恒流输出或旋转开关输入。
裸焊盘(TQFN 封装 )，EP 在内部连接至GND。将 EP 连接到地层，以改善散热性能。
_______________________________________________________________________________________ 7
MAX7360
引脚说明(续)
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
功能框图
LED ENABLE
PWM
GPIO
LOGIC
GPIO ENABLE
GPIO INPUT
PORT GPIO
AND
CONSTANTCURRENT
LED DRIVE
MAX7360
PORT0
PORT1
PORT2
PORT3
PORT4
PORT5
PORT6
PORT7
ROTARY
COLUMN ENABLE
128kHz
OSCILLATOR
GPO ENABLE
CURRENT DETECT
CURRENT
SOURCE
COLUMN
DRIVES
INTI
INTK
SDA
SCL
AD0
I2C
INTERFACE
CONTROL
REGISTERS
FIFO
KEY
SCAN
ROW ENABLE
BUS
TIMEOUT
POR
OPENDRAIN
ROW
DRIVES
COL0
COL1
COL2*
COL3*
COL4*
COL5*
COL6*
COL7*
ROW0
ROW1
ROW2
ROW3
ROW4
ROW5
ROW6
ROW7
*GPO
详细说明
MAX7360 微处理器外设是一款低噪声按键开关控制器，
能够监测多达 64 个按键开关，具有自动重复功能，按键事
件记录在16 字节 FIFO 中。MAX7360 还具有 8 路漏极开路
GPIO，可配置为数字I/O 或用作恒流驱动 LED 的输出，可
承受高达+14V的电压。
MAX7360 具有自动休眠模式和自动唤醒功能，进一步降
低了电源电流损耗。MAX7360 可以配置成在一次按键操作
后，经过可编程的时间后进入休眠模式。休眠模式下，保持
FIFO 内容，并可以读取该内容。MAX7360 在按键按下并
保持的情况下，不会进入自动休眠模式。MAX7360 的自动
唤醒功能在检测到按键按下后自动退出休眠模式，可通过
配置寄存器 (表 8) 使能 / 禁止自动休眠和自动唤醒功能。
为避免过多的中断请求使微处理器过载，可以配置在经过一
定次数 (可编程 ) 的 FIFO 访问后产生中断请求，和 / 或设置经
过一个时间周期后产生中断请求 (表10)。可随时通过读取按
键开关 FIFO 检查按键开关的状态。每次1个字节的读操作可
依次返回 FIFO 中的下一个按键事件 ( 如果存在的话) 和 FIFO
状态。如果不需要按键开关中断功能，可将INTK 配置成通
用的漏极开路输出(GPO)，用来驱动 LED。
如果应用中需要扫描的按键较少，最多可将 6 个按键开关
输出配置为漏极开路 GPO，用于驱动 LED。对于每个用作
GPO 的按键开关输出，能够监测的按键开关数量减少 8 个。
上电初始化
上电时，所有控制寄存器设置在上电初始值，MAX7360 进
入休眠模式 (表1)。
8 _______________________________________________________________________________________
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
ADDRESS
CODE
(hex)
READ/
WRITE
POWER-UP
VALUE (hex)
REGISTER
FUNCTION
0x00
Read only
0x3F
Keys FIFO
0x01
R/W
0x0A
Configuration
0x02
R/W
0xFF
Debounce
0x03
R/W
0x00
Interrupt
0x04
R/W
0xFE
GPO
0x05
R/W
0x00
Key repeat
0x06
R/W
0x07
Sleep
0x40
R/W
0x00
GPIO global configuration
DESCRIPTION
Read FIFO key-scan data out
Power-down, key-release enable, autowakeup, and I2C timeout enable
Key debounce time settling and GPO enable
Key-switch interrupt INTK frequency setting
COL2–COL7 and INTK GPO control
Delay and frequency for key repeat
Idle time to autosleep
Rotary switch, GPIO standby, GPIO reset, fade
0x41
R/W
0x00
GPIO control
0x42
R/W
0x00
GPIO debounce
PORT0–PORT7 input/output control
PORT0–PORT7 debounce time setting
0x43
R/W
0xC0
GPIO constantcurrent setting
PORT0–PORT7 constant-current output setting
0x44
R/W
0x00
GPIO output mode
0x45
R/W
0x00
Common PWM
PORT0–PORT7 output mode control
0x46
R/W
0x00
Rotary switch configuration
Rotary switch interrupt frequency and debounce time setting
0x48
Read only
0x00
I2C timeout since last POR
PORT0–PORT7 input values
Switch cycles since last read
Common PWM duty-cycle setting
0x49
Read only
0xFF
I2C timeout flag
GPIO input register
0x4A
Read only
0x00
Rotary switch count
0x50
R/W
0x00
PORT0 PWM
PORT0 individual duty-cycle setting
0x51
R/W
0x00
PORT1 PWM
PORT1 individual duty-cycle setting
0x52
R/W
0x00
PORT2 PWM
PORT2 individual duty-cycle setting
0x53
R/W
0x00
PORT3 PWM
PORT3 individual duty-cycle setting
0x54
R/W
0x00
PORT4 PWM
PORT4 individual duty-cycle setting
0x55
R/W
0x00
PORT5 PWM
PORT5 individual duty-cycle setting
0x56
R/W
0x00
PORT6 PWM
PORT6 individual duty-cycle setting
0x57
R/W
0x00
PORT7 PWM
PORT7 individual duty-cycle setting
0x58
R/W
0x00
PORT0 configuration
PORT0 interrupt, PWM mode control and blink period setting
0x59
R/W
0x00
PORT1 configuration
PORT1 interrupt, PWM mode control and blink period setting
0x5A
R/W
0x00
PORT2 configuration
PORT2 interrupt, PWM mode control and blink period setting
0x5B
R/W
0x00
PORT3 configuration
PORT3 interrupt, PWM mode control and blink period setting
0x5C
R/W
0x00
PORT4 configuration
PORT4 interrupt, PWM mode control and blink period setting
0x5D
R/W
0x00
PORT5 configuration
PORT5 interrupt, PWM mode control and blink period setting
0x5E
R/W
0x00
PORT6 configuration
PORT6 interrupt, PWM mode control and blink period setting
0x5F
R/W
0x00
PORT7 configuration
PORT7 interrupt, PWM mode control and blink period setting
_______________________________________________________________________________________ 9
MAX7360
表1. 寄存器地址和上电状态
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
表 2. 按键开关
PIN
COL0
COL1
COL2*
COL3*
COL4*
COL5*
COL6*
COL7*
ROW0
KEY 0
KEY 8
KEY 16
KEY 24
KEY 32
KEY 40
KEY 48
KEY 56
ROW1
KEY 1
KEY 9
KEY 17
KEY 25
KEY 33
KEY 41
KEY 49
KEY 57
ROW2
KEY 2
KEY 10
KEY 18
KEY 26
KEY 34
KEY 42
KEY 50
KEY 58
ROW3
KEY 3
KEY 11
KEY 19
KEY 27
KEY 35
KEY 43
KEY 51
KEY 59
ROW4
KEY 4
KEY 12
KEY 20
KEY 28
KEY 36
KEY 44
KEY 52
KEY 60
ROW5
KEY 5
KEY 13
KEY 21
KEY 29
KEY 37
KEY 45
KEY 53
KEY 61
ROW6
KEY 6
KEY 14
KEY 22
KEY 30
KEY 38
KEY 46
KEY 54
KEY 62
ROW7
KEY 7
KEY 15
*这些列输出还可配置为GPO。
KEY 23
KEY 31
KEY 39
KEY 47
KEY 55
KEY 63
按键扫描控制器
按键输入采用静态扫描，而非动态扫描，可确保工作在低
EMI状态。由于输入信号仅在开关变化时发生跳变，因此按
键矩阵的布线可靠近敏感的电路节点。
按键扫描控制器可对按键操作进行去抖，并将按键按下和
弹起事件保存在 FIFO 中( 如果启用自动重复机制，也包括自
动重复按键操作)。按键开关的排列顺序如表 2 所示。用户可
编程的按键开关去抖时间以及自动休眠定时器由 64kHz 时
钟提供，该时钟来自128kHz 振荡器。自动重试的延时以及
按键开关中断基于按键开关的去抖时间。
按键FIFO 寄存器(0x00)
按键 FIFO 寄存器包含与按键 FIFO 状态相关的信息以及经过
去抖的按键事件 (参见寄存器表中的表 7)。D0 至 D5 位表示
64个按键中的哪些按键经过去抖，按键编号如表 2 所示。
D7 表示当 D5:D0 不代表第 63 号键或第 62 号键时， FIFO
中是否还有更多数据。当 D5:D0 表示第 63 号键或第 62 号键
时，主机需要多读一次，以确认 FIFO 中是否还有更多数据。
将第 62 号键和第 63 号键用于较少使用的按键。D6 表示当
D5:D0 不代表第 63 号键或第 62号键时，是否有按键按下或
弹起动作。
根据配置寄存器 (0x01)中 D5 位的设置决定是否读取按键扫
描 FIFO 清除INTK中断。
配置寄存器(0x01)
配置寄存器控制I2 C总线超时、使能按键弹起检测、使能
自动唤醒功能并决定如何清除INTK。写 D7位，可以设置
MAX7360 进入休眠模式或工作模式。如果自动休眠和自动
唤醒使能，则相应的操作也会改变 D7位的状态 (参见寄存器
表中的表 8)。
去抖寄存器(0x02)
去抖寄存器用来设置每个去抖周期的时间以及使能或禁用
GPO 端口。D0至 D4 位能够将去抖时间设置在 9ms 至40ms
范围，步长为1ms(参见寄存器表中的表 9)。D5、D6 和 D7
位设置使能哪个 GPO 端口。注意，GPO 端口只能按照表 9
所示的组合方式使能，从全部禁用到全部使能。
按键开关中断寄存器(0x03)
中断寄存器包含与设置中断请求功能有关的信息以及INTK
输出的状态，INTK 输出也可配置为 GPO。如果 D0 至 D7位
设置为 0x00，则INTK 输出配置为 GPO，通过端口寄存器
的 D1位控制。有两种类型的中断：基于 FIFO 的中断和基于时
间的中断。设置 D0至 D4 位，可以在按键动作后经过所选择
的去抖周期数后产生中断 (参见寄存器表中的表10)。触发中
断的时间范围可以设置为1至 31个去抖周期。配置 D7、D6
和 D5 位用来设置基于 FIFO 的中断，可以配置成当 FIFO 中存
入 2 至14 个按键动作时产生中断。两种中断可同时配置，产
生INTK 的条件取决于首先发生哪种情况。根据配置寄存器
中 D5 位的状态清除INTK。
端口寄存器(0x04)
当 PORT2 至 PORT7以及INTK 端口配置成漏极开路 GPO 时，
端口寄存器用来设置这些端口的数值。对于没有配置成 GPO
的端口，该寄存器相应的设定值无效，读取该寄存器将返
回寄存器存储值(参见寄存器表中的表11)。
10 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
自动重复使能时，保持按键按下将产生按键重复动作，以
0x7E 表示。被按下的键值不再重新写入 FIFO。
无论按下多少个按键，只有一个自动重复码写入 FIFO。在发
生其它按键动作之前，自动重复码按照 D[4:6] 位设定的频率
连续写入 FIFO。按键弹起后，如果仍然还有按键保持按下
状态，MAX7360 将重新开始自动重复过程。
自动休眠寄存器(0x06)
自动休眠功能能够使 MAX7360 进入休眠模式，消耗极小
的电流。使能该功能后，如果在自动休眠时间内没有按键按
下，MAX7360 将进入休眠模式 (参见寄存器表中的表13)。
按键开关休眠模式
休眠模式下，MAX7360 消耗的电流最低。开关矩阵的电流
源被关断，上拉至 VCC。使能自动休眠模式时，如果没有按
键操作的持续时间超过自动休眠时间，器件将进入休眠模
式 (FIFO 数据保持不变 )。向配置寄存器中的 D7 写1或按键
按下，可以使 MAX7360 退出休眠状态。配置寄存器的 D7
位表示休眠状态，任何时候均可读出。休眠模式下，保持
FIFO 数据。
眠时按下按键，所有模拟电路，包括开关矩阵电流源，将
在 2ms 内开启。最初的按键操作需要持续 2ms以及去抖时间
后，才能存入 FIFO。可以向配置寄存器 (0x01) 的 D1位写 0
关闭自动唤醒功能。
GPIO
MAX7360 具有 8 个带 LED 控制功能的 GPIO 端口。这些端
口可用作逻辑输入、逻辑输出或恒流 PWMLED 驱动器。此
外，PORT7 和 PORT6 还可用作旋转开关输入对。PWM 模
式下，可将端口设置为以45°相位增量启动 PWM 周期。这
样在驱动多个 LED 时可防止 LED 电源出现较大的电流尖峰。
GPIO 全局配置寄存器(0x40)
GPIO 全局配置寄存器控制 8 个 GPIO 的主要设置(参见寄存
器表中的表14)。
D7位将 PORT[7:6] 设置为旋转开关输入，D5 位用于使能
I2 C 超时中断，D4 位为 GPIO 的主使能 / 禁止位，D3 位用于
GPIO 寄存器 (0x40 至 0x5F) 的软件复位，D[2:0] 位设置配
置为恒流吸收电流的 GPIO 的渐亮 / 渐暗时间。
GPIO 控制寄存器(0x41)
GPIO 控制寄存器可将每个端口配置为输入或输出(参见寄存
器表中的表15)。所有 GPIO 允许独立配置且在上电时默认为
输入。使能旋转开关模式时，自动将 D7 和 D6 设置为输入。
作为输入而没有驱动的端口会额外消耗电流。
GPIO 去抖配置寄存器(0x42)
GPIO 去抖配置寄存器用来设置 MAX7360 记录逻辑跳变时
GPIO 必须保持的时间(参见寄存器表中的表16)。GPIO 去抖
设置与按键开关去抖设置无关。5 位数值(D[4:0])用来设置
32个可能的去抖时间，范围为9ms 至40ms。
自动唤醒
按键按下时自动唤醒器件，MAX7360 进入工作模式。唤
醒 MAX7360 的按键操作不会丢失。如果在 MAX7360 休
______________________________________________________________________________________ 11
MAX7360
自动重复寄存器(0x05)
MAX7360 的自动重复功能可以向主机报告至少有一个按键
持续按下一段时间。自动重复寄存器用来使能或禁止该功能，
设置在按键重复码 (0x7E)写入 FIFO 之前最后一次按键操作
后的延迟时间，并设置按键重复码写入 FIFO 的频率。D7
位设置是否使能自动重复功能，0 表示禁止自动重复功能，
1表示使能自动重复功能。D0 至 D3 位以去抖周期的形式规
定了自动重复延时，设置范围为 8 至128 个去抖周期 (参见寄
存器表中的表12)。D4、D5 和 D6 位设置自动重复速率或频
率，范围为 4至 32个去抖周期。
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
GPIO 恒流设置寄存器(0x43)
GPIO 恒流设置寄存器用来设置全局恒流值(参见寄存器表中
的表17)。D1和 D0 位可以将全局电流设置在 5mA 至 20mA
范围内。
GPIO 输出模式寄存器(0x44)
GPIO 输出模式寄存器将端口 PORT[7:0] 输出设置为恒流输
出或非恒流输出(参见寄存器表中的表18)。默认状态下将输
出配置为恒流输出，防止不稳定的输出意外加载到 LED上。
未使用时，恒流调节电路自动关断，以降低电流损耗。
公共PWM 寄存器(0x45)
公共 PWM 寄存器存储公共恒流输出 PWM占空比(参见寄存
器表中的表19)。该寄存器的存储值对应于特定的 PWM占空
比，转换方式与独立 PWM 寄存器 (0x50 至 0x57) 相同。端
口可使用其独立 PWM 值，也可使用公共 PWM 值。写入该
寄存器时会立即改变多个端口的占空比。
旋转开关配置寄存器(0x46)
旋转开关配置寄存器存储 PORT7 和 PORT6 的旋转开关设
置(参见寄存器表中的表 20)。D7位决定使能状态下触发中
断的是切换次数还是延时。D[6:4] 位设置发送一个中断前需
要等待的切换次数或时间。D[3:0] 位设置旋转开关输入的去
抖周期。去抖时间范围为 0至15ms。
I2C超时标志寄存器(0x48) (只读)
I2C 超时标志寄存器仅包含一位(D0)，该位用来指示是否出
现了I2 C 超时 (参见寄存器表中的表 21)。读该寄存器，以便
清除I2 C 超时触发的中断。
GPIO 输入寄存器(0x49) (只读)
GPIO 输入寄存器包含所有 GPIO 的输入数据 (参见寄存器表
中的表 22)。配置为输出的端口进行读操作时为高电平。在
值，也可从负值切回正值。通过I2 C 读取该寄存器后将计数
值复位至零。
PORT0至PORT7 独立PWM占空比寄存器(0x50至0x57)
每个端口均具有一个独立 PWM占空比寄存器 (0x50 至
0x57，参见寄存器表中的表 24)。采用这些寄存器中的数值
0x00至 0xFE 配置输出端口的吸电流(LED点亮)，数值可以
设置在 0至 254周期与 256周期的比值。设置为 0xFF 时，输
出将连续吸电流( 始终点亮)。对于多个端口具有相同亮度的
应用，可以使用公共 PWM 寄存器 (0x45)对特定端口的配置
寄存器 (0x58 至 0x5F) 进行编程。新的 PWM 设置在 PWM 周
期开始时生效，允许在没有中断的情况下，在 PWM 周期内
从公共亮度更改到独立亮度设置。
PORT0至PORT7 配置寄存器(0x58至0x5F)
寄存器 0x58 至 0x5F用来设置每个端口的独立配置(参见寄
存器表中的表 25)。D7 和 D6 位决定输入端的中断设置，可
以在检测到逻辑跳变、上升沿或没有操作时触发中断。D5 位
将端口的 PWM 配置设置为公共 PWM 配置或独立的 PWM
配置。D[4:2] 位用于使能并设置每个端口独立的闪烁周期，
范围为 0至4096ms。D1和 D0 位设置端口的闪烁占空比。
亮度渐变
将 GPIO 全局配置寄存器 (0x40)中的亮度渐变周期设置为
非零值，可以使能渐亮 / 渐暗功能 (参见寄存器表中的表14)。
渐亮以16 级均匀步长在零至存储值范围内逐渐增强 LED 的
PWM亮度；渐暗则以16级均匀步长从当前值至零范围内逐渐
降低 LED 的 PWM 亮度。出现任意下述情况时自动触发亮度
的渐变功能：
1)将公共 PWM 寄存器值从任意值改变为零，所有使用公
共 PWM 寄存器设置的端口将逐渐变暗。采用独立 PWM
设置的端口不受影响。
检测输入端口的转换之前，提供一个去抖周期延时。这样可
防止在将端口从输出改为输入时出现错误的中断。不管中断
屏蔽设置如何，GPIO 输入寄存器均报告所有输入端口的状
态。配置为输入的端口 PORT[5:0] 具有 2 μA 至 VCC 的内部
上拉；配置为输入的端口PORT[7:6] 具有10 μA 至 VCC 的内部
上拉。
2)将公共 PWM 寄存器值从零改变为任意值，所有使用公
共 PWM 寄存器设置的端口将逐渐变亮。采用独立 PWM
旋转开关计数寄存器(0x4A) (只读)
MAX7360用 2 的补码形式保存旋转开关的旋转次数(参见
寄存器表中的表 23)。寄存器值循环计数，从正值切换到负
4)器件置于关断模式时，所有端口将逐渐变暗。在逐渐变
暗过程中，改变独立 PWM 亮度将自动取消端口的亮度渐
设置的端口不受影响。
3)器件退出关断模式时，所有端口将逐渐变亮。在逐渐变
亮过程中，改变独立 PWM 亮度将自动取消端口的亮度渐
变，并立即输出新设定的亮度值。
变，并立即进入关断模式。
12 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
旋转开关
每个端口通过寄存器 0x58 至 0x5F(参见寄存器表中的表
25) 提供闪烁控制设置。闪烁周期范围为 0(闪烁禁止 )至
4.096s。可设置的闪烁占空比范围为 6.25% 至 50%。所有
闪烁周期在同一 PWM 周期下开启，可使多个端口同步闪烁。
MAX7360 可接受 PORT6、PORT7上的 2位旋转开关输入。
顺时针旋转的开关增加计数值。通过 GPIO 全局配置寄存器
(0x40) 使能旋转开关模式。旋转开关模式下为 PORT6 和
PORT7 提供多种设置：
1) 每个端口具有10 μA 至 VCC 的上拉。
2) 寄存器 0x46用于设置去抖时间。
3)PORT6 出现经过去抖的上升沿而 PORT7为高电平时递
GPIO 端口中断(INTI)
INTI中断源有三个：I2C 超时、配置为输入的 GPIO、旋转开
关 (寄存器 0x48、0x49 以及 0x4A)。读取每个中断对应的
数据 / 状态寄存器，可清除INTI。设置寄存器 0x46用于旋转
开关中断。设置寄存器 0x58 至 0x5F用于独立的 GPI中断。
如果多个中断源产生中断，必须读取所有相关的状态寄存
器才能清除INTI。
减计数值。
4)PORT6 出现经过去抖的上升沿而 PORT7为低电平时递
增计数值。
更多信息请参考图1。
串口
PORT7
图2 给出了2 线串口的详细时序。
INCREMENT
串行寻址
PORT6
MAX7360 作为从器件，通过I2 C 兼容的 2 线接口发送和接
收数据。接口使用一条串行数据线 (SDA) 和一条串行时钟线
(SCL)完成主机与从机之间的双向通信。主机( 通常是微控制
器) 初始化所有写入或读取 MAX7360 的数据传输，并产生
同步数据传输的 SCL 时钟。
MAX7360 的 SDA 既作为输入又作为漏极开路输出，SDA
需要一个典型值为 4.7kΩ 的上拉电阻。MAX7360 的 SCL仅
PORT7
DECREMENT
PORT6
ROTARY SWITCH
DEBOUNCE
图1. 旋转开关输入信号时序
tR
SDA
tSU, DAT
tLOW
tSU, STA
tF
tF, TX
tBUF
tHD, STA
tHD, DAT
tSU, STO
tHIGH
SCL
tHD, STA
tR
START
CONDITION
tF
REPEATED
START CONDITION
STOP
CONDITION
START
CONDITION
图2.2 线串口详细时序
______________________________________________________________________________________ 13
MAX7360
闪烁
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
作为输入，如果 2 线接口上存在多个主机，或单主机系统中
的主机具有漏极开路 SCL 输出，则 SCL引脚需要外接上拉
电阻。
每次传输由主机发出 START(S) 条件 (图 3)，然后发送
MAX7360 的 7位从地址和 R/W位、一个寄存器地址字节、
1个或多个数据字节，最后是STOP(P) 条件。
START 和 STOP条件
当接口空闲时，SCL 和 SDA 均保持高电平。主机在 SCL为高
电平时将 SDA 由高电平跳变到低电平，产生一个START条
应答
应答位对应于第九个时钟脉冲 (图 5)，它是接收设备收到每
个数据字节后发出的握手信号。这样，每个字节的有效传输
需要 9 位。主机产生第 9 个时钟脉冲，接收设备在应答脉冲
期间将 SDA拉低，在时钟脉冲为高电平期间 SDA 稳定在低
电平。当主机向 MAX7360 发送数据时，MAX7360 作为接
收器件产生应答；当 MAX7360 向主机发送数据时，主机作
为接收器件产生应答。
表3. 2线接口地址映射
件，启动一次数据传输。完成与从机的通信后，主机通过在
SCL为高电平时将 SDA由低电平跳变到高电平，产生一个
STOP 条件。然后释放总线，等待下一次传输。
PIN AD0
DEVICE ADDRESS
A7
A6
A5
A4
A3
A2
A1
A0
GND
0
1
1
1
0
0
0
R/W
位传输
VCC
0
1
1
1
0
1
0
R/W
每个时钟脉冲传输一个数据位 (图 4)，SCL为高电平期间
SDA 必须保持数据稳定。
SDA
0
1
1
1
1
0
0
R/W
SCL
0
1
1
1
1
1
0
R/W
SDA
SCL
S
P
START
CONDITION
STOP
CONDITION
图3.START 和 STOP 条件
SDA
SCL
DATA LINE STABLE;
DATA VALID
CHANGE OF DATA
ALLOWED
图4. 位传输
14 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
CLOCK PULSE FOR
ACKNOWLEDGE
1
SCL
SDA
BY
TRANSMITTER
SDA
BY
RECEIVER
MAX7360
START
CONDITION
2
8
9
S
图5. 应答
0
SDA
1
1
1
A3
A2
A1
MSB
R/W
ACK
LSB
SCL
图 6. 从地址
COMMAND BYTE IS STORED ON RECEIPT OF
ACKNOWLEDGE CONDITION
ACKNOWLEDGE FROM MAX7360
S
SLAVE ADDRESS
0
D7
D6
A
D5
D4
D3
D2
D1
D0
COMMAND BYTE
R/W
A
P
ACKNOWLEDGE FROM MAX7360
图7. 接收命令字节
ACKNOWLEDGE FROM MAX7360
ACKNOWLEDGE FROM MAX7360
D7
D6
D5
D4
D3
D2
D1
D0
D7
D6
D5
D4
D3
D2
D1
D0
ACKNOWLEDGE FROM MAX7360
S
SLAVE ADDRESS
0
A
COMMAND BYTE
A
DATA BYTE
A
P
1 BYTE
R/W
AUTOINCREMENT
COMMAND BYTE ADDRESS
图 8. 接收命令字节和单个数据字节
MAX7360 具有 7位从地址(图 6)，紧随 7位从地址的是 R/W
MAX7360 连续监测总线，等待 START条件以及随后的从
地址。如果 MAX7360 识别到自己的从地址，将发送应答信
位，该位置低表示写操作，置高表示读操作。
号并准备好继续通信。
从地址
MAX7360从地址的高四位(MSB) 始终为 0111。从地址位
A3、A2 和 A1的值与器件地址输入 AD0 的状态对应，A0
对应于 R/W位，如表 3 所示。AD0 输入可以连接至四个信
号 (GND、VCC、SDA 或 SCL)中的任意一个，提供四种可能
的从地址，最多允许四片 MAX7360 共享总线。由于SDA
和 SCL为动态信号，必须保证 AD0 的瞬变不能快于SDA 和
SCL引脚的信号。
总线超时
MAX7360 的 2 线串口具有最小 20ms 的总线超时，在串行
通信结束之前，如果 SCL 由于某种原因挂起，该超时功能能
够在最大程度上防止 MAX7360 在读操作过程中将SDAI/O
始终拉为低电平。如果 SCL保持低电平的时间超过 20ms，
总线超时将使 MAX7360从内部中止串行通信，无论是读操
作还是写操作。总线超时结束后，MAX7360 等待一个有效
的 START条件，以响应后续的数据传输。用户可通过写配
置寄存器来使能或禁止该功能 (参见寄存器表中的表 8)。
______________________________________________________________________________________ 15
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
ACKNOWLEDGE FROM MAX7360
ACKNOWLEDGE FROM MAX7360
D7
D6
D5
D4
D3
D2
D1
D0
D7
D6
D5
D4
D3
D2
D1
D0
ACKNOWLEDGE FROM MAX7360
S
SLAVE ADDRESS
0
A
COMMAND BYTE
A
DATA BYTE
A
P
N BYTES
R/W
AUTOINCREMENT
COMMAND BYTE ADDRESS
图9. 接收 N 个数据字节
表4. 自动递增规则
REGISTER
FUNCTION
Keys FIFO
Autoshutdown
ADDRESS
CODE (hex)
AUTOINCREMENT
ADDRESS (hex)
0x00
0x00
0x06
0x00
All other key switch
0x01 to 0x05
Addr + 0x01
All other GPIO
0x40 to 0x5F
Addr + 0x01
写按键扫描控制器的信息格式
向 MAX7360 写数据时，首先发送从地址并将 R/W位置
零，然后发送至少1 个字节的信息。信息的第一个字节是
命令字节。命令字节决定下一字节( 如果收到话) 需要写入
MAX7360 的哪个寄存器。如果收到命令字节后检测到
STOP 条件，那么 MAX7360 除了存储命令字节外将不进行
任何操作 (图 7)。
命令字节之后收到的任何字节都是数据字节。第一个数据字
节写入由命令字节选择的 MAX7360 内部寄存器 (图 8)。
如果在检测到 STOP 条件之前传输了多个数据字节，由于
命令字节地址的自动递增特性 (表 4)，这些字节通常存入
MAX7360 的后续内部寄存器。
读取按键扫描控制器的信息格式
利用内部存储的命令字节作为地址指针读取 MAX7360，与
写操作使用存储的命令字节作为地址指针的方式相同。每读
取一个数据字节后地址指针将自动递增，与写操作相同(表
4)。这样，可首先通过写操作设置 MAX7360 的命令字节
(图 7)，然后启动读操作。按照初始化命令字节确定的地址
读取寄存器第一个数据字节后，主机可以从 MAX7360 连
续读取 n 个字节。写操作后执行读操作确认时，需要复位命
令字节的地址，因为写操作之后存储的命令字节地址通常是
自动递增的 ( 见图 9 和表 4)。
多主机工作
如果 MAX7360 的 2 线接口上挂接了多个主机，当一个主机
从 MAX7360 读取数据时，应在设置 MAX7360 地址指针
的写操作与从指定位置读取数据的读操作之间使用一个重
复开始条件。这是因为主机1设置 MAX7360 地址指针后，
但还没有读取数据之前，主机 2 可能接管总线。如果主机 2
随后复位 MAX7360 的地址指针，那么主机1可能从一个并
非所要求的地址中读取数据。
命令地址自动递增
地址自动递增功能可以使命令地址的传输次数最少，以较少
的数据传输对 MAX7360 进行设置。在写入或读取每个数
据字节后，存储在 MAX7360 中的命令地址通常会自动递增
(表4)，自动递增仅在多个地址的读、写操作时使用。
应用信息
I2C 复位
在 ESD 放电或微控制器复位等一系列事件后，采用配置寄
存器 (0x01)中的 D7位作为按键开关状态的软件复位 ( 按键开
关寄存器值和 FIFO 保持不变 )。使用 GPIO 全局配置寄存器
(0x40)中的 D4位作为 GPIO 的软件复位。
16 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
MAX7360
REGULAR KEYPRESS
EVENT
EXAMPLES OF VALID THREE-KEY COMBINATIONS
GHOST-KEY
EVENT
KEY-SWITCH MATRIX
KEY-SWITCH MATRIX
KEY-SWITCH MATRIX
图11. 有效的三按键组合
图10. 伪按键操作
消除伪按键操作
热插入
伪按键操作是按键开关矩阵的固有现象。如果同时按下一个
矩形三个角上的开关，那么矩形角上剩余的那个开关 (伪按
键 ) 也呈现为按下状态。这是因为其它三个按键的连接导致
伪按键开关两端的电位相同—其它三个按键组合造成该按键
电气短路 (图10)。由于从电特性看该按键为按下状态，所以
不可能检测出四个按键中的哪一个是伪按键。
当 MAX7360 掉电(VCC=0) 时，INTI、INTK、SCL 和
AD0 输入以及SDA保持高阻，最大耐压为+3.6V。I/O 端
口(PORT0至 PORT7) 未上电时，将保持高阻，最大耐压为
+14V。MAX7360 可用于热插拔应用。
MAX7360 采用独特的设计方案，可以检测出导致第四个伪
按键操作的三键组合方式，且不报告导致伪按键操作的第三
键动作，这意味着虽然没有检测出伪按键，但是将有效地
忽略三键同时按下的多种组合方式。对于需要使用三键组合
的应用 ( 如<Ctrl><Alt><Del>)，应确保 3 个按键不要处于某
个矩形的顶点位置(图11)。只要按键不产生伪按键操作，并
且 FIFO 没有满，则对同时按下的按键数量没有限制。
低EMI工作
MAX7360 通过两种技术将按键开关连线的 EMI辐射降至
最低。首先，无论电源电压 VCC为何值，没有处于休眠模式
时开关矩阵的电压永远不会超过+0.55V。这样，当开关按
下时，任一节点的电压摆幅最大不超过+0.55V。其次，没
有采用按键的动态扫描，从而避免按键开关连线的连续辐
射干扰，仅监测按键的吸电流( 监测按下的按键 )，且只有当
一个或多个按键实际按下时去抖电路才会工作。
错相工作的PWM
每个 PWM 周期内点亮 LED 的时间相位相差 45°，从起始位
置平均分配 8 个端口。通过为端口分配最合适的起始位置，
可在少于 8 个端口作为恒流输出时优化相位分配。例如，如
果采用 4 路恒流输出，选择 PORT0、PORT2、PORT4 和
PORT6，均分 PWM 起始位置间隔。通常情况下，应尽量选
择均分 PWM 起始位置间隔的端口。这样可优化端口负载对
电源电流的要求。
INTK/INTI
器件提供两个中断输出：INTK 和INTI，每个中断彼此独立
工作。有关这两个中断的详细信息，请参考按键开关中断寄
存器 (0x03) 和GPIO 端口中断 (INTI) 部分。
供电考虑
MAX7360工作在 +1.62V 至+3.6V电源电压，用大于等于
0.1µF的陶瓷电容将电源旁路至 GND，该电容应尽可能靠近
器件放置。
开关导通电阻
MAX7360 对电阻不敏感，无论是按键开关电阻，还是高达
4kΩ(最大值 ) 的切换至适当的 COL_ 和 ROW_ 的开关电阻，
因此控制器适合于低成本的薄膜开关和导电碳开关。
______________________________________________________________________________________ 17
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
ESD 保护
MAX7360 的所有引脚均带有 2kV人体模式 ESD 保护。按键
开关输入和 GPIO 符合IEC61000-4-2ESD 保护标准。IEC
测试是在每个极点连续进行10 次 ESD 放电，放电幅度为标
准指定的最大电平或低于该电平 (根据IEC61000-4-2)。测
试规则包括：
1)ESD 放电过程中，上电器件不会出现闭锁。
2)器件随后通过预审的最终测试。
表5 和表 6 摘自IEC61000-4-2 ：1.11999-05版：
电磁兼容
性(EMC) 测试和测量方法—静电放电抗扰性试验。
表5. ESD测试等级
1A—CONTACT
DISCHARGE
LEVEL
1B—AIR-GAP DISCHARGE
TEST
VOLTAGE (kV)
LEVEL
TEST
VOLTAGE (kV)
1
2
1
2
2
4
2
4
3
6
3
8
4
8
4
10
X
Special
X
Special
X=开放等级。该等级必须在特定设备规范中说明，如果高
于上述指定电压，可能需要特殊的测试设备。
表6. ESD波形参数
LEVEL
INDICATED
VOLTGE _
(kV)
FIRST PEAK OF
CURRENT
DISCHARGE ±10%
(A)
RISE TIME (tr) WITH
DISCHARGE SWITCH _
(ns)
CURRENT (±30%)
AT 30ns _
(A)
CURRENT
(±30%) AT 60ns
(A)
1
2
7.5
0.7 to 1
4
2
2
4
15
0.7 to 1
8
4
3
6
22.5
0.7 to 1
12
6
4
8
30
0.7 to 1
16
8
18 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
表7. 按键FIFO寄存器格式(0x00)
SPECIAL FUNCTION
KEYS FIFO REGISTER DATA
D7
D6
D5
D4
D3
D2
D1
D0
FIFO
empty
flag
Key
release
flag
X
X
X
X
X
X
FIFO is empty.
0
0
1
1
1
1
1
1
FIFO is overflow. Continue to read data in FIFO.
0
1
1
1
1
1
1
1
Key 63 is pressed. Read one more time to
determine whether there is more data in FIFO.
1
0
1
1
1
1
1
1
Key 63 is released. Read one more time to
determine whether there is more data in FIFO.
1
1
1
1
1
1
1
1
Key repeat. Indicates the last data in FIFO.
0
0
1
1
1
1
1
0
Key repeat. Indicates more data in FIFO.
0
1
1
1
1
1
1
0
Key 62 is pressed. Read one more time to
determine whether there is more data in FIFO.
1
0
1
1
1
1
1
0
Key 62 is released. Read one more time to
determine whether there is more data in FIFO.
1
1
1
1
1
1
1
0
The key number indicated by D5:D0 is a key
event. D7 is always for a key press of key 62
and key 63. When D7 is 0, the key read is the
last data in the FIFO. When D7 is 1, there is
more data in the FIFO. When D6 is 1, key data
read from FIFO is a key release. When D6 is 0,
key data read from FIFO is a key press.
______________________________________________________________________________________ 19
MAX7360
寄存器表
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
表8. 配置寄存器格式(0x01)
REGISTER
BIT
D7
DESCRIPTION
Sleep
D6
Reserved
D5
Interrupt
D4
DEFAULT
VALUE
VALUE
FUNCTION
X
(when 0x40
D4 = 1)
Key-switch operating mode. Key switches always remain active
when constant-current PWM is enabled (bit 4 of register 0x40 is
high) regardless of autosleep, autowakeup, or an I2C write to this bit.
0
(when 0x40
D4 = 0)
Key-switch sleep
mode. The entire
chip is shut down.
1
(when 0x40
D4 = 0)
Key-switch operating
mode
When constant-current PWM is disabled
(bit 4 of register 0x40 is low), I2C write,
autosleep, and autowakeup all can change
this bit. This bit can be read back by I2C
any time for current status.
0
0
—
0
0
INTK cleared when FIFO is empty
1
INTK cleared after host read. In this mode, I2C should read the
FIFO until interrupt condition is removed or further INT may be lost.
0
Reserved
0
—
0
D3
Key-release
enable
0
Disable key releases
1
Enable key releases
D2
Reserved
0
—
D1
Autowakeup
enable
0
Disable keypress wakeup
1
Enable keypress wakeup
D0
Timeout
disable
0
I2C timeout enabled
1
I2C timeout disabled
1
0
1
0
表9. 去抖寄存器格式(0x02)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
PORTS ENABLE
D2
D1
D0
DEBOUNCE TIME
Debounce time is 9ms
X
X
X
0
0
0
0
0
Debounce time is 10ms
X
X
X
0
0
0
0
1
Debounce time is 11ms
X
X
X
0
0
0
1
0
Debounce time is 12ms
X
X
X
0
0
0
1
1
.
.
.
Debounce time is 37ms
X
X
X
1
1
1
0
0
Debounce time is 38ms
X
X
X
1
1
1
0
1
Debounce time is 39ms
X
X
X
1
1
1
1
0
Debounce time is 40ms
X
X
X
1
1
1
1
1
GPO ports disabled (full key-scan functionality)
0
0
0
X
X
X
X
X
GPO port 7 enabled
0
0
1
X
X
X
X
X
GPO ports 7 and 6 enabled
0
1
0
X
X
X
X
X
20 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
PORTS ENABLE
D2
D1
D0
DEBOUNCE TIME
GPO ports 7, 6, and 5 enabled
0
1
1
X
X
X
X
X
GPO ports 7, 6, 5, and 4 enabled
1
0
0
X
X
X
X
X
GPO ports 7, 6, 5, 4, and 3 enabled
1
0
1
X
X
X
X
X
GPO ports 7, 6, 5, 4, 3, and 2 enabled
1
1
X
X
X
X
X
X
Power-up default setting
1
1
1
1
1
1
1
1
D7
D6
D5
D2
D1
D0
表10. 按键开关中断寄存器格式(0x03)
REGISTER DATA
REGISTER DESCRIPTION
D4
FIFO-BASED INTK
D3
TIME-BASED INTK
INTK used as GPO
0
0
0
FIFO-based INTK disabled
0
0
0
0
0
INTK asserts every debounce cycle
0
0
0
0
0
INTK asserts every 2 debounce cycles
0
0
0
0
0
0
0
0
0
0
1
0
1
0
Not all zero
.
.
.
INTK asserts every 29 debounce cycles
0
0
0
1
1
1
0
1
INTK asserts every 30 debounce cycles
0
0
0
1
1
1
1
0
INTK asserts every 31 debounce cycles
0
0
0
1
1
1
1
1
0
0
0
0
0
Time-based INTK disabled
Not all zero
INTK asserts when FIFO has 2 key events
0
0
1
0
0
0
0
0
INTK asserts when FIFO has 4 key events
0
1
0
0
0
0
0
0
INTK asserts when FIFO has 6 key events
0
1
1
0
0
0
0
0
1
0
0
0
0
0
0
0
.
.
.
INTK asserts when FIFO has 14 key events
1
Both time-based and FIFO-based interrupts
active
Power-up default setting
1
Not all zero
0
0
Not all zero
0
0
0
0
______________________________________________________________________________________ 21
MAX7360
表9. 去抖寄存器格式(0x02) (续)
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
表11. 端口寄存器格式(0x04)
REGISTER
DESCRIPTION
BIT
VALUE
FUNCTION
0
Clear port 7 low
1
Set port 7 high (high impedance)
0
Clear port 6 low
1
Set port 6 high (high impedance)
D7
PORT 7 Control
D6
PORT 6 Control
D5
PORT 5 Control
D4
PORT 4 Control
D3
PORT 3 Control
D2
PORT 2 Control
D1
INTK Port
Control
0
Clear port INTK low
1
D0
Reserved
0
Set port INTK high (high impedance)
—
0
Clear port 5 low
1
Set port 5 high (high impedance)
0
Clear port 4 low
1
Set port 4 high (high impedance)
0
Clear port 3 low
1
Set port 3 high (high impedance)
0
Clear port 2 low
1
Set port 2 high (high impedance)
22 ��
DEFAULT
VALUE
1
1
1
1
1
1
1
0
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
REGISTER DATA
REGISTER DESCRIPTION
D7
ENABLE
D6
D5
D4
D3
AUTOREPEAT RATE
X
X
D2
D1
D0
AUTOREPEAT DELAY
Autorepeat is disabled
0
X
X
X
X
X
Autorepeat is enabled
1
AUTOREPEAT RATE
Key-switch autorepeat delay is 8 debounce
cycles
1
X
X
X
0
0
0
0
Key-switch autorepeat delay is 16 debounce
cycles
1
X
X
X
0
0
0
1
Key-switch autorepeat delay is 24 debounce
cycles
1
X
X
X
0
0
1
0
AUTOREPEAT DELAY
.
.
.
Key-switch autorepeat delay is 112 debounce
cycles
1
X
X
X
1
1
0
1
Key-switch autorepeat delay is 120 debounce
cycles
1
X
X
X
1
1
1
0
Key-switch autorepeat delay is 128 debounce
cycles
1
X
X
X
1
1
1
1
Key-switch autorepeat frequency is 4
debounce cycles
1
0
0
0
X
X
X
X
Key-switch autorepeat frequency is 8
debounce cycles
1
0
0
1
X
X
X
X
Key-switch autorepeat frequency is 12
debounce cycles
1
0
1
0
X
X
X
X
.
.
.
Key-switch autorepeat frequency is 32
debounce cycles
1
1
1
1
X
X
X
X
Power-up default setting
0
0
0
0
0
0
0
0
______________________________________________________________________________________ 23
MAX7360
表12. 自动重复寄存器格式(0x05)
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
表13. 自动休眠寄存器格式(0x06)
REGISTER
REGISTER DATA
RESERVED
AUTOSLEEP REGISTER
AUTOSHUTDOWN TIME
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
0
0
0
0
0
8192
0
0
0
0
0
0
0
1
4096
0
0
0
0
0
0
1
0
2048
0
0
0
0
0
0
1
1
1024
0
0
0
0
0
1
0
0
512
0
0
0
0
0
1
0
1
256
0
0
0
0
0
1
1
0
256
0
0
0
0
0
1
1
1
Power-up default settings
0
0
0
0
0
1
1
1
No Autosleep
Autosleep for (ms)
表14. GPIO 全局配置寄存器(0x40)
REGISTER
BIT
DESCRIPTION
VALUE
D7
PORT6/PORT7
rotary switch
0
PORT6/PORT7 operate as GPIOs
1
PORT6/PORT7 operate as a rotary switch input
D6
Reserved
0
—
0
Disabled
1
INTI is asserted when I2C bus times out. INTI is deasserted when a
read is performed on the I2C timeout flag register (0x48).
0
PWM, constant-current circuits, and GPIs are shut down. GPO
values depend on their setting. Register 0x41 to 0x5F values are
stored and cannot be changed. The entire part is shut down if the
key switches are in sleep mode (D7 of register 0x01).
I2C
D5
D4
D3
D[2:0]
timeout interrupt
enable
GPIO enable
GPIO reset
Fade in/out
time
FUNCTION
1
Normal GPIO operation. PWM, constant-current circuits, and GPIOs are
enabled regardless of key-switch sleep mode state (see Table 8).
0
Normal operation
1
Return all GPIO registers (registers 0x40 to 0x5F) to their POR value.
This bit is momentary and resets itself to 0 after the write cycle.
000
No fading
XXX
PWM intensity ramps up (down) between the common PWM value
and 0% duty cycle in 16 steps over the following time period:
D[2:0] = 001 = 256ms
D[2:0] = 010 = 512ms
D[2:0] = 011 = 1024ms
D[2:0] = 100 = 2048ms
D[2:0] = 101 = 4096ms
D[2:0] = 110/111 = Undefined
24 ��
DEFAULT
VALUE
0
0
0
0
0
000
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
REGISTER
BIT
DESCRIPTION
D7
PORT7
D6
PORT6
D5
PORT5
D4
PORT4
D3
PORT3
D2
PORT2
D1
PORT1
D0
PORT0
VALUE
DEFAULT
VALUE
FUNCTION
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
0
0
0
0
0
0
0
表16. GPIO去抖配置寄存器(0x42)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
RESERVED
Power-up default setting_
debounce time is 9ms
0
0
D2
D1
D0
DEBOUNCE TIME
0
0
0
0
0
0
Debounce time is 10ms
0
0
0
0
0
0
0
1
Debounce time is 11ms
0
0
0
0
0
0
1
0
Debounce time is 12ms
0
0
0
0
0
0
1
1
.
.
.
Debounce time is 37ms
0
0
0
1
1
1
0
0
Debounce time is 38ms
0
0
0
1
1
1
0
1
Debounce time is 39ms
0
0
0
1
1
1
1
0
Debounce time is 40ms
0
0
0
1
1
1
1
1
______________________________________________________________________________________ 25
MAX7360
表15. GPIO 控制寄存器(0x41)
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
表17. GPIO 恒流设置寄存器(0x43)
REGISTER
BIT
DESCRIPTION
VALUE
D[7:6]
Reserved
11
D[5:2]
Reserved
0000
00
Constant current is 5mA
Constantcurrent setting
01
Constant current is 6.67mA
10
Constant current is 10mA
11
Constant current is 20mA
D[1:0]
DEFAULT
VALUE
FUNCTION
Set always as 11
11
—
0000
00
表18. GPIO 输出模式寄存器(0x44)
REGISTER
BIT
DESCRIPTION
D7
PORT7
D6
PORT6
D5
PORT5
D4
PORT4
D3
PORT3
D2
PORT2
D1
PORT1
D0
PORT0
VALUE
DEFAULT
VALUE
FUNCTION
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
0
0
0
0
0
0
0
表19. 公共PWM寄存器(0x45)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
D2
D1
D0
COMMON PWM
Power-up default setting (common
PWM ratio is 0/256)
0
0
0
0
0
0
0
0
Common PWM ratio is 1/256
0
0
0
0
0
0
0
1
Common PWM ratio is 2/256
0
0
0
0
0
0
1
0
Common PWM ratio is 3/256
0
0
0
0
0
0
1
1
.
.
.
26 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
D2
D1
D0
COMMON PWM
Common PWM ratio is 252/256
1
1
1
1
1
1
0
0
Common PWM ratio is 253/256
1
1
1
1
1
1
0
1
Common PWM ratio is 254/256
1
1
1
1
1
1
1
0
Common PWM ratio is 256/256
(100% duty cycle)
1
1
1
1
1
1
1
1
D1
D0
表 20. 旋转开关配置寄存器(0x46)
REGISTER DATA
REGISTER DESCRIPTION
No debounce time
Debounce time is 1ms
Debounce time is 2ms
Debounce time is 3ms
D7
D6
INT
TYPE
X
X
X
X
D5
D4
D3
COUNTS/CYCLES
X
X
X
X
D2
DEBOUNCE CYCLE TIME
X
X
X
X
X
X
X
X
0
0
0
0
0
0
0
0
0
0
1
1
0
1
0
1
.
.
.
Debounce time is 15ms
X
X
X
X
1
1
1
1
No interrupt generated by rotary switch
INTI asserted when rotary switch count = ±1
INTI asserted when rotary switch count = ±2
INTI asserted when rotary switch count = ±3
X
0
0
0
0
0
0
0
0
0
1
1
0
1
0
1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
1
1
X
X
X
X
.
.
.
INTI asserted when rotary switch count = ±7
0
1
INTI asserted 25ms after first debounced event
1
0
0
1
X
X
X
X
INTI asserted 50ms after first debounced event
1
0
1
0
X
X
X
X
INTI asserted 75ms after first debounced event
1
0
1
1
X
X
X
X
.
.
.
INTI asserted 175ms after first debounced event
1
1
1
1
X
X
X
X
Power-up default setting
0
0
0
0
0
0
0
0
______________________________________________________________________________________ 27
MAX7360
表19. 公共PWM寄存器(0x45) (续)
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
表 21. I2C超时标记寄存器(0x48) (只读)
REGISTER
BIT
DESCRIPTION
VALUE
D[7:1]
Reserved
0000000
D0
I2C timeout flag
DEFAULT
VALUE
FUNCTION
—
0000000
I2C
0
No
1
I2C timeout has occurred since last read or POR. This bit is reset to
zero when a read is performed on this register. I2C timeouts must
be enabled for this function to work (see Table 8).
timeout has occurred since last read or POR
0
表 22. GPIO 输入寄存器(0x49) (只读)
REGISTER
BIT
DESCRIPTION
D7
PORT7
D6
PORT6
D5
PORT5
D4
PORT4
D3
PORT3
D2
PORT2
D1
PORT1
D0
PORT0
VALUE
DEFAULT
VALUE
FUNCTION
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
1
1
1
1
1
1
1
1
表 23. 旋转开关计数寄存器(0x4A) (只读)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
D2
D1
D0
X
X
X
CYCLE COUNT
Cycle count in two’s complement (see the Rotary
Switch Configuration Register (0x46) section)
X
X
X
X
X
28 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
PORT PWM
Power-up default setting (port PWM ratio is
0/256)
0
0
0
0
0
PORT PWM ratio is 1/256
0
0
0
0
0
0
0
1
PORT PWM ratio is 2/256
0
0
0
0
0
0
1
0
PORT PWM ratio is 3/256
0
0
0
0
0
0
1
1
1
1
1
1
0
0
.
.
.
PORT PWM ratio is 252/256
1
1
PORT PWM ratio is 253/256
1
1
1
1
1
1
0
1
PORT PWM ratio is 254/256
1
1
1
1
1
1
1
0
PORT PWM ratio is 256/256 (100% duty cycle)
1
1
1
1
1
1
1
1
表 25. PORT0至PORT7 配置寄存器(0x58至0x5F)
REGISTER
BIT
DESCRIPTION
D7
Interrupt mask
D6
Edge/level
detect
D5
D[4:2]
Common PWM
Blink period
VALUE
0
Interrupt is not masked
1
Interrupt is masked. PORT7 interrupt mask is ignored when the
device is configured for rotary switch input.
0
Rising edge-triggered
interrupts
1
Rising or falling edgetriggered interrupts
0
Port uses individual PWM intensity register to set the PWM ratio
1
Port uses common PWM intensity register to set the PWM ratio
Blink-on time
Interrupts only occur when the GPIO
port is configured as an input
000
Port does not blink
001
Port blink period is 256ms
010
Port blink period is 512ms
011
Port blink period is 1024ms
100
Port blink period is 2048ms
101
Port blink period is 4096ms
110/111
D[1:0]
FUNCTION
DEFAULT
VALUE
0
0
0
000
Undefined
00
LED is on for 50% of the blink period
01
LED is on for 25% of the blink period
10
LED is on for 12.5% of the blink period
11
LED is on for 6.25% of the blink period
00
______________________________________________________________________________________ 29
MAX7360
表 24. PORT0至PORT7独立PWM占空比寄存器(0x50至0x57)
引脚配置
TOP VIEW
BUMPS IN BOTTOM
MAX7360
I.C.
PORT1
PORT3
PORT4
PORT6
ROW0
A1
A2
A3
A4
A5
A6
AD0
PORT0
PORT2
GND
PORT7
ROW1
B1
B2
B3
B4
B5
B6
VCC
N.C.
PORT5
ROW2
GND
ROW3
C1
C2
C3
C4
C5
C6
INTI
GND
INTK
ROW7
ROW5
ROW4
D1
D2
D3
D4
D5
D6
SCL
SDA
COL5
GND
COL1
ROW6
E1
E2
E3
E4
E5
E6
COL7
COL6
COL4
COL3
COL2
COL0
F1
F2
F3
F4
F5
F6
SDA
SCL
INTK
INTI
GND
VCC
N.C.
AD0
TOP VIEW
I.C.
N.C.
WLP
(2.67mm x 2.67mm)
30 29 28 27 26 25 24 23 22 21
PORT0 31
20 N.C.
PORT1 32
19 COL7
PORT2 33
18 COL6
PORT3 34
17 COL5
16 COL4
GND 35
MAX7360
PORT4 36
15 GND
14 COL3
PORT5 37
13 COL2
PORT6 38
EP*
PORT7 39
6
7
8
9
10
ROW7
N.C.
ROW3
5
ROW6
4
ROW5
3
ROW4
2
GND
1
ROW2
11 COL0
ROW1
N.C. 40
12 COL1
+
ROW0
MAX7360
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
TQFN
*EP = EXPOSED PAD, CONNECT EP TO GROUND.
30 ��
I2C 接口按键开关控制器和 LED
驱动器/GPIO，集成ESD 保护电路
+3.3V
+14V
+14V
+1.8V
COL7
VCC
COL6
PORT0
COL5
PORT1
COL4
PORT2
MAX7360
KEY 0
KEY 8
KEY 16
KEY 24
KEY 32
KEY 40
KEY 1
KEY 9
KEY 17
KEY 25
KEY 33
KEY 41
KEY 2
KEY 10
KEY 18
KEY 26
KEY 34
KEY 42
KEY 3
KEY 11
KEY 19
KEY 27
KEY 35
KEY 43
KEY 4
KEY 12
KEY 20
KEY 28
KEY 36
KEY 44
KEY 5
KEY 13
KEY 21
KEY 29
KEY 37
KEY 45
KEY 6
KEY 14
KEY 22
KEY 30
KEY 38
KEY 46
KEY 7
KEY 15
KEY 23
KEY 31
KEY 39
KEY 47
COL3
PORT3
COL2
PORT4
COL1
PORT5
COL0
PORT6
ROW7
PORT7
ROW6
+3.3V
ROW5
VCC
µC
GND
SDA
SDA
ROW4
SCL
SCL
ROW3
INTI
INTI
ROW2
INTK
INTK
ROW1
AD0
PROCESS:BiCMOS
GND
ROW0
芯片信息
封装信息
如需最近的封装外形信息和焊盘布局，请查询
china.maxim-ic.com/packages。
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MAX7360
典型应用电路
MAX7360 I²C接口键控开关控制器和LED驱动器/GPIO，集成ESD保护电路 - 概述
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Maxim > 产品 > LED照明和LCD显示器支持IC > MAX7360
Maxim > 产品 > 微控制器 > MAX7360
MAX7360
I²C接口键控开关控制器和LED驱动器/GPIO，集成ESD保护电路
为所有按键提供标准的8kV接触放电/15kV气隙放电的IEC标准ESD保护
概述技术文档定购信息用户说明 (0) 所有内容状况
状况：生产中。
概述
MAX7360 I²C接口外设能够为微处理器管理多达64个按键开关，附加
的8路LED驱动器/GPIO具有固定电流、PWM亮度调节及旋转开关控制选项。
完整的数据资料
按键开关驱动器能够与金属开关或导通电阻高达5kΩ的阻性开关连接。以静态(而
非动态扫描)方式监测按键输入，确保低EMI工作。MAX7360具有自动休眠和自动
唤醒模式，使器件功耗最低。经过1个休眠超时周期后，自动休眠功能将器件置于
低功耗状态(典型值为1µA)。检测到按键动作时，自动唤醒功能使MAX7360返回
正常工作模式。
英文
下载 Rev. 0 (PDF, 1.5MB)
中文
下载 Rev. 0 (PDF, 1.5MB)
按键控制器进行按键去抖，并将按下和释放事件保存在FIFO中(如果使能，还包括自动重复功能)。中断输出(/INTK)可配置
成按键事件或最大速率报警。
器件具有8路漏极开路I/O端口，可用于驱动LED。每路漏极开路端口的最大固定输出电流为20mA。每路漏极开路端口
的LED亮度可通过256级PWM控制信号独立调节。输入端口对(端口6、端口7)可配置成接受旋转开关的2位格雷码输入。
此外，如果未被用作按键开关控制，多达六列的引脚可作为通用漏极开路输出(GPO)，用于LED驱动或逻辑控制。
MAX7360提供带裸焊盘的40引脚(5mm x 5mm)薄型QFN封装和小型36焊球晶片级封装(WLP)，适合蜂窝电话、掌上电脑
及其它便携式消费类电子应用。MAX7360工作于-40°C至+85°C扩展级温度范围。
现备有评估板：MAX7360EVKIT
关键特性
集成ESD保护
±8kV IEC 61000-4-2接触放电
±15kV IEC 61000-4-2气隙放电
能够承受+14V电压的漏极开路I/O端口，可用作恒流LED驱动
旋转开关输入对(端口6、端口7)
独立的256级PWM LED亮度控制
独立的LED闪烁速率及256ms至4096ms LED渐亮/渐暗速率控制
FIFO队列可保存多达16个去抖按键事件
用户可配置按键去抖时间(9ms至40ms)
按键扫描采用静态矩阵监测，实现低EMI操作
+1.62V至+3.6V供电
最多可监测64个按键
每个去抖事件/FIFO级或预设时间周期结束时，产生按键开关中
断(/INTK)
输入端口中断(/INTI)，用作特殊按键功能
http://china.maxim-ic.com/datasheet/index.mvp/id/4782[2010-8-18 8:09:27]
应用/使用
蜂窝电话
手持式游戏机
仪表
PDA
便携式消费类电子
打印机
MAX7360 I²C接口键控开关控制器和LED驱动器/GPIO，集成ESD保护电路 - 概述
400kbps、+5.5V耐压、2线串口，可选择总线超时
4个I²C地址选择
Key Specifications: Keyswitch Controllers
Part
Number
Interface
MAX7360 Serial 2-Wire
400kbit
I
I
Keys SUPPLY SHUTDN
(µA)
(µA) Interr.
Out
max
typ
typ
64
35
1.5
Key Scan
I 2 C Slave
IDs
Yes
4
GPOs
6+
8(Dedicated
I/O)
查看所有Keyswitch Controllers (3)
图表
简化框图
相关产品
MAX7360EVKIT MAX7360评估板
类似产品：浏览其它类似产品线
查看所有Keyswitch Controllers (6产品)
更多信息
新品发布
[ 2009-10-19 ]
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http://china.maxim-ic.com/datasheet/index.mvp/id/4782[2010-8-18 8:09:27]
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< tr>
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MAX7360 I²C接口键控开关控制器和LED驱动器/GPIO，集成ESD保护电路 - 概述
参考文献： 19- 4566 Rev. 0; 2009- 06- 19
本页最后一次更新: 2010- 04- 05
联络我们：信息反馈、提出问题 • 对该网页的评价 • 发送本网页 • 隐私权政策 • 法律声明
© 2010 Maxim Integrated Products版权所有
http://china.maxim-ic.com/datasheet/index.mvp/id/4782[2010-8-18 8:09:27]
19-4566; Rev 1; 8/10
TION KIT
EVALUA BLE
A
IL
A
AV
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Features
The MAX7360
peripheral provides microprocessors with management of up to 64 key switches,
with an additional eight LED drivers/GPIOs that feature
constant-current, PWM intensity control, and rotary
switch control options.
S Integrated ESD Protection
The key-switch drivers interface with metallic or resistive
switches with on-resistances up to 5kI. Key inputs
are monitored statically, not dynamically, to ensure
low-EMI operation. The MAX7360 features autosleep
and autowake modes to further minimize the power
consumption of the device. The autosleep feature puts
the device in a low-power state (1FA typ) after a sleep
timeout period. The autowake feature configures the
MAX7360 to return to normal operating mode from sleep
upon a keypress.
S Rotary Switch-Capable Input Pair (PORT6, PORT7)
The key controller debounces and maintains a FIFO of
keypress and release events (including autorepeat, if
enabled). An interrupt (INTK) output can be configured
to alert keypresses, as they occur, or at maximum rate.
S +1.62V to +3.6V Operation
There are eight open-drain I/O ports, which can be used
to drive LEDs. The maximum constant-current level for
each open-drain port is 20mA. The intensity of the LED
on each open-drain port can be individually adjusted
through a 256-step PWM control. An input port pair
(PORT6, PORT7) can be configured to accept 2-bit gray
code inputs from a rotary switch. In addition, if not used
for key-switch control, up to six column pins can be used
as general-purpose open-drain outputs (GPOs) for LED
drive or logic control.
The MAX7360 is offered in a 40-pin (5mm x 5mm) thin
QFN package with an exposed pad, and a small 36-bump
wafer level package (WLP) for cell phones, pocket PCs,
and other portable consumer electronic applications. The
MAX7360 operates over the -40NC to +85NC extended
temperature range.
Q8kV IEC 61000-4-2 Contact Discharge
Q15kV IEC 61000-4-2 Air-Gap Discharge
S +14V Tolerant, Open-Drain I/O Ports Capable of
Constant-Current LED Drive
S 256-Step PWM Individual LED Intensity Control
S Individual LED Blink Rates and Common LED
Fade In/Out Rates from 256ms to 4096ms
S FIFO Queues Up to 16 Debounced Key Events
S User-Configurable Key Debounce (9ms to 40ms)
S Keyscan Uses Static Matrix Monitoring for Low
EMI Operation
S Monitors Up to 64 Keys
S Key-Switch Interrupt (INTK) on Each Debounced
Event/FIFO Level, or End of Definable Time Period
S Port Interrupt (INTI) for Input Ports for Special-Key
Functions
S 400kbps, +5.5V Tolerant 2-Wire Serial Interface
with Selectable Bus Timeout
S Four I2C Address Choices
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX7360ETL+
MAX7360EWX+
-40°C to +85°C
-40°C to +85°C
40 TQFN-EP*
36 WLP
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Simplfied Block Diagram
Applications
Cell Phones
PDAs
Handheld Games
Portable Consumer Electronics
Printers
+1.8V
TO
FC
SCL
SDA
INTI
INTK
PORT7
PORT6
MAX7360
Instrumentation
AD0
ROTARY
SWITCH
+14V
PORT0
ROW_(8x)
COL_(8x)
8x8
Pin Configurations appear at end of data sheet.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX7360
General Description
I2C-interfaced
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
ABSOLUTE MAXIMUM RATINGS
VCC to GND.............................................................. -0.3V to +4V
COL0–COL7, ROW0–ROW7 to GND....................... -0.3V to +4V
SDA, SCL, AD0, INTI, INTK to GND......................... -0.3V to +6V
PORT0–PORT7 to GND.......................................... -0.3V to +16V
All Other Pins to GND.................................-0.3V to (VCC + 0.3V)
DC Current on PORT0–PORT7, COL2–COL7.....................25mA
GND Current........................................................................80mA
Continuous Power Dissipation (TA = +70NC)
40-Pin TQFN (derate 22.2mW/NC above +70NC).......1777mW
36-Bump WLP (derate 21.7mW/NC above +70NC).....1739mW
Junction-to-Case Thermal Resistance (BJC) (Note 1)
40-Pin TQFN...................................................................2NC/W
36-Bump WLP.................................................................... N/A
Junction-to-Ambient Thermal Resistance (BJA) (Note 1)
40-Pin TQFN.................................................................45NC/W
36-Bump WLP..............................................................46NC/W
Operating Temperature Range........................... -40NC to +85NC
Junction Temperature......................................................+150NC
Storage Temperature Range............................. -65NC to +150NC
ESD Protection
Human Body Model (RD = 1.5kI, CS = 100pF)
All Pins..............................................................................Q2kV
IEC 61000-4-2 (RD = 330I, CS = 150pF)
Contact Discharge
ROW0–ROW7, COL0–COL7, PORT0–PORT7 to GND.....Q8kV
Air-Gap Discharge
ROW0–ROW7, COL0–COL7, PORT0–PORT7 to GND...Q15kV
Lead Temperature (TQFN only, soldering, 10s)...............+300NC
Soldering Temperature (reflow)........................................+260NC
Note 1:Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a single-
.layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 2, 3)
PARAMETER
Operating Supply Voltage
External Supply Voltage
PORT0–PORT7
Operating Supply Current
SYMBOL
CONDITIONS
VCC
MIN
TYP
MAX
UNITS
1.62
3.3
3.6
V
14
V
VPORT_
ICC
All key switches open, oscillator running,
COL2–COL7 configured as key switches,
VPORT_ = VCC
34
FA
34 +
20 x N
N keys pressed
Sleep-Mode Supply Current
50
ISL
1.3
3
FA
FA
Key-Switch Source Current
IKEY
20
35
Key-Switch Source Voltage
VKEY
0.43
0.5
V
Key-Switch Resistance
RKEY
5
kI
2.4
ms
0.5
V
Startup Time from Shutdown
VOL
Oscillator Frequency (PWM
Clock)
fOSC
Key-Scan Frequency
2
tSTART
Output Low Voltage
COL2–COL7
Oscillator Frequency Variation
(Note 4)
DfOSC
fKEY
ISINK = 10mA
TA = +25NC, VCC = +2.61V
125
TA = TMIN to TMAX, VCC P 3.6V
102
164
-6
+8.5
TA = +25NC
Derived from oscillator clock
128
64
2 _______________________________________________________________________________________
131
kHz
%
kHz
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 2, 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
GPIO SPECIFICATIONS
Input High Voltage
PORT0–PORT7
VIH
Input Low Voltage
PORT0–PORT7
VIL
Input Leakage Current
PORT0–PORT7
IIN
Output Low Voltage
PORT0–PORT7
VOL
0.7 x
VCC
V
0.3 x
VCC
VIN P VCC
-0.25
+0.25
VCC < VIN
-1
+5
ISINK < 20mA
0.6
Input Capacitance
PORT0–PORT7
20
10mA Port Sinking Current
PORT0–PORT7
VCC = +1.62V to +3.6V, TA = +25NC
8.55
VCC = +3.3V, VOL = +1V
8.67
20mA Port Sinking Current
PORT0–PORT7
VCC = +1.62V to +3.6V, TA = +25NC
19.40
VCC = +3.3V, VOL = +1V
19.55
Port Sink Current Variation
VCC = +3.3V, VOL = +1V, TA = +25NC,
20mA output mode
Output Logic-Low Voltage
INTI, INTK
ISINK = 10mA
PWM Frequency
fPWM
Derived from oscillator clock
FA
V
pF
11.52
9.76
V
10.51
21.33
mA
mA
20
20.69
+Q1.5
+Q2.4
%
0.6
V
500
Hz
SERIAL-INTERFACE SPECIFICATIONS
Input High Voltage
SDA, SCL, AD0
VIH
Input Low Voltage
SDA, SCL, AD0
VIL
Input Leakage Current
SDA, SCL, AD0
IIN
Output Low Voltage
SDA
VOL
Input Capacitance
SDA, SCL, AD0
CIN
I2C TIMING SPECIFICATIONS
SCL Serial-Clock Frequency
Bus Free Time Between a STOP
and START Condition
fSCL
0.7 x
VCC
V
0.3 x
VCC
VIN P VCC
-0.25
+0.25
VIN > VCC
-0.5
+0.5
ISINK = 6mA
0.6
10
Bus timeout disabled
0
V
FA
V
pF
400
kHz
tBUF
1.3
Fs
Hold Time (Repeated) START
Condition
tHD, STA
0.6
Fs
Repeated START Condition
Setup Time
tSU, STA
0.6
Fs
STOP Condition Setup Time
tSU, STO
0.6
Fs
_______________________________________________________________________________________ 3
MAX7360
ELECTRICAL CHARACTERISTICS (continued)
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +1.62V to +3.6V, TA = -40NC to +85NC, unless otherwise noted. Typical values are at VCC = +3.3V, TA = +25NC.) (Notes 2, 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
(Note 5)
MAX
0.9
UNITS
Data Hold Time
tHD, DAT
Data Setup Time
tSU, DAT
100
ns
SCL Clock Low Period
tLOW
1.3
Fs
SCL Clock High Period
tHIGH
0.7
Fs
Fs
(Notes 4, 6)
20 +
0.1Cb
300
ns
tF
(Notes 4, 6)
20 +
0.1Cb
300
ns
tF, TX
(Notes 4, 7)
20 +
0.1Cb
250
ns
Pulse Width of Spike Suppressed
tSP
(Notes 4, 8)
50
Capacitive Load for Each Bus
Line
Cb
(Note 4)
Rise Time of Both SDA and SCL
Signals, Receiving
tR
Fall Time of Both SDA and SCL
Signals, Receiving
Fall Time of SDA Signal,
Transmitting
ns
400
pF
All parameters are tested at TA = +25NC. Specifications over temperature are guaranteed by design.
All digital inputs at VCC or GND.
Guaranteed by design.
A master device must provide a hold time of at least 300ns for the SDA signal (referred to VIL of the SCL signal) to bridge
the undefined region of SCL’s falling edge.
Note 6: Cb = total capacitance of one bus line in pF. tR and tF measured between +0.3VCC and +0.7VCC.
Note 7: ISINK ≤ 6mA.
Note 8: Input filters on the SDA, SCL, and AD0 inputs suppress noise spikes less than 50ns.
Note
Note
Note
Note
2:
3:
4:
5:
4 _______________________________________________________________________________________
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
TA = -40NC
50
100
TA = -40°C
50
0
5
15
0
5
0
20
18.3
TA = -40NC, +85NC
18.2
18.1
18.0
TA = +25NC
TA = +85NC
17.9
17.8
TA = -40NC
17.7
17.6
15
20
3.2
25
2.0
2.4
3.2
2.8
SUPPLY VOLTAGE (V)
TA = +25NC
TA = +85NC
5
VCC = 3.0V
20
SINK CURRENT (mA)
TA = -40NC
0
2.0
OUTPUT VOLTAGE (V)
2.5
TA = +85NC
0.5
1.6
TA = +25NC
TA = +85NC
10
3.0
2.8
2.4
3.2
3.6
CONSTANT-CURRENT GPIO OUTPUT
SINK CURRENT vs. OUTPUT VOLTAGE
TA = -40NC
15
2.0
SUPPLY VOLTAGE (V)
25
VCC = 3.6V
20
TA = -40NC
15
TA = +25NC
TA = +85NC
10
5
0
1.5
TA = +25NC
1.0
3.6
5
1.0
1.5
CONSTANT-CURRENT GPIO OUTPUT
SINK CURRENT vs. OUTPUT VOLTAGE
MAX7360 toc07
20
2.0
0
CONSTANT-CURRENT GPIO OUTPUT
SINK CURRENT vs. OUTPUT VOLTAGE
VCC = 2.4V
TA = -40NC
TA = -40NC, +25NC
1.6
3.6
2.5
MAX7360 toc09
2.8
3.0
17.4
SUPPLY VOLTAGE (V)
0.5
10
MAX7360 toc06
VCOL0 = O
SINK CURRENT (mA)
2.4
2.0
MAX7360 toc05
18.4
17.5
0
5
0
SHUTDOWN SUPPLY CURRENT (A)
TA = -40NC
20
SINK CURRENT (mA)
15
SHUTDOWN SUPPLY CURRENT
vs. SUPPLY VOLTAGE
25
10
10
KEY-SWITCH SOURCE CURRENT
vs. SUPPLY VOLTAGE
TA = +25NC
15
TA = -40°C
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
35
25
100
SINK CURRENT (mA)
TA = +85NC
1.6
TA = +25°C
SINK CURRENT (mA)
40
15
150
SINK CURRENT (mA)
AUTOSLEEP = OFF
30
TA = +85°C
50
0
20
KEY-SWITCH SOURCE CURRENT (A)
45
10
MAX7360 toc04
0
SUPPLY CURRENT (A)
TA = +25°C
VCC = 3.6V
200
OUTPUT VOLTAGE (mV)
100
TA = +85°C
150
250
MAX7360 toc08
OUTPUT VOLTAGE (mV)
TA = +25NC
150
VCC = 3.0V
200
OUTPUT VOLTAGE (mV)
TA = +85NC
GPO OUTPUT LOW VOLTAGE
vs. SINK CURRENT (COL2–COL7)
MAX7360 toc02
VCC = 2.4V
200
250
MAX7360 toc01
250
GPO OUTPUT LOW VOLTAGE
vs. SINK CURRENT (COL2–COL7)
MAX7360 toc03
GPO OUTPUT LOW VOLTAGE
vs. SINK CURRENT (COL2–COL7)
0
0
0.5
1.0
1.5
2.0
OUTPUT VOLTAGE (V)
2.5
3.0
0
0.5
1.0
1.5
2.0
2.5
3.0
OUTPUT VOLTAGE (V)
_______________________________________________________________________________________ 5
MAX7360
Typical Operating Characteristics
(VCC = +2.5V, TA = +25NC, unless otherwise noted.)
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Pin Description
PIN
NAME
FUNCTION
TQFN
WLP
1
A6
ROW0
Row Input from Key Matrix. Leave ROW0 unconnected or connect to GND if unused.
2
B6
ROW1
Row Input from Key Matrix. Leave ROW1 unconnected or connect to GND if unused.
3
C4
ROW2
Row Input from Key Matrix. Leave ROW2 unconnected or connect to GND if unused.
4
C6
ROW3
Row Input from Key Matrix. Leave ROW3 unconnected or connect to GND if unused.
5, 15, 25,
35
B4, C5, D2,
E4
GND
6
D6
ROW4
Row Input from Key Matrix. Leave ROW4 unconnected or connect to GND if unused.
7
D5
ROW5
Row Input from Key Matrix. Leave ROW5 unconnected or connect to GND if unused.
8
E6
ROW6
Row Input from Key Matrix. Leave ROW6 unconnected or connect to GND if unused.
9
D4
ROW7
Row Input from Key Matrix. Leave ROW7 unconnected or connect to GND if unused.
10, 20, 27,
30, 40
C2
N.C.
11
F6
COL0
Column Output to Key Matrix. Leave COL0 unconnected if unused.
12
E5
COL1
Column Output to Key Matrix. Leave COL1 unconnected if unused.
13
F5
COL2
Column Output to Key Matrix. Leave COL2 unconnected if unused. COL2 can be
configured as a GPO (see Table 9 in the Register Tables section).
14
F4
COL3
Column Output to Key Matrix. Leave COL3 unconnected if unused. COL3 can be
configured as a GPO (see Table 9 in the Register Tables section).
16
F3
COL4
Column Output to Key Matrix. Leave COL4 unconnected if unused. COL4 can be
configured as a GPO (see Table 9 in the Register Tables section).
17
E3
COL5
Column Output to Key Matrix. Leave COL5 unconnected if unused. COL5 can be
configured as a GPO (see Table 9 in the Register Tables section).
18
F2
COL6
Column Output to Key Matrix. Leave COL6 unconnected if unused. COL6 can be
configured as a GPO (see Table 9 in the Register Tables section).
19
F1
COL7
Column Output to Key Matrix. Leave COL7 unconnected if unused. COL7 can be
configured as a GPO (see Table 9 in the Register Tables section).
21
E2
SDA
I2C-Compatible, Serial-Data I/O
22
E1
SCL
I2C-Compatible, Serial-Clock Input
23
D3
INTK
Active-Low Key-Switch Interrupt Output. INTK is open drain and requires a pullup
resistor.
Ground
No Connection. Not internally connected. Leave unconnected.
6 _______________________________________________________________________________________
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
PIN
TQFN
WLP
NAME
24
D1
26
C1
INTI
VCC
FUNCTION
Active-Low GPI Interrupt Output. INTI is open drain and requires a pullup resistor.
Positive Supply Voltage. Bypass VCC to GND with a 0.1FF or higher ceramic capacitor.
28
B1
AD0
Address Input. AD0 selects up to four device slave addresses (Table 3).
29
A1
I.C.
Internally Connected. Connect to GND for normal operation.
31
B2
PORT0
GPIO Port. Open-drain I/O rated at +14V. PORT0 can be configured as a constantcurrent output.
32
A2
PORT1
GPIO Port. Open-drain I/O rated at +14V. PORT1 can be configured as a constantcurrent output.
33
B3
PORT2
GPIO Port. Open-drain I/O rated at +14V. PORT2 can be configured as a constantcurrent output.
34
A3
PORT3
GPIO Port. Open-drain I/O rated at +14V. PORT3 can be configured as a constantcurrent output.
36
A4
PORT4
GPIO Port. Open-drain I/O rated at +14V. PORT4 can be configured as a constantcurrent output.
37
C3
PORT5
GPIO Port. Open-drain I/O rated at +14V. PORT5 can be configured as a constantcurrent output.
38
A5
PORT6
GPIO Port. Open-drain I/O rated at +14V. PORT6 can be configured as a constantcurrent output, or a rotary switch input.
39
B5
PORT7
GPIO Port. Open-drain I/O rated at +14V. PORT7 can be configured as a constantcurrent output, or a rotary switch input.
—
—
EP
Exposed Pad (TQFN only). EP is internally connected to GND. Connect EP to a ground
plane to increase thermal performance.
_______________________________________________________________________________________ 7
MAX7360
Pin Description (continued)
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Functional Block Diagram
LED ENABLE
PWM
GPIO
LOGIC
GPIO ENABLE
GPIO INPUT
PORT GPIO
AND
CONSTANTCURRENT
LED DRIVE
MAX7360
PORT0
PORT1
PORT2
PORT3
PORT4
PORT5
PORT6
PORT7
ROTARY
COLUMN ENABLE
128kHz
OSCILLATOR
GPO ENABLE
CURRENT DETECT
CURRENT
SOURCE
COLUMN
DRIVES
INTI
INTK
SDA
SCL
AD0
I2C
INTERFACE
CONTROL
REGISTERS
FIFO
KEY
SCAN
ROW ENABLE
BUS
TIMEOUT
POR
OPENDRAIN
ROW
DRIVES
COL0
COL1
COL2*
COL3*
COL4*
COL5*
COL6*
COL7*
ROW0
ROW1
ROW2
ROW3
ROW4
ROW5
ROW6
ROW7
*GPO
Detailed Description
The MAX7360 is a microprocessor peripheral low-noise
key-switch controller that monitors up to 64 key switches
with optional autorepeat, and key events that are
presented in a 16-byte FIFO. The MAX7360 also features
eight open-drain GPIOs configured for digital I/O or
constant-current output for LED applications up to +14V.
The MAX7360 features an automatic sleep mode and
automatic wakeup that further reduce supply current
consumption. The MAX7360 can be configured to enter
sleep mode after a programmable time following a key
event. The FIFO content is maintained and can be read
in sleep mode. The MAX7360 does not enter autosleep
when a key is held down. The autowake feature takes
the MAX7360 out of sleep mode following a keypress
event. Enable/disable autosleep and autowake through
the configuration register (Table 8).
To prevent overloading the microprocessor with too
many interrupts, interrupt requests are issued on a
programmable number of FIFO entries, and/or after a
set period of time (Table 10). The key-switch status is
checked by reading the key-switch FIFO. A 1-byte read
access returns both the next key event in the FIFO (if
there is one) and the FIFO status. INTK functions as an
open-drain general-purpose output (GPO) capable of
driving an LED if key-switch interrupts are not required.
Up to six of the key-switch outputs function as opendrain GPOs capable of driving additional LEDs when
the application requires fewer keys to be scanned. For
each key-switch output used as a GPO, the number of
monitored key switches reduces by eight.
Initial Power-Up
On power-up, all control registers are set to power-up
values and the MAX7360 is in sleep mode (Table 1).
8 _______________________________________________________________________________________
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
ADDRESS
CODE
(hex)
READ/
WRITE
POWER-UP
VALUE (hex)
REGISTER
FUNCTION
0x00
Read only
0x3F
Keys FIFO
0x01
R/W
0x0A
Configuration
0x02
R/W
0xFF
Debounce
0x03
R/W
0x00
Interrupt
0x04
R/W
0xFE
GPO
0x05
R/W
0x00
Key repeat
0x06
R/W
0x07
Sleep
DESCRIPTION
Read FIFO key-scan data out
Power-down, key-release enable, autowakeup, and I2C timeout enable
Key debounce time settling and GPO enable
Key-switch interrupt INTK frequency setting
COL2–COL7 and INTK GPO control
Delay and frequency for key repeat
Idle time to autosleep
0x40
R/W
0x00
GPIO global configuration
0x41
R/W
0x00
GPIO control
0x42
R/W
0x00
GPIO debounce
PORT0–PORT7 debounce time setting
0xC0
GPIO constantcurrent setting
PORT0–PORT7 constant-current output setting
0x43
R/W
0x44
Rotary switch, GPIO standby, GPIO reset, fade
PORT0–PORT7 input/output control
R/W
0x00
GPIO output mode
0x45
R/W
0x00
Common PWM
0x46
R/W
0x00
Rotary switch configuration
0x48
Read only
0x00
I2C timeout flag
0x49
Read only
0xFF
GPIO input register
PORT0–PORT7 input values
0x4A
Read only
0x00
Rotary switch count
Switch cycles since last read
0x50
R/W
0x00
PORT0 PWM
PORT0 individual duty-cycle setting
0x51
R/W
0x00
PORT1 PWM
PORT1 individual duty-cycle setting
0x52
R/W
0x00
PORT2 PWM
PORT2 individual duty-cycle setting
0x53
R/W
0x00
PORT3 PWM
PORT3 individual duty-cycle setting
0x54
R/W
0x00
PORT4 PWM
PORT4 individual duty-cycle setting
0x55
R/W
0x00
PORT5 PWM
PORT5 individual duty-cycle setting
0x56
R/W
0x00
PORT6 PWM
PORT6 individual duty-cycle setting
0x57
R/W
0x00
PORT7 PWM
0x58
R/W
0x00
PORT0 configuration
PORT0 interrupt, PWM mode control and blink period setting
0x59
R/W
0x00
PORT1 configuration
PORT1 interrupt, PWM mode control and blink period setting
R/W
0x00
PORT2 configuration
PORT2 interrupt, PWM mode control and blink period setting
0x5A
PORT0–PORT7 output mode control
Common PWM duty-cycle setting
Rotary switch interrupt frequency and debounce time setting
I2C timeout since last POR
PORT7 individual duty-cycle setting
0x5B
R/W
0x00
PORT3 configuration
PORT3 interrupt, PWM mode control and blink period setting
0x5C
R/W
0x00
PORT4 configuration
PORT4 interrupt, PWM mode control and blink period setting
0x5D
R/W
0x00
PORT5 configuration
PORT5 interrupt, PWM mode control and blink period setting
R/W
0x00
PORT6 configuration
PORT6 interrupt, PWM mode control and blink period setting
R/W
0x00
PORT7 configuration
PORT7 interrupt, PWM mode control and blink period setting
0x5E
0x5F
_______________________________________________________________________________________ 9
MAX7360
Table 1. Register Address Map and Power-Up Condition
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Table 2. Key-Switch Mapping
PIN
ROW0
COL0
KEY 0
COL1
KEY 8
COL2*
KEY 16
COL3*
KEY 24
COL4*
KEY 32
COL5*
KEY 40
COL6*
KEY 48
COL7*
KEY 56
ROW1
KEY 1
KEY 9
KEY 17
KEY 25
KEY 33
KEY 41
KEY 49
KEY 57
ROW2
KEY 2
KEY 10
KEY 18
KEY 26
KEY 34
KEY 42
KEY 50
KEY 58
ROW3
KEY 3
KEY 11
KEY 19
KEY 27
KEY 35
KEY 43
KEY 51
KEY 59
ROW4
KEY 4
KEY 12
KEY 20
KEY 28
KEY 36
KEY 44
KEY 52
KEY 60
ROW5
KEY 5
KEY 13
KEY 21
KEY 29
KEY 37
KEY 45
KEY 53
KEY 61
ROW6
KEY 6
KEY 14
KEY 22
KEY 30
KEY 38
KEY 46
KEY 54
KEY 62
ROW7
KEY 7
KEY 15
KEY 23
KEY 31
KEY 39
KEY 47
KEY 55
KEY 63
*These columns can be configured as GPOs.
Key-Scan Controller
Key inputs are scanned statically, not dynamically,
to ensure low-EMI operation. As inputs only toggle
in response to switch changes, the key matrix can be
routed closer to sensitive circuit nodes.
The key-scan controller debounces and maintains a FIFO
of keypress and release events (including autorepeated
keypresses, if autorepeat is enabled). Table 2 shows the
key-switch order. The user-programmable key-switch
debounce time, and autosleep timer, is derived from the
64kHz clock, which in turn is derived from the 128kHz
oscillator. Time delay for autorepeat and key-switch
interrupt is based on the key-switch debounce time.
Keys FIFO Register (0x00)
The keys FIFO register contains the information pertaining
to the status of the keys FIFO, as well as the key events
that have been debounced (see Table 7 in the Register
Tables section). Bits D0–D5 denote which of the 64 keys
have been debounced and the keys are numbered as in
Table 2.
and determines how INTK is deasserted. Write to bit D7
to put the MAX7360 into sleep mode or operating mode.
Autosleep and autowake, when enabled, also change the
status of D7 (see Table 8 in the Register Tables section).
Debounce Register (0x02)
The debounce register sets the time for each debounce
cycle, as well as setting whether the GPO ports are
enabled or disabled. Bits D0–D4 set the debounce time
in increments of 1ms starting at 9ms and ending at 40ms
(see Table 9 in the Register Tables section). Bits D5, D6,
and D7 set which of the GPO ports is enabled. Note the
GPO ports are enabled only in the combinations shown
in Table 9, from all disabled to all enabled.
Reading the key-scan FIFO clears the interrupt INTK
depending on the setting of bit D5 in the configuration
register (0x01).
Key-Switch Interrupt Register (0x03)
The interrupt register contains information related to the
settings of the interrupt request function, as well as the
status of the INTK output, which can also be configured
as a GPO. If bits D0–D7 are set to 0x00, the INTK output
is configured as a GPO that is controlled by bit D1 in the
port register. There are two types of interrupts, the FIFObased interrupt and time-based interrupt. Set bits D0–D4
to assert interrupts at the end of the selected number of
debounce cycles following a key event (see Table 10 in
the Register Tables section). This number ranges from
1–31 debounce cycles. Setting bits D7, D6, and D5 set
the FIFO-based interrupt when there are 2–14 key events
stored in the FIFO. Both interrupts can be configured
simultaneously and INTK asserts depending on which
condition is met first. INTK deasserts depending on the
status of bit D5 in the configuration register.
Configuration Register (0x01)
The configuration register controls the I2C bus timeout
feature, enables key-release detection, enables autowake,
Ports Register (0x04)
The ports register sets the values of PORT2–PORT7
and the INTK port, when configured, as open-drain
D7 indicates if there is more data in the FIFO, except
when D5:D0 indicate key 63 or key 62. When D5:D0
indicate key 63 or key 62, the host should read one more
time to determine whether there is more data in the FIFO.
Use key 62 and key 63 for rarely used keys. D6 indicates
if it is a keypress or release event, except when D5:D0
indicate key 63 or key 62.
10 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Autorepeat Register (0x05)
The MAX7360 autorepeat feature notifies the host that at
least one key has been pressed for a continuous period.
The autorepeat register enables or disables this feature,
sets the time delay after the last key event before the key
repeat code (0x7E) is entered into the FIFO, and sets
the frequency at which the key-repeat code is entered
into the FIFO thereafter. Bit D7 specifies whether the
autorepeat function is enabled with 0 denoting autorepeat
disabled, and 1 denoting autorepeat enabled. Bits D0–
D3 specify the autorepeat delay in terms of debounce
cycles ranging from 8–128 debounce cycles (see Table
12 in the Register Tables section). Bits D4, D5, and D6
specify the autorepeat rate or frequency ranging from
4–32 debounce cycles.
When autorepeat is enabled, holding the key pressed
results in a key-repeat event that is denoted by 0x7E. The
key being pressed does not show up again in the FIFO.
Only one autorepeat code is entered into the FIFO,
regardless of the number of keys pressed. The
autorepeat code continues to be entered in the FIFO at
the frequency set by bits D[4:6] until another key event
is recorded. Following the key-release event, if any keys
are still pressed, the MAX7360 restarts the autorepeat
sequence.
Autosleep Register (0x06)
Autosleep puts the MAX7360 in sleep mode to draw
minimal current. When enabled, the MAX7360 enters
sleep mode if no keys are pressed for the autosleep time
(see Table 13 in the Register Tables section).
Key-Switch Sleep Mode
In sleep mode, the MAX7360 draws minimal current.
Switch-matrix current sources are turned off and pulled
up to VCC. When autosleep is enabled, key-switch
inactivity for a period longer than the autosleep time
puts the part into sleep mode (FIFO data is maintained).
Writing a 1 to D7 in the configuration register, or a keypress, can take the MAX7360 out of sleep mode. Bit D7
in the configuration register gives the sleep-mode status
and can be read any time. The FIFO data is maintained
while in sleep mode.
Autowake
Keypresses initiate autowake and the MAX7360 goes into
operating mode. Keypresses that autowake the MAX7360
are not lost. When a key is pressed while the MAX7360
is in sleep mode, all analog circuitry, including switchmatrix current sources, turn on in 2ms. The initial key
needs to be pressed for 2ms plus the debounce time to
be stored in the FIFO. Write a 0 to D1 in the configuration
register (0x01) to disable autowakeup.
GPIOs
The MAX7360 has eight GPIO ports with LED control
functions. The ports can be used as logic inputs, logic
outputs, or constant-current PWM LED drivers. In
addition, PORT7 and PORT6 can function as a rotary
switch input pair. When in PWM mode, the ports are set
up to start their PWM cycle in 45N phase increments. This
prevents large current spikes on the LED supply voltage
when driving multiple LEDs.
GPIO Global Configuration Register (0x40)
The GPIO global configuration register controls the main
settings for the eight GPIOs (see Table 14 in the Register
Tables section).
Bit D7 enables PORT[7:6] as inputs for a rotary switch.
Bit D5 enables interrupt generation for I2C timeouts.
D4 is the main enable/shutdown bit for the GPIOs. D3
functions as a software reset for the GPIO registers (0x40
to 0x5F). Bits D[2:0] set the fade in/out time for the GPIOs
configured as constant-current sinks.
GPIO Control Register (0x41)
The GPIO control register configures each port as either
an input or an output (see Table 15 in the Register Tables
section). All GPIOs allow individual configurations,
and power up as inputs. Enabling rotary switch mode
automatically sets D7 and D6 as inputs. The ports
consume additional current if their inputs are left undriven.
GPIO Debounce Configuration Register (0x42)
The GPIO debounce configuration register sets the
amount of time a GPIO must be held for the MAX7360
to register a logic transition (see Table 16 in the
Register Tables section). The GPIO debounce setting
is independent of the key-switch debounce setting. Five
bits (D[4:0]) set 32 possible debounce times from 9ms
up to 40ms.
______________________________________________________________________________________ 11
MAX7360
GPOs. The settings in this register are ignored for ports
not configured as GPOs, and a read from this register
returns the values stored in the register (see Table 11 in
the Register Tables section).
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
GPIO Constant-Current Setting Register (0x43)
The GPIO constant-current setting register sets the global
constant-current amount (see Table 17 in the Register
Tables section). Bits D1 and D0 set the global current
values from 5mA up to 20mA.
GPIO Output Mode Register (0x44)
The GPIO output mode register sets an output as either
a constant-current or non-constant-current output for
PORT[7:0] (see Table 18 in the Register Tables section).
Outputs are configured as constant-current outputs by
default to prevent accidental loading of an LED across
an unregulated output. The constant-current circuits
automatically turn off when not in use to reduce current
consumption.
Common PWM Register (0x45)
The common PWM register stores the common constantcurrent output PWM duty cycle (see Table 19 in the
Register Tables section). The values stored in this register
translate over to a PWM duty cycle in the same manner
as the individual PWM registers (0x50 to 0x57). Ports can
use their own individual PWM value, or the common PWM
value. Write to this register to change the duty cycle of
several ports at once.
Rotary Switch Configuration Register (0x46)
The rotary switch configuration register stores rotary
switch settings for PORT7 and PORT6 (see Table 20 in
the Register Tables section). D7 determines whether
switch counts or a time delay will trigger an interrupt
if enabled. D[6:4] set the count or time amount to wait
before sending an interrupt. Bits D[3:0] set the debounce
cycle time for the rotary switch inputs. Debounce time
ranges from 0 to 15ms.
I2C Timeout Flag Register (0x48) (Read Only)
The I2C timeout flag register contains a single bit (D0),
which indicates if an I2C timeout has occurred (see Table
21 in the Register Tables section). Read this register to
clear an I2C timeout initiated interrupt.
GPIO Input Register (0x49) (Read Only)
The GPIO input register contains the input data for all of
the GPIOs (see Table 22 in the Register Tables section).
Ports configured as outputs are read as high. There is
one debounce period delay prior to detecting a transition
on the input port. This prevents a false interrupt from
occurring when changing a port from an output to an
input. The GPIO input register reports the state of all
input ports regardless of any interrupt mask settings.
Ports configured as an input have a 2FA internal pullup
to VCC for PORT[5:0] and a 10FA internal pullup to VCC
for PORT[7:6].
Rotary Switch Count Register (0x4A) (Read Only)
The MAX7360 keeps a count of the rotary switch rotations
in two’s compliment format (see Table 23 in the Register
Tables section). The register values wrap around as the
count value switches from a positive to a negative value
and back again. The count resets to zero after an I2C
read to this register.
PORT0–PORT7 Individual PWM Ratio Registers
(0x50 to 0x57)
Each port has an individual PWM ratio register (0x50 to
0x57, see Table 24 in the Register Tables section). Use
values 0x00 to 0xFE in these registers to configure the
number of cycles out of 256 the output sinks current
(LED is on), from 0 cycles to 254 cycles. Use 0xFF to
have an output continuously sink current (always on).
For applications requiring multiple ports to have the
same intensity, program a particular port’s configuration
register (0x58 to 0x5F) to use the common PWM register
(0x45). New PWM settings take place at the beginning of
a PWM cycle, to allow changes from common intensity to
individual intensity with no interruption in the PWM cycle.
PORT0–PORT7 Configuration Registers
(0x58 to 0x5F)
Registers 0x58 to 0x5F set individual configurations for
each port (see Table 25 in the Register Tables section).
Bits D7 and D6 determine the interrupt settings for the
inputs. Interrupts can assert upon detection of a logic
transition, a rising edge, or not at all. D5 sets the port’s
PWM setting to either the common or individual PWM
setting. Bits D[4:2] enable and set the ports’ individual
blink period from 0 to 4096ms. Bits D1 and D0 set a port’s
blink duty cycle.
Fading
Set the fade cycle time in the GPIO global configuration
register (0x40) to a non-zero value to enable fade in/out (see
Table 14 in the Register Tables section). Fade in increases
an LED’s PWM intensity in 16 even steps from zero to its
stored value. Fade out decreases an LED’s PWM intensity in
16 even steps from its current value to zero. Fading occurs
automatically in any of the following scenarios:
1) Change the common PWM register value from any
value to zero to cause all ports using the common
PWM register settings to fade out. No ports using
individual PWM settings are affected.
2) Change the common PWM register value to any value
from zero to cause all ports using the common PWM
register settings to fade in. No ports using individual
PWM settings are affected.
3) Put the part out of shutdown to cause all ports to
fade in. Changing an individual PWM intensity during
12 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Set registers 0x58 to 0x5F for individual GPI-based
interrupts. If multiple sources generate the interrupt, all
the related status registers must be read to clear INTI.
4) Put the part into shutdown to cause all ports to fade
out. Changing an individual PWM intensity during
fade out automatically cancels that port’s fade and
immediately turns off.
Rotary Switch
The MAX7360 can accept a 2-bit rotary switch inputs on
PORT6 and PORT7. Rotation of the switch in a clockwise
direction increments the count. Enable rotary switch
mode from the GPIO global configuration register (0x40).
Several settings for PORT6 and PORT7 occur during
rotary switch mode:
Blink
Each port has its own blink control settings through
registers 0x58 to 0x5F (see Table 25 in the Register Tables
section). The blink period ranges from 0 (blink disabled)
to 4.096s. Settable blink duty cycles range from 6.25%
to 50%. All blink periods start at the same PWM cycle for
synchronized blinking between multiple ports.
1) Each port has a 10FA pullup to VCC.
2) Register 0x46 sets the debounce time.
3) A debounced rising edge on PORT6 while PORT7 is
high decreases the count.
GPIO Port Interrupts (INTI)
Three possible sources generate INTI: I2C timeout,
GPIOs configured as inputs, and the rotary switch
(registers 0x48, 0x49, and 0x4A). Read the respective
data/status registers for each type of interrupt to clear
INTI. Set register 0x46 for rotary switch-based interrupts.
4) A debounced rising edge on PORT6 while PORT7 is
low increases the count.
For more details, see Figure 1.
Serial Interface
Figure 2 shows the 2-wire serial interface timing details.
PORT7
Serial Addressing
INCREMENT
The MAX7360 operates as a slave that sends and
receives data through an I2C-compatible 2-wire interface.
The interface uses a serial-data line (SDA) and a serialclock line (SCL) to achieve bidirectional communication
between master(s) and slave(s). A master (typically a
microcontroller) initiates all data transfers to and from the
MAX7360 and generates the SCL clock that synchronizes
the data transfer.
PORT6
PORT7
DECREMENT
PORT6
ROTARY SWITCH
DEBOUNCE
The MAX7360’s SDA line operates as both an input and
an open-drain output. A pullup resistor, typically 4.7kI,
Figure 1. Rotary Switch Input Signal Timing
tR
SDA
tSU, DAT
tLOW
tSU, STA
tF
tF, TX
tBUF
tHD, STA
tHD, DAT
tSU, STO
tHIGH
SCL
tHD, STA
tR
tF
START
CONDITION
REPEATED
START CONDITION
STOP
CONDITION
START
CONDITION
Figure 2. 2-Wire Serial Interface Timing Details
______________________________________________________________________________________ 13
MAX7360
fade in automatically cancels that port’s fade and
immediately output at its newly programmed intensity.
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
is required on SDA. The MAX7360’s SCL line operates
only as an input. A pullup resistor is required on SCL if
there are multiple masters on the 2-wire interface, or if
the master in a single-master system has an open-drain
SCL output.
Each transmission consists of a START (S) condition
(Figure 3) sent by a master, followed by the MAX7360
7-bit slave address plus R/W bit, a register address byte,
one or more data bytes, and finally, a STOP (P) condition.
START and STOP Conditions
Both SCL and SDA remain high when the interface is not
busy. A master signals the beginning of a transmission
with a START condition by transitioning SDA from high
to low while SCL is high. When the master has finished
communicating with the slave, it issues a STOP condition
by transitioning SDA from low to high while SCL is high.
The bus is then free for another transmission.
Acknowledge
The acknowledge bit is a clocked 9th bit (Figure 5), which
the recipient uses to handshake receipt of each byte of
data. Thus, each byte transferred effectively requires
9 bits. The master generates the 9th clock pulse, and
the recipient pulls down SDA during the acknowledge
clock pulse; therefore, the SDA line is stable low during
the high period of the clock pulse. When the master is
transmitting to the MAX7360, the MAX7360 generates the
acknowledge bit because the MAX7360 is the recipient.
When the MAX7360 is transmitting to the master, the
master generates the acknowledge bit because the
master is the recipient.
Table 3. 2-Wire Interface Address Map
Bit Transfer
One data bit is transferred during each clock pulse
(Figure 4). The data on SDA must remain stable while
SCL is high.
PIN AD0
DEVICE ADDRESS
A7
A6
A5
A4
A3
A2
A1
A0
GND
0
1
1
1
0
0
0
R/W
VCC
0
1
1
1
0
1
0
R/W
SDA
0
1
1
1
1
0
0
R/W
SCL
0
1
1
1
1
1
0
R/W
SDA
SCL
S
P
START
CONDITION
STOP
CONDITION
Figure 3. START and STOP Conditions
SDA
SCL
DATA LINE STABLE;
DATA VALID
CHANGE OF DATA
ALLOWED
Figure 4. Bit Transfer
14 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
CLOCK PULSE FOR
ACKNOWLEDGE
1
SCL
SDA
BY
TRANSMITTER
SDA
BY
RECEIVER
MAX7360
START
CONDITION
2
8
9
S
Figure 5. Acknowledge
SDA
0
1
1
1
A3
A2
A1
MSB
R/W
ACK
LSB
SCL
Figure 6. Slave Address
COMMAND BYTE IS STORED ON RECEIPT OF
ACKNOWLEDGE CONDITION
ACKNOWLEDGE FROM MAX7360
S
SLAVE ADDRESS
0
D7
D6
A
D5
D4
D3
D2
D1
D0
COMMAND BYTE
R/W
A
P
ACKNOWLEDGE FROM MAX7360
Figure 7. Command Byte Received
ACKNOWLEDGE FROM MAX7360
ACKNOWLEDGE FROM MAX7360
D7
D6
D5
D4
D3
D2
D1
D0
D7
D6
D5
D4
D3
D2
D1
D0
ACKNOWLEDGE FROM MAX7360
S
SLAVE ADDRESS
0
A
COMMAND BYTE
A
DATA BYTE
A
P
1 BYTE
R/W
AUTOINCREMENT
COMMAND BYTE ADDRESS
Figure 8. Command and Single Data Byte Received
Slave Addresses
The MAX7360 has a 7-bit long slave address (Figure
6). The bit following a 7-bit slave address is the R/W bit,
which is low for a write command and high for a read
command.
The first 4 bits (MSBs) of the MAX7360 slave address
are always 0111. Slave address bits A3, A2, and A1
correspond, by the matrix in Table 3, to the states of the
device address input AD0, and A0 corresponds to the
R/W bit. The AD0 input can be connected to any of four
signals (GND, VCC, SDA, or SCL), giving four possible
slave address pairs and allowing up to four MAX7360
devices to share the bus. Because SDA and SCL are
dynamic signals, care must be taken to ensure that AD0
transitions no sooner than the signals on SDA and SCL.
The MAX7360 monitors the bus continuously, waiting for a
START condition, followed by its slave address. When the
MAX7360 recognizes its slave address, it acknowledges
and is then ready for continued communication.
Bus Timeout
The MAX7360 features a 20ms minimum bus timeout
on the 2-wire serial interface, largely to prevent the
MAX7360 from holding the SDA I/O low during a read
transaction should the SCL lock up for any reason before
a serial transaction is completed. Bus timeout operates
by causing the MAX7360 to internally terminate a serial
______________________________________________________________________________________ 15
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
ACKNOWLEDGE FROM MAX7360
ACKNOWLEDGE FROM MAX7360
D7
D6
D5
D4
D3
D2
D1
D0
D7
D6
D5
D4
D3
D2
D1
D0
ACKNOWLEDGE FROM MAX7360
S
SLAVE ADDRESS
0
A
COMMAND BYTE
A
DATA BYTE
A
P
N BYTES
R/W
AUTOINCREMENT
COMMAND BYTE ADDRESS
Figure 9. N Data Bytes Received
Table 4. Autoincrement Rules
REGISTER
FUNCTION
ADDRESS
CODE (hex)
AUTOINCREMENT
ADDRESS (hex)
Keys FIFO
0x00
0x00
Autoshutdown
0x06
0x00
All other key switch
0x01 to 0x05
Addr + 0x01
All other GPIO
0x40 to 0x5F
Addr + 0x01
transaction, either read or write, if SCL low exceeds
20ms. After a bus timeout, the MAX7360 waits for a valid
START condition before responding to a consecutive
transmission. This feature can be enabled or disabled
under user control by writing to the configuration register
(Table 8 in the Register Tables section).
Message Format for Writing
the Key-Scan Controller
A write to the MAX7360 comprises the transmission of the
slave address with the R/W bit set to zero, followed by at
least 1 byte of information. The first byte of information
is the command byte. The command byte determines
which register of the MAX7360 is to be written by the next
byte, if received. If a STOP condition is detected after the
command byte is received, the MAX7360 takes no further
action (Figure 7) beyond storing the command byte.
Any bytes received after the command byte are data bytes.
The first data byte goes into the internal register of the
MAX7360 selected by the command byte (Figure 8).
If multiple data bytes are transmitted before a STOP condition
is detected, these bytes are generally stored in subsequent
MAX7360 internal registers, because the command byte
address generally autoincrements (Table 4).
Message Format for Reading
the Key-Scan Controller
The MAX7360 is read using the internally stored
command byte as an address pointer, the same way the
stored command byte is used as an address pointer for
a write. The pointer generally autoincrements after each
data byte is read using the same rules as for a write
(Table 4). Thus, a read is initiated by first configuring
the MAX7360’s command byte by performing a write
(Figure 7). The master can now read n consecutive bytes
from the MAX7360, with the first data byte being read
from the register addressed by the initialized command
byte. When performing read-after-write verification,
remember to reset the command byte’s address,
because the stored command byte address is generally
autoincremented after the write (Figure 9, Table 4).
Operation with Multiple Masters
When the MAX7360 is operated on a 2-wire interface with
multiple masters, a master reading the MAX7360 uses a
repeated start between the write that sets the MAX7360’s
address pointer, and the read(s) that takes the data
from the location(s). This is because it is possible for
master 2 to take over the bus after master 1 has set up
the MAX7360’s address pointer, but before master 1
has read the data. If master 2 subsequently resets the
MAX7360’s address pointer, master 1’s read can be from
an unexpected location.
Command Address Autoincrementing
Address autoincrementing allows the MAX7360 to be
configured with fewer transmissions by minimizing the
number of times the command address needs to be sent.
The command address stored in the MAX7360 generally
increments after each data byte is written or read (Table
4). Autoincrement only works when doing a multiburst
read or write.
Applications Information
Reset from I2C
After a catastrophic event such as ESD discharge or
microcontroller reset, use bit D7 of the configuration
register (0x01) as a software reset for the key-switch
state (the key-switch register values and FIFO remain
unaffected). Use bit D4 of the GPIO global configuration
register (0x40) as a software reset for the GPIOs.
16 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
MAX7360
REGULAR KEYPRESS
EVENT
EXAMPLES OF VALID THREE-KEY COMBINATIONS
GHOST-KEY
EVENT
KEY-SWITCH MATRIX
KEY-SWITCH MATRIX
KEY-SWITCH MATRIX
Figure 11. Valid Three-Key Combinations
Figure 10. Ghost-Key Phenomenon
Ghost-Key Elimination
Ghost keys are a phenomenon inherent with key-switch
matrices. When three switches located at the corners
of a matrix rectangle are pressed simultaneously, the
switch that is located at the last corner of the rectangle
(the ghost key) also appears to be pressed. This occurs
because the potentials at the two sides of the ghost-key
switch are identical due to the other three connections—
the switch is electrically shorted by the combination of
the other three switches (Figure 10). Because the key
appears to be pressed electrically, it is impossible to
detect which of the four keys is the ghost key.
The MAX7360 employs a proprietary scheme that detects
any three-key combination that generates a fourth ghost
key, and does not report the third key that causes a
ghost-key event. This means that although ghost keys
are never reported, many combinations of three keys
are effectively ignored when pressed at the same time.
Applications requiring three-key combinations (such
as <Ctrl><Alt><Del>) must ensure that the three keys
are not wired in positions that define the vertices of a
rectangle (Figure 11). There is no limit on the number of
keys that can be pressed simultaneously as long as the
keys do not generate ghost-key events and FIFO is not full.
Low-EMI Operation
The MAX7360 uses two techniques to minimize EMI
radiating from the key-switch wiring. First, the voltage
across the switch matrix never exceeds +0.55V if not in
sleep mode, independent of supply voltage VCC. This
reduces the voltage swing at any node when a switch
is pressed to +0.55V maximum. Second, the keys are
not dynamically scanned, which would cause the keyswitch wiring to continuously radiate interference.
Instead, the keys are monitored for current draw (only
occurs when pressed), and debounce circuitry only
operates when one or more keys are actually pressed.
Switch On-Resistance
The MAX7360 is designed to be insensitive to resistance,
either in the key switches, or the switch routing to and
from the appropriate COL_ and ROW_ up to 4kI (max).
These controllers are therefore compatible with low-cost
membrane and conductive carbon switches.
Hot Insertion
The INTI, INTK, SCL, and AD0 inputs and SDA remain
high impedance with up to +3.6V asserted on them when
the MAX7360 powers down (VCC = 0). I/O ports (PORT0–
PORT7) remain high impedance with up to +14V asserted
on them when not powered. Use the MAX7360 in hotswap applications.
Staggered PWM
The LED’s on-time in each PWM cycle are phase
delayed 45N into eight evenly spaced start positions.
Optimize phasing when using fewer than eight ports as
constant-current outputs by allocating the ports with the
most appropriate start positions. For example, if using
four constant-current outputs, choose PORT0, PORT2,
PORT4, and PORT6 because their PWM start positions
are evenly spaced. In general, choose the ports that
spread the PWM start positions as evenly as possible.
This optimally spreads out the current demand from the
ports’ load supply.
INTK/INTI
There are two interrupt outputs, INTK and INTI. Each
interrupt operates independently from the other. See
the Key-Switch Interrupt Register (0x03) and the GPIO
Port Interrupts (INTI) sections for additional information
regarding these two interrupts.
Power-Supply Considerations
The MAX7360 operates with a +1.62V to +3.6V powersupply voltage. Bypass the power supply to GND with a
0.1FF or higher ceramic capacitor as close as possible
to the device.
______________________________________________________________________________________ 17
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
ESD Protection
All of the MAX7360 pins meet the 2kV Human Body Model
ESD tolerances. Key-switch inputs and GPIOs meet IEC
61000-4-2 ESD protection. The IEC test stresses consist
of 10 consecutive ESD discharges per polarity, at the
maximum specified level and below (per IEC 61000-4-2).
Test criteria include:
Table 5. ESD Test Levels
1A—CONTACT
DISCHARGE
LEVEL
1B—AIR-GAP DISCHARGE
TEST
VOLTAGE (kV)
LEVEL
TEST
VOLTAGE (kV)
1
2
1
2
1) The powered device does not latch up during the
ESD discharge event.
2
4
2
4
3
6
3
8
2) The device subsequently passes the final test used
for prescreening.
4
8
4
10
X
Special
X
Special
Tables 5 and 6 are from the IEC 61000-4-2: Edition 1.1
1999-05: Electromagnetic compatibility (EMC) Testing
and measurement techniques—Electrostatic discharge
immunity test.
X = Open level. The level has to be specified in the
dedicated equipment specification. If higher voltages
than those shown are specified, special test equipment
could be needed.
Table 6. ESD Waveform Parameters
LEVEL
INDICATED
VOLTGE
(kV)
FIRST PEAK OF
CURRENT
DISCHARGE ±10%
(A)
RISE TIME (tr) WITH
DISCHARGE SWITCH
(ns)
CURRENT (±30%)
AT 30ns
(A)
CURRENT
(±30%) AT 60ns
(A)
1
2
7.5
0.7 to 1
4
2
2
4
15
0.7 to 1
8
4
3
6
22.5
0.7 to 1
12
6
4
8
30
0.7 to 1
16
8
18 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Table 7. Keys FIFO Register Format (0x00)
SPECIAL FUNCTION
KEYS FIFO REGISTER DATA
D7
D6
D5
D4
D3
D2
D1
D0
FIFO
empty
flag
Key
release
flag
X
X
X
X
X
X
FIFO is empty.
0
0
1
1
1
1
1
1
FIFO is overflow. Continue to read data in FIFO.
0
1
1
1
1
1
1
1
Key 63 is pressed. Read one more time to
determine whether there is more data in FIFO.
1
0
1
1
1
1
1
1
Key 63 is released. Read one more time to
determine whether there is more data in FIFO.
1
1
1
1
1
1
1
1
Key repeat. Indicates the last data in FIFO.
0
0
1
1
1
1
1
0
Key repeat. Indicates more data in FIFO.
0
1
1
1
1
1
1
0
Key 62 is pressed. Read one more time to
determine whether there is more data in FIFO.
1
0
1
1
1
1
1
0
Key 62 is released. Read one more time to
determine whether there is more data in FIFO.
1
1
1
1
1
1
1
0
The key number indicated by D5:D0 is a key
event. D7 is always for a key press of key 62
and key 63. When D7 is 0, the key read is the
last data in the FIFO. When D7 is 1, there is
more data in the FIFO. When D6 is 1, key data
read from FIFO is a key release. When D6 is 0,
key data read from FIFO is a key press.
______________________________________________________________________________________ 19
MAX7360
Register Tables
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Table 8. Configuration Register Format (0x01)
REGISTER
BIT
D7
D6
DESCRIPTION
Sleep
FUNCTION
X
(when 0x40
D4 = 1)
Key-switch operating mode. Key switches always remain active
when constant-current PWM is enabled (bit 4 of register 0x40 is
high) regardless of autosleep, autowakeup, or an I2C write to this bit.
0
(when 0x40
D4 = 0)
Key-switch sleep
mode. The entire
chip is shut down.
1
(when 0x40
D4 = 0)
Key-switch operating
mode
Reserved
When constant-current PWM is disabled
(bit 4 of register 0x40 is low), I2C write,
autosleep, and autowakeup all can change
this bit. This bit can be read back by I2C
any time for current status.
0
0
—
0
0
INTK cleared when FIFO is empty
1
INTK cleared after host read. In this mode, I2C should read the
FIFO until interrupt condition is removed or further INT may be lost.
0
0
D5
Interrupt
D4
Reserved
0
—
Key-release
enable
0
Disable key releases
1
Enable key releases
D3
DEFAULT
VALUE
VALUE
1
D2
Reserved
0
—
D1
Autowakeup
enable
0
Disable keypress wakeup
0
1
Enable keypress wakeup
D0
Timeout
disable
0
I2C timeout enabled
1
I2C timeout disabled
1
0
Table 9. Debounce Register Format (0x02)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
Debounce time is 9ms
PORTS ENABLE
X
X
X
Debounce time is 10ms
X
X
X
Debounce time is 11ms
X
X
Debounce time is 12ms
X
X
D4
D3
D2
D1
D0
0
DEBOUNCE TIME
0
0
0
0
0
0
0
0
1
X
0
0
0
1
0
X
0
0
0
1
1
.
.
.
Debounce time is 37ms
X
X
X
1
1
1
0
0
Debounce time is 38ms
X
X
X
1
1
1
0
1
Debounce time is 39ms
X
X
X
1
1
1
1
0
Debounce time is 40ms
X
X
X
1
1
1
1
1
GPO ports disabled (full key-scan functionality)
0
0
0
X
X
X
X
X
GPO port 7 enabled
0
0
1
X
X
X
X
X
GPO ports 7 and 6 enabled
0
1
0
X
X
X
X
X
20 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
PORTS ENABLE
D2
D1
D0
DEBOUNCE TIME
GPO ports 7, 6, and 5 enabled
0
1
1
X
X
X
X
X
GPO ports 7, 6, 5, and 4 enabled
1
0
0
X
X
X
X
X
GPO ports 7, 6, 5, 4, and 3 enabled
1
0
1
X
X
X
X
X
GPO ports 7, 6, 5, 4, 3, and 2 enabled
1
1
X
X
X
X
X
X
Power-up default setting
1
1
1
1
1
1
1
1
D2
D1
D0
Table 10. Key-Switch Interrupt Register Format (0x03)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
INTK used as GPO
FIFO-BASED INTK
0
0
0
FIFO-based INTK disabled
0
0
0
INTK asserts every debounce cycle
0
0
INTK asserts every 2 debounce cycles
0
0
D4
D3
0
TIME-BASED INTK
0
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
Not all zero
.
.
.
INTK asserts every 29 debounce cycles
0
0
0
1
1
1
0
1
INTK asserts every 30 debounce cycles
0
0
0
1
1
1
1
0
INTK asserts every 31 debounce cycles
0
0
0
1
1
1
1
1
0
0
0
0
0
Not all zero
Time-based INTK disabled
INTK asserts when FIFO has 4 key events
0
0
1
0
0
0
0
0
INTK asserts when FIFO has 6 key events
0
1
0
0
0
0
0
0
INTK asserts when FIFO has 8 key events
0
1
1
0
0
0
0
0
1
0
0
0
0
0
0
0
.
.
.
INTK asserts when FIFO has 14 key events
1
Both time-based and FIFO-based interrupts
active
Power-up default setting
1
Not all zero
0
0
Not all zero
0
0
0
0
______________________________________________________________________________________ 21
MAX7360
Table 9. Debounce Register Format (0x02) (continued)
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Table 11. Ports Register Format (0x04)
REGISTER
DESCRIPTION
BIT
VALUE
FUNCTION
0
Clear port 7 low
1
Set port 7 high (high impedance)
0
Clear port 6 low
1
Set port 6 high (high impedance)
D7
PORT 7 Control
D6
PORT 6 Control
D5
PORT 5 Control
D4
PORT 4 Control
D3
PORT 3 Control
D2
PORT 2 Control
D1
INTK Port
Control
0
Clear port INTK low
1
D0
Reserved
0
Set port INTK high (high impedance)
—
0
Clear port 5 low
1
Set port 5 high (high impedance)
0
Clear port 4 low
1
Set port 4 high (high impedance)
0
Clear port 3 low
1
Set port 3 high (high impedance)
0
Clear port 2 low
1
Set port 2 high (high impedance)
22 ��
DEFAULT
VALUE
1
1
1
1
1
1
1
0
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
REGISTER DATA
REGISTER DESCRIPTION
D7
ENABLE
D6
D5
D4
D3
AUTOREPEAT RATE
X
X
D2
D1
D0
AUTOREPEAT DELAY
Autorepeat is disabled
0
X
Autorepeat is enabled
1
X
X
X
X
AUTOREPEAT RATE
Key-switch autorepeat delay is 8 debounce
cycles
1
X
X
X
0
0
0
0
Key-switch autorepeat delay is 16 debounce
cycles
1
X
X
X
0
0
0
1
Key-switch autorepeat delay is 24 debounce
cycles
1
X
X
X
0
0
1
0
AUTOREPEAT DELAY
.
.
.
Key-switch autorepeat delay is 112 debounce
cycles
1
X
X
X
1
1
0
1
Key-switch autorepeat delay is 120 debounce
cycles
1
X
X
X
1
1
1
0
Key-switch autorepeat delay is 128 debounce
cycles
1
X
X
X
1
1
1
1
Key-switch autorepeat frequency is 4
debounce cycles
1
0
0
0
X
X
X
X
Key-switch autorepeat frequency is 8
debounce cycles
1
0
0
1
X
X
X
X
Key-switch autorepeat frequency is 12
debounce cycles
1
0
1
0
X
X
X
X
.
.
.
Key-switch autorepeat frequency is 32
debounce cycles
1
1
1
1
X
X
X
X
Power-up default setting
0
0
0
0
0
0
0
0
______________________________________________________________________________________ 23
MAX7360
Table 12. Autorepeat Register Format (0x05)
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Table 13. Autosleep Register Format (0x06)
REGISTER
REGISTER DATA
RESERVED
AUTOSLEEP REGISTER
AUTOSHUTDOWN TIME
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
0
0
0
0
0
8192
0
0
0
0
0
0
0
1
4096
0
0
0
0
0
0
1
0
2048
0
0
0
0
0
0
1
1
1024
0
0
0
0
0
1
0
0
512
0
0
0
0
0
1
0
1
256
0
0
0
0
0
1
1
0
256
0
0
0
0
0
1
1
1
Power-up default settings
0
0
0
0
0
1
1
1
No Autosleep
Autosleep for (ms)
Table 14. GPIO Global Configuration Register (0x40)
REGISTER
BIT
DESCRIPTION
VALUE
D7
PORT6/PORT7
rotary switch
0
PORT6/PORT7 operate as GPIOs
1
PORT6/PORT7 operate as a rotary switch input
D6
Reserved
0
—
Disabled
D5
I C timeout
interrupt
enable
0
1
INTI is asserted when I2C bus times out. INTI is deasserted when a
read is performed on the I2C timeout flag register (0x48).
0
PWM, constant-current circuits, and GPIs are shut down. GPO
values depend on their setting. Register 0x41 to 0x5F values are
stored and cannot be changed. The entire part is shut down if the
key switches are in sleep mode (D7 of register 0x01).
2
D4
D3
D[2:0]
GPIO enable
GPIO reset
Fade in/out
time
FUNCTION
1
Normal GPIO operation. PWM, constant-current circuits, and GPIOs
are enabled regardless of key-switch sleep mode state (see Table 8).
0
Normal operation
1
Return all GPIO registers (registers 0x40 to 0x5F) to their POR
value. This bit is momentary and resets itself to 0 after the write
cycle.
000
No fading
XXX
PWM intensity ramps up (down) between the common PWM value
and 0% duty cycle in 16 steps over the following time period:
D[2:0] = 001 = 256ms
D[2:0] = 010 = 512ms
D[2:0] = 011 = 1024ms
D[2:0] = 100 = 2048ms
D[2:0] = 101 = 4096ms
D[2:0] = 110/111 = Undefined
24 ��
DEFAULT
VALUE
0
0
0
0
0
000
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
REGISTER
BIT
DESCRIPTION
D7
PORT7
D6
PORT6
D5
PORT5
D4
PORT4
D3
PORT3
D2
PORT2
D1
PORT1
D0
PORT0
VALUE
DEFAULT
VALUE
FUNCTION
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
Port is an input
1
Port is an output
0
0
0
0
0
0
0
0
Table 16. GPIO Debounce Configuration Register (0x42)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
RESERVED
Power-up default setting
debounce time is 9ms
0
0
D2
D1
D0
DEBOUNCE TIME
0
0
0
0
0
0
Debounce time is 10ms
0
0
0
0
0
0
0
1
Debounce time is 11ms
0
0
0
0
0
0
1
0
Debounce time is 12ms
0
0
0
0
0
0
1
1
0
1
1
1
0
0
.
.
.
Debounce time is 37ms
0
0
Debounce time is 38ms
0
0
0
1
1
1
0
1
Debounce time is 39ms
0
0
0
1
1
1
1
0
Debounce time is 40ms
0
0
0
1
1
1
1
1
______________________________________________________________________________________ 25
MAX7360
Table 15. GPIO Control Register (0x41)
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Table 17. GPIO Constant-Current Setting Register (0x43)
REGISTER
BIT
DESCRIPTION
VALUE
D[7:6]
Reserved
11
D[5:2]
Reserved
0000
00
Constant current is 5mA
Constantcurrent setting
01
Constant current is 6.67mA
10
Constant current is 10mA
11
Constant current is 20mA
D[1:0]
DEFAULT
VALUE
FUNCTION
Set always as 11
11
—
0000
00
Table 18. GPIO Output Mode Register (0x44)
REGISTER
BIT
DESCRIPTION
D7
PORT7
D6
PORT6
D5
PORT5
D4
PORT4
D3
PORT3
D2
PORT2
D1
PORT1
D0
PORT0
VALUE
DEFAULT
VALUE
FUNCTION
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
Port is a constant-current open-drain output
1
Port is a non-constant-current open-drain output
0
0
0
0
0
0
0
0
Table 19. Common PWM Register (0x45)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
COMMON PWM
Power-up default setting (common
PWM ratio is 0/256)
0
0
0
0
0
Common PWM ratio is 1/256
0
0
0
0
0
0
0
1
Common PWM ratio is 2/256
0
0
0
0
0
0
1
0
Common PWM ratio is 3/256
0
0
0
0
0
0
1
1
.
.
.
26 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
D2
COMMON PWM
1
1
D1
D0
Common PWM ratio is 252/256
1
1
1
1
0
0
Common PWM ratio is 253/256
1
1
1
1
1
1
0
1
Common PWM ratio is 254/256
1
1
1
1
1
1
1
0
Common PWM ratio is 256/256
(100% duty cycle)
1
1
1
1
1
1
1
1
D1
D0
Table 20. Rotary Switch Configuration Register (0x46)
REGISTER DATA
REGISTER DESCRIPTION
No debounce time
Debounce time is 1ms
Debounce time is 2ms
Debounce time is 3ms
D7
INT
TYPE
X
X
X
X
D6
D5
D4
D3
COUNTS/CYCLES
X
X
X
X
D2
DEBOUNCE CYCLE TIME
X
X
X
X
X
X
X
X
0
0
0
0
0
0
0
0
0
0
1
1
0
1
0
1
.
.
.
Debounce time is 15ms
X
X
X
X
1
1
1
1
No interrupt generated by rotary switch
X
0
0
0
0
0
0
0
0
0
1
1
0
1
0
1
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
1
1
X
X
X
X
INTI asserted when rotary switch count = ±1
INTI asserted when rotary switch count = ±2
INTI asserted when rotary switch count = ±3
.
.
.
INTI asserted when rotary switch count = ±7
0
1
INTI asserted 25ms after first debounced event
1
0
0
1
X
X
X
X
INTI asserted 50ms after first debounced event
1
0
1
0
X
X
X
X
INTI asserted 75ms after first debounced event
1
0
1
1
X
X
X
X
.
.
.
INTI asserted 175ms after first debounced event
1
1
1
1
X
X
X
X
Power-up default setting
0
0
0
0
0
0
0
0
______________________________________________________________________________________ 27
MAX7360
Table 19. Common PWM Register (0x45) (continued)
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Table 21. I2C Timeout Flag Register (0x48) (Read Only)
REGISTER
BIT
DESCRIPTION
VALUE
D[7:1]
Reserved
0000000
D0
I2C timeout flag
DEFAULT
VALUE
FUNCTION
—
0000000
0
No I2C timeout has occurred since last read or POR
1
I2C timeout has occurred since last read or POR. This bit is reset to
zero when a read is performed on this register. I2C timeouts must
be enabled for this function to work (see Table 8).
0
Table 22. GPIO Input Register (0x49) (Read Only)
REGISTER
BIT
DESCRIPTION
D7
PORT7
D6
PORT6
D5
PORT5
D4
PORT4
D3
PORT3
D2
PORT2
D1
PORT1
D0
PORT0
VALUE
DEFAULT
VALUE
FUNCTION
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
0
Port is input low
1
Port is input high
1
1
1
1
1
1
1
1
Table 23. Rotary Switch Count Register (0x4A) (Read Only)
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
D2
D1
D0
X
X
X
CYCLE COUNT
Cycle count in two’s complement (see the
Rotary Switch Configuration Register (0x46)
section)
X
X
X
X
X
28 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
REGISTER DATA
REGISTER DESCRIPTION
D7
D6
D5
D4
D3
D2
D1
D0
0
0
0
PORT PWM
Power-up default setting (port PWM ratio is
0/256)
0
0
0
0
0
PORT PWM ratio is 1/256
0
0
0
0
0
0
0
1
PORT PWM ratio is 2/256
0
0
0
0
0
0
1
0
PORT PWM ratio is 3/256
0
0
0
0
0
0
1
1
.
.
.
PORT PWM ratio is 252/256
1
1
1
1
1
1
0
0
PORT PWM ratio is 253/256
1
1
1
1
1
1
0
1
PORT PWM ratio is 254/256
1
1
1
1
1
1
1
0
PORT PWM ratio is 256/256 (100% duty cycle)
1
1
1
1
1
1
1
1
Table 25. PORT0–PORT7 Configuration Registers (0x58 to 0x5F)
REGISTER
BIT
DESCRIPTION
D7
Interrupt mask
D6
Edge/level
detect
D5
D[4:2]
Common PWM
Blink period
VALUE
0
Interrupt is not masked
1
Interrupt is masked. PORT7 interrupt mask is ignored when the
device is configured for rotary switch input.
0
Rising edge-triggered
interrupts
1
Rising or falling edgetriggered interrupts
0
Port uses individual PWM intensity register to set the PWM ratio
1
Port uses common PWM intensity register to set the PWM ratio
Blink-on time
Interrupts only occur when the GPIO
port is configured as an input
000
Port does not blink
001
Port blink period is 256ms
010
Port blink period is 512ms
011
Port blink period is 1024ms
100
Port blink period is 2048ms
101
Port blink period is 4096ms
110/111
D[1:0]
FUNCTION
DEFAULT
VALUE
0
0
0
000
Undefined
00
LED is on for 50% of the blink period
01
LED is on for 25% of the blink period
10
LED is on for 12.5% of the blink period
11
LED is on for 6.25% of the blink period
00
______________________________________________________________________________________ 29
MAX7360
Table 24. PORT0–PORT7 Individual PWM Ratio Registers (0x50 to 0x57)
Pin Configurations
TOP VIEW
BUMPS IN BOTTOM
MAX7360
I.C.
PORT1
PORT3
PORT4
PORT6
ROW0
A1
A2
A3
A4
A5
A6
AD0
PORT0
PORT2
GND
PORT7
ROW1
B1
B2
B3
B4
B5
B6
VCC
N.C.
PORT5
ROW2
GND
ROW3
C1
C2
C3
C4
C5
C6
INTI
GND
INTK
ROW7
ROW5
ROW4
D1
D2
D3
D4
D5
D6
SCL
SDA
COL5
GND
COL1
ROW6
E1
E2
E3
E4
E5
E6
COL7
COL6
COL4
COL3
COL2
COL0
F1
F2
F3
F4
F5
F6
SDA
SCL
INTK
INTI
GND
VCC
N.C.
AD0
TOP VIEW
I.C.
N.C.
WLP
(2.67mm x 2.67mm)
30 29 28 27 26 25 24 23 22 21
PORT0 31
20 N.C.
PORT1 32
19 COL7
PORT2 33
18 COL6
PORT3 34
17 COL5
16 COL4
GND 35
MAX7360
PORT4 36
15 GND
14 COL3
PORT5 37
13 COL2
PORT6 38
EP*
PORT7 39
6
7
8
9
10
ROW7
N.C.
ROW3
5
ROW6
4
ROW5
3
ROW4
2
GND
1
ROW2
11 COL0
ROW1
N.C. 40
12 COL1
+
ROW0
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
TQFN
*EP = EXPOSED PAD, CONNECT EP TO GROUND.
30 ��
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
+3.3V
+14V
+14V
+1.8V
COL7
VCC
COL6
PORT0
COL5
PORT1
COL4
PORT2
MAX7360
KEY 0
KEY 8
KEY 16
KEY 24
KEY 32
KEY 40
KEY 1
KEY 9
KEY 17
KEY 25
KEY 33
KEY 41
KEY 2
KEY 10
KEY 18
KEY 26
KEY 34
KEY 42
KEY 3
KEY 11
KEY 19
KEY 27
KEY 35
KEY 43
KEY 4
KEY 12
KEY 20
KEY 28
KEY 36
KEY 44
KEY 5
KEY 13
KEY 21
KEY 29
KEY 37
KEY 45
KEY 6
KEY 14
KEY 22
KEY 30
KEY 38
KEY 46
KEY 7
KEY 15
KEY 23
KEY 31
KEY 39
KEY 47
COL3
PORT3
COL2
PORT4
COL1
PORT5
COL0
PORT6
ROW7
PORT7
ROW6
+3.3V
ROW5
VCC
µC
GND
SDA
SDA
ROW4
SCL
SCL
ROW3
INTI
INTI
ROW2
INTK
INTK
ROW1
AD0
GND
ROW0
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages.
Package TYPE
Package CODE
DOCUMENT NO.
40 TQFN-EP
T4055+1
21-0140
36 WLP
W362A2+1
21-0301
______________________________________________________________________________________ 31
MAX7360
Typical Application Circuit
MAX7360
I2C-Interfaced Key-Switch Controller and LED
Driver/GPIOs with Integrated ESD Protection
Revision History
REVISION REVISION
NUMBER
DATE
0
1
DESCRIPTION
4/09
Initial release
6/10
Updated Absolute Maxim Ratings and Notes 7 and 8 (now Notes 6 and 7) in
Electrical Characteristics
PAGES
CHANGED
—
2, 3, 4
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time.
32
© 2010
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.

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