MAX7316AEE+T ,10-Port I/O Expander with LED Intensity Control, Interrupt, and Hot-Insertion ProtectionFeatures2The MAX7316 I C/SMBus™-compatible serial interfaced♦ 400kbps, 2-Wire Serial Interface, 5.5 ..
MAX7316ATE+ ,10-Port I/O Expander with LED Intensity Control, Interrupt, and Hot-Insertion ProtectionApplications0.047μFLCD Backlights Keypad BacklightsV+LED Status Indication RGB LED Drivers P0μCP1Re ..
MAX7317AEE+ ,10-Port SPI-Interfaced I/O Expander with Overvoltage and Hot-Insertion ProtectionFeaturesThe MAX7317 serial-interfaced peripheral provides ● Industry-Standard 4-Wire Interface Sim ..
MAX7317AEE+ ,10-Port SPI-Interfaced I/O Expander with Overvoltage and Hot-Insertion ProtectionElectrical Characteristics(Typical Operating Circuit, V+ = 2.25V to 3.6V, T = T to T , unless other ..
MAX7317AEE+T ,10-Port SPI-Interfaced I/O Expander with Overvoltage and Hot-Insertion ProtectionMAX7317 10-Port SPI-Interfaced I/O Expander with Overvoltage and Hot-Insertion Protection
MAX7317ATE+ ,10-Port SPI-Interfaced I/O Expander with Overvoltage and Hot-Insertion ProtectionGeneral Description Beneits and
MB508 , TECHNICAL SPECIFICATIONS OF SINGLE-PHASE SILICON BRIDGE RECTIFIER
MB510 ,2.7GHz TWO MODULUS PRESCALERFEATURES High Frequency Operation: 2.7GHz max. Power Dissipation: 50mW typ. Pulse Swallow Functi ..
MB511 , 1GHz HIGH SPEED PRESCALER
MB511 , 1GHz HIGH SPEED PRESCALER
MB511 , 1GHz HIGH SPEED PRESCALER
MB54502PFV ,Low noise amplifier (2 circuits)applications such as handy phones and car phones. Both of the amplifiers achieve low current consu ..
MAX7316AEE+T-MAX7316ATE+
10-Port I/O Expander with LED Intensity Control, Interrupt, and Hot-Insertion Protection
General DescriptionThe MAX7316 I2C/SMBus™-compatible serial interfaced
peripheral provides microprocessors with eight additional
I/O ports plus one output-only port and one input-only
port. Each I/O port can be individually configured as
either an open-drain current-sinking output rated to 50mA
at 5.5V or as a logic input with transition detection. The
output-only port can also be assigned as an interrupt out-
put for transition detection. The outputs are capable of
driving LEDs, or can provide logic outputs with external
resistive pullup up to 5.5V.
Eight-bit PWM current control is available for all nine out-
put ports. Four bits are global control and apply to all LED
outputs to provide coarse adjustment of current from fully
off to fully on in 14 intensity steps. Additionally each out-
put then has individual 4-bit control, which further divides
the globally set current into 16 more steps. Alternatively,
the current control can be configured as a single 8-bit
control that sets all outputs at once.
Each output has independent blink timing with two blink
phases. LEDs can be individually set to be on or off dur-
ing either blink phase or to ignore the blink control. The
blink period is controlled by an external clock input (up to
1kHz) on BLINK or by a register. The BLINK input can
also be used as a logic control to turn the LEDs on and
off, or as a general-purpose input.
The MAX7316 supports hot insertion. All port pins, the
INToutput, SDA, SCL, RST, BLINK, and the slave
address input ADO remain high impedance in power-
down (V+ = 0V) with up to 6V asserted upon them.
The MAX7316 is controlled through a 2-wire serial inter-
face, and can be set to one of four I2C addresses.
Applications
Features400kbps, 2-Wire Serial Interface, 5.5V Tolerant2V to 3.6V OperationOverall 8-Bit PWM LED Intensity Control
Global 16-Step Intensity Control
Plus Individual 16-Step Intensity Controls2-Phase LED BlinkingHigh Output Current (50mA max per Port)Supports Hot InsertionOutputs are 5.5V-Rated Open DrainInputs are Overvoltage Protected to 5.5VTransition Detection with Interrupt OutputRST
Input Clears Serial Interface and Restores
Power-Up Default StateLow Standby Current (1.2µA (typ), 3.3µA (max))Small 3mm x 3mm, Thin QFN Package-40°C to +125°C Temperature Range
MAX7316
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection11109
INT/O8P7P6
GND
RST
BLINK34
AD0P1P2
SDA
SCL
THIN QFNTOP VIEW
MAX7316ATE
Pin ConfigurationsMAX7316
3.3V
SDASDA
AD0
SCLSCL
BLINKI/O
RSTI/O
OUTPUT 1
GND
INPUT 1
INPUT 2
INPUT 3
0.047μF
INTINT/O8
Typical Application Circuit19-3055; Rev 3; 1/05
Ordering Information
PARTTEMP
RANGE
PIN-
PACKAGE
TOP
MARK
PKG
CODEMAX7316ATE-40°C to +125°C
16 Thin QFN
3mm x 3mm
x 0.8mm
AAVT1633-4
MAX7316AEE-40°C to +125°C16 QSOP——
LCD Backlights
LED Status Indication
Relay Drivers
Keypad Backlights
RGB LED Drivers
System I/O Ports
SMBus is a trademark of Intel Corp.,
MAX7316
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
ABSOLUTE MAXIMUM RATINGSStresses 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.
Voltage (with respect to GND)
V+.............................................................................-0.3V to +4V
SCL, SDA, AD0, BLINK, RST, P0–P7.......................-0.3V to +6V
INT/O8......................................................................-0.3V to +8V
DC Current on P0–P7, INT/O8............................................55mA
DC Current on SDA.............................................................10mA
Maximum GND Current....................................................190mA
Continuous Power Dissipation (TA= +70°C)
16-Pin QSOP (derate 8.3mW/°C over +70°C)..............667mW
16-Pin QFN (derate 14.7mW/°C over +70°C)............1177mW
Operating Temperature Range (TMINto TMAX)-40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
ELECTRICAL CHARACTERISTICS(Typical Operating Circuit, V+ = 2V to 3.6V, TA= TMINto TMAX, unless otherwise noted. Typical values are at V+ = 3.3V, TA = +25°C.)
(Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSOperating Supply VoltageV+2.03.6V
Output Load External Supply
VoltageVEXT05.5V
TA = +25°C1.22.3
TA = -40°C to +85°C2.6Standby Current
(Interface Idle, PWM Disabled)I+C L and S D A at V + ; other i g i tal i np uts at V + or GN D ;WM i ntensi ty contr ol d i sab l ed TA = TMIN to TMAX3.3
TA = +25°C712.1
TA = -40°C to +85°C13.3Supply Current
(Interface Idle, PWM Enabled)I+C L and S D A at V + ; other i g i tal i np uts at V + or GN D ;WM i ntensi ty contr ol enab l ed TA = TMIN to TMAX14.4
TA = +25°C4076
TA = -40°C to +85°C78
Supply Current
(Interface Running, PWM
Disabled)
fSCL = 400kHz; other digital
inputs at V+ or GND; PWM
intensity control disabledTA = TMIN to TMAX80
TA = +25°C51110
TA = -40°C to +85°C117
Supply Current
(Interface Running, PWM
Enabled)
fSCL = 400kHz; other digital
inputs at V+ or GND; PWM
intensity control enabledTA = TMIN to TMAX122
Input High Voltage
SDA, SCL, AD0, BLINK, P0–P7VIH0.7 xV
Input Low Voltage
SDA, SCL, AD0, BLINK, P0–P7VIL0.3 xV
Input Leakage Current
SDA, SCL, AD0, BLINK, P0–P7IIH, IILInput = GND or V+-0.2+0.2µA
Input Capacitance
SDA, SCL, AD0, BLINK, P0–P78pF
MAX7316
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
ELECTRICAL CHARACTERISTICS (continued)(Typical Operating Circuit, V+ = 2V to 3.6V, TA= TMINto TMAX, unless otherwise noted. Typical values are at V+ = 3.3V, TA= + 25°C.)
(Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSTA = +25°C0.150.25
TA = -40°C to +85°C0.29V+ = 2V, ISINK = 20mA
TA = TMIN to TMAX0.31
TA = +25°C0.130.22
TA = -40°C to +85°C0.25V+ = 2.5V, ISINK = 20mA
TA = TMIN to TMAX0.27
TA = +25°C0.120.22
TA = -40°C to +85°C0.23
Output Low Voltage
P0–P7, INT/O8VOL
V+ = 3.3V, ISINK = 20mA
TA = TMIN to TMAX0.25
Output Low-Voltage SDAVOLSDAISINK = 6mA0.4V
PWM Clock FrequencyfPWM32kHz
TIMING CHARACTERISTICS(Typical Operating Circuit, V+ = 2V to 3.6V, TA= TMINto TMAX, unless otherwise noted. Typical values are at V+ = 3.3V, TA = +25°C.)
(Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSSerial Clock FrequencyfSCL400kHz
Bus Free Time Between a STOP and a START
ConditiontBUF1.3µs
Hold Time, Repeated START ConditiontHD, STA0.6µs
Repeated START Condition Setup TimetSU, STA0.6µs
STOP Condition Setup TimetSU, STO0.6µs
Data Hold TimetHD, DAT(Note 2)0.9µs
Data Setup TimetSU, DAT180ns
SCL Clock Low PeriodtLOW1.3µs
SCL Clock High PeriodtHIGH0.7µs
Rise Time of Both SDA and SCL Signals, ReceivingtR(Notes 3, 4)20 +
0.1Cb300ns
Fall Time of Both SDA and SCL Signals, ReceivingtF(Notes 3, 4)20 +
0.1Cb300ns
Fall Time of SDA TransmittingtF.TX(Notes 3, 5)20 +
0.1Cb250ns
Pulse Width of Spike SuppressedtSP(Note 6)50ns
Capacitive Load for Each Bus LineCb(Note 3)400pF
RST Pulse WidthtW1µs
MAX7316
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
TIMING CHARACTERISTICS (continued)(Typical Operating Circuit, V+ = 2V to 3.6V, TA= TMINto TMAX, unless otherwise noted. Typical values are at V+ = 3.3V, TA = +25°C.)
(Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSInterrupt ValidtIVFigure 106.5µs
Interrupt ResettIRFigure 101.0µs
Output Data ValidtDVFigure 105.0µs
Input Data Setup TimetDSFigure 10100ns
Input Data Hold TimetDHFigure 101µs
Note 1:All parameters tested at TA= +25°C. Specifications over temperature are guaranteed by design.
Note 2:A master device must provide a hold time of at least 300ns for the SDA signal (referred to VILof the SCL signal) to bridge
the undefined region of SCL’s falling edge.
Note 3:Guaranteed by design.
Note 4:Cb= total capacitance of one bus line in pF. tRand tFmeasured between 0.3 x VDDand 0.7 x VDD.
Note 5:ISINK≤6mA. Cb= total capacitance of one bus line in pF. tRand tFmeasured between 0.3 x VDDand 0.7 x VDD.
Note 6:Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns.
STANDBY CURRENT vs. TEMPERATUREMAX7316 toc01
TEMPERATURE (°C)
STANDBY CURRENT (
V+ = 3.6V
PWM ENABLED
V+ = 2.7V
PWM ENABLED
V+ = 2V
PWM DISABLED
V+ = 2.7V
PWM DISABLED
V+ = 3.6V
PWM
DISABLED
V+ = 2V
PWM ENABLED
SUPPLY CURRENT vs. TEMPERATURE
(PWM DISABLED; fSCL = 400kHz)MAX7316 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (
V+ = 3.6V
V+ = 2.7V
V+ = 2V
SUPPLY CURRENT vs. TEMPERATURE
(PWM ENABLED; fSCL = 400kHz)MAX7316 toc03
TEMPERATURE (°C)
SUPPLY CURRENT (
V+ = 3.6V
V+ = 2.7V
V+ = 2V
__________________________________________Typical Operating Characteristics(TA = +25°C, unless otherwise noted.)
MAX7316
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
PORT OUTPUT LOW VOLTAGE WITH 50mA
LOAD CURRENT vs. TEMPERATUREPORT OUTPUT LOW VOLTAGE V
(V)
MAX7316 toc04
TEMPERATURE (°C)
V+ = 3.6V
V+ = 2.7V
V+ = 2V
PORT OUTPUT LOW VOLTAGE WITH 20mA
LOAD CURRENT vs. TEMPERATUREMAX7316 toc05
TEMPERATURE (°C)
PORT OUTPUT LOW VOLTAGE V
(V)
ALL OUTPUTS LOADED
V+ = 3.6VV+ = 2.7V
V+ = 2V
PWM CLOCK FREQUENCY
vs. TEMPERATUREMAX7316 toc06
TEMPERATURE (°C)
PWM CLOCK FREQUENCY
V+ = 3.6V
V+ = 2VV+ = 2.7V
NORMALIZED TO V+ = 3.3V, TA = 25°C
SCOPE SHOT OF 2 OUTPUT PORTS MAX7316 toc07
2ms/div
OUTPUT 1
2V/div
OUTPUT 2
2V/div
MASTER INTENSITY SET TO 1/15
OUTPUT 1 INDIVIDUAL INTENSITY
SET TO 1/16
OUTPUT 2 INDIVIDUAL INTENSITY
SET TO 15/16
SCOPE SHOT OF 2 OUTPUT PORTSMAX7316 toc08
2ms/div
OUTPUT 1
2V/div
OUTPUT 2
2V/div
OUTPUT 1 INDIVIDUAL INTENSITY
SET TO 1/16
MASTER INTENSITY SET TO 14/15
OUTPUT 2 INDIVIDUAL INTENSITY
SET TO 14/15
SINK CURRENT vs. VOLMAX7316 toc09
SINK CURRENT (mA)
(V)40302010
V+ = 2V
V+ = 2.7V
ONLY ONE OUTPUT LOADED
V+ = 3.3V
V+ = 3.6V
Typical Operating Characteristics (continued)(TA = +25°C, unless otherwise noted.)
MAX7316
Functional OverviewThe MAX7316 is a general-purpose input/output (GPIO)
peripheral that provides eight I/O ports, P0–P7, con-
trolled through an I2C-compatible serial interface. A 9th
output-only port, INT/O8, can be configured as an inter-
rupt output or as a general-purpose output port. All out-
put ports sink loads up to 50mA connected to external
supplies up to 5.5V, independent of the MAX7316’s
supply voltage. The MAX7316 is rated for a ground cur-
rent of 190mA, allowing all nine outputs to sink 20mA at
the same time. Figure 1 shows the output structure of
the MAX7316. The ports default to inputs on power-up.
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
Pin DescriptionFigure 1. Simplified Schematic of I/O Ports
DATA FROM
SHIFT REGISTER
DATA FROM
SHIFT REGISTER
WRITE
CONFIGURATION
PULSE
WRITE PULSE
READ PULSE
CONFIGURATION
REGISTER
INPUT PORT
REGISTER
OUTPUT
PORT
REGISTER
OUTPUT PORT
REGISTER DATA
I/O PIN
GND
INPUT PORT
REGISTER DATA
TO INT
PIN
QSOPQFNNAMEFUNCTION15BLINKInput Port Configurable as Blink Control or General-Purpose Input
216RSTReset Input. Active low clears the 2-wire interface and puts the device in the
same condition as power-up reset.1AD0Address Input. Sets device slave address. Connect to either GND, V+, SCL,
or SDA to give four logic combinations. See Table 1.
4–7, 9–122–5, 7–10P0–P7Input/Output Ports. P0–P7 are open-drain I/Os rated at 5.5V, 50mA.6GNDGround. Do not sink more than 190mA into the GND pin.11INT/O8Output Port. Open-drain output rated at 7V, 50mA. Configurable as interrupt
output or general-purpose output.12SCLI2C-Compatible Serial Clock Input13SDAI2C-Compatible Serial Data I/O14V+Positive Supply Voltage. Bypass V+ to GND with a 0.047µF ceramic
capacitor.PADExposed padExposed Pad on Package Underside. Connect to GND.
Port Inputs and Transition DetectionThe input ports register reflects the incoming logic lev-
els of the port pins, regardless of whether the pin is
defined as an input or an output. Reading the input
ports register latches the current-input logic level of the
affected eight ports. Transition detection allows all
ports configured as inputs to be monitored for changes
in their logic status. The action of reading the input
ports register samples the corresponding 8 port bits’
input condition. This sample is continuously compared
with the actual input conditions. A detected change in
input condition causes the INT/O8 interrupt output to go
low, if configured as an interrupt output. The interrupt is
cleared either automatically if the changed input
returns to its original state, or when the input ports reg-
ister is read.
The INT/O8 pin can be configured as either an interrupt
output or as a 9th output port with the same static or
blink controls as the other eight ports (Table 4).
Port Output Control and LED BlinkingThe blink phase 0 register sets the output logic levels of
the eight ports P0–P7 (Table 8). This register controls
the port outputs if the blink function is disabled. A
duplicate register, the blink phase 1 register, is also
used if the blink function is enabled (Table 9). In blink
mode, the port outputs can be flipped between using
the blink phase 0 register and the blink phase 1 regis-
ter using hardware control (the BLINK input) and/or
software control (the blink flip flag in the configuration
register) (Table 4).
The logic level of the BLINK input can be read back
through the blink status bit in the configuration register
(Table 4). The BLINK input, therefore, can be used as a
general-purpose logic input (GPI port) if the blink func-
tion is not required.
PWM Intensity ControlThe MAX7316 includes an internal oscillator, nominally
32kHz, to generate PWM timing for LED intensity control.
PWM intensity control can be enabled on an output-by-
output basis, allowing the MAX7316 to provide any mix
of PWM LED drives and glitch-free logic outputs (Table
10). PWM can be disabled entirely, in which case all out-
put ports are static and the MAX7316 operating current
is lowest because the internal oscillator is turned off.
PWM intensity control uses a 4-bit master control and 4
bits of individual control per output (Tables 13, 14). The
4-bit master control provides 16 levels of overall intensi-
ty control, which applies to all PWM-enabled output
ports. The master control sets the maximum pulse
width from 1/15 to 15/15 of the PWM time period. The
individual settings comprise a 4-bit number further
reducing the duty cycle to be from 1/16 to 15/16 of the
time window set by the master control.
For applications requiring the same PWM setting for all
output ports, a single global PWM control can be used
instead of all the individual controls to simplify the con-
trol software and provide 240 steps of intensity control
(Tables 10 and 13).
Standby ModeWhen the serial interface is idle and the PWM intensity
control is unused, the MAX7316 automatically enters
standby mode. If the PWM intensity control is used, the
operating current is slightly higher because the internal
PWM oscillator is running. When the serial interface is
active, the operating current also increases because
the MAX7316, like all I2C slaves, has to monitor every
transmission.
MAX7316
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion ProtectionSCL
SDA tF
tBUF
START
CONDITION
STOP
CONDITION
REPEATED START CONDITION START CONDITION
tSU,STO
tHD,STA
tSU,STA
tHD,DAT
tSU,DAT tLOW
tHIGH
tHD,STA
MAX7316
Serial Interface
Serial AddressingThe MAX7316 operates as a slave that sends and
receives data through an I2C-compatible 2-wire inter-
face. The interface uses a serial data line (SDA) and a
serial clock line (SCL) to achieve bidirectional commu-
nication between master(s) and slave(s). A master (typ-
ically a microcontroller) initiates all data transfers to and
from the MAX7316 and generates the SCL clock that
synchronizes the data transfer (Figure 2).
The MAX7316 SDA line operates as both an input and
an open-drain output. A pullup resistor, typically 4.7kΩ,
is required on SDA. The MAX7316 SCL line operates
only as an input. A pullup resistor, typically 4.7kΩ, 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 condition
(Figure 3) sent by a master, followed by the MAX7316
7-bit slave address plus R/Wbit, a register address
byte, one or more data bytes, and finally a STOP condi-
tion (Figure 3).
Start and Stop ConditionsBoth SCL and SDA remain high when the interface is
not busy. A master signals the beginning of a transmis-
sion with a START (S) 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 (P) condition by transitioning SDA from low to
high while SCL is high. The bus is then free for another
transmission (Figure 3).
Bit TransferOne data bit is transferred during each clock pulse.
The data on SDA must remain stable while SCL is high
(Figure 4).
AcknowledgeThe acknowledge bit is a clocked 9th bit that the recipi-
ent uses to handshake receipt of each byte of data
(Figure 5). 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 so the SDA line is stable low
during the high period of the clock pulse. When the
master is transmitting to the MAX7316, the device gen-
erates the acknowledge bit because the MAX7316 is
the recipient. When the MAX7316 is transmitting to the
master, the master generates the acknowledge bit
because the master is the recipient.
Slave AddressThe MAX7316 has a 7-bit long slave address (Figure 6).
The eighth bit following the 7-bit slave address is the
R/Wbit. The R/Wbit is low for a write command, high
for a read command.
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion ProtectionFigure 3. Start and Stop Conditions
SDA
SCL
START
CONDITION
STOP
CONDITION
Figure 4. Bit Transfer
SDA
SCL
DATA LINE STABLE;
DATA VALID
CHANGE OF DATA
ALLOWED
Figure 5. Acknowledge
SCL
SDA BY
TRANSMITTER
CLOCK PULSE
FOR ACKNOWLEDGESTART
CONDITION
SDA BY
RECEIVER89
SDA
SCL
MSBLSB
ACK00A600A2R/W
The second (A5), third (A4), fourth (A3), sixth (A1), and
last (A0) bits of the MAX7316 slave address are always
1, 0, 0, 0, and 0. Slave address bits A6 and A2 are
selected by the address input AD0. AD0 can be con-
nected to GND, V+, SDA, or SCL. The MAX7316 has four
possible slave addresses (Table 1), and therefore a
maximum of four MAX7316 devices can be controlled
independently from the same interface.
Message Format for Writing the MAX7316A write to the MAX7316 comprises the transmission of
the MAX7316’s slave address with the R/Wbit set to
zero, followed by at least 1 byte of information. The first
byte of information is the command byte. The com-
mand byte determines which register of the MAX7316
is to be written to by the next byte, if received (Table 2).
If a STOP condition is detected after the command byte
is received, then the MAX7316 takes no further action
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 MAX7316 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 MAX7316 internal registers because the
command byte address autoincrements (Table 2). A
diagram of a write to the output ports registers (blink
phase 0 register or blink phase 1 register) is given in
Figure 10.
MAX7316
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
Table 1. MAX7316 I2C Slave Address Map
DEVICE ADDRESSPIN AD0A6A5A4A3A2A1A0SCL1100000
SDA1100100
GND01000000100100
Figure 8. Command and Single Data Byte ReceivedAAP0SLAVE ADDRESSCOMMAND BYTEDATA BYTE
BYTE
AUTOINCREMENT MEMORY ADDRESS
D15D14D13D12D11D10D9D8D1D0D3D2D5D4D7D6
ACKNOWLEDGE FROM MAX7316ACKNOWLEDGE FROM MAX7316
ACKNOWLEDGE FROM MAX7316
HOW COMMAND BYTE AND DATA BYTE MAP INTO
MAX7316'S REGISTERS
R/WAAP0SLAVE ADDRESSCOMMAND BYTEDATA BYTE
BYTES
AUTOINCREMENT MEMORY ADDRESS
D15D14D13D12D11D10D9D8D1D0D3D2D5D4D7D6
ACKNOWLEDGE FROM MAX7316ACKNOWLEDGE FROM MAX7316
ACKNOWLEDGE FROM MAX7316
HOW COMMAND BYTE AND DATA BYTE MAP INTO
MAX7316'S REGISTERS
R/W
Figure 7. Command Byte ReceivedAP0SLAVE ADDRESSCOMMAND BYTE
ACKNOWLEDGE FROM MAX7316
D15D14D13D12D11D10D9D8COMMAND BYTE IS STORED ON RECEIPT OF
STOP CONDITION
ACKNOWLEDGE FROM MAX7316R/W
MAX7316
Message Format for ReadingThe MAX7316 is read using the MAX7316’s 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 autoincrements after
each data byte is read using the same rules as for a
write (Table 2). Thus, a read is initiated by first configur-
ing the MAX7316’s command byte by performing a
write (Figure 7). The master can now read n consecu-
tive bytes from the MAX7316 with the first data byte
being read from the register addressed by the initial-
ized command byte. When performing read-after-write
verification, remember to reset the command byte’s
address because the stored command byte address
has been autoincremented after the write (Table 2). A
diagram of a read from the input ports register is shown
in Figure 10 reflecting the states of the ports.
Operation with Multiple MastersIf the MAX7316 is operated on a 2-wire interface with
multiple masters, a master reading the MAX7316 should
use a repeated start between the write, which sets the
MAX7316’s address pointer, and the read(s) that takes
the data from the location(s) (Table 2). This is because it
is possible for master 2 to take over the bus after master
1 has set up the MAX7316’s address pointer but before
master 1 has read the data. If master 2 subsequently
changes the MAX7316’s address pointer, then master
1’s delayed read can be from an unexpected location.
Command Address AutoincrementingThe command address stored in the MAX7316 circu-
lates around grouped register functions after each data
byte is written or read (Table 2).
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion ProtectionFigure 10. Read, Write, and Interrupt Timing Diagrams
SLAVE ADDRESS23456789A6A5A4A3A2A1A00A0000000
COMMAND BYTEAAP
START CONDITIONACKNOWLEDGE FROM SLAVEACKNOWLEDGE FROM SLAVEACKNOWLEDGE FROM SLAVESTOP
CONDITION
P7–P0DATA1 VALIDDATA2 VALID
SLAVE ADDRESS23456789A6A5A4A3A2A1A01A
COMMAND BYTE
ANA
START CONDITIONACKNOWLEDGE FROM SLAVEACKNOWLEDGE FROM MASTER
P7–P0
STOP CONDITION
NO ACKNOWLEDGE FROM
MASTER
DATA2DATA3
tDVtDV
SLAVE ADDRESS23456789A6A5A4A3A2A1A01A
COMMAND BYTE
ANA
START CONDITIONACKNOWLEDGE FROM SLAVEACKNOWLEDGE FROM MASTER
P7–P0
STOP CONDITION
NO ACKNOWLEDGE FROM
MASTER
DATA1DATA2DATA3DATA4
tDHtDS
DATA1
tIVtIRtIRtIV
SCL
SDA
SCL
SDA
SCL
SDA
WRITE TO OUTPUT PORTS REGISTERS (BLINK PHASE 0 REGISTERS/BLINK PHASE 1 REGISTERS)
READ FROM INPUT PORTS REGISTERS
INTERRUPT VALID/RESETR/W
MSBLSBDATA1
MSBLSBDATA1
MSBLSBDATA2MSBLSBDATA4
MSBLSBDATA4
MSBLSBDATA2
R/W
R/W
INT
Device ResetThe reset input RSTis an active-low input. When taken
low, RSTclears any transaction to or from the MAX7316
on the serial interface and configures the internal regis-
ters to the same state as a power-up reset (Table 3).
The MAX7316 then waits for a START condition on the
serial interface.
Detailed Description
Initial Power-UpOn power-up, and whenever the RSTinput is pulled
low, all control registers are reset and the MAX7316
enters standby mode (Table 3). Power-up status makes
all ports into inputs and disables both the PWM oscilla-
tor and blink functionality. RSTcan be used as a hard-
ware shutdown input, which effectively turns off any
LED (or other) loads and puts the device into its lowest
power condition.
Configuration RegisterThe configuration register is used to configure the PWM
intensity mode, interrupt, and blink behavior, operate
the INT/O8 output, and read back the interrupt status
(Table 4).
Ports ConfigurationThe eight I/O ports P0 through P7 can be configured to
any combination of inputs and outputs using the ports
configuration register (Table 5). The INT/O8 output can
also be configured as an extra general-purpose output,
and the BLINK input can be configured as an extra
general-purpose input using the configuration register
(Table 4).
Input PortsThe input ports register is read only (Table 6). It reflects
the incoming logic levels of the ports, regardless of
whether the port is defined as an input or an output by the
ports configuration registers. Reading the input ports reg-
ister latches the current-input logic level of the affected
eight ports. A write to the input ports register is ignored.
Transition DetectionAll ports configured as inputs are always monitored for
changes in their logic status. The action of reading the
input ports register or writing to the configuration regis-
ter samples the corresponding 8 port bits’ input condi-
tion (Tables 4, 6). This sample is continuously
compared with the actual input conditions. A detected
change in input condition causes an interrupt condition.
The interrupt is cleared either automatically if the
changed input returns to its original state, or when the
input ports register is read, updating the compared
data (Figure 10). Randomly changing a port from an
output to an input may cause a false interrupt to occur
if the state of the input does not match the content of
the input ports register. The interrupt status is available
as the interrupt flag INTin the configuration register
(Table 4).
The input status of all ports are sampled immediately
after power-up as part of the MAX7316’s internal initial-
ization, so if all the ports are pulled to valid logic levels
at that time an interrupt does not occur at power-up.
MAX7316
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
Table 2. Register Address Map
REGISTERADDRESS CODE
(hex)
AUTOINCREMENT
ADDRESSRead input ports0x000x00 (no change)
Blink phase 0 outputs0x010x01 (no change)
Ports configuration0x030x03 (no change)
Blink phase 1 outputs0x090x09 (no change)
Master, O8 intensity0x0E0x0E (no change)
Configuration0x0F0x0F (no change)
Outputs intensity P1, P00x100x11
Outputs intensity P3, P20x110x12
Outputs intensity P5, P40x120x13
Outputs intensity P7, P60x130x10
MAX7316INT/O8 Output
The INT/O8 output pin can be configured as either the
INToutput that reflects the interrupt flag logic state or as
a general-purpose output O8. When used as a general-
purpose output, INT/O8 has the same blink and PWM
intensity control capabilities as the other ports.
Set the interrupt enable I bit in the configuration register
to configure INT/O8 as the INToutput (Table 4). Clear
interrupt enable to configure INT/O8 as the O8. The O8
logic state is set by the 2 bits O1 and O0 in the configu-
ration register. O8 follows the rules for blinking selected
by the blink enable flag E in the configuration register. If
blinking is disabled, then interrupt output control O0
alone sets the logic state of the INT/O8 pin. If blinking is
enabled, then both interrupt output controls O0 and O1
set the logic state of INT/O8 according to the blink
phase. PWM intensity control for O8 is set by the 4
global intensity bits in the master and O8 intensity reg-
ister (Table 13).
Blink ModeIn blink mode, the output ports can be flipped between
using either the blink phase 0 register or the blink
phase 1 register. Flip control is both hardware (the
BLINK input) and software control (the blink flip flag B
in the configuration register) (Table 4).
The blink function can be used for LED effects by pro-
gramming different display patterns in the two sets of
output port registers, and using the software or hard-
ware controls to flip between the patterns.
If the blink phase 1 register is written with 0xFF, then
the BLINK input can be used as a hardware disable to,
for example, instantly turn off an LED pattern pro-
grammed into the blink phase 0 register. This technique
can be further extended by driving the BLINK input with
a PWM signal to modulate the LED current to provide
fading effects.
The blink mode is enabled by setting the blink enable flag
E in the configuration register (Table 4). When blink mode
is enabled, the states of the blink flip flag and the BLINK
input are EXOR’ed to set the phase, and the output ports
are set by either the blink phase 0 register or the blink
phase 1 register (Figure 11) (Table 7).
10-Port I/O Expander with LED Intensity
Control, Interrupt, and Hot-Insertion Protection
Table 3. Power-Up Configuration
REGISTER DATAREGISTER FUNCTIONPOWER-UP CONDITION
ADDRESS
CODE
(HEX)D7D6D5D4D3D2D1D0Blink phase 0 outputs P7–P0High-impedance outputs0x0111111111
Ports configuration P7–P0Ports P7–P0 are inputs0x0311111111
Blink phase 1 outputs P7–P0High-impedance outputs0x0911111111
Master, O8 intensityPWM oscillator is disabled;
O8 is static logic output0x0E00001111
Configuration
INT/O8 is interrupt output;
blink is disabled;
global intensity is enabled
0x0F00001100
Outputs intensity P1, P0P1, P0 are static logic outputs0x1011111111
Outputs Intensity P3, P2P3, P2 are static logic outputs0x1111111111
Outputs intensity P5, P4P5, P4 are static logic outputs0x1211111111
Outputs intensity P7, P6P7, P6 are static logic outputs0x1311111111
