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參數(shù)資料
| 型號： | MAX7321ATE+T |
| 廠商： | Maxim Integrated Products |
| 文件頁數(shù)： | 4/15頁 |
| 文件大?。?/td> | 0K |
| 描述： | IC I/O EXPANDER I2C 8B 16TQFN-EP |
| 產(chǎn)品培訓模塊： | Lead (SnPb) Finish for COTS Obsolescence Mitigation Program |
| 標準包裝： | 2,500 |
| 接口： | I²C |
| 輸入/輸出數(shù)： | 8 |
| 中斷輸出： | 是 |
| 頻率 - 時鐘： | 400kHz |
| 電源電壓： | 1.71 V ~ 5.5 V |
| 工作溫度： | -40°C ~ 125°C |
| 安裝類型： | 表面貼裝 |
| 封裝/外殼： | 16-WFQFN 裸露焊盤 |
| 供應商設備封裝： | 16-TQFN-EP（3x3） |
| 包裝： | 帶卷 (TR) |
| 包括： | POR |
MAX7321
I2C Port Expander with 8 Open-Drain I/Os
12
Maxim Integrated
Writing to the MAX7321
A write to the MAX7321 starts with the master transmit-
ting the MAX7321’s slave address with the R/W bit set
low. The MAX7321 acknowledges the slave address,
and samples the ports (takes a snapshot) during
acknowledge. INT goes high (high impedance if an
external pullup resistor is not fitted) during the slave
acknowledge. Typically, the master proceeds to trans-
mit 1 or more bytes of data. The MAX7321 acknowl-
edges these subsequent bytes of data and updates the
I/O ports with each new byte until the master issues a
STOP condition (Figure 8).
Applications Information
Port Input and I2C Interface Level
Translation from Higher or Lower
Logic Voltages
The MAX7321’s SDA, SCL, AD0, AD2, RST, INT, and I/O
ports P0–P7 are overvoltage protected to +6V indepen-
dent of V+. This allows the MAX7321 to operate from a
lower supply voltage, such as +3.3V, while the I2C inter-
face and/or any of the eight I/O ports are driven as inputs
driven from a higher logic level, such as +5V.
The MAX7321 can operate from a higher supply volt-
age, such as +3V, while the I2C interface and/or some
of the I/O ports P0–P7 are driven from a lower logic
level, such as +2.5V. Apply a minimum voltage of 0.7 x
V+ to assert a logic-high on any I/O port. For example,
a MAX7321 operating from a +5V supply may not rec-
ognize a +3.3V nominal logic-high. One solution for
input-level translation is to drive MAX7321 I/Os from
open-drain outputs. Use a pullup resistor to V+ or a
higher supply to ensure a high logic voltage greater
than 0.7 x V+.
Port-Output Port-Level Translation
The open-drain output architecture allows for level
translation to higher or lower voltages than the
MAX7321’s supply. Use an external pullup resistor on
any output to convert the high-impedance logic-high
condition to a positive voltage level. The resistor can be
connected to any voltage up to +6V, and the resistor
value chosen to ensure no more than 20mA is sunk in
the logic-low condition. For interfacing CMOS inputs, a
pullup resistor value of 220k
is a good starting point.
Use a lower resistance to improve noise immunity, in
applications where power consumption is less critical,
or where a faster rise time is needed for a given capac-
itive load.
Each of the I/O ports P0–P7 has a protection diode to
GND (Figure 9). When a port is driven to a voltage
lower than GND, the protection diode clamps the volt-
age to a diode drop below GND.
Each of the I/O ports P0–P7 also has a 40k
(typ) pullup
resistor that can be enabled or disabled. When a port is
driven to a voltage higher than V+, the body diode of the
pullup enable switch conducts and the 40k
pullup
resistor is enabled. When the MAX7321 is powered
down (V+ = 0), each I/O port appears as a 40k
resistor
in series with a diode connected to zero. I/O ports are
protected to +6V under any of these circumstances
(Figure 9).
SCL
SDA
START CONDITION
R/W
SLAVE ADDRESS
S0
123
4
5
6
7
8
AA
A
tPV
DATA 1
DATA 2
tPV
DATA TO PORT
tPV
DATA 2 VALID
DATA 1 VALID
INTERNAL WRITE
TO PORT
DATA OUT
FROM PORT
tPV
S = START CONDITION
SHADED = SLAVE TRANSMISSION
P = STOP CONDITION
N = NOT ACKNOWLEDGE
Figure 8. Writing to the MAX7321
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相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| MAX7321AUP | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:I2C Port Expander with 8 Open-Drain I/Os |
| MAX7322 | 制造商:MAXIM 制造商全稱:Maxim Integrated Products 功能描述:I2C Port Expander with 4 Push-Pull Outputs |
| MAX7322AEE | 功能描述:接口-I/O擴展器 RoHS:否 制造商:NXP Semiconductors 邏輯系列: 輸入/輸出端數(shù)量: 最大工作頻率:100 kHz 工作電源電壓:1.65 V to 5.5 V 工作溫度范圍:- 40 C to + 85 C 安裝風格:SMD/SMT 封裝 / 箱體:HVQFN-16 封裝:Reel |
| MAX7322AEE+ | 功能描述:接口-I/O擴展器 I2C Port Expander w/4 P-P Out & 4 In RoHS:否 制造商:NXP Semiconductors 邏輯系列: 輸入/輸出端數(shù)量: 最大工作頻率:100 kHz 工作電源電壓:1.65 V to 5.5 V 工作溫度范圍:- 40 C to + 85 C 安裝風格:SMD/SMT 封裝 / 箱體:HVQFN-16 封裝:Reel |
| MAX7322AEE+T | 功能描述:接口-I/O擴展器 I2C Port Expander w/4 P-P Out & 4 In RoHS:否 制造商:NXP Semiconductors 邏輯系列: 輸入/輸出端數(shù)量: 最大工作頻率:100 kHz 工作電源電壓:1.65 V to 5.5 V 工作溫度范圍:- 40 C to + 85 C 安裝風格:SMD/SMT 封裝 / 箱體:HVQFN-16 封裝:Reel |
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