参数资料
型号: BU9880GUL-WE2
厂商: Rohm Semiconductor
文件页数: 18/25页
文件大小: 0K
描述: IC EEPROM 64KBIT 2WIRE VCSP50L1
标准包装: 3,000
格式 - 存储器: EEPROMs - 串行
存储器类型: EEPROM
存储容量: 64K (8K x 8)
速度: 400kHz
接口: I²C,2 线串口
电源电压: 1.7 V ~ 5.5 V
工作温度: -40°C ~ 85°C
封装/外壳: 6-UFBGA,CSPBGA
供应商设备封装: VCSP50L1
包装: 带卷 (TR)
BU9880GUL-W (64Kbit)
Datasheet
In I C BUS, it is recommended that SDA port is of open drain input/output. However, when to use CMOS input / output of
● Cautions on microcontroller connection
Rs
2
tri state to SDA port, insert a series resistance Rs between the pull up resistance Rpu and the SDA terminal of EEPROM.
This is controls over current that occurs when PMOS of the microcontroller and NMOS of EEPROM are turned ON
simultaneously. Rs also plays the role of protection of SDA terminal against surge. Therefore, even when SDA port is
open drain input/output, Rs can be used.
ACK
R S
SCL
SDA
'H' output of microcontroller
'L' output of EEPROM
Microcontroller
EEPROM
Over current flows to SDA line by 'H'
output of microcontroller and 'L' output
of EEPROM.
Figure 41. I/O circuit diagram
Figure 42. Input/output collision timing
○ Maximum value of Rs
The maximum value of Rs is determined by following relations.
(1) SDA rise time to be determined by the capacity (CBUS) of bus line of Rpu and SDA shoulder be tR or below.
And AC timing should be satisfied even when SDA rise time is late.
(2) The bus electric potential A to be determined by Rpu and Rs the moment when EEPROM outputs 'L' to SDA bus
should sufficiently secure the input 'L' level (V IL ) of microcontroller including recommended noise margin 0.1Vcc.
V CC
(V CC - V OL )×R S
R PU +R S
+ V OL +0.1V CC ≦ V IL
R S
A
R PU=10 kΩ
V OL
∴ R S ≦
V IL V OL 0.1V CC
1.1V CC - V IL
× R PU
I OL
Example) When V CC =3V, V IL =0.3V CC, V OL =0.4V, R PU =10k ? ,
× 10×10
V IL
Bus line
capacity CBUS
Microcontroller
EEPROM
from(2),
R S ≦
0.3×3 0.4 0.1×3
1.1×3 - 0.3×3
3
≦ 0.835 [ k ? ]
Figure 43. I/O circuit diagram
○ Maximum value of Rs
The minimum value of Rs is determined by over current at bus collision. When over current flows, noises in power source
line, and instantaneous power failure of power source may occur. When allowable over current is defined as I, the
following relation must be satisfied. Determine the allowable current in consideration of impedance of power source line
in set and so forth. Set the over current to EEPROM 10mA or below.
R PU =10 Ω
V CC
R S
I
'L' output
R S
Over current Ⅰ
∴ R S ≧
V CC
I
'H' output
Example ) When V CC =3V , I=10mA
Microcontroller
EEPROM
R S
3
10×10 -3
≧ 300 [Ω]
Figure 44. I/O circuit diagram
www.rohm.com
? 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111 ? 15 ? 001
18/22
TSZ02201-0R2R0G100340-1-2
21.AUG.2012 Rev.001
相关PDF资料
PDF描述
BU9882FV-WE2 IC EEPROM 2KBIT 400KHZ 14SSOP
BU9883FV-WE2 IC EEPROM 6KBIT 400KHZ SSOP16
BU9889GUL-WE2 IC EEPROM 8KBIT 2WIRE VCSP50L1
BU9891GUL-WE2 IC EEPROM 4KBIT VCSP T/R
BU9897GUL-WE2 IC EEPROM SERIAL VCSP50L2
相关代理商/技术参数
参数描述
BU9881 制造商:未知厂家 制造商全称:未知厂家 功能描述:I2C Serial EEPROM
BU9881F 制造商:未知厂家 制造商全称:未知厂家 功能描述:I2C Serial EEPROM
BU9882FV-W 制造商:ROHM 制造商全称:Rohm 功能描述:EDID Memory (For display)
BU9882FV-WE2 功能描述:电可擦除可编程只读存储器 2K BIT 128 X 8 X 2 3.3V/5V 14PIN RoHS:否 制造商:Atmel 存储容量:2 Kbit 组织:256 B x 8 数据保留:100 yr 最大时钟频率:1000 KHz 最大工作电流:6 uA 工作电源电压:1.7 V to 5.5 V 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:SOIC-8
BU9882F-W 制造商:ROHM 制造商全称:Rohm 功能描述:EDID Memory (For display)