參數(shù)資料
型號： EM6821TQ52B
英文描述： Advanced Synchronous Rectified Buck MOSFET Drivers with Pre-POR OVP; Temperature Range: 0&degC to 70°C; Package: 8-EPSOIC
中文描述： 微控制器
文件頁數(shù)： 10/69頁
文件大?。?/td> 852K
代理商： EM6821TQ52B
EM6821
10/01, Revision A/386
Copyright
2001, EM Microelectronic-Marin SA
18
www.emmicroelectronic.com
6.4.2 Pull-up or Pull-down
On each terminal of PB[3:0] an internal input pull-up (metal mask MPBPU[n]) or pull-down (metal mask
MPBPD[n]) resistor can be connected per metal mask option. Per default the two resistors are in place. In this
case one can chose per software to have either a pull-up, a pull-down or no resistor. See below.
For Metal mask selection and available resistor values refer to chapter 18.1.3.
Pull-down ON : MPBPD[n] must be in place ,
AND bit NoPdPB[n] must be ‘0’ .
Pull-down OFF: MPBPD[n] is not in place,
OR if MPBPD[n] is in place NoPdPB[n] = ‘1’ cuts off the pull-down.
OR selecting NchOpDPB[n] = ‘1’ cuts off the pull-down.
Pull-up ON *
: MPBPU[n] must be in place,
AND bit NchOpDPB[n] must be ‘1’ ,
AND (bit PBIOCntl[n] = ‘0’ (input mode) OR if PBIOCntl[n] = ‘1’ while PBData[n] = 1. )
Pull-up OFF* : MPBPU[n] is not in place,
OR if MPBPU[n] is in place NchOpDPB[n] = ‘0’ cuts off the pull-up,
OR if MPBPU[n] is in place and if NchOpDPB[n] = ‘1’ then PBData[n] = 0 cuts off the pull-up.
Never pull-up and pull-down can be active at the same time.
For POWER SAVING one can switch off the port B pull resistors between two read phases. No cross current
flows in the input amplifier while the port B is not read. The recommended order is :
Switch on the pull resistor.
Allow sufficient time - RC constant - for the pull resistor to drive the line to either VSS or VDD.
Read the port B
Switch off the pull resistor
Minimum time with current on the pull resistor is 4 system clock periods, if the RC time constant is lower than 1
system clock period. Adding a NOP instruction before reading moves the number of periods with current in the
pull resistor to 6 and the maximum RC delay to 3 clock periods.
6.4.3 CMOS / NCH. Open Drain Output
The port B outputs can be configured as either CMOS or Nch. open drain outputs. In CMOS both logic ‘1’ and
‘0’ are driven out on the terminal. In Nch. Open Drain only the logic ‘0’ is driven on the terminal, the logic ‘1’
value is defined by the internal pull-up resistor (if implemented), or high impedance.
Figure 12. CMOS or Nch. Open Drain Outputs
I / O
T e rm inal
PB[n ]
MU X
Ac tiv e Pu llu p
fo r H ig h S ta te
DR[n ]
F requenc y
Ou tp u ts
T ri-S tate O u tput
B u ffer : H igh
Im pedanc e fo r
Da ta = 1
I / O
T e rm inal
PB[n ]
MU X
DR[n ]
F requenc y
Ou tp u ts
T ri-S tate O u tput
B u ffer : c los ed
Da ta
1
C M OS Ou tp u t
N c h. O pen D rain O u tput
相關(guān)PDF資料
PDF描述
EM6821TQ52D Advanced Synchronous Rectified Buck MOSFET Drivers with Pre-POR OVP; Temperature Range: -40°C to 85°C; Package: 8-SOIC
EM73MA89B Advanced Synchronous Rectified Buck MOSFET Drivers with Pre-POR OVP; Temperature Range: -40°C to 85°C; Package: 8-EPSOIC T&R
EM78156E Dual Advanced Synchronous Rectified Buck MOSFET Drivers with Pre-POR OVP; Temperature Range: 0&degC to 70°C; Package: 14-SOIC
EM78458 Dual Advanced Synchronous Rectified Buck MOSFET Drivers with Pre-POR OVP; Temperature Range: 0&degC to 70°C; Package: 16-QFN
EM78459 Dual Advanced Synchronous Rectified Buck MOSFET Drivers with Pre-POR OVP; Temperature Range: -40°C to 85°C; Package: 14-SOIC
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
EM685 制造商:Distributed By MCM 功能描述:UTILITY MOTOR
EM68C16CWVB-25H 制造商:Etron 功能描述:DDRII SDRAM,1Gb,64M*16,Pb & Halogen free
EM6A8160TSA 制造商:ETRON 制造商全稱:ETRON 功能描述:4M x 16 DDR Synchronous DRAM (SDRAM)
EM6A8160TSA-5G 制造商:ETRON 制造商全稱:ETRON 功能描述:4M x 16 DDR Synchronous DRAM (SDRAM)
EM6A9160 制造商:ETRON 制造商全稱:ETRON 功能描述:8M x 16 DDR Synchronous DRAM (SDRAM)
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。

采購需求

(若只采購一條型號，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺，查看報價

發(fā)布成功！您可以繼續(xù)發(fā)布采購。也可以進(jìn)入我的后臺，查看報價

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*