參數(shù)資料
型號： 101-0494
廠商： Rabbit Semiconductor
文件頁數(shù)： 77/90頁
文件大小： 0K
描述： MODULE RABBITCORE RCM2250
標(biāo)準(zhǔn)包裝： 1
系列： RabbitCore®
模塊/板類型： 單板計(jì)算機(jī)模塊
適用于相關(guān)產(chǎn)品： RCM2250
User’s Manual
73
C.2 Chip Select Circuit
The RCM2200 has provision for battery backup, which kicks in to keep VRAM from
dropping below 2 V.
When the RCM2200 is not powered, the battery keeps the SRAM memory contents and
the real-time clock (RTC) going. The SRAM has a powerdown mode that greatly reduces
power consumption. This powerdown mode is activated by raising the chip select (CS)
signal line. Normally the SRAM requires Vcc to operate. However, only 2 V is required
for data retention in powerdown mode. Thus, when power is removed from the circuit, the
battery voltage needs to be provided to both the SRAM power pin and to the CS signal
line. The CS control switch accomplishes this task for the CS signal line.
Figure C-3 shows a schematic of the chip select control switch.
Figure C-3. Chip Select Control Switch
In a powered-up condition, the CS control switch must allow the processor’s chip select
signal /CS1 to control the SRAM’s CS signal /CSRAM. So, with power applied, /CSRAM
must be the same signal as /CS1, and with power removed, /CSRAM must be held high
(but only needs to be as high as the battery voltage). Q3 and Q4 are MOSFET transistors
with opposing polarity. They are both turned on when power is applied to the circuit. They
allow the CS signal to pass from the processor to the SRAM so that the processor can peri-
odically access the SRAM. When power is removed from the circuit, the transistors will
turn off and isolate /CSRAM from the processor. The isolated /CSRAM line has a 100 k
pullup resistor to VRAM (R28). This pullup resistor keeps /CSRAM at the VRAM voltage
level (which under no power condition is the backup battery’s regulated voltage at a little
more than 2 V).
Transistors Q3 and Q4 are of opposite polarity so that a rail-to-rail voltages can be passed.
When the /CS1 voltage is low, Q3 will conduct. When the /CS1 voltage is high, Q4 will
conduct. It takes time for the transistors to turn on, creating a propagation delay. This
delay is typically very small, about 10 ns to 15 ns.
/CS1
/CSRAM
/RESET_OUT
Q3
Q4
R28
VRAM
100 kW
VRAM
SWITCH
相關(guān)PDF資料
PDF描述
101-0518 MODULE RABBITCORE RCM3110
101-0521 MODULE RABBITCORE RCM3210
101-0525 COMPUTER SINGLE-BOARD LP3500 FOX
101-0602 COMPUTER SNGL BRD BL2500 44.2MHZ
101-0673 MODULE RABBITCORE RCM3610
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
101-0495 功能描述:處理器配件 Baseplate RoHS:否 制造商:Olimex Ltd. 產(chǎn)品:Cable 用于:
101-0497 功能描述:單板計(jì)算機(jī) OP6810 RoHS:否 制造商:Ampro By ADLINK 外觀尺寸:EPIC 處理器類型:Intel Atom D510 頻率:1.66 GHz 存儲容量:2 GB (max) 存儲類型:DDR2, L2 Cache 接口類型:Ethernet, PS/2, SATA, Serial, USB 工作電源電壓:5 V, 12 V 功耗:13 W 最大工作溫度:+ 70 C 尺寸:165.1 mm x 114.3 mm
10104997-00C-10B 功能描述:高速/模塊連接器 XCEDE 2W 6PVH 6COL RoHS:否 制造商:Molex 系列:iPass 產(chǎn)品類型: 排數(shù): 列數(shù): 位置/觸點(diǎn)數(shù)量:38 安裝角:Right 節(jié)距:0.8 mm 安裝風(fēng)格:Plug 端接類型:SMD/SMT 外殼材料:Thermoplastic 觸點(diǎn)材料:High Performance Alloy (HPA) 觸點(diǎn)電鍍:Gold
10104997-00C-10DLF 功能描述:高速/模塊連接器 XCEDE 2W 6PVH 6COL RoHS:否 制造商:Molex 系列:iPass 產(chǎn)品類型: 排數(shù): 列數(shù): 位置/觸點(diǎn)數(shù)量:38 安裝角:Right 節(jié)距:0.8 mm 安裝風(fēng)格:Plug 端接類型:SMD/SMT 外殼材料:Thermoplastic 觸點(diǎn)材料:High Performance Alloy (HPA) 觸點(diǎn)電鍍:Gold
10104997-00C-20B 功能描述:高速/模塊連接器 XCEDE 2W LT 6PVH6COL RoHS:否 制造商:Molex 系列:iPass 產(chǎn)品類型: 排數(shù): 列數(shù): 位置/觸點(diǎn)數(shù)量:38 安裝角:Right 節(jié)距:0.8 mm 安裝風(fēng)格:Plug 端接類型:SMD/SMT 外殼材料:Thermoplastic 觸點(diǎn)材料:High Performance Alloy (HPA) 觸點(diǎn)電鍍:Gold
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(bào)價(jià)

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(bào)價(jià)

*型號 *數(shù)量 廠商 批號 封裝
添加更多采購

我的聯(lián)系方式

*
*
*