參數(shù)資料
型號(hào)： 20-101-0494
廠商： Rabbit Semiconductor
文件頁(yè)數(shù)： 77/90頁(yè)
文件大?。?/td> 0K
描述： MODULE RABBITCORE RCM2250
標(biāo)準(zhǔn)包裝： 1
系列： RabbitCore®
模塊/板類(lèi)型： MPU 核心模塊
適用于相關(guān)產(chǎn)品： RCM2250
產(chǎn)品目錄頁(yè)面： 620 (CN2011-ZH PDF)
其它名稱(chēng)： 316-1092
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
AT25020N-10SI-2.7 IC EEPROM 2KBIT 2.1MHZ 8SOIC
345-030-521-801 CARDEDGE 30POS DUAL .100 GREEN
12FMN-BMTTN-A-TF CONN FMN HSNG 12POS STAG NOR SMD
AT25020-10PI-2.7 IC EEPROM 2KBIT 2.1MHZ 8DIP
345-030-521-204 CARDEDGE 30POS DUAL .100 GREEN
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
20-101-0495 功能描述:處理器配件 BASEPLATE RoHS:否 制造商:Olimex Ltd. 產(chǎn)品:Cable 用于:
20-101-0497 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(lèi)型:Intel Atom D510 頻率:1.66 GHz 存儲(chǔ)容量:2 GB (max) 存儲(chǔ)類(lèi)型:DDR2, L2 Cache 接口類(lèi)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
201-01050 功能描述:鋁質(zhì)電解電容器 - 帶引線 1 uF Electrolytic Capacitor RoHS:否 制造商:Kemet 引線類(lèi)型: 電容:220 uF 容差:20 % 電壓額定值:25 V 工作溫度范圍: 端接類(lèi)型:Radial 外殼直徑:8 mm 外殼長(zhǎng)度:11 mm 引線間隔:5 mm 產(chǎn)品:General Purpose Electrolytic Capacitors 封裝:Bulk
201-0105-01 功能描述:印刷電路板和試驗(yàn)板 JTAG 20 Pin Connector RoHS:否 制造商:3M Electronic Solutions Division 產(chǎn)品:Jumper & Insulated Wires 描述/功能:Jumper wire, 22 AWG 0.1 inch 長(zhǎng)度:0.1 in 寬度:
20-101-0502 功能描述:處理器配件 Keypad/Display Unit 5V Panle Mount RoHS:否 制造商:Olimex Ltd. 產(chǎn)品:Cable 用于:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

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

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

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*