参数资料
| 型号： | 101-0488 |
| 厂商： | Rabbit Semiconductor |
| 文件页数： | 77/90页 |
| 文件大小： | 0K |
| 描述： | MODULE RABBITCORE RCM2210 |
| 标准包装： | 1 |
| 系列： | RabbitCore® |
| 模块/板类型： | 单板计算机模块 |
| 适用于相关产品： | RCM2210 |
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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
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相关代理商/技术参数 |
参数描述 |
|---|---|
| 101-0492 | 功能描述:单板计算机 OP6800 RoHS:否 制造商:Ampro By ADLINK 外观尺寸:EPIC 处理器类型:Intel Atom D510 频率:1.66 GHz 存储容量:2 GB (max) 存储类型:DDR2, L2 Cache 接口类型:Ethernet, PS/2, SATA, Serial, USB 工作电源电压:5 V, 12 V 功耗:13 W 最大工作温度:+ 70 C 尺寸:165.1 mm x 114.3 mm |
| 101-0494 | 功能描述:模块化系统 - SOM RCM2250 RABBITCORE RoHS:否 制造商:Digi International 外观尺寸:ConnectCore 9P 处理器类型:ARM926EJ-S 频率:150 MHz 存储容量:8 MB, 16 MB 存储类型:NOR Flash, SDRAM 接口类型:I2C, SPI, UART 工作电源电压:3.3 V 最大工作温度:+ 85 C 尺寸:1.97 in x 1.97 in x 6.1 in |
| 101-0495 | 功能描述:处理器配件 Baseplate RoHS:否 制造商:Olimex Ltd. 产品:Cable 用于: |
| 101-0497 | 功能描述:单板计算机 OP6810 RoHS:否 制造商:Ampro By ADLINK 外观尺寸:EPIC 处理器类型:Intel Atom D510 频率:1.66 GHz 存储容量:2 GB (max) 存储类型:DDR2, L2 Cache 接口类型:Ethernet, PS/2, SATA, Serial, USB 工作电源电压:5 V, 12 V 功耗:13 W 最大工作温度:+ 70 C 尺寸:165.1 mm x 114.3 mm |
| 10104997-00C-10B | 功能描述:高速/模块连接器 XCEDE 2W 6PVH 6COL RoHS:否 制造商:Molex 系列:iPass 产品类型: 排数: 列数: 位置/触点数量:38 安装角:Right 节距:0.8 mm 安装风格:Plug 端接类型:SMD/SMT 外壳材料:Thermoplastic 触点材料:High Performance Alloy (HPA) 触点电镀:Gold |
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