参数资料
型号: CY2273A-2
厂商: Cypress Semiconductor Corp.
英文描述: Pentium㈢/II, 6x86, K6 Clock Synthesizer/Driver for Desktop PCs with Intel 82430TX, 82440LX or ALI IV/IV+, AGP and 3 DIMMs
中文描述: 奔腾㈢/ 2,6x86,K6时钟合成器/与英特尔82430TX,82440LX或阿里四/四,AGP和3个DIMM台式机驱动
文件页数: 1/14页
文件大小: 178K
代理商: CY2273A-2
Pentium/II, 6x86, K6 Clock Synthesizer/Driver for Desktop PCs
with Intel 82430TX, 82440LX or ALI IV/IV+, AGP and 3 DIMMs
Features
Mixed 2.5V and 3.3V operation
Complete clock solution for Pentium, Pentium II,
Cyrix, and AMD processor-based motherboards
—Four CPU clocks at 2.5V or 3.3V
—Up to twelve 3.3V SDRAM clocks
—Seven synchronous PCI clocks, one free-running
—One 3.3V 48 MHz USB clock
—One 2.5V IOAPIC clock (-3 option only)
—Two AGP clocks at 60 or 66.6MHz (-2 option only)
—One 3.3V Ref. clock at 14.318 MHz
I
2
C Serial Configuration Interface
Factory-EPROM programmable output drive and slew
rate for EMI customization
Factory-EPROM programmable CPU clock frequencies
for custom configurations
Power-down, CPU stop and PCI stop pins
Available in space-saving 48-pin SSOP package
Functional Description
The CY2273A is a clock synthesizer/driver for a Pentium, Pen-
tium II, Cyrix, or AMD processor-based PC using Intel’s
82430TX, 82440LX, ALI Aladdin IV or Aladdin IV+ chipsets.
The CY2273A-1 outputs four CPU clocks at 2.5V or 3.3V with
up to 83.3MHz operation. There are seven PCI clocks, running
at 30 and 33.3MHz. One of the PCI clocks is free-running.
Additionally, the part outputs up to twelve 3.3V SDRAM clocks,
one 3.3V USB clock at 48 MHz, and one 3.3V reference clock
at 14.318 MHz. The CY2273A-2 is similar, except that
PCICLK4 and PCICLK5 are now AGP clocks. The CY2273A-3
is more suited to Pentium II systems, as it outputs one 2.5V
IOAPIC clock. Finally, the CY2273A-4 is similar to the
CY2273A-1 except that is supports 0-ns CPU-PCI delay.
CY2273A
Cypress Semiconductor Corporation
3901 North First Street
San Jose
CA 95134
408-943-2600
October 12, 1998
The CY2273A possesses power-down, CPU stop, and PCI
stop pins for power management control. These inputs are
multiplexed with SDRAM clock outputs, and are selected when
the MODE pin is driven low. Additionally, the signals are syn-
chronized on-chip, and ensure glitch-free transitions on the
outputs. When the CPU_STOP input is asserted, the CPU
clock outputs are driven LOW. When the PCI_STOP input is
asserted, the PCI clock outputs (except the free-running PCI
clock) are driven LOW. When the PWR_DWN pin is asserted,
the reference oscillator and PLLs are shut down, and all out-
puts are driven LOW.
The CY2273A outputs are designed for low EMI emissions.
Controlled rise and fall times, unique output driver circuits and
factory-EPROM programmable output drive and slew-rate en-
able optimal configurations for EMI control.
CY2273A Selector Guide
Note:
1.
One free-running PCI clock.
Clocks Outputs
CPU (60, 66.6, 75,
83.3 MHz)
CPU (60, 66.6 MHz)
SDRAM
PCI (30, 33.3MHz)
USB/IR (48MHz)
AGP (60 or 66MHz)
IOAPIC (14.318MHz)
Ref (14.318MHz)
CPU-PCI delay
-1
4
-2
4
-3
--
-4
4
--
--
4
--
9/12
7
[1]
1
--
--
1
1–5.5 ns
9/12
5
[1]
1
2
--
1
1–5.5 ns
9/12
7
[1]
1
--
1
1
0 ns
9/12
7
[1]
1
--
--
1
0 ns
Intel and Pentium are registered trademarks of Intel Corporation. I
2
C is a trademark of Philips Corporation.
Logic Block Diagram
IOAPIC
V
DDQ2
REF0 (14.318 MHz)
CY2273A-3 only
EPROM
XTALOUT
XTALIN
14.318
MHz
OSC.
SDRAM [0-4],[8-11]
SDRAM6/CPU_STOP
SEL0
SEL1
CY2273A-1,-2,-4 only
SDRAM7/PCI_STOP
CPU
PLL
MODE
SCLK
SDATA
CPUCLK [0-3]
V
DDCPU
PCI [0-5], PCI [0-3]
PCICLK_F
STOP
LOGIC
STOP
LOGIC
SDRAM5/PWR_DWN
USBCLK (48 MHz)
SYS PLL
AGP [0,1]
INTERFACE
CONTROL
LOGIC
SERIAL
/1 or /2
CY2273A-2 only
/1 or /1.25
Delay (-1,-2 option)
相关PDF资料
PDF描述
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相关代理商/技术参数
参数描述
CY2273A-3 制造商:CYPRESS 制造商全称:Cypress Semiconductor 功能描述:Pentium㈢/II, 6x86, K6 Clock Synthesizer/Driver for Desktop PCs with Intel 82430TX, 82440LX or ALI IV/IV+, AGP and 3 DIMMs
CY2273A-4 制造商:CYPRESS 制造商全称:Cypress Semiconductor 功能描述:Pentium㈢/II, 6x86, K6 Clock Synthesizer/Driver for Desktop PCs with Intel 82430TX, 82440LX or ALI IV/IV+, AGP and 3 DIMMs
CY2273APVC-1 制造商:Cypress Semiconductor 功能描述:
CY2273APVC-1T 制造商:未知厂家 制造商全称:未知厂家 功能描述:CPU System Clock Generator
CY2273APVC-2 制造商:CYPRESS 制造商全称:Cypress Semiconductor 功能描述:Pentium㈢/II, 6x86, K6 Clock Synthesizer/Driver for Desktop PCs with Intel 82430TX, 82440LX or ALI IV/IV+, AGP and 3 DIMMs