W250-03_技术文档

3

PRELIMINARY

W250-03

FTG for VIA Apollo Pro-266

Table 1. Pin Selectable Frequency (continued)

Features

Input Address

CPU,

(MHz)

PCI

(MHz)

Spread

Spectrum

• Maximized EMI Suppression using Cypress’s Spread

Spectrum Technology

• System frequency synthesizer for VIA Apollo Pro-266

• Supports Intel® Pentium® II and Pentium® III class pro-

cessor

• Three copies of CPU output

• Nine copies of PCI output

FS4 FS3 FS2 FS1 FS0

AGP

80.0

75.0

72.5

70.0

68.0

65.0

62.0

66.6

78.7

66.6

66.8

76.7

66.8

73.3

66.8

70.0

60.0

56.7

78.0

66.6

75.0

66.6

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

160.0

150.0

145.0

140.0

136.0

130.0

124.0

66.6

40.0

37.5

36.3

35.0

34.0

32.5

31.0

33.3

39.3

33.3

33.4

38.3

33.4

36.7

33.4

35.0

30.0

28.3

39.0

33.3

37.5

33.3

OFF

• One 48-MHz output for USB

OFF

• One 24-MHz or 48-MHz output for SIO

• Two buffered reference outputs

• Three copies of APIC output

• Supports frequencies up to 200 MHz

• SMBus interface for programming

• Power management control inputs

• Available in 48-pin SSOP

OFF

100.0

118.0

133.3

66.8

OFF

+0.25%

OFF

100.2

115.0

133.6

66.8

Key Specifications

CPU Cycle-to-Cycle Jitter:................................................ 250 ps

CPU to CPU Output Skew:............................................... 175 ps

PCI Cycle to Cycle Jitter:.................................................. 500 ps

PCI to PCI Output Skew:.................................................. 500 ps

+0.25%

+0.5%

OFF

100.2

110.0

133.6

105.0

90.0

+0.5%

OFF

Table 1. Pin Selectable Frequency

Input Address

OFF

CPU,

PCI

Spread

FS4 FS3 FS2 FS1 FS0

(MHz)

AGP

66.6

63.3

60.0

56.7

83.0

(MHz)

Spectrum

85.0

OFF

0

1

0

1

0

1

0

1

0

200.0

190.0

180.0

170.0

166.0

33.3

31.7

30.0

28.3

41.5

OFF

78.0

OFF

66.6

-0.5%

OFF

100.0

75.0

133.3

-0.5%

Pin Configuration^[1]

Block Diagram

VDD_REF

REF0

VDD_REF

GND_REF

X1

48

REF0

1

REF1/FS4

X1

X2

XTAL

OSC

47

46

45

44

43

42

41

40

39

38

37

36

35

34

33

32

31

30

29

28

27

26

25

REF1/FS4*

VDD_APIC

APIC0

2

3

VDD_APIC

PLL Ref Freq

X2

4

APIC0:2

VDD_AGP

VDD_48 MHz

FS3*/48 MHz

FS2*/24_48 MHz

GND_48 MHz

PCI_F

5

APIC1

DIV

6

GND_APIC

APIC2

7

AGP0:2

8

VDD_CPU

GND_CPU

CPU1

CPU_STOP#

VDD_CPU

9

PCI1

PCI2

GND_PCI

PCI3

PCI4

VDD_PCI

PCI5

PCI6

PCI7

GND_PCI

PCI8

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

PWR_DWN#

FS0:1

CPU2

VDD_CPU

GND_CPU

CPU3

Stop

Clock

CPU1:3

PLL 1

Control

VDD_PCI

PCI_F

CPU_STOP#*

PCI_STOP#*

PWR_DWN#*

VDD_CORE

GND_CORE

SDATA

SCLK

AGP2

AGP1

GND_AGP

÷2,3,4

PCI1:8

Stop

Clock

PCI_STOP#

*FS1

*FS0

AGP0

VDD_AGP

Control

SDATA

SCLK

SMBus

Logic

VDD_48 MHz

48MHz/FS3

Note:

1. Signals marked with ‘*’ have internal pull-up resistors.

PLL2

÷2

24_48MHz/FS2

Intel and Pentium are registered trademarks of Intel Corporation.

Cypress Semiconductor Corporation

•

3901 North First Street

•

San Jose

•

CA 95134

•

408-943-2600

Document #: 38-07254 Rev. *A

Revised December 14, 2002

PRELIMINARY

W250-03

Pin Definitions

Type

Pin Name

Pin No.

Pin Description

CPU1:3

39, 38, 35

O

CPU Clock Output: Frequency is set by the FS0:4 input or through serial input interface.

The CPU1:3 output are gated by the CLK_STOP# input.

CPU_STOP#*

PCI1:8

34

I

CPU Output Control: 3.3V LVTTL compatible input that stop CPU1:3 clocks.

10, 11, 13,

14, 16, 17,

18, 20

O

PCI Clock Outputs 1 through 8: Frequency is set by FS0:4 inputs or through serial input

interface, see Table 1 and Table 5 for details. Output voltage swing is controlled by voltage

applied to VDD_PCI.

PCI_STOP#*

PCI_F

33

9

O

PCI_STOP# Input: 3.3V LVTTL compatible input that stops PCI1:8.

Free-Running PCI Clock Output: Output voltage swing is controlled by the voltage

applied to VDD_PCI. See Table 1. and Table 5. for detailed frequency information.

PWR_DWN#*

APIC0:2

32

45, 44, 42

6

I

PWR_DWN# Input: LVTTL-compatible input that places the device in power-down mode

when held LOW.

O

APIC Clock Output: APIC clock outputs. The output voltage swing is controlled by

VDD_APIC.

48MHz/FS3*

I/O 48-MHz Output/Frequency Select 3: 48 MHz is provided in normal operation. In stan-

dard PC systems, this output can be used as the reference for the Universal Serial Bus

host controller. This pin also serves as a power-on strap option to determine device

operating frequency as described in Table 1.

24_48MHz/

FS2*

7

I/O 24_48-MHz Output/Frequency Select 2: In standard PC systems, this output can be

used as the clock input for a Super I/O chip. The output frequency is controlled by Con-

figuration Byte 3 bit[6]. The default output frequency is 24 MHz. This pin also serves as

a power-on strap option to determine device operating frequency as described in Table 1.

REF1/FS4*

47

I/O Reference Clock Output 1/Frequency Select 4: 3.3V 14.318-MHz output clock. This

pin also serves as a power-on strap option to determine device operating frequency as

described in Table 1. Upon power-up, FS4 input will be latched which will set clock fre-

quencies as described in Table 1.

REF0

SCLK

SDATA

X1

48

28

29

3

O

I

Reference Clock Output 0: 3.3V 14.318 MHz output clock.

Clock pin for serial interface circuitry.

I/O Data pin for serial interface circuitry.

I

Crystal Connection or External Reference Frequency Input: This pin has dual func-

tions. It can be used as an external 14.318-MHz crystal connection or as an external

reference frequency input.

X2

4

I

Crystal Connection: An input connection for an external 14.318-MHz crystal. If using an

external reference, this pin must be left unconnected.

FS0,FS1

22, 21

FS0, FS1 Inputs: Latched frequency select inputs. These latched input serve as a power-

on strap option to determine device operating frequency as described in Table 1.

AGP0:2

23, 26, 27

O

P

AGP Outputs: Output frequency is set by FS0:4 inputs or through serial interface.

VDD_REF,

VDD_48MHz,

VDD_PCI,

1, 5,15, 24,

31

Power Connection: Power supply for core logic, PLL circuitry, PCI outputs, reference

outputs, 48-MHz output, and 24_48-MHz output, connect to 3.3V supply.

VDD_AGP,

VDD_CORE

VDD_CPU,

VDD_APIC

41, 46, 37

P

Power Connection: Power supply for APIC and CPU1 output buffers, connect to 2.5V.

Ground Connections: Connect all ground pins to the common system ground plane.

GND_REF,

2, 8, 12, 19,

G

GND_48MHz, 25, 30, 36,

GND_PCI,

GND_AGP,

GND_CORE,

GND_CPU,

GND_APIC

40, 43

Document #: 38-07254 Rev. *A

Page 2 of 12

PRELIMINARY

W250-03

changes are normally made upon system initialization, if any

are required. The interface can also be used during system

operation for power management functions. Table 2 summa-

rizes the control functions of the serial data interface.

Serial Data Interface

The serial data interface can be used to configure internal reg-

ister settings that control particular device functions. Upon

power-up, the W250-03 initializes with default register set-

tings, therefore the use of this serial data interface is optional.

The serial interface is write-only (to the clock chip) and is the

dedicated function of device pins SDATA and SCLOCK. In

motherboard applications, SDATA and SCLOCK are typically

driven by two logic outputs of the chipset. Clock device register

Operation

Data is written to the W250-03 in eleven bytes of eight bits

each. Bytes are written in the order shown in Table 3.

Table 2. Serial Data Interface Control Functions Summary

Control Function

Description

Common Application

Clock Output Disable

Any individual clock output(s) can be disabled. Dis- Unused outputs are disabled to reduce EMI

abled outputs are actively held LOW.

and system power. Examples are clock out-

puts to unused PCI slots.

CPU Clock Frequency

Selection

Provides CPU/PCI frequency selections through

software. Frequency is changed in a smooth and

controlled fashion.

For alternate microprocessors and power

management options. Smooth frequency

transition allows CPU frequency change un-

der normal system operation.

Spread Spectrum

Enabling

Enables or disables spread spectrum clocking.

Puts clock output into a high impedance state.

For EMI reduction.

Output Three-state

(Reserved)

Production PCB testing.

Reserved function for future device revision or pro- No user application. Register bit must be writ-

duction device testing.

ten as 0.

Table 3. Byte Writing Sequence

Byte Sequence

Byte Name

Bit Sequence

Byte Description

1

Slave Address 11010010

Commands the W250-03 to accept the bits in Data Bytes 0–6 for internal

register configuration. Since other devices may exist on the same com-

mon serial data bus, it is necessary to have a specific slave address for

each potential receiver. The slave receiver address for the W250-03 is

11010010. Register setting will not be made if the Slave Address is not

correct (or is for an alternate slave receiver).

2

3

Command

Code

Don’t Care

Unused by the W250-03, therefore bit values are ignored (“don’t care”).

This byte must be included in the data write sequence to maintain proper

byte allocation. The Command Code Byte is part of the standard serial

communication protocol and may be used when writing to another ad-

dressed slave receiver on the serial data bus.

Byte Count

Unused by the W250-03, therefore bit values are ignored (“don’t care”).

This byte must be included in the data write sequence to maintain proper

byte allocation. The Byte Count Byte is part of the standard serial com-

munication protocol and may be used when writing to another ad-

dressed slave receiver on the serial data bus.

4

5

Data Byte 0

Data Byte 1

Data Byte 2

Data Byte 3

Data Byte 4

Data Byte 5

Data Byte 6

Data Byte 7

Refer to Table 4 The data bits in Data Bytes 0–7 set internal W250-03 registers that

control device operation. The data bits are only accepted when the Ad-

dress Byte bit sequence is 11010010, as noted above. For description

of bit control functions, refer to Table 4, Data Byte Serial Configuration

Map.

6

7

8

9

10

11

Document #: 38-07254 Rev. *A

Page 3 of 12

PRELIMINARY

W250-03

Writing Data Bytes

7. Table 4 gives the bit formats for registers located in Data

Bytes 0–7.

Each bit in Data Bytes 0–7 controls a particular device function

except for the “reserved” bits which must be written as a logic

0. Bits are written MSB (most significant bit) first, which is bit

Table 5 details additional frequency selections that are avail-

able through the serial data interface.

Table 4. Data Bytes 0–7 Serial Configuration Map

Affected Pin

Bit Control

Bit(s) Pin No.

Data Byte 0

Pin Name

Control Function

0

1

Default

7

--

(Reserved)

SEL_2

--

0

1

0

6

See Table 5

5

SEL_1

4

SEL_0

3

Hardware/Software Frequency Select

Hardware

See Table 5

Software

2

SEL_4

SEL_3

1

0

Normal

Three-stated

Data Byte 1

7

6

5

4

--

(Reserved)

--

0

1

(Reserved)

--

(Reserved)

--

(Reserved)

--

3

2

1

0

35

38

39

42

CPU3

CPU2

CPU1

APIC2

Clock Output Disable

Low

Active

Data Byte 2

7

6

5

4

3

2

1

0

20

PCI8

PCI7

PCI6

PCI5

PCI4

PCI3

PCI2

PCI1

Clock Output Disable

Low

Active

1

18

17

16

14

13

11

10

Data Byte 3

7

6

--

(Reserved)

--

0

SEL_48MHz SEL 48MHz as the output frequency for

24_48MHz

24 MHz

48 MHz

5

4

3

6

7

9

48MHz

Clock Output Disable

Low

Active

1

24_48MHz Clock Output Disable

PCI_F

AGP2

AGP1

Clock Output Disable

2

1

27

26

Document #: 38-07254 Rev. *A

Page 4 of 12

PRELIMINARY

W250-03

Table 4. Data Bytes 0–7 Serial Configuration Map (continued)

Affected Pin

Bit Control

Bit(s) Pin No.

23

Pin Name

Control Function

Clock Output Disable

0

1

Default

0

AGP0

Low

Active

1

Data Byte 4

7

--

(Reserved)

--

0

6

5

4

3

2

1

0

Data Byte 5

7

6

--

(Reserved)

--

0

1

0

1

(Reserved)

5

4

3

2

1

0

44

45

--

APIC1

APIC0

--

Clock Output Disable

(Reserved)

Low

--

Active

--

(Reserved)

--

47

48

REF1

REF0

Clock Output Disable

Low

Active

Data Byte 6

7

--

(Reserved)

--

0

6

5

4

3

2

1

0

Data Byte 7

7

6

5

4

3

2

1

0

--

(Reserved)

--

0

Document #: 38-07254 Rev. *A

Page 5 of 12

PRELIMINARY

W250-03

Table 5. Additional Frequency Selections through Serial Data Interface Data Bytes

Input Conditions

Output Frequency

Data Byte 0, Bit 3 = 1

Bit 2

Bit 1

Bit 6

Bit 5

Bit 4

SEL_4

SEL_3

SEL_2

SEL_1

SEL_0

CPU

200.0

190.0

180.0

170.0

166.0

160.0

150.0

145.0

140.0

136.0

130.0

124.0

66.6

AGP

66.6

63.3

60.0

56.7

83.0

80.0

75.0

72.5

70.0

68.0

65.0

62.0

66.6

78.7

66.6

66.8

76.7

66.8

73.3

66.8

70.0

60.0

56.7

78.0

66.6

75.0

66.6

PCI

33.3

31.7

30.0

28.3

41.5

40.0

37.5

36.3

35.0

34.0

32.5

31.0

33.3

39.3

33.3

33.4

38.3

33.4

36.7

33.4

35.0

30.0

28.3

39.0

33.3

37.5

33.3

Spread Spectrum

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

0

1

OFF

100.0

118.0

133.3

66.8

OFF

±0.25%

OFF

100.2

115.0

133.6

66.8

±0.25%

±0.5%

OFF

100.2

110.0

133.6

105.0

90.0

±0.5%

OFF

85.0

OFF

78.0

OFF

66.6

–0.5%

OFF

100.0

75.0

133.3

–0.5%

Document #: 38-07254 Rev. *A

Page 6 of 12

PRELIMINARY

W250-03

Absolute Maximum Ratings ^[2]

Stresses greater than those listed in this table may cause per-

manent damage to the device. These represent a stress rating

above those specified in the operating sections of this specifi-

cation is not implied. Maximum conditions for extended peri-

ods may affect reliability.

only. Operation of the device at these or any other conditions

.

Parameter

V_DD, V_IN

Description

Voltage on any pin with respect to GND

Storage Temperature

Rating

–0.5 to +7.0

–65 to +150

–55 to +125

0 to +70

Unit

V

T_STG

T_B

°C

kV

Ambient Temperature under Bias

Operating Temperature

T_A

ESD_PROT

Input ESD Protection

2 (min.)

DC Electrical Characteristics: T_A= 0°C to +70°C, 3.3V, V_DD= 3.3V±5%, 2.5V, V_DD= 2.5V±5%

Parameter

Description

Test Condition

Min.

Typ.

Max.

Unit

Supply Current

I_DD

3.3V Supply Current

2.5V Supply Current

CPU1:3 = 133 MHz ^[3]

TBD

mA

I_DD

Logic Inputs

V_IL

V_IH

I_IL

Input Low Voltage

Input High Voltage

Input Low Current^[4]

Input High Current^[4]

GND – 0.3

0.8

V_DD+ 0.3

–25

V

2.0

µA

I_IH

10

Clock Outputs

V_OL

V_OH

Output Low Voltage

I_OL= 1 mA

50

mV

V

Output High Voltage

I_OH= –1 mA

3.1

2.2

Output High Voltage CPU1:3,

APIC0:2

V

I_OL

Output Low Current CPU1:3

V_OL= 1.25V

V_OL= 1.5V

V_OL= 1.25V

V_OL= 1.5V

V_OH= 1.25V

V_OH= 1.5V

V_OL= 1.5V

V_OH= 1.25V

V_OH= 1.5V

27

20.5

40

25

31

40

27

25

57

53

85

37

55

85

87

44

37

97

139

140

76

mA

PCI_F, PCI1:8

AGP0:2

APIC 0:2

REF0:1

48 MHz

76

24 MHz

76

I_OH

Output High Current CPU1:3

97

PCI_F, PCI1:8

139

140

155

94

AGP0:2

APIC0:2

48 MHz

24 MHz

76

Notes:

2. Multiple Supplies: The voltage on any input or I/O pin cannot exceed the power pin during power-up. Power supply sequencing is NOT required.

3. All clock outputs loaded with 6" 60Ω transmission lines with 22-pF capacitors.

4. Inputs have internal pull-up resistors.

Document #: 38-07254 Rev. *A

Page 7 of 12

PRELIMINARY

W250-03

DC Electrical Characteristics: T_A= 0°C to +70°C, 3.3V, V_DD= 3.3V±5%, 2.5V, V_DD= 2.5V±5% (continued)

Parameter

Description

Test Condition

Min.

Typ.

Max.

Unit

Crystal Oscillator

V_TH

X1 Input Threshold Voltage^[5]

V_DDQ3= 3.3V

1.65

18

V

C_LOAD

Load Capacitance, Imposed on

External Crystal^[6]

pF

C_IN,X1

X1 Input Capacitance^[7]

Pin X2 unconnected

Except X1 and X2

28

pF

Pin Capacitance/Inductance

C_IN

Input Pin Capacitance

5

6

7

pF

nH

C_OUT

L_IN

Output Pin Capacitance

Input Pin Inductance

AC Electrical Characteristics

T_A= 0°C to +70°C, 3.3V, V_DD= 3.3V±5%, 2.5V, V_DD= 2.5V± 5% f_XTL= 14.31818 MHz

AC clock parameters are tested and guaranteed over stated operating conditions using the stated lump capacitive load at the

clock output; Spread Spectrum is disabled.

CPU Clock Outputs (Lump Capacitance Test Load = 20 pF)

CPU = 66.6 MHz

CPU = 100 MHz

CPU = 133 MHz

Test Condition/

Comments

Parameter

Description

Period

Min. Typ. Max. Min. Typ. Max. Min. Typ. Max. Unit

t_P

Measured on rising edge

at 1.25

15

15.5

10

3.0

2.8

1

10.5 7.5

1.87

8.0

ns

t_H

t_L

t_R

t_F

t_D

t_JC

High Time

Low Time

Duration of clock cycle

above 2.0V

5.2

Duration of clock cycle be- 5.0

low 0.4V

1.67

ns

Output Rise

Edge Rate

Measured from 0.4V to

2.0V

1

4

1

4

V/ns

%

OutputFallEdge Measured from 2.0V to

1

Rate

0.4V

Duty Cycle

Measured on rising and

falling edge at 1.25V

45

55

250

45

55

250

45

55

250

Jitter,

Cycle-to-Cycle

Measured on rising edge

at 1.25V. Maximum differ-

ence of cycle time be-

ps

tween two adjacent cycles.

t_SK

f_ST

Output Skew

Measured on rising edge

at 1.25V

175

3

175

3

175

3

ps

Frequency

Assumes full supply volt-

age reached within 1 ms

from power-up. Short cy-

cles exist prior to frequen-

cy stabilization.

ms

Stabilization

from Power-up

(cold start)

Z_o

AC Output

Impedance

Average value during

switching transition. Used

for determining series ter-

mination value.

20

Ω

Notes:

5. X1 input threshold voltage (typical) is 3.3V/2.

6. The W250-03 contains an internal crystal load capacitor between pin X1 and ground and another between pin X2 and ground. Total load placed on crystal is

18 pF; this includes typical stray capacitance of short PCB traces to crystal.

7. X1 input capacitance is applicable when driving X1 with an external clock source (X2 is left unconnected).

Document #: 38-07254 Rev. *A

Page 8 of 12

PRELIMINARY

W250-03

PCI Clock Outputs, PCI0:5 (Lump Capacitance Test Load = 30 pF)

Parameter

Description

Period

Test Condition/Comments

Measured on rising edge at 1.5V

Min.

30

12

1

Typ.

Max.

Unit

ns

t_P

t_H

t_L

High Time

Duration of clock cycle above 2.4V

Duration of clock cycle below 0.4V

Measured from 0.4V to 2.4V

ns

Low Time

ns

t_R

t_F

Output Rise Edge Rate

Output Fall Edge Rate

Duty Cycle

4

V/ns

%

Measured from 2.4V to 0.4V

1

t_D

t_JC

Measured on rising and falling edge at 1.5V

45

55

500

Jitter, Cycle-to-Cycle

Measured on rising edge at 1.5V. Maximum

ps

difference of cycle time between two adjacent cycles.

t_SK

t_O

Output Skew

Measured on rising edge at 1.5V

500

4

ps

ns

CPU to PCI Clock Skew Covers all CPU/PCI outputs. Measured on rising

edge at 1.5V. CPU leads PCI output.

1.5

f_ST

Frequency Stabilization

from Power-up (cold

start)

Assumes full supply voltage reached within 1 ms

from power-up. Short cycles exist prior to frequency

stabilization.

3

ms

Z_o

AC Output Impedance

Average value during switching transition. Used for

determining series termination value.

30

Ω

AGP Clock Outputs (Lump Capacitance test Load = 30 pF)

Parameter

Description

Test Condition/Comments

Measured on rising edge at 1.5V

Duration of clock cycle above 2.4V

Duration of clock cycle below 0.4V

Measured from 0.4V to 2.4V

Min.

Typ.

Max. Unit

t_P

t_H

t_L

Period

15

5.25

5.05

1

ns

High Time

Low Time

t_R

t_F

Output Rise Edge Rate

Output Fall Edge Rate

Duty Cycle

4

V/ns

%

Measured from 2.4V to 0.4V

1

t_D

t_JC

Measured on rising and falling edge at 1.5V

45

55

500

Jitter, Cycle-to-Cycle

Measured on rising edge at 1.5V. Maximum

difference of cycle time between two adjacent

cycles.

ps

t_SK

f_ST

Output Skew

Measured on rising edge at 1.5V

250

3

ps

FrequencyStabilizationfrom Assumes full supply voltage reached within 1

Power-up (cold start)

ms

ms from power-up. Short cycles exist prior to

frequency stabilization.

Z_o

AC Output Impedance

Average value duringswitching transition. Used

for determining series termination value.

30

Ω

APIC Clock Output (Lump Capacitance Test Load = 20 pF)

Parameter

Description

Frequency, Actual

Output Rise Edge Rate

Output Fall Edge Rate

Duty Cycle

Test Condition/Comments

Frequency generated from PCI divided by 2

Measured from 0.4V to 2.4V

Min.

Typ.

Max. Unit

f

PCI/2

MHz

t_R

0.5

45

2

V/ns

%

t_F

Measured from 2.4V to 0.4V

t_D

Measured on rising and falling edge at 1.5V

55

3

f_ST

FrequencyStabilizationfrom Assumes full supply voltage reached within

ms

Power-up (cold start)

1 ms from power-up. Short cycles exist prior to

frequency stabilization.

Z_o

AC Output Impedance

Average value duringswitching transition. Used

for determining series termination value.

20

Ω

Document #: 38-07254 Rev. *A

Page 9 of 12

PRELIMINARY

W250-03

REF Clock Outputs (Lump Capacitance Test Load = 20 pF)

Parameter

Description

Frequency, Actual

Output Rise Edge Rate

Output Fall Edge Rate

Duty Cycle

Test Condition/Comments

Frequency generated by crystal oscillator

Measured from 0.4V to 2.4V

Min.

Typ.

Max. Unit

f

14.318

MHz

t_R

0.5

45

2

V/ns

%

t_F

Measured from 2.4V to 0.4V

t_D

Measured on rising and falling edge at 1.5V

55

3

f_ST

FrequencyStabilizationfrom Assumes full supply voltage reached within

ms

Power-up (cold start)

1 ms from power-up. Short cycles exist prior to

frequency stabilization.

Z_o

AC Output Impedance

Average value duringswitching transition. Used

for determining series termination value.

40

Ω

48-MHz Clock Output (Lump Capacitance Test Load = 20 pF)

Parameter

Description

Frequency, Actual

Deviation from 48 MHz

PLL Ratio

Test Condition/Comments

Determined by PLL divider ratio (see m/n below)

(48.008 – 48)/48

Min.

Typ.

48.008

+167

Max. Unit

MHz

f

f_D

ppm

m/n

t_R

(14.31818 MHz x 57/17 = 48.008 MHz)

Measured from 0.4V to 2.4V

57/17

Output Rise Edge Rate

Output Fall Edge Rate

Duty Cycle

0.5

45

2

V/ns

%

t_F

Measured from 2.4V to 0.4V

t_D

Measured on rising and falling edge at 1.5V

55

3

f_ST

Frequency Stabilization

Assumes full supply voltage reached within 1 ms

ms

from Power-up (cold start) from power-up. Short cycles exist prior to fre-

quency stabilization.

Z_o

AC Output Impedance

Average value during switching transition. Used

for determining series termination value.

40

Ω

24-MHz Clock Output (Lump Capacitance Test Load = 20 pF)

Parameter

Description

Frequency, Actual

Deviation from 24 MHz

PLL Ratio

Test Condition/Comments

Determined by PLL divider ratio (see m/n below)

(24.004 – 24)/24

Min.

Typ.

24.004

+167

Max. Unit

MHz

f

f_D

ppm

m/n

t_R

(14.31818 MHz x 57/34 = 24.004 MHz)

Measured from 0.4V to 2.4V

57/34

Output Rise Edge Rate

Output Fall Edge Rate

Duty Cycle

0.5

45

2

V/ns

%

t_F

Measured from 2.4V to 0.4V

t_D

Measured on rising and falling edge at 1.5V

55

3

f_ST

Frequency Stabilization

Assumes full supply voltage reached within 1 ms

ms

from Power-up (cold start) from power-up. Short cycles exist prior to fre-

quency stabilization.

Z_o

AC Output Impedance

Average value during switching transition. Used

for determining series termination value.

40

Ω

Ordering Information

Package

Name

Ordering Code

Package Type

W250-03

H

48-pin SSOP (300 mils)

Document #: 38-07254 Rev. *A

Page 10 of 12

PRELIMINARY

W250-03

Package Diagram

48-Pin Small Shrink Outline Package (SSOP, 300 mils)

Summary of nominal dimensions in inches:

Body Width: 0.296

Lead Pitch: 0.025

Body Length: 0.625

Body Height: 0.102

Document #: 38-07254 Rev. *A

Page 11 of 12

PRELIMINARY

W250-03

Document Title: W250-03 FTG for VIA Apollo Pro-266

Document Number: 38-07254

Issue

Orig. of

Change

REV.

**

ECN NO.

110519

Date

Description of Change

01/07/02

12/14/02

SZV

RBI

Change from Spec number: 38-01080 to 38-07254

*A

122856

Power up requirements added to Operating Conditions Information

Document #: 38-07254 Rev. *A

Page 12 of 12

of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize

its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress

Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.


型号：	W250-03
厂家：	ETC
描述：	Clocks and Buffers 时钟和缓冲器\n 时钟
文件：	总12页 (文件大小：123K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

W250-03 [ETC]

相关型号：

W250-03H

W250-03HT

W2500EP

W2500ET

W250HT

W2523SURC/E

W2530-12D12

W2530-12D15

W2530-12D5

W2530-12S12

W2530-12S15

W2530-12S3.3