ETC IMISG571DTB

SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
FREQUENCY TABLE
PRODUCT FEATURES
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•

Supports Pentium Processors.
3 Hi Drive CPU clocks.
Up to 8 SDRAM clocks for 2 DIMMs.
Supports Power Management.
7 PCI synchronous clocks.
Optional common or mixed supply mode:
(Vdd = Vddq3 = Vddq2 = 3.3V) or
(Vdd = Vddq3 = 3.3V, Vddq2 = 2.5V)
< 250ps skew CPU and SDRAM clocks.
< 250ps skew among PCI clocks.
I2C 2-Wire serial interface
Programmable registers featuring:
- enable/disable each output pin
- mode as tri-state, test, or normal
- 24/48 MHz selections
1 IOAPIC clock for multiprocessor support.
48-pin SSOP and TSSOP package
Spread Spectrum Technology for up to
13dB of EMI reduction
Xin
Xout
REF
OSC
3
CPU
PCI
0
60.0
30.0
1
66.6*
*Spread Spectrum mode capable
33.3*
CONNECTION DIAGRAM
IMISG571D
BLOCK DIAGRAM
Buffers
SEL
REF0,1,2
Vddq2
IOAPIC0
REF1
1
48
Vdd
REF0
2
47
REF2
Vss
3
46
Vddq2
Xin
4
45
IOAPIC0
Xout
5
44
PWR_DWN#
MODE
6
43
Vss
Vddq3
7
42
CPUMCLK0
PCICLK_F
8
41
CPUCLK
PCICLK0
9
40
Vddq2
Vss
10
39
CPUMCLK1
PCICLK1
11
38
PCICLK2
12
37
Vss
PCICLK3
13
36
SDRAM0
PCICLK4
14
35
SDRAM1
Vddq3
15
34
Vddq3
PCICLK5
16
33
SDRAM2
Vss
17
32
SDRAM3
SEL
18
31
Vss
SDATA
19
30
SDRAM4
SDCLK
20
29
SDRAM5
Vddq3
N/C
Buffer
Vddq2
SDATA
SDCLK
3
Buffers
Vddq3
SEL
PLL1
dly
8
Buffers
6
CPUMCLK (0:1)
CPUCLK
SDRAM0~7
PCICLK0~5
Vddq3
21
28
48/24MHZ
22
27
SDRAM6/CPU_STOP#
48/24MHZ
23
26
SDRAM7/PCI_STOP#
Vss
24
25
Vdd
Buffers
PCI_STOP#
CPU_STOP#
PWR_DWN#
MODE
PCICLK_F
Buffer
2
Buffer
48/24MHZ
PLL2
Buffer
48/24MHZ
Purchase of I C components of International Microcircuits, Inc. or one
of its sublicensed Associated Companies conveys a license under the
2
2
Philips I C Patent Rights to use these components in an I C system,
2
provided that the system conforms to the I C Standard Specification
as defined by Philips.
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 1 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
PIN DESCRIPTION
Xin, Xout - These pins form an on-chip reference oscillator
when connected to terminals of an external parallel resonant
crystal (nominally 14.318 MHz). Xin may also serve as input
for an externally generated reference signal.
PCICLK_F - A PCI clock output that does not stop until in
power down mode. It is synchronous with other PCI clocks.
SEL - Standard frequency select input. It has internal pull-up.
IOAPIC0 - Buffered output of 14.3MHZ for multiprocessor
support. It is powered by Vddq2.
CPUCLK - Hose clock output primarily use to drive the
SDRAM.
CPUMCLK(0:1) - High drive host clock output primarily used

to drive Mobil Pentium processor modules.
SDRAM(0:5) - Synchronous DRAM DIMs clocks. They are
powered by Vddq3.
SDRAM6/CPU_STOP# - If MODE=1, this pin is a
Synchronous DRAM DIMs clock output. If MODE=0, this pin
is a CPU_STOP# input signal, where a low level stops the
CPU however, the SDRAM clocks will stay active. It has an
internal pull-up.
SDRAM7/PCI_STOP# - If MODE=1, this pin is a
Synchronous DRAM DIMs clock output. If MODE=0, this pin
is a PCI_STOP# input signal, where a low level stops the PCI
clocks. It has an internal pull-up.
MODE - A low level on this pin causes pins 26, and 27 to be
power management inputs PCI_STOP#, and CPU_STOP#
respectly. A high level on this pin causes pins 26, and 27 to
be clock output signals SDRAM7, and SDRAM6 respectively.
It has an internal pull-up resistor.
REF(0:2) - Buffered outputs of on-chip reference.
PWR_DWN# - Power down pin. When this pin is asserted
low, the IC is in shutdown mode where all circuitry is turned
off including VCO, crystal buffer and PCICLK_F. It has an
2
internal pull-up. The I C interface is disabled with the
PWR_DWN# pin is low.
48/24MHz(0:1) - Programmable 48 MHZ or 24 MHZ clock
outputs.
2
SDATA - serial data of I C 2-wire control interface. Has
internal pull-up resistor.
2
SDCLK - serial clock of I C 2-wire control interface. Has
internal pull-up resistor.
Vss - Ground pins for the chip.
Vdd - 3.3 Volt power supply pins for analog circuit and core
logic.
Vddq3 - Power supply pins for 3.3V IO pins.
Vddq2 - Power supply pins for 2.5V/3.3V IO pins.
PCICLK(0:5) - Low skew (<250pS) clock outputs for PCI
frequencies.
These buffers voltage level is controlled by
Vddq3
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 2 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
POWER MANAGEMENT FUNCTIONS
All clocks can be individually enabled or stopped via the 2-wire control interface. All clocks are stopped in the low state.
All clocks maintain a valid high period on transitions from running to stopped and on transitions from stopped to running
when the chip was not powered down. On power up, the VCOs will stabilize to the correct pulse widths within about 0.2
mS. The CPU, SDRAM, and PCI clocks transition between running and stopped by waiting for one positive edge on
PCICLK_F followed by a negative edge on the clock of interest, after which high levels of the output are either enabled
or disabled.
When MODE=0, pins 26 and 27 are inputs PCI_STOP# and CPU_STOP# respectively (when MODE=1, these functions
are not available). A particular output is enabled only when both the serial interface and these pins indicate that it should
be enabled. The IMISG571D clocks may be disabled according to the following table in order to reduce power
consumption. All clocks are stopped in the low state. All clocks maintain a valid high period on transitions from running
to stopped. On low to high transitions of PWR_DWN#, external circuitry should allow 0.2 mS for the VCOs to stabilize
prior to assuming the clock periods are correct. The CPU and PCI clocks transition between running and stopped by
waiting for one positive edge on PCICLK_F followed by a negative edge on the clock of interest, after which high levels
of the output are either enabled or disabled.
CPU_STOP#
X
0
0
1
1
PCI_STOP#
X
0
1
0
1
PWR_DWN#
0
1
1
1
1
CPUCLK
LOW
LOW
LOW
66/60 MHZ
66/60 MHZ
PCICLK
LOW
LOW
33/30 MHZ
LOW
33/30 MHZ
OTHER CLKs
LOW
RUNNING
RUNNING
RUNNING
RUNNING
XTAL & VCOs
OFF
RUNNING
RUNNING
RUNNING
RUNNING
POWER MANAGEMENT TIMING
PCICLK_F
PCI_STOP#
PCICLK(0:5)
CPU_STOP#
CPUCLK(0:2)
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 3 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
2-WIRE I2C CONTROL INTERFACE
The 2-wire control interface implements a write only slave interface. The IMISG571D cannot be read back. Subaddressing is not supported, thus all preceding bytes must be sent in order to change one of the control bytes. The 2wire control interface allows each clock output to be individually enabled or disabled. It also allows 24/48 MHZ frequency
selection and test mode enable.
During normal data transfer, the SDATA signal only changes when the SDCLK signal is low, and is stable when
SDCLK is high. There are two exceptions to this. A high to low transition on SDATA while SDCLK is high is used to
indicate the start of a data transfer cycle. A low to high transition on SDATA while SDCLK is high indicates the end of a
data transfer cycle. Data is always sent as complete 8-bit bytes, after which an acknowledge is generated. The first
byte of a transfer cycle is a 7-bit address with a Read/Write bit as the LSB. Data is transferred MSB first.
The device will respond to writes to 10 bytes (max) of data to address D2 by generating the acknowledge (low)
signal on the SDATA wire following reception of each byte. The device will not respond to any other control interface
2
conditions. The I C interface is disabled when the PWR_DWN# pin is low. Previously set control registers are retained.
SERIAL CONTROL REGISTERS
NOTE: The Pin# column lists the affected pin number where applicable. The @Pup column gives the state at true
power up. Bytes are set to the values shown only on true power up, and not when the PWR_DWN# pin is activated.
Following the acknowledge of the Address Byte (D2), two additional bytes must be sent:
1) “Command Code “ byte, and
2) “Byte Count” byte.
Although the data (bits) in these two bytes are considered “don’t care”, they must be sent and will be acknowledged.
Byte 0: Function Select Register
Bit
7
6
5
4
3
2
1
0
@Pup
0
0
0
0
1
1
0
0
Pin#
*
*
*
*
23
22
Description
Reserved
Reserved
Reserved
Reserved
48/24 Mhz (a”1” sets the output to 48MHz, a “0” sets the output to 24MHz)
48/24 Mhz (a”1” sets the output to 48MHz, a “0” sets the output to 24MHz)
Bit1 Bit0
1
1 Tri-State
1
0 Spread Spectrum operating mode
0
1 Test Mode
0
0 Normal operating mode
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 4 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
SERIAL CONTROL REGISTERS (Cont.)
Function Table
Function
Description
Tri-State
Test Mode
Normal SEL=1
Normal SEL=0
CPU
Hi-Z
Tclk/2
66
60
PCI
Hi-Z
Tclk/4
CPU/2
CPU/2
SDRAM
Hi-Z
Tclk/2
CPU
CPU
Outputs
Ref
Hi-Z
Tclk
14.318
14.318
IOAPIC
Hi-Z
Tclk
14.318
14.318
24MHZ
Hi-Z
Tclk/4
24
24
48MHZ
Hi-Z
Tclk/2
48
48
Notes:
1. Tclk is a test clock over driven on the Xin input during test mode.
2. The frequency ratio Fout/Fin for the USB output is 3.35294.
Byte 1: CPU, 48/24 MHz Clock Register (1 = enable, 0 = Stopped)
Bit
@Pup
Pin#
7
6
5
4
3,2
1
1
x
x
1
23
22
39
1
0
1
1
41
42
Description
48/24 MHz enable/Stopped
48/24 MHz enable/Stopped
Reserved
Reserved
Power Control for CPUMCLK1
Bit 2
Bit 3
0
0
= Disabled
1
0
= Not Allowed
0
1
= Not Allowed
1
1
= High Drive
CPUCLK enable/Stopped
CPUMCLK0 enable/Stopped
Byte 2: PCI Clock Register (1 = enable, 0 = Stopped)
Bit
7
6
5
4
3
2
1
0
@Pup
x
1
1
1
1
1
1
1
Pin#
8
16
14
13
12
11
9
Description
Reserved
PCICLK_F enable/Stopped
PCICLK5 enable/Stopped
PCICLK4 enable/Stopped
PCICLK3 enable/Stopped
PCICLK2 enable/Stopped
PCICLK1 enable/Stopped
PCICLK0 enable/Stopped
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 5 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
SERIAL CONTROL REGISTERS(Continued)
Byte 3: SDRAM Clock Register ( 1 = enable, 0 = Stopped )
Bit
7
6
5
4
3
2
1
0
@Pup
1
1
1
1
1
1
1
1
Pin#
26
27
29
30
32
33
35
36
Description
SDRAM7 enable/Stopped
SDRAM6 enable/Stopped
SDRAM5 enable/Stopped
SDRAM4 enable/Stopped
SDRAM3 enable/Stopped
SDRAM2 enable/Stopped
SDRAM1 enable/Stopped
SDRAM0 enable/Stopped
Byte 4: Additional SDRAM Clock Register (1 = enable, 0 = Stopped)
Bit
7
6
5
4
3
2
1
0
@Pup
x
x
x
x
x
x
x
x
Pin#
-
Description
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Reserved
Byte 5: Peripheral Control (1 = enable, 0 = Stopped)
Bit
7
6
5
4
3
2
1
0
@Pup
x
x
1
1
x
1
1
1
Pin#
45
47
1
2
Description
Reserved
Reserved
Reserved
IOAPIC0 enable/Stopped
Reserved
REF2 enable/Stopped
REF1 enable/Stopped
REF0 enable/Stopped
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 6 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
SPREAD SPECTRUM CLOCK GENERATION (SSCG)
Spread Spectrum is a modulation technique applied here for maximum efficiency in minimizing Electro-Magnetic
Interference radiation generated from repetitive digital signals mainly clocks. A clock accumulates EM energy at the
center frequency it is generating. Spread Spectrum distributes this energy over a small frequency bandwidth therefore
spreading the same amount of energy over a spectrum. This technique is achieved by modulating the clock down from
its resting frequency by a certain percentage (which also determines the energy distribution bandwidth). In this product,
the modulation is 1.0% down from the resting frequency.
Amplitude
(dB)
Without Spectrum Spread
With Spectrum Spread
Modulated Center
Frequency
Frequency(MHz)
Rested Center
frequency
Spectrum Analysis
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 7 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
MAXIMUM RATINGS
This device contains circuitry to protect the inputs
against damage due to high static voltages or electric
Voltage Relative to VSS:
-0.3V
field; however, precautions should be taken to avoid
Voltage Relative to VDD:
0.3V
application of any voltage higher than the maximum
Storage Temperature:
rated voltages to this circuit. For proper operation, Vin
-65ºC to + 150ºC
Operating Temperature:
and Vout should be constrained to the range:
0ºC to +70ºC
Maximum Power Supply:
VSS<(Vin or Vout)<VDD
7V
Unused inputs must always be tied to an appropriate
logic voltage level (either VSS or VDD).
ELECTRICAL CHARACTERISTICS
Characteristic
Symbol
Min
Typ
Max
Units
Conditions
Input Low Voltage
VIL
-
-
0.8
Vdc
-
Input High Voltage
VIH
2.0
-
-
Vdc
-
Input Low Current
IIL
-66
µA
Input High Current
IIH
5
µA
Output Low Voltage
IOL = 4mA
VOL
-
-
0.4
Vdc
All Outputs (see buffer spec)
Output High Voltage
IOH = 4mA
VOH
2.4
-
-
Vdc
All Outputs Using 3.3V Power
(see buffer spec)
Tri-State leakage Current
Ioz
-
-
10
µA
Dynamic Supply Current
Idd
-
-
100
mA
CPU = 66.6 MHz, PCI = 33.3 MHz
Static Supply Current
Isdd
-
-
1
mA
Powered Down = Active
Short Circuit Current
ISC
25
-
-
mA
1 output at a time - 30 seconds
VDD = VDDQ3 =3.3V ±5%, VDDQ2 = 2.5V±5% , TA = 0ºC to +70ºC
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 8 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
SWITCHING CHARACTERISTICS
Characteristic
Symbol
Min
Typ
Max
Units
Conditions
Output Duty Cycle
-
45
50
55
%
Measured at 1.5V
CPU to PCI Offset
tOFF
1
-
4
ns
15 pf Load Measured at 1.5V
tSKEW
-
-
250
ps
15 pf Load Measured at 1.5V
∆Period Adjacent Cycles
∆P
-
-
+250
ps
-
Jitter Spectrum 20 dB
Bandwidth from Center
BWJ
500
KHz
Overshoot/Undershoot
Beyond Power Rails
Vover
-
1.5
V
22 ohms @ source of 8 inch PCB run
to 15 pf load
Ring Back Exclusion
VRBE
0.7
2.1
V
note1
Buffer out Skew All CPU
and PCI Buffer Outputs
-
VDD = VDDQ3 =3.3V ±5%, VDDQ2 = 2.5V±5% , TA = 0ºC to +70ºC
note 1: Ring Back must not enter this range.
TB40_V TYPE BUFFER CHARACTERISTICS FOR IOAPIC AND CPUCLKs
Characteristic
Symbol
Min
Typ
Max
Units
Conditions
Pull-Up Current
IOH
22
-
31
mA
Vout = VDD - .5V
Pull-Up Current
IOH
37
-
56
mA
Vout = 1.25V
Pull-Down Current
IOL
30
-
41
mA
Vout = 0.4V
Pull-Down Current
IOL
75
-
102
mA
Vout = 1.2V
Rise/Fall Time Min Between 0.4 V and 2.0 V
TRFmin
0.4
-
-
nS
10 pF Load
Rise/Fall Time Max Between 0.4 V and 2.0 V
TRFmax
-
-
1.9
nS
20 pF Load
VDD = VDDQ3 =3.3V ±5%, VDDQ2 = 2.5V±5% , TA = 0ºC to +70ºC
TB5L TYPE BUFFER CHARACTERISTICS FOR REF(1:2) and 48/24 MHz
Characteristic
Symbol
Min
Typ
Max
Units
Conditions
Pull-Up Current
IOH
13
-
17
mA
Vout = VDD - .5V
Pull-Up Current
IOH
30
-
44
mA
Vout = 1.5V
Pull-Down Current
IOL
13
-
19
mA
Vout = 0.4V
Pull-Down Current
IOL
32
44
19
mA
Vout = 1.5V
Rise/Fall Time Min Between 0.4 V and 2.4 V
TRFmin
1.0
-
-
nS
10 pF Load
Rise/Fall Time Max Between 0.4 V and 2.4 V
TRFmax
-
-
2.0
nS
20 pF Load
VDD = VDDQ3 =3.3V ±5%, VDDQ2 = 2.5V±5% , TA = 0ºC to +70ºC
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 9 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
TB40AX TYPE BUFFER CHARACTERISTICS FOR REF0 and SDRAM(0:7)
Characteristic
Symbol
Min
Typ
Max
Units
Conditions
Pull-Up Current
IOH
30
-
39
mA
Vout = VDD - .5V
Pull-Up Current
IOH
75
-
109
mA
Vout = 1.5V
Pull-Down Current
IOL
30
-
40
mA
Vout = 0.4V
Pull-Down Current
IOL
75
-
103
mA
Vout = 1.2V
Rise/Fall Time Min Between 0.4 V and 2.4 V
TRFmin
0.5
-
-
nS
20 pF Load
Rise/Fall Time Max Between 0.4 V and 2.4 V
TRFmax
-
-
2.0
nS
30 pF Load
VDD = VDDQ3 =3.3V ±5%, VDDQ2 = 2.5V±5% , TA = 0ºC to +70ºC
TB4L TYPE BUFFER CHARACTERISTICS FOR PCICLK(0:5,F)
Characteristic
Symbol
Min
Typ
Max
Units
Conditions
Pull-Up Current
IOH
18
-
23
mA
Vout = VDD -.5V
Pull-Up Current
IOH
44
-
64
mA
Vout = 1.5V
Pull-Down Current
IOL
18
-
25
mA
Vout = 0.4V
Pull-Down Current
IOL
50
-
70
mA
Vout = 1.5V
Rise/Fall Time Min Between 0.4 V and 2.4 V
TRFmin
0.5
-
-
nS
15 pF Load
Rise/Fall Time Max Between 0.4 V and 2.4 V
TRFmax
-
-
2.0
nS
30 pF Load
VDD = VDDQ3 =3.3V ±5%, VDDQ2 = 2.5V±5% , TA = 0ºC to +70ºC
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 10 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
TYPE 6 BUFFER CHARACTERISTICS FOR CPUMCLK IN HIGH DRIVE MODE
Characteristic
Symbol
Min
Typ
Max
Units
Conditions
Pull-Up Current
IOH
130
180
250
mA
Vout = 1.0 V
Pull-Up Current
IOH
65
90
120
mA
Vout = 2.0 V
Pull-Down Current
IOL
125
170
220
mA
Vout = 1.2 V
Pull-Down Current
IOL
40
60
80
mA
Vout = 0.3 V
Rise/Fall Time Min
Between 0.4 V and 2.0 V
TRFmin
0.4
-
-
nS
10 pF Load
Rise/Fall Time Max
Between 0.4 V and 2.0 V
TRFmax
-
-
1.6
nS
20 pF Load
VDD = VDDQ3 =3.3V ±5%, VDDQ2 = 2.5V±5% , TA = 0ºC to +70ºC
CRYSTAL AND REFERENCE OSCILLATOR PARAMETERS
Characteristic
Symbol
Min
Typ
Max
Units
Frequency
Fo
12.00
14.31818
16.00
MHz
Tolerence
TC
-
-
+/-100
PPM
Calibration note 1
TS
-
-
+/- 100
PPM
Stability (Ta -10 to +60C) note 1
TA
-
-
5
PPM
Aging (first year @ 25C) note 1
Mode
OM
-
-
-
Pin Capacitance
CP
DC Bias Voltage
VBIAS
0.3Vdd
Vdd/2
0.7Vdd
V
Startup time
Ts
-
-
30
µS
Load Capacitance
CL
-
20
-
pF
Effective Series
resonant
resistance
R1
-
-
40
Ohms
Power Dissipation
DL
-
-
0.10
mW
Shunt Capacitance
CO
-
--
8
pF
6
Conditions
Parallell Resonant
pF
Capacitance of XIN and Xout pins to
ground (each)
the crystals rated load. note 1
note 1
crystals internal package
capacitance (total)
For maximum accuracy,the total circuit loading capacitance should be equal to CL. This loading capacitance is the
effective capacitance across the crystal pins and includes the device pin capacitance (CP) in parallel with any circuit
traces, the clock generator and any onboard discrete load capacitors.
Budgeting Calculations
Typical trace capacitance, (< half inch) is 4 pF, Load to the crystal is therefore
2.0 pF
Clock generator internal pin capacitance of 36 pF, Load to the crystal is therefore
3.0 pF
External crystal loading capacitors (connect to ground)
15.0 pF
the total parasitic capacitance would therefore be
= 20.0.0 pF.
Note 1: It is recommended but not mandatory that a crystal meets these specifications.
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 11 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
PCB LAYOUT SUGGESTION
Via to VDD Island
Via to GND plane
IMISG571D
3.3V
VCC
FB1
48
1
2
3
C3
4
22µF
5
C4
6
7
47
46
C11
45
44
FB2
43
VCC2.5V
42
41
8
C12
40
C10
9
10
11
12
13
C5
14
15
16
17
18
19
C6
20
21
22
23
24
39
22µF
38
C14
37
36
35
34
C9
33
32
31
30
29
28
C8
27
26
25
C7
This is only a layout recommendation for best performance and lower EMI. The designer may choose a
different approach but C4, C5, C6, C7, C8, C9, C10, C11and C12 (all are 0.1µf) should always be used and
placed close to their VDD pins.
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 12 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
PACKAGE DRAWING AND DIMENSIONS
48 PIN SSOP OUTLINE DIMENSIONS
INCHES
SYMBOL
C
L
MIN
NOM
MAX
MIN
NOM
MAX
A
0.095
0.102
0.110
2.41
2.59
2.79
A1
0.008
0.012
0.016
0.20
0.31
0.41
A2
0.085
0.090
0.095
2.16
2.29
2.41
b
0.008
0.010
0.0135
0.203
0.254
0.343
c
0.005
.008
0.010
0.127
0.20
0.254
D
0.620
0.625
0.637
15.75
15.88
16.18
E
0.291
0.295
0.299
7.39
7.49
7.59
H
E
D
a
A2
e
0.0256 BSC
0.640 BSC
H
0.395
0.408
0.420
10.03
10.36
10.67
L
0.024
0.030
0.040
0.61
0.76
1.02
a
0º
4º
8º
0º
4º
8º
A
A1
B
MILLIMETERS
e
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 13 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
PACKAGE DRAWING AND DIMENSIONS (Cont.)
48 PIN TSSOP DIMENSIONS
D
R0.1
INCHES
SYMBOL
NOM
MAX
MIN
NOM
MAX
E
E1
BO
L20
-B385
MIN
MILLIMETERS
A
-
-
0.0433
-
-
1.10
A1
0.002
0.004
0.006
0.05
0.10
0.15
A2
0.033
0.035
0.037
0.85
0.90
0.95
L
0.019
0.023
0.029
0.50
0.60
0.75
R
0.043
-
-
0.10
-
-
b
0.006
-
0.010
0.170
-
0.27
b1
0.006
0.008
0.009
0.170
0.20
0.225
c
0.004
-
0.007
0.105
-
0.175
c1
0.004
0.005
0.006
0.105
0.125
0.145
θ
0°
-
8°
0°
-
8°
SURFACES ROUGHNESS: 6+ 27n(RZ)
4
RD
[10° TYP
-C-
0.07
C
B
e
R1.30
0.10~0.15
1.0
0.00 ~ 0.05
e
SECTION V-V
[2?
0.50 BSC
D
0.488
0.492
0.496
12.40
12.50
12.60
E
0.313
0.319
0.325
7.95
8.1
8.25
E1
0.236
0.240
0.244
6.00
6.1
6.20
0.05 MAX.
R0.15
4
0.020 BSC
1.0
0.05 MAX.
1.0
A
E
b
.08
C B
A
(8?)
c1
0.25
c
A
A2
R
A1
L
b1
L1
DET
DET
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 14 of 15
SG571D
I2C Frequency Clock Generator w/ EMI Reduction Spread Spectrum Technology
for Pentium Processor Based Designs.
Approved Product
ORDERING INFORMATION
Part Number
Package Type
Production Flow
IMISG571DYB
48 PIN SSOP
Commercial, 0ºC to +70ºC
IMISG571DTB
48 PIN TSSOP
Commercial, 0ºC to +70ºC
Note:
The ordering part number is formed by a combination of device number, device revision, package style, and
screening as shown below.
Marking: Example:
IMI
SG571DYB
Date Code, Lot #
IMISG571DYB
Flow
B = Commercial, 0ºC to + 70ºC
Package
Y = SSOP
T = TSSOP
Revision
IMI Device Number
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.4
8/10/98
Page 15 of 15