ICS ICS9248YG-92

Integrated
Circuit
Systems, Inc.
ICS9248-92
TM
Mobile Pentium II System Clock Chip
Recommended Application:
The ICS9248-92 is a fully compliant timing solution for the
Intel mobile 440BX/MX chipset requirements.
Features
General Description:
Features include two strong CPU, seven PCI and eight SDRAM
clocks. Three reference outputs are available equal to the
crystal frequency. Stronger drive CPUCLK outputs typically
provide greater than 1 V/ns slew rate into 20pF loads. This
device meets rise and fall requirements with 2 loads per CPU
output (ie, one clock to CPU and NB chipset, one clock to two
L2 cache inputs).
•
PWR_DWN# pin allows low power mode by stopping crystal
OSC and PLL stages. For optional power management,
CPU_STOP# can stop CPU (0:1) clocks and PCI_STOP# will
stop PCICLK (0:5) clocks
PCICLK outputs typically provide better than 1V/ns slew rate
into 30pF loads while maintaining 50±5% duty cycle. The REF
clock outputs typically provide better than 0.5V/ns slew rates.
•
•
•
•
•
•
•
•
•
Generates system clocks for CPU, SDRAM, PCI, plus
14.318 MHz REF(0:2), USB, Plus Super I/O
I2C serial configuration interface provides output clock
disabling and other functions
MODE input pin selects optional power management
input control pins
Two fixed outputs separately selectable as 24 or 48MHz
2.5V outputs: CPU
3.3V outputs: SDRAM, PCI, REF, 48/24 MHz
No power supply sequence requirements
Uses external 14.318MHz crystal
48 pin 240 mil TSSOP package
Output enable register
for serial port control:
1 = enable
0 = disable
The ICS9248-92 accepts a 14.318MHz reference crystal or
clock as its input and runs on a 3.3V core supply.
Pin Configuration
Block Diagram
48-Pin TSSOP 240 mil Package
Functionality
Crystal (X1, X2) = 14.31818 MHz
Pentium is a trademark on Intel Corporation.
9248-92 Rev E 02/21/01
SEL
100/66#
0
CPUCLK
(MHz)
66.6
PCICLK
(MHz)
33.3
1
100
33.3
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.
ICS9248-92
Pin Descriptions
PIN NUMBER
PIN NAME
TYPE
45, 1, 2
3, 10, 17, 24,
31, 37, 43
4
REF [2:0]
OUT
Reference clock Output
GND
PWR
Ground (common)
X1
IN
5
X2
OUT
6
MODE
IN
7, 15
8
VDDPCI
PCICLK_F
PWR
OUT
Supply for PCICLK_F, PCICLK [0:5], nominal 3.3V
Free running PCI clock, not affected by PCI_STOP#
9, 11, 12, 13, 14, 16
PCICLK [0:5]
OUT
18
SEL100/66#
IN
19
SDATA
IN
PCI clocks
Selects 66.6MHz or 100MHz for SDRAM and CPU
(see tables page 1, 3)
I2C data input
20
SCLK
IN
I2C clock input
21
VDD48
PWR
Supply for 48/24MHzA, 48/24MHzB, nominal 3.3V
22
48/24MHzA
OUT
48/24MHz driver output for USB or Super I/O
23
48/24MHzB
OUT
48/24MHz driver output for USB or Super I/O
25
VDDCOR
PWR
Supply for PLL core, nominal 3.3V
SDRAM7
PCI_STOP#
SDRAM6
OUT
IN
OUT
SDRAM clock output, fanout buffer output from BUF_IN pin
Halts PCI Bus [0:5] at logic "0" level when low
SDRAM clock output, fanout buffer output from BUF_IN pin
CPU_STOP#
IN
28, 34
VDDSDR
PWR
40
VDDLCPU
PWR
42, 41
CPUCLK [0:1]
OUT
36, 35, 33, 32, 30, 29
SDRAM [0:5]
OUT
38
FB
OUT
39
BUF_IN
IN
44
PWR_DWN#
IN
48, 46
VDDREF
PWR
26
27
DESCRIPTION
Crystal or reference input, has internal crystal load cap
Crystal output, has internal load cap and feedback
resistor to X1
Input function selection (see table page 3)
Halts CPU clocks at logic "0" level when low
Supply for SDRAM [0:5], SDRAM6/CPU_STOP#,
SDRAM7/PCI_STOP#, nominal 3.3V
Supply for CPUCLK [0:1] 2.5V nominal
CPUCLK clock output, powered by VDDL2
SDRAM clock outputs, fanout buffer outputs from
BUF_IN pin
Feedback out
Input for SDRAM buffers
When driven active (low) powers down the device into low
power state. Internal clocks are disabled, VCO and crystal
OSC are stopped.
Supply for REF [0:2], X1, X2, nominal 3.3V
Power Groups
VDDCOR = Supply for PLL core
VDDREF = REF [0:2], X1, X2
VDDPCI = PCICLK_F, PCICLK [0:5]
VDDSDR = SDRAM [0:7]
VDD48 = 48/24MHzA, 48/24MHz
VDDLCPU = CPUCLK [0:1]
2
ICS9248-92
Power-On Conditions
SEL
100/66.6#
MODE
1
1
0
1
1
0
0
0
PIN #
DESCRIPTION
41, 42
16, 14, 13, 12,
11, 9, 8
41, 42
16, 14, 13, 12,
11, 9, 8
CPUCLKs
100 MHz - w/serial config enable/disable
PCICLKs
33.3 MHz - w/serial config enable/disable
CPUCLKs
66.6 MHz - w/serial config enable/disable
PCICLKs
33.3 MHz - w/serial config enable/disable
26
PCI_STOP#
27
CPU_STOP#
8
PCICLK_F
41, 42
CPUCLKs
16, 14, 13, 12,
11, 9
PCICLKs
26
PCI_STOP#
27
CPU_STOP#
8
PCICLK_F
41, 42
CPUCLKs
16, 14, 13, 12,
11, 9
PCICLKs
FUNCTION
Power Management, PCI [0:5] Clocks
Stopped when low
Power Management, CPU [0:5] Clocks
Stopped when low
33.3 MHz - PCI Clock Free running
100 MHz - CPU Clocks w/external Stop Control and serial
config individual enable/disable.
33.3 MHz - PCI Clocks w/external Stop control and serial
config individual enable/disable.
Power Management, PCI [0:5] Clocks
Stopped when low
Power Management, CPU [0:5] Clocks
Stopped when low
33.3 MHz - PCI Clock Free running for Power Management
66.6 MHz - CPU Clocks w/external Stop control and serial
config individual enable/disable.
33.3 MHz - PCI Clocks w/external Stop control and serial
config individual enable/disable.
Example:
a) if MODE = 1, pins 26 and 27 are configured as SDRAM7 and SDRAM6 respectively.
b) if MODE = 0, pins 26 and 27 are configured as PCI_STOP# and CPU_STOP# respectively.
Power-On Default Conditions
At power-up and before device programming, all clocks will default to an enabled and “on” condition. The frequencies that are then produced
are on the MODE pin as shown in the table below.
CLOCK
REF (0:2)
48/24 MHz
D E FAU LT C O N D I T I O N AT P OW E R - U P
14.31818 MHz
48 MHz
3
ICS9248-92
General I2C serial interface information
The information in this section assumes familiarity with I2C programming.
For more information, contact ICS for an I2C programming application note.
How to Write:
How to Read:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Controller (host) sends a start bit.
Controller (host) sends the write address D2 (H)
ICS clock will acknowledge
Controller (host) sends a dummy command code
ICS clock will acknowledge
Controller (host) sends a dummy byte count
ICS clock will acknowledge
Controller (host) starts sending first byte (Byte 0)
through byte 5
• ICS clock will acknowledge each byte one at a time.
• Controller (host) sends a Stop bit
Controller (host) will send start bit.
Controler (host) sends the read address D3 (H)
ICS clock will acknowledge
ICS clock will send the byte count
Controller (host) acknowledges
ICS clock sends first byte (Byte 0) through byte 5
Controller (host) will need to acknowledge each byte
Controller (host) will send a stop bit
How to Write:
Controller (Host)
Start Bit
Address
D2(H)
ICS (Slave/Receiver)
How to Read:
Controller (Host)
Start Bit
Address
D3(H)
ACK
Dummy Command Code
ACK
ICS (Slave/Receiver)
ACK
Byte Count
Dummy Byte Count
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
Stop Bit
Byte 0
Byte 0
Byte 1
Byte 1
Byte 2
Byte 2
Byte 3
Byte 3
Byte 4
Byte 4
Byte 5
Byte 5
Stop Bit
Notes:
1.
2.
3.
4.
5.
6.
The ICS clock generator is a slave/receiver, I2C component. It can read back the data stored in the latches for verification.
Read-Back will support Intel PIIX4 "Block-Read" protocol.
The data transfer rate supported by this clock generator is 100K bits/sec or less (standard mode)
The input is operating at 3.3V logic levels.
The data byte format is 8 bit bytes.
To simplify the clock generator I2C interface, the protocol is set to use only "Block-Writes" from the controller. The
bytes must be accessed in sequential order from lowest to highest byte with the ability to stop after any complete byte
has been transferred. The Command code and Byte count shown above must be sent, but the data is ignored for those
two bytes. The data is loaded until a Stop sequence is issued.
At power-on, all registers are set to a default condition, as shown.
4
ICS9248-92
Serial Configuration Command Bitmaps
Byte 0: Functional and Frequency Select Clock Register (default on Bits 7, 6, 5, 4, 1, 0 = 0)
(default on Bits 3, 2 = 1)
Note: PWD = Power-Up Default
BIT
Bit 7
Bit 6
PIN#
-
Bit 5
-
Bit 4
Bit 3
Bit 2
23
22
Bit 1
Bit 0
-
DESCRIPTION
R e s e r ve d
R e s e r ve d
In Spread Spectrum, Controls type
( 0 = c e n t e r e d , 1 = d ow n s p r e a d )
In Spread Spectrum, Controls Spreading
(0=±0.5% 1=±0.25%)
4 8 / 2 4 M H z ( F r e q u e n cy S e l e c t ) 1 = 4 8 M H z , 0 = 2 4 M H z
4 8 / 2 4 M H z ( F r e q u e n cy S e l e c t ) 1 = 4 8 M H z , 0 = 2 4 M H z
Bit0
Bit1
1 - Tr i - S t a t e
1
0 - Spread Spectrum Enable
1
1 - Te s t m o d e
0
0 - Normal operation
0
PWD
0
0
1
0
1
1
10
Select Functions
Functionality
CPU
Tristate
HI - Z
Testmode
TCLK/2
PCI,
PCI_F
HI - Z
1
TCLK/4
1
SDRAM
REF
HI - Z
HI - Z
1
TCLK/2
TCLK
1
24 MHz
Selection
48 MHz
Selection
HI - Z
HI - Z
TCLK/4
Notes:
1. TCLK is a test clock driven on the X1 (crystal in pin) input during test mode.
5
1
TCLK/21
ICS9248-92
Byte 2: PCICLK Clock Register
Byte 1: CPU, 24/48 MHz Clock Register
BIT
PIN#
PWD
Bit 7
23
1
BIT
DESCRIPTION
PIN#
PWD
DESCRIPTION
48/24 MHz (Act/Inact)
Bit 7
-
1
R e s e r ve d
8
1
PCICLK_F (Act/Inact)
1
PCICLK5 (Act/Inact)
Bit 6
22
1
48/24 MHz (Act/Inact)
Bit 6
Bit 5
-
1
R e s e r ve d
Bit 5
16
Bit 4
-
1
R e s e r ve d
Bit 4
14
1
PCICLK4 (Act/Inact)
Bit 3
-
1
R e s e r ve d
Bit 3
13
1
PCICLK3 (Act/Inact)
Bit 2
-
1
R e s e r ve d
Bit 2
12
1
PCICLK2 (Act/Inact)
Bit 1
41
1
CPUCLK1 (Act/Inact)
Bit 1
11
1
PCICLK1 (Act/Inact)
Bit 0
42
1
CPUCLK0 (Act/Inact)
Bit 0
9
1
PCICLK0 (Act/Inact)
Notes: 1 = Enabled; 0 = Disabled, outputs held low
Notes: 1 = Enabled; 0 = Disabled, outputs held low
Byte 4: SDRAM Clock Register
Byte 3: SDRAM Clock Register
BIT
PIN#
PWD
DESCRIPTION
BIT
PIN#
PWD
-
1
R e s e r ve d
DESCRIPTION
Bit 7
26
1
SDRAM7 (Act/Inact)
Bit 7
Bit 6
27
1
SDRAM6 (Act/Inact)
Bit 6
-
1
R e s e r ve d
Bit 5
29
1
SDRAM5 (Act/Inact)
Bit 5
-
1
R e s e r ve d
Bit 4
-
1
R e s e r ve d
Bit 4
30
1
SDRAM4 (Act/Inact)
Bit 3
32
1
SDRAM3 (Act/Inact)
Bit 3
-
1
R e s e r ve d
Bit 2
-
1
R e s e r ve d
Bit 2
33
1
SDRAM2 (Act/Inact)
Bit 1
35
1
SDRAM1(Act/Inact)
Bit 1
-
1
R e s e r ve d
SDRAM0 (Act/Inact)
Bit 0
-
1
R e s e r ve d
Bit 0
36
1
Notes: 1 = Enabled; 0 = Disabled, outputs held low
Notes: 1 = Enabled; 0 = Disabled, outputs held low
Byte 5: Peripheral Clock Register
Byte 6: Optional Register for Future
BIT
PIN#
PWD
Bit 7
-
1
R e s e r ve d
DESCRIPTION
Bit 7
-
1
R e s e r ve d
Bit 6
-
1
R e s e r ve d
Bit 6
-
1
R e s e r ve d
Bit 5
-
1
R e s e r ve d
Bit 5
-
1
R e s e r ve d
Bit 4
-
1
R e s e r ve d
Bit 4
-
1
R e s e r ve d
BIT
PIN#
PWD
DESCRIPTION
Bit 3
-
1
R e s e r ve d
Bit 3
-
1
R e s e r ve d
Bit 2
45
1
REF2 (Act/Inact)
Bit 2
-
1
R e s e r ve d
Bit 1
1
1
REF1 (Act/Inact)
Bit 1
-
1
R e s e r ve d
Bit 0
2
1
REF0 (Act/Inact)
Bit 0
-
1
R e s e r ve d
Notes: 1 = Enabled; 0 = Disabled, outputs held low
PWD = Power-Up Default
Notes:
1. Byte 6 is reserved by Integrated Circuit Systems for
future applications.
Note: PWD = Power-Up Default
6
ICS9248-92
Power Management
Clock Enable Configuration
C P U _ S TO P #
P C I _ S TO P #
P W R _ DW N #
CPUCLK
PCICLK
X
0
0
1
1
X
0
1
0
1
0
1
1
1
1
L ow
Low
Low
100/66.6 MHz
100/66.6 MHz
L ow
Low
33.3 MHz
Low
33.3 MHz
Other Clocks,
SDRAM,
REF,
48/24 MHz A
48/24 MHz B
Stopped
Running
Running
Running
Running
Crystal
VCOs
O ff
Running
Running
Running
Running
O ff
Running
Running
Running
Running
Full clock cycle timing is guaranteed at all times after the system has initially powered up except where noted. During power
up and power down operations using the PWR PD# select pin will not cause clocks of a short or longer pulse than that of the
running clock. The first clock pulse coming out of a stopped clock condition may be slightly distorted due to clock network
charging circuitry. Board routing and signal loading may have a large impact on the initial clock distortion also.
ICS9248-92 Power Management Requirements
SIGNAL
SIGNAL STATE
C P U _ S TO P #
0 (Disabled)2
1 (Enabled)1
0 (Disabled)2
1 (Enabled)1
1 (Normal Operation)3
0 (Power Down)4
P C I _ S TO P #
PWR_DWN#
L a t e n cy
No. of rising edges of free running
PCICLK
1
1
1
1
3mS
2max
Notes.
1. Clock on latency is defined from when the clock enable goes active to when the first valid clock comes out of the device.
2. Clock off latency is defined from when the clock enable goes inactive to when the last clock is driven low out of the device.
3. Power up latency is when PD# goes inactive (high) to when the first valid clocks are output by the device.
4. Power down has controlled clock counts applicable to CPUCLK, SDRAM, PCICLK only.
The REF will be stopped independant of these.
7
ICS9248-92
CPU_STOP# Timing Diagram
CPUSTOP# is an asychronous input to the clock synthesizer. It is used to turn off the CPUCLKs for low power operation.
CPU_STOP# is synchronized by the ICS9248-92. The minimum that the CPUCLK is enabled (CPU_STOP# high pulse) is 100
CPUCLKs. All other clocks will continue to run while the CPUCLKs are disabled. The CPUCLKs will always be stopped in a low
state and start in such a manner that guarantees the high pulse width is a full pulse. CPUCLK on latency is less than 4 CPUCLKs
and CPUCLK off latency is less than 4 CPUCLKs.
Notes:
1. All timing is referenced to the internal CPUCLK.
2. CPU_STOP# is an asynchronous input and metastable conditions may exist. This signal is
synchronized to the CPUCLKs inside the ICS9248-92.
3. All other clocks continue to run undisturbed.
4. PD# and PCI_STOP# are shown in a high (true) state.
PCI_STOP# Timing Diagram
PCI_STOP# is an asynchronous input to the ICS9248-92. It is used to turn off the PCICLK (0:5) clocks for low power operation.
PCI_STOP# is synchronized by the ICS9248-92 internally. The minimum that the PCICLK (0:5) clocks are enabled (PCI_STOP#
high pulse) is at least 10 PCICLK (0:5) clocks. PCICLK (0:5) clocks are stopped in a low state and started with a full high pulse
width guaranteed. PCICLK (0:5) clock on latency cycles are only one rising PCICLK clock off latency is one PCICLK clock.
(Drawing shown on next page.)
8
ICS9248-92
Notes:
1. All timing is referenced to the Internal CPUCLK (defined as inside the ICS9248 device.)
2. PCI_STOP# is an asynchronous input, and metastable conditions may exist. This signal is required to be synchronized
inside the ICS9248.
3. All other clocks continue to run undisturbed.
4. PD# and CPU_STOP# are shown in a high (true) state.
PD# Timing Diagram
The power down selection is used to put the part into a very low power state without turning off the power to the part. PD# is
an asynchronous active low input. This signal is synchronized internal by the ICS9248-92 prior to its control action of
powering down the clock synthesizer. Internal clocks will not be running after the device is put in power down state. When PD#
is active (low) all clocks are driven to a low state and held prior to turning off the VCOs and the Crystal oscillator. The power on
latency is guaranteed to be less than 3mS. The power down latency is less than three CPUCLK cycles. PCI_STOP# and
CPU_STOP# are don’t care signals during the power down operations.
Notes:
1. All timing is referenced to the Internal CPUCLK (defined as inside the ICS9248 device).
2. PD# is an asynchronous input and metastable conditions may exist. This signal is synchronized inside the ICS9248.
3. The shaded sections on the VCO and the Crystal signals indicate an active clock is being generated.
9
ICS9248-92
Absolute Maximum Ratings
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 V
Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . GND –0.5 V to VDD +0.5 V
Ambient Operating Temperature . . . . . . . . . . . . 0°C to +70°C
Case Temperature . . . . . . . . . . . . . . . . . . . . . . . . 115°C
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . –65°C to +150°C
Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are
stress specifications only and functional operation of the device at these or any other conditions above those listed in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods
may affect product reliability.
Electrical Characteristics - Input/Supply/Common Output Parameters
T A = 0 - 70C; Supply Voltage V DD = 3.3 V +/-5% VDDL = 2.5V +/-5% (unless otherwise stated)
PARAM ETER
Input High Voltage
Input Low Voltage
Supply Current
Input frequency
Input Capacitance 1
1
SYMBOL
VIH
VIL
IDD
ID D L 2 .5
Fi
C IN
C INX
Transition Time 1
T tran s
Clk Stabilization 1
Skew 1
T STAB
T CPU-PCI
CONDITIONS
M IN
2
VSS -0.3
C L = 0 pF; Select @ 66M
VDD = 3.3 V;
Logic Inputs
X1 & X2 pins
27
To 1st crossing of target Freq.
TYP
M AX UNITS
VDD+0.3
V
0.8
V
77
180
mA
2.8
25
mA
14.318
M Hz
5
pF
36
45
ps
1.5
From V DD = 3.3 V to 1% target Freq.
VTP CI = 1.5 V; VTCP U = 1.25 V
Guarenteed by design, not 100% tested in production.
10
1.5
2.2
3
ms
3
ms
4.0
ns
ICS9248-92
Electrical Characteristics - CPUCLK
TA = 0 - 70º C; VDD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; C L = 20 pF (unless otherwise stated)
PARAMETER
Period
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
SYMBOL
period(norm)
VOH2B
VOL2B
IOH2B
IOL2B
CONDITIONS
VT = 1.25 V; 100MHz
IOH = -12.0 mA
IOL = 12 mA
VOH = 1.7 V
VOL = 0.7 V
t r2B1
VOL = 0.4 V, VOH = 2.0 V
1
VOH = 2.0 V, VOL = 0.4 V
Duty Cycle
d t2B
1
VT = 1.25 V
Skew
t sk2B1
VT = 1.25 V
VT = 1.25 V
Rise Time
Fall Time
Jitter
1
t f2B
t cyc-cyc
1
MIN
10
1.8
TYP
10
2.3
0.31
MAX
10.5
0.4
-27
27
1
45
UNITS
ns
V
V
mA
mA
1.6
ns
1.6
ns
50
55
%
30
95
ps
186
250
ps
Guaranteed by design, not 100% tested in production.
Electrical Characteristics - REF, 48MHz,24MHz
TA = 0 - 70º C; VDD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; CL = 20 pF (unless otherwise stated)
PARAMETER
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
SYMBOL
VOH5
VOL5
IOH5
IOL5
CONDITIONS
IOH = -14 mA
IOL = 6.0 mA
VOH = 2.0 V
VOL = 0.8 V
MIN
2
TYP
3.21
0.21
29
MAX UNITS
V
0.4
V
-23
mA
mA
Rise Time1
tr5
VOL = 0.4 V, VOH = 2.4 V
1
2.5
4
ns
Fall Time1
tf5
VOH = 2.4 V, VOL = 0.4 V
1
2.5
4
ns
Duty Cycle1
dt5
VT = 1.5 V
45
52
55
%
Jitter, Absolute1
Jitter, Absolute1
1
tjabs5
VT = 1.5 V, REF
385
800
ps
tjabs5
VT = 1.5 V, 48 MHz
469
800
ps
Guaranteed by design, not 100% tested in production.
11
ICS9248-92
Electrical Characteristics - PCICLK
T A = 0 - 70º C; V DD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; C L = 30 pF (unless otherwise stated)
PA RA M ETER
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
Ris e Time
Fall Time
1
1
Duty Cycle
Skew
1
1
1
Jitter, A bs olute
Jitter, Cycle-to-cycle 1
1
SYM BOL
VO H 1
VO L 1
IO H 1
IO L 1
CONDITIONS
IO H = -18 mA
IO L = 9.4 mA
VO H = 2.0 V
VO L = 0.8 V
M IN
2.1
TYP
3.3
0.17
30
M A X UNITS
V
0.4
V
-24
mA
mA
t r1
VO L = 0.4 V, VO H = 2.4 V
0.5
1.6
2
ns
t f1
VO H = 2.4 V, VO L = 0.4 V
0.5
1.8
2
ns
d t1
VT = 1.5 V
45
50
55
%
t sk 1
VT = 1.5 V
222
500
ps
t jab s1
t jcy c-cyc1
VT = 1.5 V
VT = 1.5 V
227
250
500
ps
ps
-250
Guaranteed by des ign, not 100% tes ted in production.
Electrical Characteristics - SDRAM
TA = 0 - 70º C; VDD = 3.3 V +/-5%, VDDL = 2.5 V +/-5%; CL = 30 pF (unless otherwise stated)
PARAMETER
Output High Voltage
Output Low Voltage
Output High Current
Output Low Current
TYP
3.18
0.35
-74
54
MAX UNITS
V
0.4
V
-46
mA
mA
tr1
VOL = 0.8 V, VOH = 2.4 V
0.5
1.54
1.6
ns
tf1
VOH = 2.4 V, VOL = 0.4 V
0.5
1.51
1.6
ns
dt1
VT = 1.5 V
45
51
55
%
tsk1
VT = 1.5 V
200
250
ps
tp1
VT = 1.5 V
3.5
5
ns
Duty Cycle
Skew
Propagation Delay1
1
MIN
2.2
1
1
1
CONDITIONS
IOH = -28 mA
IOL = 19 mA
VOH = 2.0 V
VOL = 0.8 V
1
Rise Time
Fall Time
SYMBOL
VOH1
VOL1
IOH1
IOL1
1
Guaranteed by design, not 100% tested in production.
12
ICS9248-92
General Layout Precautions:
1) Use a ground plane on the top routing
layer of the PCB in all areas not used
by traces.
2) Make all power traces and ground
traces as wide as the via pad for lower
inductance.
Ferrite
Bead
VDD
3.3V Power Route
C1
Notes:
1 All clock outputs should have
provisions for a 15pf capacitor
between the clock output and series
terminating resistor. Not shown in all
places to improve readability of
diagram.
C1
2
2 Optional crystal load capacitors are
recommended. They should be
included in the layout but not inserted
unless needed.
Component Values:
C1 : Crystal load values determined by user
C2 : 22 F/20V/D case/Tantalum
AVX TAJD226M020R
C3 : 15pF capacitor
FB = Fair-Rite products 2512066017X1
All unmarked capacitors are 0.01 F ceramic
C2
22µF/20V
Tantalum
Ferrite
Bead
C2
22µF/20V
Tantalum
1
48
2
47
3
46
4
45
5
44
6
43
7
42
8
41
9
40
10
39
11
38
12
37
13
36
14
35
15
34
16
33
17
32
18
31
19
30
20
29
21
28
22
27
23
26
24
25
VDD
C4
1
Clock Load
2.5V Power Route
C3
3.3V Power Route
= Routed Power
= Ground Connection Key (component side copper)
Connections to VDD:
= Ground Plane Connection
= Power Route Connection
= Solder Pads
= Clock Load
13
ICS9248-92
SYMBOL
In Millimeters
In Inches
COMMON DIMENSIONS COMMON DIMENSIONS
MIN
MAX
MIN
MAX
A
-
1.20
-
.047
A1
0.05
0.15
.002
.006
A2
0.80
1.05
.032
.041
b
0.17
0.27
.007
.011
c
0.09
0.20
SEE VARIATIONS
D
8.10 BASIC
E
E1
.0035
.008
SEE VARIATIONS
6.00
e
6.20
0.319
.236
0.50 BASIC
L
N
0.45
0.75
SEE VARIATIONS
.244
0.020 BASIC
.018
.30
SEE VARIATIONS
α
0°
8°
0°
8°
aaa
-
0.10
-
.004
MIN
MAX
MIN
12.40
12.60
VARIATIONS
N
6.10 mm. Body, 0.50 mm. pitch TSSOP
(0.020 mil)
(240 mil)
48
D mm.
D (inch)
MAX
.488
.496
MO-153 JEDEC
Doc.# 10-0039
7/6/00 Rev B
Ordering Information
ICS9248yG-92
Example:
ICS XXXX y G - PPP
Pattern Number (2 or 3 digit number for parts with ROM code patterns)
Package Type
G=TSSOP
Revision Designator
Device Type (consists of 3 or 4 digit numbers)
Prefix
ICS, AV = Standard Device
14
ICS reserves the right to make changes in the device data identified in
this publication without further notice. ICS advises its customers to
obtain the latest version of all device data to verify that any
information being relied upon by the customer is current and accurate.