ICS ICS93725

ICS93725
Integrated
Circuit
Systems, Inc.
DDR and SDRAM Zero Delay Buffer
Recommended Application:
DDR & SDRAM Zero Delay Buffer for SIS 635/640/645/
650 & 735/740/746 style chipsets.
Pin Configuration
Product Description/Features:
• Low skew, Zero Delay Buffer
• 1 to 13 SDRAM PC133 clock distribution
• 1 to 6 pairs of DDR clock distribution
• I2C for functional and output control
• Separate feedback path for both memory mode to
adjust synchronization.
• Supports up to 2 DDR DIMMs or 3 SDRAM DIMMs
• Frequency support for up to 200MHz
• Individual I2C clock stop for power mananagement
• CMOS level control signal input
Switching Characteristics:
• OUTPUT - OUTPUT skew: <100ps
• Output Rise and Fall Time for DDR outputs: 550ps 1150ps
• DUTY CYCLE: 47% - 53%
Functionality
PLL1
DDRFB_OUT
Control
SDATA
SCLK
3
3
Config.
Reg.
0606A—08/01/03
MODE
PIN 48
VDD
3.3_2.5
DDR
Mode
SEL_DDR=1
2.5V
DDR/SD
Mode
SEL_DDR=0
3.3V
SDRAMFB_OUT
Logic
SEL_DDR*
DDRFB_IN
DDRFB_OUT
VDD2.5
DDRT5
DDRC5
DDRT4
DDRC4
GND
VDD2.5
DDRT3
DDRC3
DDRT2
DDRC2
GND
VDD2.5
DDRT1
DDRC1
DDRT0
DDRC0
GND
VDD2.5
SCLK
SDATA
*Internal Pull-up Resistor of 120K to VDD
SDRAM (12:0)
SEL_DDR*
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
48-Pin SSOP
Block Diagram
BUFFER_IN
SDRAMFB_IN
DDRFB_IN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
ICS93725
VDD3.3
SDRAM0
SDRAM1
SDRAM2
SDRAM3
GND
VDD3.3
SDRAM4
SDRAM5
BUFFER_IN
SDRAM6
SDRAM7
GND
VDD3.3
SDRAM8
SDRAM9
SDRAM10
SDRAM11
GND
VDD3.3
SDRAM12
SDFB_OUT
SDFB_IN
GND
DDRT (5:0)
DDRCC (5:0)
ICS93725
Pin Descriptions
PIN NUMBER
1, 7, 14, 20
PIN NAME
TYPE
DESCRIPTION
VDD3.3
PWR
3.3V voltage supply for SDRAM.
GND
PWR
Ground
44, 42, 38,
36, 32, 30
DDRT (5:0)
OUT
"Tr ue" Clock of differential pair outputs.
43, 41, 37,
35, 31, 29
DDRC (5:0)
OUT
"Complementor y" clocks of differential pair outputs.
OUT
SDRAM clock outputs
PWR
2.5V voltage supply for DDR.
6, 13, 19, 24, 34,
28, 40
21, 18, 17, 16, 15,
12, 11, 9, 8, 5,
SDRAM (12:0)
4, 3, 2
27, 39, 45
VDD2.5
10
BUFFER_IN
IN
22
SDRAMFB_OUT
23
SDFB_IN
IN
Feedback input for SDRAM
25
SDATA
I/O
Data pin for I2C circuitr y 5V tolerant
26
SCLK
IN
Clock input of I2C input, 5V tolerant input
46
DDRFB_OUT
47
DDRFB_IN
IN
Feedback input for DDR
48
SEL_DDR
IN
Select input for DDR mode or DDR/SD mode
0=SD mode 1=DDR mode
OUT
OUT
Single ended buffer input
Feedback output for SDRAM
Feedback output for DDR
0606A—08/01/03
2
ICS93725
Byte 6: Output Control
(1= enable, 0 = disable)
BIT
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PIN#
48
44, 43
42, 41
38, 37
36, 35
32, 31
PWD
1
1
1
1
1
1
1
Byte 7: Output Control
(1= enable, 0 = disable)
DESCRIPTION
SEL_DDR (Read back only)
(Reserved)
(Reserved)
DDRT5, DDRC5
DDRT4, DDRC4
DDRT3, DDRC3
DDRT2, DDRC2
DDRT1, DDRC1
0606A—08/01/03
3
BIT
Bit 7
Bit 6
PIN#
30, 29
21
Bit 5
17, 18
Bit 4
15, 16
Bit 3
11, 12
Bit 2
8, 9
Bit 1
4, 5
Bit 0
2, 3
PWD
DESCRIPTION
1 DDRT0, DDRC0
1
SDRAM12
SDRAM10
1
SDRAM11
SDRAM8
1
SDRAM9
SDRAM6
1
SDRAM7
SDRAM4
1
SDRAM5
SDRAM2
1
SDRAM3
SDRAM1
1
SDRAM0
ICS93725
Absolute Maximum Ratings
Supply Voltage (VDD & VDD2.5) . . . . . . . . .
Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . .
Ambient Operating Temperature . . . . . . . . . .
Case Temperature . . . . . . . . . . . . . . . . . . . . .
Storage Temperature . . . . . . . . . . . . . . . . . . .
-0.5V to 3.6V
GND –0.5 V to VDD +0.5 V
0°C to +85°C
115°C
–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
SEL_DDR=0 SDRAM Outputs VDD=3.3V, TA=0 - 85°C; (unless otherwise stated)
PARAMETER
Operating Supply Current
SYMBOL
IDD3.3
Output High Current
Output Low Current
IOH
IOL
High-level output voltage
VOH
Low-level output voltage
VOL
CONDITIONS
MIN
TYP
100MHz, RL=0Ω, CL = 0pF
130
133MHz, RL=0Ω, CL = 0pF
173
200MHz, RL=0Ω, CL = 0pF
VDD=3.3V, VOUT=1V
VDD=3.3V, VOUT=1.2V
VDD=3.3V
IOH = -12 mA
VDD=3.3V
IOH = 12 mA
VI = GND or VDD
247
26
-40
34
1.7
2
1
CIN
Input Capacitance
Guaranteed by design, not 100% tested in production.
0.4
MAX
UNITS
mA
mA
-18
mA
mA
V
0.6
2
V
pF
1
Recommended Operating Condition
SEL_DDR=0 SDRAM Outputs VDD=3.3V, TA=0 - 85°C; (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
MIN
V
3
Power Supply Voltage
DD3.3
VIH
SEL_DDR, PD# input
2
Input High Voltage
VIL
SEL_DDR, PD# input
Input Low Voltae
VIN
Input Voltage Level
0
1
Guaranteed by design, not 100% tested in production.
0606A—08/01/03
4
TYP
3.3
MAX
3.6
3.3
0.8
3.6
UNITS
V
V
V
V
ICS93725
Electrical Characteristics - Input/Supply/Common Output Parameters
SEL_DDR=1 DDR Outputs VDD=2.5V, TA=0 - 85°C; (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
100MHz, RL=0Ω, CL = 0pF
IDD2.5
Operating Supply Current
133MHz, RL=0Ω, CL = 0pF
200MHz, RL=0Ω, CL = 0pF
VDD=2.5V, VOUT=1V
IOH
Output High Current
VDD=2.5V, VOUT=1.2V
IOL
Output Low Current
VDD=2.5V
VOH
High-level output voltage
IOH = -12 mA
VDD=2.5V
VOL
Low-level output voltage
IOH = 12 mA
VDD = 2.5V
Output differential-pair
VOC
100/133/166/ 200 Mhz
Crossing voltage
1
CIN
VI = GND or VDD
Input Capacitance
1
MIN
26
TYP
141
188
271
-43
38
1.7
2
1.05
MAX
-18
UNITS
mA
mA
mA
mA
mA
V
0.4
0.6
V
1.25
1.45
V
2
pF
Guaranteed by design, not 100% tested in production.
Recommended Operating Condition
SEL_DDR=1 DDR Outputs VDD=2.5V, TA=0 - 85°C; (unless otherwise stated)
PARAMETER
SYMBOL
CONDITIONS
VDD2.5
Power Supply Voltage
VIH
SEL_DDR, PD# input
Input High Voltage
VIL
SEL_DDR, PD# input
Input Low Voltage
VIN
Input Voltage Level
1
Guaranteed by design, not 100% tested in production.
0606A—08/01/03
5
MIN
2.3
2
0
TYP
2.5
MAX
2.7
2.5
0.8
2.7
UNITS
V
V
V
V
ICS93725
Switching Characteristics
PARAMETER
Operating Frequency
Input Clock Duty Cycle
DDR Static Phase Error
SDRAM Static Phase Error
SYMBOL
DDR output to output Skew
Tskewd
SDRAM output to output Skew
Tskews
din
tped
tpes
DDR Duty Cycle
DC
2
SDRAM Duty Cycle
DC
2
DDR Rise Time
trd
DDR Fall Time
tfd
SDRAM Rise Time
SDRAM Fall Time
trs
tfs
DDR Cycle to Cycle Jitter
t(C-C)D
SDRAM Cycle to Cycle Jitter
t(C-C)S
1
2
CONDITIONS
Not including FBOUT
to outputs
Not including FBOUT
to outputs
66MHz to 100MHz
101MHz to 200MHz
66MHz to 100MHz
101MHz to 200MHz
Measured between
20% and 80% output, CL=16pF
VOL = 0.4V, VOH = 2.4V,
CL=30pF
SEL_DDR=1,VDD=2.5V ,
CL=16pF
SEL_DDR=0,VDD=3.3V ,
CL=30pF
MIN
66
40
-100
-100
TYP
-50
-20
MAX
200
60
100
100
UNITS
MHz
%
ps
ps
60
100
ps
200
300
ps
48
48
48
48
0.55
0.68
52
53
52
56
0.95
%
%
%
%
ns
0.63
0.91
1.15
ns
0.5
0.5
1.4
1.65
1.7
1.8
ns
ns
23
38
ps
36
57
ps
Guaranteed by design, not 100% tested in production.
While the pulse skew is almost constant over frequency, the duty cycle error increases at
higher frequencies. This is due to the formula: duty cycle=t2/t1, where the cycle (t1) decreases
as the frequency goes up.
Switching Waveforms
Duty Cycle Timing
t2
1.5V
1.5V
t1
1.5V
SDRAM Buffer LH and HL Propagation Delay
INPUT
OUTPUT
t6
t7
0606A—08/01/03
6
ICS93725
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 D4 (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 6
• ICS clock will acknowledge each byte one at a time.
• Controller (host) sends a Stop bit
How to Write:
Controller (Host)
Start Bit
Address
D4(H)
Controller (host) will send start bit.
Controller (host) sends the read address D5 (H)
ICS clock will acknowledge
ICS clock will send the byte count
Controller (host) acknowledges
ICS clock sends first byte (Byte 0) through byte 7
Controller (host) will need to acknowledge each byte
Controller (host) will send a stop bit
How to Read:
ICS (Slave/Receiver)
Controller (Host)
Start Bit
Address
D5(H)
ACK
ICS (Slave/Receiver)
ACK
Byte Count
Dummy Command Code
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
ACK
Stop Bit
Dummy Byte Count
Byte 0
Byte 0
Byte 1
Byte 1
Byte 2
Byte 2
Byte 3
Byte 3
Byte 4
Byte 4
Byte 5
Byte 5
Byte 6
Byte 6
Byte 7
Byte 7
ACK
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.
0606A—08/01/03
7
ICS93725
c
N
SYMBOL
A
A1
b
c
D
E
E1
e
h
L
N
α
L
E1
INDEX
AREA
E
1 2
α
h x 45°
D
A
N
48
A1
-C-
In Millimeters
COMMON DIMENSIONS
MIN
MAX
2.41
2.80
0.20
0.40
0.20
0.34
0.13
0.25
SEE VARIATIONS
10.03
10.68
7.40
7.60
0.635 BASIC
0.38
0.64
0.50
1.02
SEE VARIATIONS
0°
8°
VARIATIONS
D mm.
MIN
MAX
15.75
16.00
In Inches
COMMON DIMENSIONS
MIN
MAX
.095
.110
.008
.016
.008
.0135
.005
.010
SEE VARIATIONS
.395
.420
.291
.299
0.025 BASIC
.015
.025
.020
.040
SEE VARIATIONS
0°
8°
D (inch)
MIN
.620
Reference Doc.: JEDEC Publication 95, MO-118
10-0034
e
SEATING
PLANE
b
.10 (.004) C
300 mil SSOP Package
Ordering Information
ICS93725yFT
Example:
ICS XXXX y F - T
Designation for tape and reel packaging
Package Type
F = SSOP
Revision Designator (will not correlate with datasheet revision)
Device Type
Prefix
ICS = Standard Device
0606A—08/01/03
8
MAX
.630