NPC SM8703AV

SM8703AV
Clock Generator for MPEG2 System
NIPPON PRECISION CIRCUITS INC.
OVERVIEW
The SM8703AV is a 27 MHz master clock, 5-system output clock generator for MPEG2 system. It has 2 builtin PLLs that, with the addition of a single crystal oscillator element, can generate 384fs, 512fs and 768fs
clocks which are necessary for MPEG2 system, plus independent fixed-frequency 27 MHz and 33.8688 MHz
output clocks. Each output can stop unused output by using disable function, therefore, unnecessary radiation
can be suppressed. Also, visual and audio synchronous is not disrupted since each output frequency is kept in
the normal ratio. Supported sampling frequencies (fs) include 44.1 or 48 kHz.
FEATURES
■
■
■
■
■
■
27 MHz master clock (internal PLL reference
clock)
Generated clocks
• 27 MHz output
• 33.8688 MHz output
• 384fs output
• 512fs output
• 768fs output
Sampling frequency fs
• 44.1/48 kHz
Output disable function
Low jitter output: 100 ps (typ, 15pF load)
Supply voltage: 3.3 V
24-pin VSOP package
(Top View)
VDD
VSS
MO1
MCK
MLEN
VDDA
VSSA
XTI
XTO
RSV
RSV
SO1
1
24
SM8703AV
■
PINOUT
12
13
MO2
FSEL/MDT
SO5
RSV
SO2
VDD1
VSS1
RSV
SO3
SO4
VDD2
VSS2
APPLICATIONS
PACKAGE DIMENSIONS
P ackag e
S M 8 7 0 3 AV
24-pin V S O P
+ 0.05
0.15 − 0.02
7.8 ± 0.1
0.5 ± 0.2
D e vice
(Unit: mm)
7.6 ± 0.2
ORDERING INFORMATION
+ 0.2
1.25 − 0.1
■
DVD players
Set top box
MPEG2 system
0.65
0.1
+ 0.1
0.22 − 0.05
0 to 10
0.1 ± 0.1
■
5.6 ± 0.1
■
0.13 M
NIPPON PRECISION CIRCUITS—1
SM8703AV
BLOCK DIAGRAM
FSEL/MDT
MCK
MLEN
External
Interface
Divider0
XTI
Phase
Comparator0
Charge
Pump0
SO5
LPF0
VCO0
Oscillator
SO4
XTO
Divider
Divider0
SO3
SO2
Divider1
Phase
Comparator1
Charge
Pump1
LPF1
VCO1
SO1
Divider1
MO1
MO2
NIPPON PRECISION CIRCUITS—2
SM8703AV
PIN DESCRIPTION
Number
Name
I/O
1
VDD
–
Pow er supply for Digital block
2
VSS
–
VSS for Digital block
3
MO1
O
27 MHz fixed-frequency output 1
MCK
Ip 1
Serial interface bit clock input
5
MLEN
Ip 1
Serial interface latch enable input
6
VDDA
–
Pow er supply for Analog block
7
VSSA
–
VSS for Analog block
8
XTI
I
Reference signal crystal oscillator element connection or external clock input
9
X TO
O
Reference signal crystal oscillator element connection
10
RSV
–
Reser ved (must be open)
11
RSV
–
Reser ved (must be open)
12
SO1
O
33.8688 MHz fixed-frequency output
13
VSS2
–
VSS for Output buffer
14
VDD2
–
Pow er supply for Output buffer
15
SO4
O
512fs output
16
SO3
O
512fs output
17
RSV
–
Reser ved (must be open)
18
VSS1
–
VSS for Output buffer
19
VDD1
–
Pow er supply for Output buffer
20
SO2
O
384fs output
21
RSV
–
Reser ved (must be open)
22
SO5
O
768fs output
23
FSEL/MDT
Ip 1
P arallel mode: Sampling frequency select signal input
Serial mode: Control data input
24
MO2
O
27 MHz fixed-frequency output 2
4
Description
1. Schmitt trigger input with internal pull-up resistor
NIPPON PRECISION CIRCUITS—3
SM8703AV
SPECIFICATIONS
Absolute Maximum Ratings
P arameter
Rating
Unit
V D DA , V DD ,
V DD1 , V DD2
−0.3 to 6.5
V
Supply voltage deviation
V DDA – V DD ,
V DDA – V DD1 ,
V DDA – V DD2 ,
VDD – VDD1 ,
VDD – VDD2 ,
VDD1 – VDD2
±0.1
V
Ground voltage deviation
VSSA – VSS ,
V SSA – V SS1 ,
V SSA – V SS2 ,
V SS – V SS1 ,
V SS – V SS2 ,
V SS1 – V SS2
±0.1
V
Supply voltage range
Input voltage range
Output voltage range
Symbol
Condition
V IN
Digital inputs
−0.3 to V D D + 0.3
V
VOUT
Digital outputs
−0.3 to V D D + 0.3
V
Pow er dissipation
PD
300
mW
Storage temperature range
T stg
−55 to 125
°C
Rating
Unit
V D DA , V DD ,
V DD1 , V DD2
3.0 to 3.6
V
T opr
–40 to 85
°C
Recommended Operating Conditions
P arameter
Supply voltage ranges
Operating temperature range
Symbol
Condition
NIPPON PRECISION CIRCUITS—4
SM8703AV
DC Electrical Characteristics
External clock, Ta = –40 to 85 °C, VDDA = VDD = VDD1 = VDD2 = 3.0 to 3.6 V unless otherwise stated
Rating
P arameter
Symbol
Condition
Unit
min
typ
max
–
32
45
mA
Current consumption
ID D
All supplies.
V D D A = V D D = V D D 1 = V D D 2 = 3.3V,
T a = 25 °C , fs = 48 kHz,
Cr ystal oscillator element,
no load on all outputs
HIGH-level input voltage
V IH
XTI, FSEL/MDT, MCK, MLEN
0.8 V D D
–
–
V
L O W -level input voltage
V IL
XTI, FSEL/MDT, MCK, MLEN
–
–
0.2 V D D
V
HIGH-level input current
IIH1
F S E L / M D T, MCK, MLEN, V IN = V D D
–
–
1
µA
L O W -level input current
IIL1
F S E L / M D T, MCK, MLEN, V IN = 0 V
–
–
−100
µA
HIGH-level input current
IIH2
XTI, V IN = V D D
–
–
40
µA
L O W -level input current
IIL2
XTI, V IN = 0 V
–
–
−40
µA
HIGH-level output voltage
VOH
All outputs. IO H = −2 m A
V D D − 0.4
–
–
V
L O W -level output voltage
VOL
All outputs. IO L = 4 mA
–
–
0.4
V
AC Electrical Characteristics
External clock, Ta = –40 to 85 °C, VDDA = VDD = VDD1 = VDD2 = 3.0 to 3.6 V unless otherwise stated
Rating
P arameter
Symbol
Condition
Unit
min
typ
max
–
27.0000
–
MHz
XTI external input clock frequency
fM
Output clock rise time
tR
All outputs, 0.2 to 0.8V D D ,
C L = 15 p F
–
2.0
–
ns
Output clock fall time
tF
All outputs, 0.8 to 0.2V D D ,
C L = 15 p F
–
2.0
–
ns
Output clock jitter1
JITTER
All outputs, Standard tolerance,
Cr ystal oscillator element,
C L = 15 p F
–
100
–
ps
Output clock duty 1
DUTY
All outputs, Crystal oscillator
element, 1.4V to 1.4V, C L = 15 p F
45
50
55
%
tS
All outputs
–
–
100
ns
tP
All outputs
–
15
30
ms
Settling time
Pow er-up
time 2
1. 1.4V to 1.4V. Ta = 2 0 °C . The characteristics of output clock jitter and output clock duty depends on crystal oscillator.
N P C ’s standard crystal oscillator: R = 10.5 Ω, L = 5.38 mH, Ca = 6.74 fF, Cb = 1.85 p F
measurement apparatus: HP4195
Load capacitance: C1 = 7 p F, C2 = 11 p F
Cb
L
Ca
R
2. Time from OFF condition to stable frequency output.
NIPPON PRECISION CIRCUITS—5
SM8703AV
Serial Interface AC Characteristics
External clock, Ta = –40 to 85 °C, VDDA = VDD = VDD1 = VDD2 = 3.0 to 3.6 V unless otherwise stated
Rating
P arameter
Symbol
Condition
Unit
min
typ
max
MCK HIGH-level pulsewidth
tM C W H
40
–
–
ns
M C K L O W -level pulsewidth
tM C W L
40
–
–
ns
MCK pulse cycle time
tM C Y
100
–
–
ns
MDT setup time
tM D S
40
–
–
ns
MDT hold time
tM D H
40
–
–
ns
MLEN setup
time 1
tM L S
40
–
–
ns
time 2
tM L H
40
–
–
ns
MLEN HIGH-level pulsewidth
tM H H
200
–
–
ns
M L E N L OW -level pulsewidth
tM L L
16 × tM C Y
–
–
ns
MLEN hold
1. Time from the MLEN falling edge to the next MCK rising edge. If the MCK clock stops after the LSB, the MLEN rise timing is optional.
2. Time from MCK rising edge corresponding to the LSB to the MLEN rising edge.
tMCWH tMCWL
tMLH
tMLS
MCK
0.5VDD
tMCY
MDT
MSB
LSB
tMLS
tMDS
tMDH
tMLL
0.5VDD
tMHH
MLEN
0.5VDD
NIPPON PRECISION CIRCUITS—6
SM8703AV
FUNCTIONAL DESCRIPTION
27 MHz Master Clock
The 27 MHz master clock is generated either by connecting a crystal oscillator element between XTI (pin 8)
and XTO (pin 9), as shown in figure 1, or by connecting an external 27 MHz clock to XTI, as shown in figure
2. Input 27MHz master clock on XTI when using an external clock. Crystal oscillator element must be fundamental.
C2
XTI (Pin8)
Internal
Circuits
Oscillator
XTO (Pin9)
C1
C1, C2 = 5 to 33pF
MO1 (Pin3)
MO2 (Pin24)
SM8703AV
Figure 1. Crystal oscillator connection
External Clock
XTI (Pin8)
Oscillator
Open
Internal
Circuits
XTO (Pin9)
MO1 (Pin3)
MO2 (Pin24)
SM8703AV
Figure 2. External clock input
NIPPON PRECISION CIRCUITS—7
SM8703AV
Sampling Frequency and Output Clock Frequency
The SM8703AV generates several output clocks from the 27 MHz master clock, with frequencies of 384fs
(SO2), 512fs (SO3, SO4) and 768fs (SO5), where fs is the sampling frequency selected by external control
inputs. SO1 outputs 33.8688 MHz clock. The supported sampling frequencies are 44.1 kHz and 48 kHz,
selected by the sampling frequency select pin (FSEL). The generated frequencies are shown in table 1.
Table 1. Sampling frequency and output clock frequency
Output clock frequency (MHz)
Sampling
frequency fs
FSEL
SO1
SO2
SO3, SO4
SO5
LOW
44.1 kHz
33.8688
16.9344
22.5792
33.8688
HIGH
48 kHz
33.8688
18.4320
24.5760
36.8640
Enable/Disable control
3 wire serial interface is available by using MCK(pin4), MLEN(pin5) and MDT(pin23:FSEL common) pins as
serial mode. At the serial control mode, each enable (fixed as "LOW" at disable) of output frequency can be set
to stop unnecessary outputs.
MCK
FSEL/MDT
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
MLEN
Figure 3. Serial control format
16-bit mode resister (MREG) construction in Figure 4. The name and function of each bit are shown in Table 2
and 3. Set the mode-resister D15-D10 as "011100" in the serial control.
MREG
0
1
1
1
0
0
RSV
CE5
CE4
CE3
CE2
CE1
RSV
RSV
RSV
RSV
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Note: RSV is fixed as LOW .
Figure 4. Mode resister construction
NIPPON PRECISION CIRCUITS—8
SM8703AV
Table 2. Mode resister function
Bit
Name
Function
D9
RSV
Must be "LOW "
D8
CE5
MO1, MO2 output enable/disable
D7
CE4
SO5 output enable/disable
D6
CE3
SO3, SO4 output enable/disable
D5
CE2
SO2 output enable/disable
D4
CE1
SO1 output enable/disable
D3/D2/D1/D0
RSV
Must be "LOW "
Table 3. Clock output control settings(CE5 to 1)
CE5 to CE1
Clock output
LOW
Disable (Output fixed as "LOW")
HIGH
E n a ble (Default)
Note
Output frequency changes according to the MDT pin condition, as MDT and FSEL pin (Sampling frequency
select signal input) are common. Refer to the section “Settling Time (when the sampling frequency is changed)”.
MCK
MREG (16bit data)
FSEL/MDT
MLEN
ts
SO2 to 5
Stable
Unstable
Stable
Figure 5. Serial transfer timing
NIPPON PRECISION CIRCUITS—9
SM8703AV
Settling Time (when the sampling frequency is changed)
The output response when the frequency is changed is shown in figure 6.
FSEL/MDT
tS
SO2
SO3
SO4
SO5
fs = 44.1kHz
tS
fs = 48kHz
MO1
MO2
27.0000MHz
SO1
33.8688MHz
fs = 44.1kHz
Figure 6. System clock transient timing
NIPPON PRECISION CIRCUITS—10
SM8703AV
TYPICAL APPLICATION
+3.3V
+3.3V
CPU
27MHz
VDD
MO2
27MHz
C3
VSS
FSEL/MDT
MO1
SO5
MCK
RSV
MLEN
SO2
VDDA
VDD1
VSSA
VSS1
768fs
384fs
C5
C4
C1
XTI
RSV
XTO
SO3
512fs
RSV
SO4
512fs
RSV
VDD2
SO1
VSS2
X'tal
C2
C6
SM8703AV
33.8688MHz
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Connect the decoupling capacitors (approximately
0.1µF and 1000pF) in parallel, as close to power
supply pins as possible.
In order to minimize noise, it is useful to make
VSS as solid pattern.
Master clock stability affects the other outputs stability. In the usage of crystal oscillator, load
capacitor and crystal oscillator should be placed as
close to the SM8703AV as possible, and wired
shortly. Select crystal oscillators and load capacitance carefully, depending on the condition, as
those combination will have influence on the frequency accuracy(C1, C2).
Supply pattern including decoupling capacitors
needs careful attention to make the IC’s performance better, since the SM8703AV outputs several high frequency clocks. Pattern capacitance
from output pins should not to be large for prevention of the noise. Connecting output pins to buffers is useful if it is necessary.
■
Power supply and VSS pins.
• VDD : Power supply for digital block
(CPU I/F*, MO1, MO2)
• VSS : VSS for digital block
(CPU I/F*, MO1, MO2)
• VDDA : Power supply for PLL block
(XTI, XTO, PLL/VCO)
• VSSA : VSS for PLL block
(XTI, XTO, PLL/VCO)
• VDD1 : Power supply for output block
(except SO1)
• VSS1 : VSS for output block
(except SO1)
• VDD2 : Power supply for SO1
• VSS2 : VSS for SO1
*: CPU I/F: FSEL/MDT, MLEN, MCK
NIPPON PRECISION CIRCUITS—11
SM8703AV
NIPPON PRECISION CIRCUITS INC. reserves the right to make changes to the products described in this data sheet in order to
improve the design or performance and to supply the best possible products. Nippon Precision Circuits Inc. assumes no responsibility fo r
the use of any circuits shown in this data sheet, conveys no license under any patent or other rights, and makes no claim that the circuits
are free from patent infringement. Applications for any devices shown in this data sheet are for illustration only and Nippon Precision
Circuits Inc. makes no claim or warranty that such applications will be suitable for the use specified without further testing or modification.
The products described in this data sheet are not intended to use for the apparatus which influence human lives due to the failure or
malfunction of the products. Customers are requested to comply with applicable laws and regulations in effect now and hereinafter,
including compliance with expor t controls on the distribution or dissemination of the products. Customers shall not expor t, directly or
indirectly, any products without first obtaining required licenses and approvals from appropriate government agencies.
NIPPON PRECISION CIRCUITS INC.
NIPPON PRECISION CIRCUITS INC.
4-3, Fukuzumi 2-chome
Koto-ku, Tokyo 135-8430, Japan
Telephone: 03-3642-6661
Facsimile: 03-3642-6698
NC9902AE
2000.03
NIPPON PRECISION CIRCUITS—12