NPC SM8721AB

SM8721AB
3-PLL Multi-Output Clock Generator
OVERVIEW
The SM8721AB is a clock generator IC with 3 built-in PLLs. It can simultaneously generate and output 3
clocks with different frequency derived from a single master clock. The generated output clock frequency can
be switched using control pins and one clock can be turned ON/OFF (CLK2). The master clock can be selected
from a low-cost 14.31818MHz or small 28.636363MHz crystal. The device is available in compact 20-pin
QFN packages, making it ideal for portable digital still cameras and other applications which require multiple
clocks.
■
■
■
■
■
3.0 to 3.6V supply voltage
Crystal oscillator circuit built-in
14.318182/28.636363MHz master clock
(internal PLL reference clock)
Generated clocks
• 14.318182/17.734450MHz (REF_CLK)
• 71.877274/90.314686/96.016044
/114.54546MHz (CLK1)
• 48.008022/96.016044MHz (CLK2)
Low jitter output
• 30ps typ. (1-sigma)
• 180ps typ. (peak-to-peak)
Output load
• 15pF
20-pin QFN package (Pb free)
15 14 13 12 11
CLK2
VSS2
VDD2
REF_CLK
TEST2
10
9
8
7
6
16
17
18
19
20
FS1
FS2
FS3
XTAL_SEL
TEST1
1 2 3 4 5
PACKAGE DIMENSIONS
APPLICATIONS
■
(Top view)
VDD1
VDD1
VSS1
CLK2ON
CLK1
■
■
PINOUT
VDD3
VDD3
VSS3
XTI
XTO
FEATURES
(Unit: mm)
Weight: 0.037g
Digital still cameras
ORDERING INFORMATION
4.20 ± 0.20
10
16
20
6
1
5
0.22
0.60 ± 0.10
0.50
1.00max
20-pin QFN
11
+ 0.03
0.02 − 0.02
SM8721AB
4.00 ± 0.10
15
4.00 ± 0.10
Package
4.20 ± 0.20
Device
0.05
0.22 ± 0.05
0.05 M
SEIKO NPC CORPORATION —1
SM8721AB
BLOCK DIAGRAM
Reference
Divider 1
Phase
Detector 1
Charge
Pump 1
LPF 1
VCO 1
CLK1
Charge
Pump 2
LPF 2
VCO 2
CLK2
Charge
Pump 3
LPF 3
VCO 3
REF_CLK
XTI
Oscillator
XTO
(PLL1)
Reference
Divider 2
CLK2ON
(PLL2)
FS1
Reference
Divider 3
FS2
FS3
XTAL_SEL
Loop
Divider 1
Phase
Detector 2
Loop
Divider 2
Phase
Detector 3
Control
Logic
TEST1
(PLL3)
TEST2
Loop
Divider 3
PIN DESCRIPTION
Number
Name
I/O
Description
1
VDD3
–
Analog supply voltage 3
2
VDD3
–
Analog supply voltage 3
3
VSS3
–
Analog supply ground 3
4
XTI
I
Crystal oscillator element connection pin (14.318182/28.636363MHz)
5
XTO
O
Crystal oscillator element connection pin
6
TEST1
I
Test pin 1. Built-in pull-down resistance (leave open circuit or connect to VSS)
7
XTAL_SEL
I
Crystal oscillator element selection pin. Built-in pull-up resistance
(HIGH = 28.636MHz, LOW = 14.318MHz)
8
FS3
I
CLK1, CLK2 output select 3. Built-in pull-up resistance
9
FS2
I
CLK1, CLK2 output select 2. Built-in pull-up resistance
10
FS1
I
REF_CLK output select 1. Built-in pull-up resistance
11
CLK1
O
Clock output (71/90/96/114MHz switchable output)
12
CLK2ON
I
CLK2 output enable. Built-in pull-up resistance (HIGH = enable, LOW = disable)
13
VSS1
–
Digital supply ground 1
14
VDD1
–
Digital supply voltage 1
15
VDD1
–
Digital supply voltage 1
16
CLK2
O
Clock output (48/96MHz switchable output)
17
VSS2
–
Digital supply ground 2
18
VDD2
–
Digital supply voltage 2
19
REF_CLK
O
Clock output (14.318/17.734MHz switchable output)
20
TEST2
I
Test pin 2. Built-in pull-down resistance (leave open circuit or connect to VSS)
SEIKO NPC CORPORATION —2
SM8721AB
ABSOLUTE MAXIMUM RATINGS
VDD = (VDD1, VDD2, VDD3), VSS = (VSS1, VSS2, VSS3) unless otherwise noted.
Parameter
Supply voltage range
Supply voltage deviation
Input voltage range
Output voltage range
Power dissipation*1
Storage temperature range
Symbol
Rating
Unit
VDD1, VDD2, VDD3
−0.3 to 6.5
V
VDD1 − VDD2, VDD1 − VDD3,
VDD2 − VDD3
±0.1
V
VIN
−0.3 to VDD + 0.3
V
VOUT
−0.3 to VDD + 0.3
V
PD
215
mW
TSTG
−55 to 125
°C
*1. The power dissipation rating is for a surface-mounted device operating at 85°C.
RECOMMENDED OPERATING CONDITIONS
VSS = (VSS1, VSS2, VSS3) = 0V, unless otherwise noted.
Rating
Parameter
Supply voltage*1
Output load capacitance
Master clock frequency
Operating temperature
Symbol
Conditions
Unit
min
typ
max
3.0
–
3.6
V
All outputs excluding XTO
–
–
15
pF
fXTAL1
XTAL_SEL = LOW
–
14.318182
–
MHz
fXTAL2
XTAL_SEL = HIGH
–
28.636363
–
MHz
−40
–
+85
°C
VDD1, VDD2,
VDD3
CL
TOPR
*1. The supply voltages are with reference to VSS = 0V.
It is recommended that the voltages applied to pins VDD1, VDD2, VDD3 be supplied from a single source.
If various voltage sources are used on pins VDD1, VDD2, VDD3, the voltage supplies should be applied simultaneously. If the timing of applying
voltage supplies varies, the device may be damaged.
SEIKO NPC CORPORATION —3
SM8721AB
ELECTRICAL CHARACTERISTICS
DC Characteristics
VDD = (VDD1, VDD2, VDD3) = 3.3 ± 0.3V, VSS = (VSS1, VSS2, VSS3) = 0V, Ta = −40 to +85°C unless otherwise
noted.
Rating
Parameter
Current consumption
Input voltage
Symbol
IDD
VDD
VIH
XTAL_SEL, FS1,
FS2, FS3, CLK2ON,
TEST1, TEST2*1,*2
VIL
IIH1
IIL1
Input current
Pins
IIH2
XTAL_SEL, FS1,
FS2, FS3, CLK2ON*1
TEST1, TEST2*2
IIL2
IIH3
XTI
IIL3
Output voltage
VOH
VOL
CLK1, CLK2,
REF_CLK
Conditions
Unit
min
typ
max
–
40
50
mA
0.8VDD
–
–
V
–
–
0.2VDD
V
VIN = VDD
–
–
1
µA
VIN = 0V
−100
–
–
µA
VIN = VDD
–
–
100
µA
VIN = 0V
−1
–
–
µA
VIN = VDD
–
–
40
µA
VIN = 0V
–40
–
–
µA
VDD − 0.4
–
–
V
–
–
0.4
V
VDD = 3.3V, Ta = 25°C, all
outputs operating without load
VDD = 3.3V
IOH = −2mA
IOL = 2mA
*1. XTAL_SEL, FS1, FS2, FS3, CLK2ON pins have Schmitt-trigger inputs with internal pull-up resistance.
*2. TEST1, TEST2 pins have Schmitt-trigger inputs with internal pull-down resistance.
SEIKO NPC CORPORATION —4
SM8721AB
AC Characteristics
VDD = (VDD1, VDD2, VDD3) = 3.3 ± 0.3V, VSS = (VSS1, VSS2, VSS3) = 0V, Ta = −40 to +85°C unless otherwise
noted.
Rating
Parameter
Symbol
Pins
Conditions
Unit
min
typ
max
Output clock rise time*1
tr
CLK1, CLK2,
REF_CLK
CL = 15pF, VOL = 0.2VDD to
VOH = 0.8VDD transition
–
2.0
–
ns
Output clock fall time*1
tf
CLK1, CLK2,
REF_CLK
CL = 15pF, VOH = 0.8VDD to
VOL = 0.2VDD transition
–
2.0
–
ns
tjitter
(1-sigma)
CLK1, CLK2,
REF_CLK
Ta = 25°C, CL = 15pF,
VO = 0.5VDD
–
30
–
ps
tjitter
(peak-peak)
CLK1, CLK2,
REF_CLK
Ta = 25°C, CL = 15pF,
VO = 0.5VDD
–
180
–
ps
Dt1
CLK1, CLK2,
REF_CLK
Ta = 25°C, CL = 15pF,
VO = 0.5VDD
45
50
55
%
Dt2
CLK1
Ta = 25°C, CL = 15pF,
VO = 0.5VDD, 114.54546MHz
40
50
60
%
tP
CLK1, CLK2,
REF_CLK
–
1
5
ms
Output clock jitter*2,*3
Output clock duty cycle*1, *3
Power-up time*3,*4,*5
*1. Measured using the circuit shown in figure 1 on the NPC standard evaluation board.
*2. Measured using the circuit shown in figure 2 on the NPC standard evaluation board.
*3. The crystal oscillator element coefficients for characteristics measurements are described below (HP4195 measurement equipment).
f = 14.318182MHz crystal: R = 12.16Ω, L = 10.34mH, Ca = 11.95fF, Cb = 4.03pF
f = 28.636363MHz crystal: R = 12.50Ω, L = 5.89mH, Ca = 5.25fF, Cb = 1.65pF
Cb
L
Ca
R
*4. The power-up time is the time from when the supply reaches 3.0V after the supply is turned ON until each output clock reaches its designated
frequency to within ±0.1%.
*5. Measured using the NPC standard evaluation board.
14.318182/
28.636363MHz
DUT
14.318182/
28.636363MHz
Active Probe
(HP1152A)
DUT:Device under test
Passive Probe
(HP10435A)
Oscilloscope
(Infinium
HP54845A)
Frequency &
Time Interval
Analyzer
(HP5371A)
Figure 1. Measurement circuit 1
Active Probe
(HP1152A)
DUT
Oscilloscope
(Infinium
HP54845A)
Jitter
Measurement
System
(ASA, M1)
DUT:Device under test
Figure 2. Measurement circuit 2
SEIKO NPC CORPORATION —5
SM8721AB
FUNCTIONAL DESCRIPTION
14.318182/28.636363MHz Master Clock
The 14.318182/28.636363MHz master clock is generated by the crystal oscillator formed by connecting a
crystal (14.318182/28.636363MHz fundamental frequency) between pins XTI (pin 4) and XTO (pin 5), as
shown in figure 3.
14.318182/
28.636363MHz
XTI (Pin 4)
Oscillator
1/2
C1, C2 = 0 to 33pF
PLL
XTO (Pin 5)
Selector
C2
Selector
C1
REF_CLK (Pin 19)
Figure 3. Crystal oscillator connection
SEIKO NPC CORPORATION —6
SM8721AB
Output Clock Frequency
The SM8721AB generates 3 output clocks with frequency 14.318182/17.734450MHz (REF_CLK),
71.877274/90.314686/96.016044/114.54546MHz (CLK1), and 48.008022/96.016044MHz (CLK2), derived
from the master clock.
A list of the supported clock frequency and control settings is shown in table 1.
Table 1. Output clock frequency
14.318182MHz master clock frequency: XTAL_SEL = LOW
28.636363MHz master clock frequency: XTAL_SEL = HIGH
Output clock frequency [MHz]
FS1
(Pin 10)
FS2
(Pin 9)
FS3
(pin 8)
CLK2ON
(pin 12)
HIGH
REF_CLK
(Pin 19)
CLK1
(Pin 11)
CLK2
(Pin 16)
14.318182
HIGH
96.016044
LOW
17.734450
HIGH
HIGH
14.318182
LOW
90.314686
LOW
48.008022
17.734450
HIGH
HIGH
14.318182
HIGH
71.877274
LOW
17.734450
LOW
HIGH
14.318182
LOW
114.54546
LOW
96.016044
17.734450
HIGH
14.318182
HIGH
96.016044
LOW
17.734450
HIGH
HIGH
14.318182
LOW
90.314686
LOW
17.734450
LOW
HIGH
Fixed LOW
14.318182
HIGH
71.877274
LOW
17.734450
LOW
HIGH
14.318182
LOW
LOW
114.54546
17.734450
SEIKO NPC CORPORATION —7
SM8721AB
Please pay your attention to the following points at time of using the products shown in this document.
The products shown in this document (hereinafter “Products”) are not intended to be used for the apparatus that exerts harmful influence on
human lives due to the defects, failure or malfunction of the Products. Customers are requested to obtain prior written agreement for such
use from SEIKO NPC CORPORATION (hereinafter “NPC”). Customers shall be solely responsible for, and indemnify and hold NPC free and
harmless from, any and all claims, damages, losses, expenses or lawsuits, due to such use without such agreement. NPC reserves the right
to change the specifications of the Products in order to improve the characteristic or reliability thereof. NPC makes no claim or warranty that
the contents described in this document dose not infringe any intellectual property right or other similar right owned by third parties.
Therefore, NPC shall not be responsible for such problems, even if the use is in accordance with the descriptions provided in this document.
Any descriptions including applications, circuits, and the parameters of the Products in this document are for reference to use the Products,
and shall not be guaranteed free from defect, inapplicability to the design for the mass-production products without further testing or
modification. Customers are requested not to export or re-export, directly or indirectly, the Products to any country or any entity not in
compliance with or in violation of the national export administration laws, treaties, orders and regulations. Customers are requested
appropriately take steps to obtain required permissions or approvals from appropriate government agencies.
SEIKO NPC CORPORATION
15-6, Nihombashi-kabutocho, Chuo-ku,
Tokyo 103-0026, Japan
Telephone: +81-3-6667-6601
Facsimile: +81-3-6667-6611
http://www.npc.co.jp/
Email: [email protected]
NC0120BE
2006.04
SEIKO NPC CORPORATION —8