ETC IMISG536AXB

SG536
Low EMI Clock Generator for Multi-Function Products
Approved Product
CONNECTION DIAGRAM
PRODUCT FEATURES
„ Supports clocking requirements for Multi-
VDD
XIN
XOUT
Function Products supporting Printers,
Copiers, Scanners, Fax/modem integration.
Programmable CPU clock output.
Operates from 3.3V or 5V supply
60 mA buffer switching current
16 Pin SOIC for minimum board space
„
„
„
„
„ Integrates a Spectrum Spread
VSS
CPUsel1
CPUsel0
VSS
VDD
technology for EMI attenuation of up to
15dB at harmonic frequencies.
The IMISG536 is a clock generator that integrates
clocking requirements for Multi-Function Products
or stand alone products such as Printers, Copiers,
and Scanners.
In addition, it integrates a
Spectrum Spread technology , a modulation
technique designed specifically for reducing EMI
at the fundamental frequency and at its
harmonics. The EMI attenuation is proportional to
the frequency, therefore achieving greater
reduction at the harmonics where it is more
difficult to pass federal regulations for radiated
emissions (such as FCC, CSPIR, etc.).
The IMISG536 operates from a 20 MHz
crystal oscillator across pins 2 and 3, or from an
external clock source. The REF output is a
buffered output of the input signal at XIN. CPUclk
is the modulated output for EMI attenuation. This
clock has optional frequency outputs which can
be selected with CPUsel(0:1).
VIDclk (60 MHz) and SCNclk(40 MHz) are highly
accurate fixed frequencies and therefore are not
modulated.
This device is packaged in a 16 pin SOIC
package for minimum occupation of board space.
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
REF
CPUclk
VSS
VDD
SCNclk
VIDclk
VSS
MODsel
CPUclk SELECTION TABLE
CPUsel1
CPUsel0
CPUclk (MHz)
0
0
16
0
1
33
1
0
25
1
1
50
BLOCK DIAGRAM
XIN
20 MHz
REF
B
REF
PLL1
SSCG
Control
B
CPUclk
PLL2
B
VIDclk
B
SCNclk
XOUT
CPUsel1
CPUsel0
MODsel
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.1
6/26/97
Page 1 of 6
SG536
Low EMI Clock Generator for Multi-Function Products
Approved Product
PIN DESCRIPTION
OSCin, OSCout - These pins form an on-chip reference oscillator when connected to terminals of an external parallel
resonant crystal. OSCin may also serve as an input for an externally generated CMOS level or AC coupled reference
signal.
CPUsel(0:1) - Input controls pins used to select the clock frequency of the CPUclk output. See table page 1. These
pins have internal pull-ups.
MODsel - This pin is used to control the Spectrum Spread enable/disable. When Low, Spectrum Spread is not applied
to the CPUclk output. When High (default), this pin enables the CPUclk to be modulated at +/-1.25 % of its center
frequency as described in figure 2, Page 4 and reduces EMI as described in figure 1. It has an internal pull-up.
CPUclk - SSCG modulated clock output for system CPU. Frequency may be selected based on the table on page 1.
SCNclk - Non-modulated clock output for system scanner processing. It is centered exactly at 40.00000 MHz.
VIDclk - Non-modulated clock output for system engine logic. It is centered exactly at 60.00000 MHz.
VDD - Circuit positive power supply.
VSS - Circuit ground.
A bypass capacitor (0.1µF) should be placed as close as possible to each VDD pin. If these bypass capacitors
are not close to the pins their high frequency filtering characteristic will be canceled by the lead inductances of
the traces.
MAXIMUM RATINGS
This device contains circuitry to protect the inputs
Voltage Relative to VSS:
-0.3V
against damage due to high static voltages or electric
field; however, precautions should be taken to avoid
Voltage Relative to VDD:
Storage Temperature:
0.3V
-65ºC to + 150ºC
application of any voltage higher than the maximum
rated voltages to this circuit. For proper operation, Vin
Ambient Temperature:
Maximum Power Supply:
-55ºC to +125ºC
7V
and Vout should be constrained to the range:
VSS<(Vin or Vout)<VDD
Unused inputs must always be tied to an appropriate
logic voltage level (either VSS or VDD).
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.1
6/26/97
Page 2 of 6
SG536
Low EMI Clock Generator for Multi-Function Products
Approved Product
ELECTRICAL CHARACTERISTICS
Characteristic
Input Low Voltage
Input High Voltage
Input Low, or High Current
with Pull- up or Pull-down
Output Low Voltage
IOL = 12mA
Output High Voltage
IOH = 12mA
Dynamic Supply Current
Static Supply Current
Short Circuit Current
Symbol
Min
Typ
Max
Units
Conditions
VIL
VIH
IIL, IIH
2.0
-
-
0.8
66
Vdc
Vdc
µA
CPUsel (0:1), MODsel
CPUsel (0:1), MODsel
CPUsel (0:1), MODsel
VOL
-
-
0.4
Vdc
All Outputs
VOH
2.4
-
-
Vdc
All Outputs
Icc
Icc (PD)
ISC
25
200
-
40
-
mA
µA
mA
CPUclk = 50 MHz
1 output at a time - 30 seconds
VDD = 5 V, TA = 0ºC to +70ºC
SWITCHING CHARACTERISTICS
Characteristic
Output Rise (0.4V - 2.0V)
and Fall (2.0V-0.4V) time
Output Duty Cycle
∆Period Adjacent Cycles
CPU
Jitter Absolute
CPU
Switching Current Low*
Switching Current High*
Symbol
Min
Typ
Max
Units
Conditions
2
ns
15 pf Load
tTLH,
tTHL
-
-
-
45
50
55
∆P
-
-
+250
%
ps
Measured at 1.5V
-
tjab
-
500
ps
MODsel = 0
IOL(AC)
IOH(AC)
-
-
mA
mA
VOL = 1.5V
VOL = 1.5V
60
60
VDD = 5 V, TA = 0ºC to +70ºC
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.1
6/26/97
Page 3 of 6
SG536
Low EMI Clock Generator for Multi-Function Products
Approved Product
SPECTRUM SPREAD
Amplitude
(dB)
Without Spectrum Spread
With Spectrum Spread
Spectrum Analysis
Center
Frequency(MHz)
Modulation Domain Analysis
Modulation Profile
Modulated
Fout freq.
(MHz)
Time
Note : The modulation rate, fr, is dependent on the Input frequency (Xin).
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.1
6/26/97
Page 4 of 6
SG536
Low EMI Clock Generator for Multi-Function Products
Approved Product
PCB LAYOUT SUGGESTION
Via to Ground Plane
IMISG536
1
C3
2
16
15
3
14
4
13
5
12
6
11
7
10
8
9
C5
C4
C8
22µf
FB1
Via to VCC
Note: Bypass capacitors C3, C4, and C5,
(0.1µf) should be placed as close as
possible to each VDD pin. If these bypass
capacitors are not close to the pins their
high frequency filtering characteristic will
be canceled by the lead inductances of the
traces.
NOTES
1. POWER SUPPLY BYPASS CAPS (O.1UF) MUST BE POSITIONED CLOSE TO VDD PINS TO BE EFFECTIVE.
2. C3, C4, C5, C and C8 CAPS MUST BE LOW LEAKAGE SUCH AS MULTILAYER CERAMIC Z5U OR X7R MATERIAL.
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.1
6/26/97
Page 5 of 6
SG536
Low EMI Clock Generator for Multi-Function Products
Approved Product
PACKAGE DRAWING AND DIMENSIONS
16 PIN SOIC OUTLINE DIMENSIONS
INCHES
C
SYMBOL
L
H
E
D
MAX
MIN
NOM
MAX
A
0.097
0.101
0.104
2.46
2.56
0.0020
0.009
0.0015
0.060
0.22
0.38
A2
0.090
0.092
0.111
2.29
2.34
2.39
0.48
e
2.64
B
0.014
0.016
0.019
0.35
0.41
C
0.0091
0.010
0.0125
0.23
0.25
0.32
D
.399
.407
.412
10.13
10.34
10.46
E
0.285
0.296
0.299
7.24
7.52
7.59
e
A
A1
B
MILLIMETERS
NOM
A1
a
A2
MIN
0.050 BSC
1.27 BSC
H
0.400
0.406
0.40
10.16
10.31
a
0°
5°
10°
0°
5°
10.41
10°
L
0.24
0.032
0.040
0.61
0.81
1.02
ORDERING INFORMATION
Part Number
Package Type
IMISG536AXB
16 PIN SOIC
Production Flow
Commercial, 0ºC to + 70ºC
Marking: Example: IMI
SM536AXB
Date Code, Lot#
IMISM536AXB
Flow
B = Commercial, 0°C to + 70°C
Package
X = SOIC
Revisions
IMI Device Number
INTERNATIONAL MICROCIRCUITS, INC. 525 LOS COCHES ST.
MILPITAS, CA 95035. TEL: 408-263-6300. FAX 408-263-6571
Rev.1.1
6/26/97
Page 6 of 6