1©2016 Integrated Device Technology, Inc. Revision D September 27, 2016
General Description
The 83905 is a low skew, 1-to-6 LVCMOS / LVTTL Fanout Buffer.
The low impedance LVCMOS/LVTTL outputs are designed to
drive 50 series or parallel terminated transmission lines. The
effective fanout can be increased from 6 to 12 by utilizing the
ability of the outputs to drive two series terminated lines.
The 83905 is characterized at full 3.3V, 2.5V, and 1.8V, mixed
3.3V/2.5V, 3.3V/1.8V and 2.5V/1.8V output operating supply
mode. Guaranteed output and part-to-part skew characteristics
along with the 1.8V output capabilities makes the 83905 ideal fo r
high performance, single ended application s that also require a
limited output voltage.
Pin Assignments
Features
Six LVCMOS / LVTTL outputs
Outputs able to drive 12 series terminated lines
Crystal Oscillator Interface
Crystal input frequency range: 10MHz to 40MHz
Output skew: 80ps (maximum)
RMS phase jitter @ 25MHz, (100Hz – 1MHz): 0.26ps (typical),
VDD = VDDO = 2.5V
Offset Noise Power
100Hz.................-129.7 dBc/Hz
1kHz...................-144.4 dBc/Hz
10kHz.................-147.3 dBc/Hz
100kHz...............-157.3 dBc/Hz
5V tolerant enable inputs
Synchronous output enables
Operating power supply modes:
Full 3.3V, 2.5V, 1.8V
Mixed 3.3V core/2.5V output operating supply
Mixed 3.3V core/1.8V output operating supply
Mixed 2.5V core/1.8V output operating supply
0°C to 70°C ambient operating temperature
Lead-free (RoHS 6) packaging
Block Diagram
6 7 8 9 10
19
20 18 17 16
1
2
3
4
5
13
14
15
12
11
GND
VDDO
GND
B
CLK0
B
CLK1
BCLK
4
BCLK
5
VDDO
GND
GND
VDD
B
CLK2
GND
GND
B
CLK3
ENABLE1
ENABLE2
XTAL_IN
XTAL_OU
T
nc
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
XTAL_IN
ENABLE
1
BCLK5
VDDO
BCLK4
GND
BCLK3
V
DD
BCLK2
GND
BCLK1
VDDO
BCLK0
GND
ENABLE2
X
TAL_OUT
83905
16-Lead SOIC, 150 Mil
3.9mm x 9.9mm x 1.38mm
package body
M Package
Top View
16-Lead TSSOP
4.4mm x 5. 0mm x 0.925mm
package body
G Package
Top View
83905
20-Lead VFQFN
4mm x 4mm x 0.925mm
package body
K Package
Top View
SYNCHRONIZE
SYNCHRONIZE
BCLK
0
BCLK
1
BCLK
2
BCLK
3
BCLK
4
BCLK
5
XTAL_IN
X
TAL_OUT
ENABLE 1
ENABLE 2
83905
Datasheet
Low Skew, 1:6 Crystal-to-LVCMOS/
LVTTL Fanout Buffer
2©2016 Integrated Device Technology, Inc. Revision D September 27, 2016
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Pin Descriptions and Characteristics
Table 1. Pin Descriptions
Table 2. Pin Characteristics
Function Table
Table 3. Clock Enable Function Table
Figure 1. Enable Timing Diagram
Name Type Description
XTAL_OUT Output Crystal oscillator interface. XTAL_OUT is the output.
XTAL_IN Input Crystal oscillator interface. XTAL_IN is the input.
ENABLE1, ENABLE2 Input Clock enable. LVCMOS/LVTTL interface levels. See Table 3.
BCLK0, BCLK1, BCL K2,
BCLK3, BCLK4, BCLK5 Output Clock outputs. LVCMOS/LVTTL interface levels.
GND Power Power supply ground.
VDD Power Pow er su pp l y pi n.
VDDO Power Output supply pin.
nc Unused No connect.
Symbol Parameter Test Conditions Minimum Typical Maximum Units
CIN Input Capacitance 4 pF
CPD
Power Dissipation
Capacitance
(per output)
VDDO = 3.465V 19 pF
VDDO = 2.625V 18 pF
VDDO = 2.0V 16 pF
ROUT Output Impedance
VDDO = 3.3V ± 5% 7
VDDO = 2.5V ± 5% 7
VDDO = 1.8V ± 0.2V 10
Control Inputs Outputs
ENABLE 1 ENABLE2 BCLK[0:4] BCLK5
0 0 LOW LOW
0 1 LOW Toggling
1 0 Toggling LOW
1 1 Toggling Toggling
BCLK5
BCLK[0:4]
ENABLE2
ENABLE1
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Absolute Maximum Ratings
NOTE: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are
stress specifications only. Fun c tional operation of product at these conditions or any conditions beyond those listed in the DC
Characteristics or AC Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
product reliability.
DC Electrical Characteristics
Table 4A. Power Supply DC Characteristics, VDD = VDDO = 3.3V ± 5%, TA = 0°C to 70°C
Table 4B. Power Supply DC Characteristics, VDD = VDDO = 2.5V ± 5%, TA = 0°C to 70°C
Table 4C. Power Supply DC Characteristics, VDD = VDDO = 1.8V ± 0.2V, TA = 0°C to 70°C
Item Rating
Supply Voltage, VDD 4.6V
Inputs, VI-0.5V to VDD + 0.5V
Outputs, VO-0.5V to VDDO+ 0.5V
Package Thermal Impedan ce, JA
16-Lead SOIC package
16-Lead TSSOP package
20-Lead VFQFN package
78.8C/W (0 mps)
100.3C/W (0 mps)
57.5C/W (0 mps)
Storage Temperature, TSTG -65C to 150C
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VDD Power Supply Voltage 3.135 3.3 3.465 V
VDDO Output Supply Voltage 3.135 3.3 3.465 V
IDD Power Supply Current ENABLE [1:2] = 00 10 mA
IDDO Output Supply Current ENABLE [1:2] = 00 5 mA
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VDD Power Supply Voltage 2.375 2.5 2.625 V
VDDO Output Supply Voltage 2.375 2.5 2.625 V
IDD Power Supply Current ENABLE [1:2] = 00 8 mA
IDDO Output Supply Current ENABLE [1:2] = 00 4 mA
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VDD Power Supply Voltage 1.6 1.8 2.0 V
VDDO Output Supply Voltage 1.6 1.8 2.0 V
IDD Power Supply Current ENABLE [1:2] = 00 5 mA
IDDO Output Supply Current ENABLE [1:2] = 00 3 mA
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Table 4D. Power Supply DC Characteristics, VDD = 3.3V ± 5%, VDDO = 2.5V ± 5%, TA = 0°C to 70°C
Table 4E. Power Supply DC Characteristics, 3.3V ± 5%, VDDO = 1.8V ± 0.2V, TA = 0°C to 70°C
Table 4F. Power Supply DC Characteristics, VDD = 2.5V ± 5%, VDDO = 1.8V ± 0.2V, TA = 0°C to 70°C
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VDD Power Supply Voltage 3.135 3.3 3.465 V
VDDO Output Supply Voltage 2.375 2.5 2.625 V
IDD Power Supply Current ENABLE [1:2] = 00 10 mA
IDDO Output Supply Current ENABLE [1:2] = 00 4 mA
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VDD Power Supply Voltage 3.135 3.3 3.465 V
VDDO Output Supply Voltage 1.6 1.8 2.0 V
IDD Power Supply Current ENABLE [1:2] = 00 10 mA
IDDO Output Supply Current ENABLE [1:2] = 00 3 mA
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VDD Power Supply Voltage 2.375 2.5 2.625 V
VDDO Output Supply Voltage 1.6 1.8 2.0 V
IDD Power Supply Current ENABLE [1:2] = 00 8 mA
IDDO Output Supply Current ENABLE [1:2] = 00 3 mA
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Table 4G. LVCMOS/LVTTL DC Characteristics, TA = 0°C to 70°C
NOTE 1: Outputs terminated with 50 to VDDO/2. See Parameter Measurement Information, Output Load Test Circuit diagrams.
Table 5. Crystal Characteristics
Symbol Parameter Test Conditions Minimum Typical Maximum Units
VIH Input
High Voltage ENABLE1,
ENABLE2
VDD = 3.3V ± 5% 2 VDD + 0.3 V
VDD = 2.5V ± 5% 1.7 VDD + 0.3 V
VDD = 1.8V ± 0.2V 0.65 * VDD VDD + 0.3 V
VIL Input
Low Voltage ENABLE1,
ENABLE2
VDD = 3.3V ± 5% -0.3 0.8 V
VDD = 2.5V ± 5% -0.3 0.7 V
VDD = 1.8V ± 0.2V -0.3 0.35 * VDD V
VOH Output High Voltage
VDDO = 3.3V ± 5%; NOTE 1 2.6 V
VDDO = 2.5V ± 5%; IOH = -1mA 2.0 V
VDDO = 2.5V ± 5%; NOTE 1 1.8 V
VDDO = 1.8V ± 0.2V; NOTE 1 VDDO - 0.3 V
VOL Output Low Voltage; NOTE 1
VDDO = 3.3V ± 5%; NOTE 1 0.5 V
VDDO = 2.5V ± 5%; IOL = 1mA 0.4 V
VDDO = 2.5V ± 5%; NOTE 1 0.45 V
VDDO = 1.8V ± 0.2V; NOTE 1 0.35 V
Parameter Test Conditions Minimum Typical Maximum Units
Mode of Oscillation Fundamental
Frequency 10 40 MHz
Equivalent Series Resistance (ESR) 50
Shunt Capacitance 7pF
Drive Level 1mW
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AC Electrical Characteristics
Table 6A. AC Characteristics, VDD = VDDO = 3.3V ± 5%, TA = 0°C to 70°C
NOTE: Electrical parameters are guaranteed ov er the specified ambient operating temperature range, which is established when the
device is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after
thermal equilibrium has been reached under these conditions.
All parameters measured at ƒ fMAX using a crystal input unless noted otherwise.
Terminated at 50 to VDDO/2.
NOTE 1: XTAL_IN can be overdriven by a single-ende d LVCMOS signal. Please refer to Application Information section.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equa l load conditions. Measured at VDDO/2.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
NOTE 4: See phase noise plot.
NOTE 5: These parameters are guaranteed by characterization. Not tested in production.
Table 6B. AC Characteristics, VDD = VDDO = 2.5V ± 5%, TA = 0°C to 70°C
NOTE: Electrical parameters are guaranteed ov er the specified ambient operating temperature range, which is established when the
device is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after
thermal equilibrium has been reached under these conditions.
All parameters measured at ƒ fMAX using a crystal input unless noted otherwise.
Terminated at 50 to VDDO/2.
NOTE 1: XTAL_IN can be overdriven by a single-ende d LVCMOS signal. Please refer to Application Information section.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equa l load conditions. Measured at VDDO/2.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
NOTE 4: See phase noise plot.
NOTE 5: These parameters are guaranteed by characterization. Not tested in production.
Symbol Parameter Test Conditions Minimum Typical Maximum Units
fMAX Output Frequency Using External Crystal 10 40 MHz
Using External Clock
Source NOTE 1 DC 100 MHz
tsk(o) Output Skew; NOTE 2, 3 80 ps
tjit(Ø) RMS Phase Jitter (Random); NOTE 4 25MHz, Integration Range:
100Hz – 1MHz 0.13 ps
tR / tFOutput Rise/Fall Time 20% to 80% 200 800 ps
odc Output Duty Cycle 48 52 %
tEN Output Enable
Time; NOTE 5 ENABLE1 4 cycles
ENABLE2 4 cycles
tDIS Output Disable
Time; NOTE 5 ENABLE1 4 cycles
ENABLE2 4 cycles
Symbol Parameter Test Conditions Minimum Typical Maximum Units
fMAX Output Frequency Using External Crystal 10 40 MHz
Using External Clock
Source NOTE 1 DC 100 MHz
tsk(o) Output Skew; NOTE 2, 3 80 ps
tjit RMS Phase Jitter (Random); NOTE 4 25MHz, Integration Range:
100Hz – 1MHz 0.26 ps
tR / tFOutput Rise/Fall Time 20% to 80% 200 800 ps
odc Output Duty Cycle 47 53 %
tEN Output Enable
Time; NOTE 5 ENABLE1 4 cycles
ENABLE2 4 cycles
tDIS Output Disable
Time; NOTE 5 ENABLE1 4 cycles
ENABLE2 4 cycles
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Table 6C. AC Characteristics, VDD = VDDO = 1.8V ± 0.2V, TA = 0°C to 70°C
NOTE: Electrical parameters are guaranteed ov er the specified ambient operating temperature range, which is established when the
device is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after
thermal equilibrium has been reached under these conditions.
All parameters measured at ƒ fMAX using a crystal input unless noted otherwise.
Terminated at 50 to VDDO/2.
NOTE 1: XTAL_IN can be overdriven by a single-ende d LVCMOS signal. Please refer to Application Information section.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equa l load conditions. Measured at VDDO/2.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
NOTE 4: These parameters are guaranteed by characterization. Not tested in production.
Table 6D. AC Characteristics, VDD = 3.3V ± 5%, VDDO = 2.5V ± 5%, TA = 0°C to 70°C
NOTE: Electrical parameters are guaranteed ov er the specified ambient operating temperature range, which is established when the
device is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after
thermal equilibrium has been reached under these conditions.
All parameters measured at ƒ fMAX using a crystal input unless noted otherwise.
Terminated at 50 to VDDO/2.
NOTE 1: XTAL_IN can be overdriven by a single-ende d LVCMOS signal. Please refer to Application Information section.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equa l load conditions. Measured at VDDO/2.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
NOTE 4: These parameters are guaranteed by characterization. Not tested in production.
Symbol Parameter Test Conditions Minimum Typical Maximum Units
fMAX Output Frequency Using External Crystal 10 40 MHz
Using External Clock
Source NOTE 1 DC 100 MHz
tsk(o) Output Skew; NOTE 2, 3 80 ps
tjit(Ø) RMS Phase Jitter (Random) 25MHz, Integration Range:
100Hz – 1MHz 0.27 ps
tR / tFOutput Rise/Fall Time 20% to 80% 200 900 ps
odc Output Duty Cycle 47 53 %
tEN Output Enable
Time; NOTE 4 ENABLE1 4 cycles
ENABLE2 4 cycles
tDIS Output Disable
Time; NOTE 4 ENABLE1 4 cycles
ENABLE2 4 cycles
Symbol Parameter Test Conditions Minimum Typical Maximum Units
fMAX Output Frequency Using External Crystal 10 40 MHz
Using External Clock
Source NOTE 1 DC 100 MHz
tsk(o) Output Skew; NOTE 2, 3 80 ps
tjit RMS Phase Jitter (Random) 25MHz, Integration Range:
100Hz – 1MHz 0.14 ps
tR / tFOutput Rise/Fall Time 20% to 80% 200 800 ps
odc Output Duty Cycle 48 52 %
tEN Output Enable
Time; NOTE 4 ENABLE1 4 cycles
ENABLE2 4 cycles
tDIS Output Disable
Time; NOTE 4 ENABLE1 4 cycles
ENABLE2 4 cycles
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Table 6E. AC Characteristics, VDD = 3.3V ± 5%, VDDO = 1.8V ± 0.2V, TA = 0°C to 70°C
NOTE: Electrical parameters are guaranteed ov er the specified ambient operating temperature range, which is established when the
device is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after
thermal equilibrium has been reached under these conditions.
All parameters measured at ƒ fMAX using a crystal input unless noted otherwise.
Terminated at 50 to VDDO/2.
NOTE 1: XTAL_IN can be overdriven by a single-ende d LVCMOS signal. Please refer to Application Information section.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equa l load conditions. Measured at VDDO/2.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
NOTE 4: These parameters are guaranteed by characterization. Not tested in production.
Table 6F. AC Characteristics, VDD = 2.5V ± 5%, VDDO = 1.8V ± 0.2V, TA = 0°C to 70°C
NOTE: Electrical parameters are guaranteed ov er the specified ambient operating temperature range, which is established when the
device is mounted in a test socket with maintained transverse airflow greater than 500 lfpm. The device will meet specifications after
thermal equilibrium has been reached under these conditions.
All parameters measured at ƒ fMAX using a crystal input unless noted otherwise.
Terminated at 50 to VDDO/2.
NOTE 1: XTAL_IN can be overdriven by a single-ende d LVCMOS signal. Please refer to Application Information section.
NOTE 2: Defined as skew between outputs at the same supply voltage and with equa l load conditions. Measured at VDDO/2.
NOTE 3: This parameter is defined in accordance with JEDEC Standard 65.
NOTE 4: These parameters are guaranteed by characterization. Not tested in production.
Symbol Parameter Test Conditions Minimum Typical Maximum Units
fMAX Output Frequency Using External Crystal 10 40 MHz
Using External Clock
Source NOTE 1 DC 100 MHz
tsk(o) Output Skew; NOTE 2, 3 80 ps
tjit RMS Phase Jitter (Random) 25MHz, Integration Range:
100Hz – 1MHz 0.18 ps
tR / tFOutput Rise/Fall Time 20% to 80% 200 900 ps
odc Output Duty Cycle 48 52 %
tEN Output Enable
Time; NOTE 4 ENABLE1 4 cycles
ENABLE2 4 cycles
tDIS Output Disable
Time; NOTE 4 ENABLE1 4 cycles
ENABLE2 4 cycles
Symbol Parameter Test Conditions Minimum Typical Maximum Units
fMAX Output Frequency Usin g External Crystal 10 40 MHz
Using External Clock
Source NOTE 1 DC 100 MHz
tsk(o) Output Skew; NOTE 2, 3 80 ps
tjit RMS Phase Jitter (Random) 25MHz, Integration Rang e:
100Hz – 1MHz 0.19 ps
tR / tFOutput Rise/Fall Time 20% to 80% 200 900 ps
odc Outpu t D ut y Cycl e 4 7 53 %
tEN Output Enable
Time; NOTE 4 ENABLE1 4 cycles
ENABLE2 4 cycles
tDIS Output Disable
Time; NOTE 4 ENABLE1 4 cycles
ENABLE2 4 cycles
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Typical Phase Noise at 25MHz (2.5V Core/2.5V Output)
Raw Phase Noise Data
25MHz
RMS Phase Jitter (Random)
100Hz to 1MHz = 0.26ps (typical)
Noise Power(dBc/Hz)
Offset Frequency (Hz)
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Parameter Measurement Information
3.3V Core/3.3V LVCMOS Output Load AC Test Circuit
1.8V Core/1.8V LVCMOS Output Load AC Test Circuit
3.3V Core/1.8V LVCMOS Output Load AC Test Circuit
2.5V Core/2.5V LVCMOS Output Load AC Test Circuit
3.3V Core/2.5V LVCMOS Output Load AC Test Circuit
2.5V Core/1.8V LVCMOS Output Load AC Test Circuit
SCOPE
Qx
GND
VDD,
-1.65V±5%
1.65V±5%
VDDO
SCOPE
Qx
GND
V
DD,
-0.9V±0.1V
0.9V±0.1V
VDDO
SCOPE
Qx
GND
VDD
-0.9V±0.1V
2.4V±0.9V
VDDO
0.9V±0.1V
SCOPE
Qx
GND
V
DD,
-1.25±5%
1.25V±5%
VDDO
SCOPE
Qx
GND
VDD
-1.25±5%
2.05V±5%
VDDO
1.25V±5%
SCOPE
Qx
GND
VDD
-0.9V±0.1V
1.6V±0.025%
VDDO
0.9V±0.1V
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Parameter Measurement Information, continued
Output Skew
Output Rise/Fall Time
Output Duty Cycle/Pulse Width/Period
Qx
Qy
tsk(b)
VDDO
2
VDDO
2
20%
80% 80%
20%
tRtF
BCLK[0:5]
BCLK[0:5]
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Application Information
Crystal Input Interface
Figure 2 shows an example of 83905 crystal in terface with a
parallel resonant crystal. The frequency accuracy can be fine
tuned by adjusting the C1 and C2 values. For a parallel crystal with
loading capacitance CL = 18pF, to start with, we suggest C1 =
15pF and C2 = 15pF. These values may be slightly fine tuned
further to optimize the frequency accuracy for different board
layouts. Slightly increasing the C1 and C2 values will slightly
reduce the frequency. Slightly decreas ing the C1 and C2 values
will slightly increase the frequency. For the oscillator circuit below,
R1 can be used, but is not required. For new designs, it is
recommended that R1 not be used.
Figure 2. Crystal Input Int erface
LVCMOS to XTAL Interface
The XTAL_IN input can accept a single-ended LVCMOS signal
through an AC coupling capacitor. A gene ral interface diagram is
shown in Figure 3. The XTAL_OUT pin can be left floating. The
input edge rate can be as slow as 10ns. For LVCMOS inputs, it is
recommended that the amplitude be reduced from full swing to half
swing in order to prevent signal interference with the power rail and
to reduce noise. This configuration requires that the output
impedance of the driver (Ro) plus the series resistance (Rs) equals
the transmission line impedance. In addition, matched termination
at the crystal input will attenuate the signal in half. This can be
done in one of two ways. First, R1 and R2 in parallel should equal
the transmission line impedance. For most 50 app lications, R1
and R2 can be 100. This can also be accomplished by removing
R1 and making R2 50. By overdriving th e cr ystal oscillator, the
device will be functional, but note, the device performance is
guaranteed by using a quartz crystal.
Figure 3. General Diagram f or LVCMOS Driver to XTAL Input Interface
XTAL_IN
XTAL_OUT
C1
15p
C2
15p
X1
18pF Parallel Crystal
R1 (optional)
0
XTAL_IN
XTAL_OUT
Ro Rs
Zo = Ro + Rs
50Ω0.1µf
R1
R2
V
DD
V
DD
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VFQFN EPAD Thermal Release Path
In order to maximize both the removal of heat from the package
and the electrical performance, a land pattern must be
incorporated on the Printed Circuit Board (PCB) within the footprint
of the package corresponding to the exposed metal pad or
exposed heat slug on the package, as sh own in Figure 4. The
solderable area on the PCB, as defined by the solder mask, should
be at least the same size/shape as the exposed pad/slug area on
the package to maximize the thermal/electrical performance.
Sufficient clearance should be designed on the PCB between the
outer edges of the land pattern and the inner edges of pad pattern
for the leads to avoid any shorts.
While the land pattern on the PC B provides a means of heat
transfer and electrical grounding from the package to the board
through a solder joint, thermal vias are necessary to effectively
conduct from the surface of the PCB to the ground plane(s). The
land pattern must be connected to ground through these vias. The
vias act as “heat pipes”. The number of vias (i.e. “heat pipes”) are
application speci fic and dependent upon the packag e power
dissipation as well as electrical conductivity requirements. Thus,
thermal and electrical analysis and/or testing are recommended to
determine the minimum number needed. Maximum thermal and
electrical performance is achieved when an array of vias is
incorporated in the land pattern. It is recommended to use as many
vias connected to ground as possible. It is also recommended that
the via diameter should be 12 to 13mils (0.30 to 0.33mm) with 1oz
copper via barrel plating. This is desirable to avoid any solder
wicking inside th e via during the soldering process which may
result in voids in solder between the exposed pad/slug and the
thermal land. Precautions should be taken to eliminate any solder
voids between the exposed heat slug and the land pattern. Note:
These recom mendations are to be used as a gu i d el i ne only. For
further information, please refer to the Application Note on the
Surface Mount Assembly of Amkor’s Thermally/Electrically
Enhance Leadframe Base Package, Amkor Technology.
Figure 4. P.C. Assembly for Exposed Pad Thermal Release Path – Side View (drawing not to scale)
Recommendations for Unused Input and Output Pins
Inputs:
LVCMOS Control Pins
All control pins have internal pull-ups or pull-downs; additional
resistance is not required but can be added for additional
protection. A 1k resistor can be used .
Outputs:
LVCMOS Outputs
All unused L VCMOS output can be left floating. There should be no
trace attached.
SOLDERSOLDER PINPIN EXPOSED HEAT SLUG
PIN PAD PIN PADGROUND PLANE LAND PATTERN
(GROUND PAD)
THERMAL VIA
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Layout Guideline
Figure 5 shows an example of 83905 application schematic. The
schematic example focuses on functional connections and is not
configuration specific. In this example, the device is operated at
VDD = 3.3V and VDDO = 1.8V. The crystal inputs are loaded with an
18pf load resonant quartz crystal. The tuning capacitors (C1, C2)
are fairly accurate, but minor adjustments might be required. Refer
to the pin description and functional tables in the datasheet to
ensure the logic control inputs are properly set. For the LVCMOS
output drivers, two termination examples are shown in the
schematic. For additional termination examples are shown in the
LVCMOS Termination Application Note.
As with any high speed analog circuitry , the power supply pins are
vulnerable to random noise. To achieve optimum jitter
performance, power supply isolation is required. The 83905
provides separate VDD and VDDO power supplies to isolate any
high switching noise from coupling into the internal oscillator. In
order to achieve the best possible filtering, it is highly
recommended that the 0.1uF capacitors on the device side of the
ferrite beads be placed on the device side of the PCB as close to
the power pins as possible. This is represented by the placement
of these capacitors in the schematic. If space is limited, the ferrite
beads, 10uF and 0.1uF capacitor connected to the board supplies
can be placed on the opposite side of the PCB. If space permits,
place all filter components on the device side of the board.
Power supply filter recommendations are a general guideline to be
used for reducing external noise from coupling into the devices .
The filter performance is desig ned for a wide range of noise
frequencies. This low-pass filter starts to attenuate noise at
approximately 0kHz. If a specific frequency noise component is
known, such as switching power supplies frequencies, it is
recommended that component values be adjusted and if required,
additional filtering be added. Additionally, good general design
practices for power plane voltage stability suggests adding bu lk
capacitance in the local area of all devi ces.
Figure 5. Schematic of Recommended Layout
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Power Considerations
This section provides information on power dissipation and jun c tion temperature for the 83905.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the 83905 is the sum of the core power plus the analog power plus the power dissipated due to the load.
The following is the power dissipation for VDD = 3.3V + 5% = 3.465V, which gives worst case results.
Power (core) MAX = VDD_MAX * (IDD + IDDO) = 3.465V *(10mA + 5mA) = 51.9mW
Output Impedance ROUT Power Dissipation due to Loading 50 to VDD/2
Output Current IOUT = VDD_MAX / [2 * (50 + ROUT)] = 3.465V / [2 * (50 + 7)] = 30.4mA
Power Dissipation on the ROUT per LVCMOS output
Power (ROUT) = ROUT * (IOUT)2 = 7 * (30.4mA)2 = 6.5mW per output
Total Power Dissipation on the ROUT
Total Power (ROUT) = 6.5mW * 6 = 39mW
Dynamic Pow er Dissipatio n at 25 MH z
Power (25MHz) = CPD * Frequency * (VDD)2 = 19pF * 25MHz * (3.465V)2 = 5.70mW per output
Total Power (25MHz) = 5.70mW * 6 = 34.2mW
Total Power Dissipation
Total Power
= Power (core)MAX + Total Power (ROUT) + Total Power (25MHz)
= 51.98mW + 39mW + 34.2mW
= 125.1mW
2. Junction Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the device.
The maximum recommended junction temperature is 125°C.
The equation for Tj is as follows: Tj = JA * Pd_total + TA
Tj = Junction Temperature
JA = Junction-to-Ambient Thermal Resistance
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)
TA = Ambient Temperature
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance JA must be used. Assuming no air flow
and a multi-layer board, the appropriate va lue is 100.3°C/W per Table 7 belo w.
Therefore, Tj for an ambient te mperature of 70°C with all outputs switching is:
70°C + 0.125W *100.3°C/W = 82.5°C. This is below the limit of 125°C.
This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow and the
type of board (multi-layer).
Table 7. Thermal Resistance JA for 16-Lead TSSOP, Forced Convection
JA by Velocity
Meters per Second 012.5
Multi-Layer PCB, JEDEC Standard Test Boards 100.3°C/W 96.0°C/W 93.9°C/W
16©2016 Integrated Device Technology, Inc. Revision D September 27, 2016
83905 Datashee t
Reliability Information
Table 8A. JA vs. Air Flow Table for a 16-Lead TSSOP
Table 8B. JA vs. Air Flow Table for a 16-Lead SOIC
Table 8C. JA vs. Air Flow Table for a 20-Lead VFQFN
Transistor Count
The transistor count for 83905: 339
JA vs. Air Flow
Meters per Second 012.5
Multi-Layer PCB, JEDEC Standard Test Boards 100.3°C/W 96.0°C/W 93.9°C/W
JA vs. Air Flow
Meters per Second 012.5
Multi-Layer PCB, JEDEC Standard Test Boards 78.8°C/W 71.1°C/W 66.2°C/W
JA vs. Air Flow
Meters per Second 012.5
Multi-Layer PCB, JEDEC Standard Test Boards 57.5°C/W 50.3°C/W 45.1°C/W
17©2016 Integrated Device Technology, Inc. Revision D September 27, 2016
83905 Datashee t
Package Outline and Package Dimensions
Package Outline - G Suffix for 16-Lead TSSOP
Table 9A. Package Dimensions for 16-Lead TSSOP
Reference Document: JEDEC Publication 95, MO-153
Package Outline - M Suffix for 16-Lead SOIC
Table 9B. Package Dimensions for 16-Lead SOIC
Reference Document: JEDEC Publication 95, MS-012
All Dimensions in Millimeters
Symbol Minimum Maximum
N16
A1.20
A1 0.05 0.15
A2 0.80 1.05
b0.19 0.30
c0.09 0.20
D4.90 5.10
E6.40 Basic
E1 4.30 4.50
e0.65 Basic
L0.45 0.75
aaa 0.10
All Dimensions in Millimeters
Symbol Minimum Maximum
N16
A1.35 1.75
A1 0.10 0.25
B0.33 0.51
C0.19 0.25
D9.80 10.00
E3.80 4.00
e1.27 Basic
H5.80 6.20
h0.25 0.50
L0.40 1.27
150 il (N B d ) SOIC
18©2016 Integrated Device Technology, Inc. Revision D September 27, 2016
83905 Datashee t
Package Outline and Package Dimensions
Package Outline - K Suffix for 20-Lead VFQFN
Table 10. Package Dimensions
Reference Document: JEDEC Publication 95, MO-220
NOTE:
The drawing and dime nsion data originate from IDT package
outline drawing PSC-4170, rev03.
1. Dimensions and tolerances conform to ASME Y14.5M-1994
2. All dimensions are in millimeters. All angles are in degrees.
3. N is the total number of terminals.
4. All specifications comply with JEDEC MO-220.
All Dimensions in Millimeters
Symbol Minimum Nominal Maximum
N20
A0.80 1.00
A1 00.05
A3 0.2 Ref.
b0.20 0.25 0.30
ND & NE5
D & E 4.00 Basic
D2 & E2 1.95 2.25
e0.50 Basic
L0.45 0.55 0.65
19©2016 Integrated Device Technology, Inc. Revision D September 27, 2016
83905 Datashee t
Ordering Information
Table 11. Ordering Information
Part/Order Number Marking Package Shipping Packaging Temperature
83905AMLF 83905AML “Lead-Free” 16-Lead SOIC Tube 0C to 70C
83905AMLFT 83905AML “Lead-Free” 16-Lead SOIC Tape & Reel 0C to 70C
83905AGLF 83905AGL “Lead-Free” 16-Lead TSSOP Tube 0C to 70C
83905AGLFT 83905AGL “Lead-Free” 16-Lead TSSOP Tape & Reel 0C to 70C
83905AKLF 3905AL “Lead-Free” 20-Lead VFQFN Tray 0C to 70C
83905AKLFT 3905AL “Le ad-Free” 20-Lead VFQFN Tape & Reel 0C to 70C
20©2016 Integrated Device Technology, Inc. Revision D September 27, 2016
83905 Datashee t
Revision History Sheet
Rev Table Page Description of Change Date
A 2 Added Enable Timing Diagram. 3/28/05
BT6A - T6F 1
5 - 7
8
Features Section - added RMS Phase Jitter bullet.
AC Characteristics Tables - added RMS Phase Jitter specs.
Added Phase Noise Plot. 4/8/05
B T9 14 Ordering Information Table - added TSSOP, non -LF part number. 4/25/05
B11
12 Added Crystal Input Interface in Application Section.
Added Schematic layout. 5/16/05
B
3
11
13
Absolute Maximum Ratings - corrected 20-Lead VFQFN package Thermal
Impedance.
Added Recommendations for Unused Input and Output Pins.
Corrected Theta JA Air Flow Table for 20-Lead VFQFN.
10/2/06
BT9
11
12
17
Added LVCMOS to XTAL Interface section.
Added Thermal Release Path section.
AC Characteristics Table - added lead-free marking for 20-Lead VFQFN package. 7/9/07
BT7B - T7C
3
12
14
16
Absolute Maximum Ratings - updated TSSOP and VFQFN Thermal Impedance.
Updated Thermal Release Path section.
Updated TSSOP and VFQFN Th ermal Impedance.
Added note to VFQFN Package Outline.
1/24/08
B15 Added Power Considerations section.
Converted datasheet format. 7/20/09
B T10 19 Removed leaded order-able parts from Ordering Information table 11/14/12
C
T6D
T9A
T11
1, 15
1
7
14
17
18
19
Deleted HiPerClockS references.
Features, last bullet: updated packaging note.
Mixed AC Characteristics Table - corrected typo, switched Output Rise/Fall Time
spec with Output Duty Cycle spec.
Replaced schematic.
16-Lead TSSOP Package Table - corrected dimensi on A1 Minimum = 0.05.
Updated VFQFN package outline page.
Ordering Information table - deleted Lead-free note, and quantit y from Tape and
Reel.
4/18/13
C 1 Pin Assignment: Corrected 20-Lead illustration cut-off text 2/27/14
C
T6A - T6F
T10
1
6 - 8
9
11
18
21
Pin Assignment, 20-Lead VFQFN: removed the Epad dimensio ns.
Changed NOTE 1to XTAL_IN can be overdriven by a single-ended LVCMOS signal.
Please refer to Application Information section.
Deleted 3.3V Phase Noise Plot
Deleted RMS Phase Jitter graph.
Modified dimensions to reflect tightened tolerance s .
Updated contact information.
8/6/14
D2 Figure 1 corrected.
Updated datasheet header/footer.
Deleted “ICS” prefix from part number throughout the datasheet 9/27/16
83905 Datashee t
21©2016 Integrated Device Technology, Inc. Revision D September 27, 2016
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