AOZ8007
Ultra-Low Capacitance TVS Diode Array
General Description
The AOZ8007 is a transient voltage suppressor array designed to protect high speed data lines such as HDMI and Gigabit Ethernet from damaging ESD events. This device incorporates eight surge rated, low capacitance steering diodes and a TVS in a single package. During transient conditions, the steering diodes direct the transient to either the positive side of the power supply line or to ground. The AOZ8007 provides a typical line to line capacitance of 0.47pF and low insertion loss up to 2.58GHz providing greater signal integrity making it ideally suited for HDMI 1.3 applications, such as Digital TVs, DVD players, set-top boxes and mobile computing devices. The AOZ8007 comes in RoHS compliant, tiny SOT-23-6 and MSOP-10 packages and is rated -40°C to +85°C junction temperature range. The MSOP package features a flow through layout design.
Features
●
● ● ● ● ● ●
ESD protection for high-speed data lines: – IEC 61000-4-2, level 4 (ESD) immunity test – ±15kV (air discharge) and ±8kV (contact discharge) – Human Body Model (HBM) ±15kV Array of surge rated diodes with internal TVS diode Small package saves board space Protects four I/O lines Low capacitance between I/O lines: 0.47pF Low clamping voltage Low operating voltage: 5.0V
Applications
● ● ● ● ● ● ● ●
HDMI ports Monitors and flat panel displays Set-top box USB 2.0 power and data line protection Video graphics cards Digital Video Interface (DVI) 10/100/1000 Ethernet Notebook computers
Typical Application
AOZ8007 AOZ8007
TX2+ TX2TX1+ TX1HDMI Transmitter TX0+ TX0CLK+ CLKConnector Connector
RX2+ RX2RX1+ RX1RX0+ RX0CLK+ CLK-
HDMI Receiver
AOZ8007
AOZ8007
Figure 1. HDMI Ports
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AOZ8007
Ordering Information
Part Number
AOZ8007CI AOZ8007FI
Ambient Temperature Range
-40°C to +85°C
Package
SOT-23-6 MSOP-10
Environmental
RoHS Compliant
• All AOS products are offered in packages with Pb-free plating and compliant to RoHS standards. • Parts marked as Green Products (with “L” suffix) use reduced levels of Halogens, and are also RoHS compliant. Please visit www.aosmd.com/web/quality/rohs_compliant.jsp for additional information.
Pin Configuration
CH1
1 6
CH4
CH1 CH2
1 2 3 4 5
10 9 8 7 6
NC NC VP NC NC
VN
2
5
VP
VN CH3
CH2
3
4
CH3
CH4
SOT23-6
(Top View)
MSOP-10
(Top View)
Absolute Maximum Ratings
Exceeding the Absolute Maximum ratings may damage the device.
Parameter
Storage Temperature (TS) ESD Rating per IEC61000-4-2, ESD Rating per Human Body contact(1) ESD Rating per IEC61000-4-2, air(1) Model(2) ±8kV ±15kV ±15kV
Rating
-65°C to +150°C
Notes: 1. IEC 61000-4-2 discharge with CDischarge = 150pF, RDischarge = 330Ω. 2. Human Body Discharge per MIL-STD-883, Method 3015 CDischarge = 100pF, RDischarge = 1.5kΩ.
Maximum Operating Ratings
Parameter
Junction Temperature (TJ)
Rating
-40°C to +125°C
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AOZ8007
Electrical Characteristics
TA = 25°C unless otherwise specified. Specifications in BOLD indicate a temperature range of -40°C to +85°C.
Symbol
VRWM VBR IR VF VCL
Parameter
Reverse Working Voltage Reverse Breakdown Voltage Reverse Leakage Current Diode Forward Voltage Channel Clamp Voltage Positive Transients Negative Transient Channel Clamp Voltage Positive Transients Negative Transient Channel Clamp Voltage Positive Transients Negative Transient Between VP
Conditions
and VN(3) and VN(4)
Min.
Typ.
Max.
5.5
Units
V V
IT = 1mA, between VP IF = 15mA
6.6 1 0.70 Ground(5) 10.50 -2.00 0.85 1
VRWM = 5V, between VP and VN IPP = 1A, tp = 100ns, any I/O pin to
µA V V V V V V V pF pF pF pF pF
IPP = 5A, tp = 100ns, any I/O pin to Ground(5) 12.50 -3.50 IPP = 12A, tp = 100ns, any I/O pin to Ground(5) 16.00 -5.50 VR = 0V, f = 1MHz, any I/O pin to Ground(6) VR = 0V, f = 1MHz, between I/O pins(6) VP = 3.3V, VR = 1.65V, f = 1MHz, any I/O pin to Ground VP = 5.0V, VR = 2.5V, f = 1MHz, any I/O pins to ground 1.0 0.47 0.75 0.75 1.05 0.50 0.85 0.85 0.03
Cj
Channel Input Capacitance
∆Cj
Channel Input Capacitance Matching
VR = 0V, f = 1MHz, between I/O pins
Notes: 3. The working peak reverse voltage, VRWM, should be equal to or greater than the DC or continuous peak operating voltage level. 4. VBR is measured at the pulse test current IT. 5. Measurements performed using a 100ns Transmission Line Pulse (TLP) system. 6. Measure performed with no external capacitor on VP.
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AOZ8007
Typical Operating Characteristics
Clamping Voltage vs. Peak Pulse Current
(tperiod = 100ns, tr = 1ns) 15 Clamping Voltage, Vcl (V) 14 Forward Voltage (V) 13 12 11 10 9 8 7 6 5 0 2 4 6 8 Peak Pulse Current (A) 10 12 7 6 5 4 3 2 1 0 0 2 4 6 8 10 Forward Current (A) 12 14
Forward Voltage vs. Forward Current
(tperiod = 100ns, tr = 1ns)
Capacitance vs. Reverse Voltage
1.5 3 0 VP = Floating S21 (dB) 1 VP = 3.3V 0.5 -9 0 0 0.5 1 1.5 2.5 3.5 2 3 Reverse Volts, Vr (V) 4 4.5 5 -12 1 -3 -6
Insertion Loss vs. Frequency
Capacitance (pF)
VP = Floating -3dB 2,565MHz
10
100 Frequency (MHz)
1,000
10,000
ESD Response (8kV Contact per IEC61000-4-2)
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AOZ8007
Application Information
The AOZ8007 TVS is design to protect four high speed data lines from ESD and transient over-voltage by clamping them to a fixed voltage. When the voltages on the protected lines exceed the limit, the internal steering diode are forward bias will conduct the harmful transient away from the sensitive circuitry. As system frequency increase, printed circuit board layout becomes more complex. A successful high speed board must integrate the device and traces while avoiding signal transmission problems associated with HDMI data speed. transient over-voltages by clamping them to a fixed reference. The low inductance and construction minimizes voltage overshoot during high current surges. When the voltage on the protected line exceeds the reference voltage the internal steering diodes are forward biased, conducting the transient current away from the sensitive circuitry. The AOZ8007 is designed for the ease of PCB layout by allowing the traces to run underneath the device. The pinout of the AOZ8007 is design to simply drop onto the IO lines of a High Definition Multimedia Interface (HDMI) design without having to divert the signal lines that may add more parasitic inductance. Pins 1, 2, 4 and 5 are connected to the internal TVS devices and pins 6, 7, 9 and 10 are no connects. The no connects was done so the package can be securely soldered onto the PCB surface. See Figure 2.
CH 1 CH 2 VN CH 3 CH 4 CH 1 CH 2 VP CH 3 CH 4
High Speed HDMI PCB Layout Guidelines
Printed circuit board layout is the key to achieving the highest level of surge immunity on power and data lines. The location of the protection devices on the PCB is the simplest and most important design rule to follow. The AOZ8007 devices should be located as close as possible to the noise source. The placement of the AOZ8007 devices should be used on all data and power lines that enter or exit the PCB at the I/O connector. In most systems, surge pulses occur on data and power lines that enter the PCB through the I/O connector. Placing the AOZ8007 devices as close as possible to the noise source ensures that a surge voltage will be clamped before the pulse can be coupled into adjacent PCB traces. In addition, the PCB should use the shortest possible traces. A short trace length equates to low impedance, which ensures that the surge energy will be dissipated by the AOZ8007 device. Long signal traces will act as antennas to receive energy from fields that are produced by the ESD pulse. By keeping line lengths as short as possible, the efficiency of the line to act as an antenna for ESD related fields is reduced. Minimize interconnecting line lengths by placing devices with the most interconnect as close together as possible. The protection circuits should shunt the surge voltage to either the reference or chassis ground. Shunting the surge voltage directly to the IC’s signal ground can cause ground bounce. The clamping performance of TVS diodes on a single ground PCB can be improved by minimizing the impedance with relatively short and wide ground traces. The PCB layout and IC package parasitic inductances can cause significant overshoot to the TVS’s clamping voltage. The inductance of the PCB can be reduced by using short trace lengths and multiple layers with separate ground and power planes. One effective method to minimize loop problems is to incorporate a ground plane in the PCB design. The AOZ8007 ultra-low capacitance TVS is designed to protect four high speed data transmission lines from
Figure 2. Flow through Layout for two Line Pair
It is crucial that the layout is successful for a HDMI design PCB board. Some of the problems associated with high speed design are matching impedance of the traces and to minimize the crosstalk between parallel traces. This application note is to provide you as much information to successfully design a high speed PCB using Alpha & Omega devices. The HDMI video signals are transmitted on a very high speed pair of traces and any amount of capacitance, inductance or even bends in a trace can cause the impedance of a differential pair to drop as much as 40Ω. This is not desirable because HDMI ports must maintain a 100Ω ±15% on each of the four pairs of its differential lines per HDMI Compliance Test Specifications. The HDMI CTS specifies that the impedance on the differential pair of a receiver must be measured using a Time Domain Reflectometry method with a pulse rise time of ≤200pS. The TDR measurements of the PCB traces allows to locate and model discontinuities cause by the geometrical features of a bend and by the frequencydependant losses of the trace itself. These fast edge rates can contribute to noise and crosstalk, depending on the traces and PCB dielectric construction material.
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AOZ8007
Material selection is another aspect that determines good characteristic impedance in the lines. Different material will give you different results. The dielectric material will have the dielectric constant (εr). Where Q1, Q2 = charges, r = distance between charges (m), F = force(N), ε = permittivity of dielectric (F/m). By solving for Zo you can calculate the differential impedance with the equation below.
– 0.96 --- h Zdiff = 2 × Zo 1 – 0.48e D
(4)
Q1 Q2 F = -------------2 4 πε r
Zdiff = 100.77
(1)
Each PCB substrate has a different relative dielectric constant. The dielectric constant is the permittivity of a relative that of empty space. Where εr = dielectric constant, ε = permittivity, and εo = permittivity of empty space.
Adjust the trace width, height, distance between the traces and FR4 thickness to obtain the desired 100Ω differential impedance. The general rule of thumb is to route the traces as short as possible, use differential routing strategies whenever feasible and match the length and bends to each of the differential traces. The graphs below show the differential impedance with varying trace width without the AOZ8007 MSOP-10 package part on it. Each of the graphs and board layout represent changing trace width from 50Ω to 80Ω in increment of 10Ω.
ε ε r = ---εo
(2)
The dielectric constant affects the impedance of a transmission line and can propagate faster in materials that have a lower εr . The frequency in your design will depend on the material being used. With equation 1 you can determine the type of material to use. If higher frequency is required other board material maybe considered. GETEK is another material that can be used in high speed boards. They have a typical εr between 3.6 to 4.0. The most common type of dielectric material used for PCB is FR-4. Typical dielectric constant for FR-4 is between 4.0 to 4.5. Most PCB manufacture will be able to give you the exact value of the FR-4 dielectric constant. Once you determined the dielectric constant of the board material you can start to calculate the impedance of each trace. Below are the formulas for a microstrip layout. This impedance is dependant on the width of the microstrip (W) the thickness (t) of the trace and the height (h) of the FR4 material, and (D) trace edge to edge spacing.
W Trace D W t
Figure 4. 100Ω Differential Impedance Max 103Ω, Min 97Ω
εr
Ground
Dielectric Material
H
Figure 3.
Typical value of W = 12.6 mil, h = 10mils, D = 10mils, t = 1.4mils and εr = 4.0 with the equation below for a microstrip impedance yields:
Figure 5. 120Ω Differential Impedance Max 110Ω, Min 102Ω
(3)
5.98 × h 87 Zo = ------------------------- = ln --------------------- 0.8W + - t ε r + 1.41 Zo = 61.73 Ω
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AOZ8007
X
Zo = 61Ω Z1 C(TVS)
Zo = 61Ω
Figure 7.
Z1 K = ----Z0
Figure 6. 140Ω Differential Impedance Max 102Ω, Min 92Ω
(5)
Z 0 C TVS K X = -------------------- --------------- - - 2 τ K –1
(6)
Z0 is the normal 61Ω differential impedance on the trace. Z1 is the needed impedance to compensate for the added C(TVS) K is defined as the unloaded impedance of the adjusted trace. X is the length of the trace needed for the compensation.
Figure 7. 160Ω Differential Impedance Max 123Ω, Min 109Ω
140 Differentail Impedance (Ω) 120 100 80 60 40 20 0 50 55 60 65 70 75 80
Min. Max.
τ is the propagation delay time required for a signal to travel from one point to another. This value should be less than 200pS. From the above method the designer should layout the boards with a 50Ω common mode trace. The result should give you approximately 100Ω differential impedance. Z1 is the impedance that you choose in order to compensate the TVS capacitance. Based on Z1 value, we can get the length of the segment from the above equations. With the value of Z1 = 80Ω, Zo = 61Ω, C(TVS) = 0.94 and τ = 180. The X(mils) equates to 580 mils. Page 8 has a series of graph that represent changing width and length of the trace from 50Ω to 80Ω in increment of 10Ω with a MSOP-10 package solder onto the board. As you can observe from the graphs, a small incremental capacitance that is added to the differential lines can significantly decrease the differential impedance. Thus violated the HDMI specification of 100Ω±15%.
Common Mode Impedance (Ω)
Figure 8. Differential Impedance
By adding a TVS onto the traces it can have a large effect on the impedance of the line. This addition of a capacitance added to a 100Ω differential transmission line without any compensation may decrease the impedance as much as 20Ω or more. Below is a formula to calculate the length for the compensation of C(TVS).
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AOZ8007
Figure 10. 100Ω Differential Impedance with AOZ8007 MSOP-10 Package on it Max. 97Ω, Min. 80Ω
Figure 12. 140Ω Differential Impedance with AOZ8007 MSOP-10 Package on it Max. 102Ω, Min. 92Ω
Figure 11. 120Ω Differential Impedance with AOZ8007 MSOP-10 Package on it Max. 99Ω, Min. 86Ω
Figure 13. 160Ω Differential Impedance with AOZ8007 MSOP-10 Package on it Max. 101Ω, Min. 95Ω
From Figure 13 we are able to get the best result from using all of the equation above. With the value of Z1 = 80Ω, Z0 = 61Ω, C(TVS) = 0.94, τ = 180 and from Table 1. The X(mils) equates to 580mils to give the best compensated differential impedance on the traces for the added capacitance from the AOZ8007.
Table 1. AOZ8007 MSOP-10 HDMI Evaluation Board Specification
Number of layers Copper Trace Thickness Dielectric Constant εr Overall Board Thickness Dielectric thickness between top and ground layer 4 1.4 mils 4 62 mils 10 mils
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AOZ8007
Conclusion
This application section discusses ESD protection while maintaining the differential impedance of a HMDI sink device. Since the TVS add capacitance we must design the board to meet the HDMI requirements. This application note is a guideline to calculate and layout the PCB. Different board manufacture and process will fluctuate and will cause the final board to vary slightly. You must carefully plan out a successful high speed HDMI PCB. Factor such as PCB stack up, ground bounce, crosstalk and signal reflection can interfere with a signal. The layout, trace routing, board materials and impedance calculation discussed in this application note can help you design a more effective PCB using the AOZ8007 devices.
100Ω Differential
132Ω Differential
580 mils
Figure 14. Recommend Layout for MSOP-10 Package
100Ω Differential
Table 2. AOZ8007 SOT-23-6 Evaluation Board Specifications
Number of layers Copper Trace Thickness Dielectric Constant εr Overall Board Thickness 4 1.4 mils 4 62 mils 10 mils
132Ω Differential
580 mils Total Distance
Dielectric thickness between top and ground layer
Figure 15. Recommended Layout for SOT-23 Package
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AOZ8007
Package Dimensions, SOT23-6L
Gauge Plane D e1 c L Seating Plane 0.25mm
E E1
θ1 e b
A
A2 .010mm A1
Dimensions in millimeters
RECOMMENDED LAND PATTERN
Symbols A A1 A2 b c D E E1 e e1 L θ1 Min. 0.90 0.00 0.80 0.30 0.08 2.70 2.50 1.50 Nom. — — 1.10 0.40 0.13 2.90 2.80 1.60 Max. 1.25 0.15 1.20 0.50 0.20 3.10 3.10 1.70
Dimensions in inches
Symbols A A1 A2 b c D E E1 e e1 L θ1 Min. 0.035 0.00 0.031 0.012 0.003 0.106 0.098 0.059 Nom. — — 0.043 0.016 0.005 0.114 0.110 0.063 Max. 0.049 0.006 0.047 0.020 0.008 0.122 0.122 0.067
2.40 0.80 0.95 0.63
UNIT: mm
0.95 BSC 1.90 BSC 0.30 — 0.60 0° — 8°
0.037 BSC 0.075 BSC 0.012 — 0.024 0° — 8°
Notes: 1. Package body sizes exclude mold flash and gate burrs. Mold flash at the non-lead sides should be less than 5 mils each. 2. Dimension “L” is measured in gauge plane. 3. Tolerance ±0.100mm (4 mil) unless otherwise specified. 4. Followed from JEDEC MO-178C & MO-193C. 6. Controlling dimension is millimeter. Converted inch dimensions are not necessarily exact.
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AOZ8007
Tape and Reel Dimensions, SOT23-6L
Tape
T D1 P2 E1 P1
E2 B0
E
K0
Unit: mm
A0
D0
P0
Feeding Direction
D0 1.00 Min. D1 1.50 ±0.10 E 8.00 ±0.30 E1 1.75 ±0.10 E2 3.50 ±0.05 P0 4.00 ±0.10 P1 4.00 ±0.10 P2 2.00 ±0.05 T 0.25 ±0.05
Package SOT-23 (8mm)
A0 3.15 ±0.10
B0 3.20 ±0.10
K0 1.40 ±0.10
Reel
W1
S G N
M V
K
R
Unit: mm
H
W Tape Size 8mm Reel Size ø180 M ø180.00 ±0.50 N ø60.50 W 9.00 ±0.30 W1 11.40 ±1.00 H ø13.00
+0.50 / -0.20
K 10.60
S 2.00 ±0.50
G ø9.00
R 5.00
V 18.00
Leader/Trailer and Orientation
Trailer Tape
(300mm min., 75 Empty Pockets)
Components Tape Orientation in Pocket
Leader Tape
(500mm min., 125 Empty Pockets)
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AOZ8007
Package Dimensions, MSOP-10L
Gauge Plane Seating Plane 0.25
C
L
E1
E
D
12°(4x)
A2 A
b
e
A1
RECOMMENDED LAND PATTERN
Dimensions in millimeters
Symbols A Min. 0.81 0.05 0.76 0.15 0.13 2.90 4.70 2.90 — 0.40 — 0° Nom. 1.02 — 0.86 0.20 0.15 3.00 4.90 3.00 0.50 0.53 — — Max. 1.12 0.15 0.97 0.30 0.23 3.10 5.10 3.10 — 0.66 0.10 6°
Dimensions in inches
Symbols A A1 A2 b C D E E1 e L y θ Min. 0.032 Nom. 0.040 Max. 0.044
0.76
0.30
4.37
0.50
A1 A2 b C D E E1 e L y θ
0.002 — 0.006 0.030 0.034 0.038 0.006 0.008 0.012 0.005 0.006 0.009 0.114 0.118 0.122 0.185 0.193 0.201 0.114 0.118 0.122 — 0.0197 — 0.016 0.021 0.026 — — 0.004 0° — 6°
UNIT: mm
Notes: 1. All dimensions are in millimeters. 2. Tolerance 0.10mm unless otherwise specified. 3. Package body sizes exclude mold flash and gate burrs. Mold flash at the non-lead sides should be less than 5 mils each. 4. Dimension L is measured in gauge plane. 5. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact.
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AOZ8007
Tape and Reel Dimensions, MSOP-10
Carrier Tape
D1 T P1 P2 E1 E2 E B0
K0
D0 P0 A0
Section Y-Y'
UNIT: mm
Feeding Direction
Package MSOP-10 (12mm)
A0 5.3 ±0.1
B0 3.4 ±0.1
K0 1.4 ±0.1
D0 1.6 ±0.1
D1 1.5 +0.1/-0
E 12.0 ±0.3
E1 1.75 ±0.10
E2 5.50 ±0.05
P0 8.00 ±0.10
T P2 P1 0.30 2.00 4.00 ±0.05 ±0.05 ±0.05
Reel
W1
S G M V N K
R H UNIT: mm Tape Size Reel Size 12mm ø330 M ø330 ±0.5 N ø97.0 ±1.0 W 13.00 W1 17.40 W H ø13.0 +0.5/-0.2 K 10.60 S 2.0 ±0.5 G — R — V —
Leader/Trailer and Orientation
Trailer Tape 300mm min. or 75 empty sockets
Components Tape Orientation in Pocket
Leader Tape 500mm min. or 125 empty sockets
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AOZ8007
Part Marking
AOZ8007CI
(SOT-23)
AEOW
LT
Assembly Lot Code
Part Number Code
Week & Year Code
Option & Assembly Location Code
AOZ8007FI
(MSOP-10)
Product Name Extension Character Option Code
8 007 IO76 P11
Part Number Code, Underscore Denotes Green Part Week Code Year Code Assembly Lot Code Assembly Location Code
This datasheet contains preliminary data; supplementary data may be published at a later date. Alpha & Omega Semiconductor reserves the right to make changes at any time without notice. LIFE SUPPORT POLICY ALPHA & OMEGA SEMICONDUCTOR PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support, device, or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.
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