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| Issue X-2 CM1234 PicoGuard XSTM ESD Clamp Array For High Speed Data Line Protection Features * * ESD protection for 4 pairs of differential channels ESD protection to IEC61000-4-2 Level 4 * 15kV contact discharge * 20kV air discharge Pass-through impedance matched clamp architecture Flow-through routing for high-speed signal integrity Minimal line capacitance change with temperature and voltage 100 matched impedance for each paired differential channel Each I/O pin can withstand over 1000 ESD strikes* RoHS compliant (lead-free) TDFN-16 package Product Description The PicoGuard XS (Xtreme Speed) protection family is specifically designed for next generation deep submicron high speed data line protection. The CM1234 is ideal for protecting systems with high data and clock rates or for circuits requiring low capacitive loading and tightly controlled signal skews (with channel-to-channel matching at 2% max deviation). The device is particularly well-suited for protecting systems using high-speed ports such as DVI or HDMI, along with corresponding ports in removable storage, digital camcorders, DVD-RW drives and other applications where extremely low loading capacitance with ESD protection are required. The CM1234 also features easily routed "passthrough" pinouts in a RoHS compliant (lead-free),16lead TDFN, small footprint package. * * * * * * Applications * * DVI ports, HDMI ports in notebooks, set top boxes, digital TVs, LCD displays General purpose high-speed data line ESD protection Electrical Schematic Out_1+ Out_1Out_2+ Out_2Out_3+ Out_3Out_4+ Out_4In_1+ In_1In_2+ In_2In_3+ In_3In_4+ In_4- Gnd = 100 differential matched characteristic impedance *Standard test condition is IEC61000-4-2 level 4 test circuit with each pin subjected to 8kv contact discharge for 1000 pulses. Discharges are timed at 1 second intervals and all 1000 strikes are completed in one continuous test run. The part is then subjected to standard production test to verify that all of the tested parameters are within spec afterh the 1000 strkes. (c) 2008 California Micro Devices Corp. All rights reserved. 4/24/2008 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 1 Issue X-2 CM1234 PicoGuard XS ESD Protection Architecture Conceptually, an ESD protection device performs the following actions upon an ESD strike discharge into a protected ASIC (see Figure 1): 1. When an ESD potential is applied to the system under test (contact or air-discharge), Kirchoff's Current Law (KCL) dictates that the Electrical Overstress (EOS) currents will immediately divide throughout the circuit, based on the dynamic impedance of each path. 2. Ideally, the classic shunt ESD clamp will switch within 1ns to a low-impedance path and return the majority of the EOS current to the chassis shield/ reference ground. In actuality, if the ESD component's response time (tCLAMP) is slower than the ASIC it is protecting, or if the Dynamic Clamping Resistance (RDYN) is not significantly lower than the ASIC's I/O cell circuitry, then the ASIC will have to absorb a large amount of the EOS energy, and be more likely to fail. 3. Subsequent to the ESD/EOS event, both devices must immediately return to their original specifications, and be ready for an additional strike. Any deterioration in parasitics or clamping capability should be considered a failure, since it can then affect signal integrity or subsequent protection capability. (This is known as "multi-strike" capability.) In the CM1234 PicoGuard XS architecture, the signal line leading the connector to the ASIC routes through the CM1234 chip which provides 100 matched differential channel characteristic impedance that helps optimize 100 load impedance applications such as the HDMI high speed data lines. Note:When each of the channels are used individually for single-ended signal lines protection, the individual channel provides 50 characteristic impedance matching. The load impedance matching feature of the CM1234 helps to simplify system designer's PCB layout considerations in impedance matching and also eliminates associated passive components. The route through the PicoGuard XS architecture enables the CM1234 to provide matched impedance for the signal path between the connector and the ASIC. Besides this function, this circuit arrangement also changes the way the parasitic inductance interacts with the ESD protection circuit and helps reduce the IRESIDUAL current to the ASIC. ESD Strike ESD ESD Protection PROTECTION Device DEVICE I /O Connector ASIC I SHUNT IRESIDUAL Figure 1. Standard ESD Protection Device Block Diagram (c) 2008 California Micro Devices Corp. All rights reserved. 2 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 4/24/2008 Issue X-2 CM1234 The PicoGuard XS Architecture Advantages element. This limits the speed that the ESD pulse can discharge through the ESD protection element. In the PicoGuard XS architecture, the inductive elements are in series to the conduction path leading to the protected device. The elements actually help to limit the current and voltage striking the protected device. First the reactance of the inductive element, L1, on the connector side when an ESD strike occurs, acts in the opposite direction of the ESD striking current. This helps limit the peak striking voltage. Then the reactance of the inductive element, L2, on the ASIC side forces this limited ESD strike current to be shunted through the ESD protection diodes. At the same time, the voltage drop across both series element acts to lower the clamping voltage at the protected device terminal. Through this arrangement, the inductive elements also tune the impedance of the ESD protection element by cancelling the capacitive load presented by the ESD diodes to the signal line. This improves the signal integrity and makes the overall ESD protection device more transparent to the high bandwidth data signals passing through the channel. The innovative PicoGuard XS architecture turns the disadvantages of the parasitic inductive elements into useful components that help to limit the ESD current strike to the protected device and also improves the signal integrity of the system by balancing the capacitive loading effects of the ESD diodes. At the same time, this architecture provides an impedance matched signal path for 50 loading applications. Board designs can take advantage of precision internal component matching for improved signal integrity, which is not otherwise possible with discrete components at the system level. This helps to simplify the PCB layout considerations by the system designer and eliminates the associated passive components for load matching that is normally required with standard ESD protection circuits. Each ESD channel consists of a pair of diodes in series which steer the positive or negative ESD current pulse to either the Zener diode or to ground. This embedded Zener diode also serves to eliminate the need for a separate bypass capacitor to absorb positive ESD strikes to ground. The CM1234 protects against ESD pulses up to 18kv contact per the IEC 61000-4-2 standard. Figure 2 illustrates a standard ESD protection device. The inductor element represents the parasitic inductance arising from the bond wire and the PCB trace leading to the ESD protection diodes. Connector ASIC Bond Wire Inductance ESD Stage Figure 2. Standard ESD Protection Model Figure 3 illustrates one of the channels. Similarly, the inductor elements represent the parasitic inductance arising from the bond wire and PCB traces leading to the ESD protection diodes as well. Connector 50 L1 L2 ASIC ESD Device Figure 3. CM1234 PicoGuard XS ESD Protection Model CM1234 Inductor Elements In the CM1234 PicoGuard XS architecture, the inductor elements and ESD protection diodes interact differently compared to the standard ESD model. In the standard ESD protection device model, the inductive element presents high impedance against high slew rate strike voltage, i.e. during an ESD strike. The impedance increases the resistance of the conduction path leading to the ESD protection (c) 2008 California Micro Devices Corp. All rights reserved. 4/24/2008 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 3 Issue X-2 CM1234 Package/Pin Information PACKAGE / PINOUT DIAGRAMS Bottom View (Solder Side) Out_1+ Out_1Out_2+ Out_2Out_3+ Out_3Out_4+ Out_4In_1+ In_1In_2+ In_2In_3+ In_3In_4+ In_4- Note: 1) This drawing is not to scale. PIN DESCRIPTIONS Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 PAD Name In_1+ In_1In_2+ In_2In_3+ In_3In_4+ In_4Out_4Out_4+ Out_3Out_3+ Out_2Out_2+ Out_1Out_1+ GND Description Bidrectional Clamp to ASIC (inside system) Bidrectional Clamp to ASIC (inside system) Bidrectional Clamp to ASIC (inside system) Bidrectional Clamp to ASIC (inside system) Bidrectional Clamp to ASIC (inside system) Bidrectional Clamp to ASIC (inside system) Bidrectional Clamp to ASIC (inside system) Bidrectional Clamp to ASIC (inside system) Bidrectional Clamp to Connector (outside system) Bidrectional Clamp to Connector (outside system) Bidrectional Clamp to Connector (outside system) Bidrectional Clamp to Connector (outside system) Bidrectional Clamp to Connector (outside system) Bidrectional Clamp to Connector (outside system) Bidrectional Clamp to Connector (outside system) Bidrectional Clamp to Connector (outside system) Ground return to shield Ordering Information PART NUMBERING INFORMATION PIN 16 PACKAGE TDFN-16 LEAD-FREE FINISH Part Marking CM1234-08 CM1234-08DE Note 1: Parts are shipped in Tape & Reel form unless otherwise specified. (c) 2008 California Micro Devices Corp. All rights reserved. 4 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 4/24/2008 Issue X-2 CM1234 Specifications ABSOLUTE MAXIMUM RATINGS* PARAMETER Operating Temperature Range Storage Temperature Range Breakdown Voltage (Positive) RATING -40 to +85 -65 to +150 6 UNITS C C V *Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL OPERATING CHARACTERISTICS (SEE NOTE 1) SYMBOL PARAMETER VIN IIN IF VESD I/O Voltage Relative to GND Continuous Current through signal pins (IN to OUT) 1000 Hr Channel Leakage Current ESD Protection - Peak Discharge Voltage at any channel input, in system: a) Contact discharge per IEC 61000-4-2 Standard and b) Air discharge per IEC 61000-4-2 Standard Residual ESD Peak Current on RDUP (Resistance of Device Under Protection) Channel Clamp Voltage (Channel clamp voltage per IEC 61000-4-5 Standard) Positive Transients Negative Transients Dynamic Resistance Positive Transients Negative Transients Differential Channels pair characteristic impedance Channel-to-Channel Impedance Match (Differential) Individual Channel Characteristic Impedance in Single-ended Connection Channel-to-Channel Impedance Match (Individual) TA = 25C; VN = 0V, VTEST = 5V CONDITIONS MIN -0.5 100 0.1 1.0 TYP MAX 5.5 UNITS V mA A TA = 25C; Note 2 TA = 25C; Note 2 IEC 61000-4-2 8kV; RDUP = 5, TA = 25C; Note 2 IPP = 1A, TA = 25C, tP = 8/20S; Note 2 15 20 kV kV IRES 2.5 A VCL +9 -1.5 0.44 0.38 100 V V RDYN IPP = 1A, TA = 25C, tP = 8/20S; Note 2 TR = 200ps; Note 2 TR = 200ps; Note 2 TR = 200ps Zo Zo 2 % ZCHANNEL 50 ZCHANNEL TR = 200ps; Note 2 2 % Note 1: All parameters specified at TA = -40C to +85C unless otherwise noted. Note 2: This parameter is guaranteed by design and verified by device characterization (c) 2008 California Micro Devices Corp. All rights reserved. 4/24/2008 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 5 Issue X-2 CM1234 Performance Information Graphical Comparison and Test Setup Figure 4 shows that the CM1234 (PicoGuard XS ESD protector) lowers the peak voltage and clamping voltage by 45% across a wide range of loading conditions in comparison to a standard ESD protection device. Figure 5 also indicates that the DUP/ASIC protected by the CM1234 dissipates less energy than a standard ESD protection device. This data was derived using the test setups shown in Figure 6. 1.2 VCLAMP (peak) [Normalized] 1 0.8 0.6 0.4 0.2 0 0 2 4 6 8 10 RDUP () 12 14 16 18 20 CM1234-08 STD ESD Device Figure 4. VCLAMP vs. RDUP* (ASIC) - 8kV Contract Strike IRESIDUAL (peak) [Normalized] 1.2 1 0.8 0.6 0.4 0.2 0 0 2 4 6 8 10 RDUP () 12 14 16 18 20 CM1234-08 STD ESD Device Figure 5. IRESIDUAL vs RDUP* (ASIC) - 8kV Contract Strike * RDUP is the emulated Dynamic Resistance (load) of the Device Under Protection (DUP). See Figure (c) 2008 California Micro Devices Corp. All rights reserved. 6. 6 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 4/24/2008 Issue X-2 CM1234 IEC 6100-4-2 Test Standards Voltage Probe IEC 6100-4-2 Test Standards CM1234 Voltage Probe Device Under Protection (DUP) Standard ESD Device RVARIABLE Device Under Protection (DUP) RVARIABLE Standard ESD Device Test Setup Current Probe IRESIDUAL CM1234 Test Setup Current Probe IRESIDUAL Figure 6. Test Setups: Standard Device (Left) and CM1234 (Right) (c) 2008 California Micro Devices Corp. All rights reserved. 4/24/2008 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 7 Issue X-2 CM1234 Application Information CM1234 Application and Guidelines As a general rule, the CM1234 ESD protection array should be located as close as possible to the point of entry of expected electrostatic discharges with minimum PCB trace lengths to the ground planes and between the signal input and the ESD device to minimize stray series inductance. VCC CM1234 Path of ESD current pulse (IESD) Channel Output Channel Input Circuitry Under Protection Line Being Protected VCL VN Ground Rail Figure 7. Application of Positive ESD Pulse Between Input Channel and Ground Figure 8. Typical PCB Layout Additional Information See also California Micro Devices Application Note AP209, "Design Considerations for ESD Protection," in the Applications section at www.calmicro.com. (c) 2008 California Micro Devices Corp. All rights reserved. 8 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 4/24/2008 Issue X-2 CM1234 Mechanical Details TDFN-16 Mechanical Specifications, 0.75mm The 16-lead, 6.0x4.0mm, 0.75mm pitch TDFN package dimensions are presented below. Mechanical Package Diagrams TOP VIEW D PACKAGE DIMENSIONS Package JEDEC No. Leads Dim. A A1 A3 b D D2 E E2 e K L # per tape and reel 0.35 Millimeters Min 0.70 0.00 0.175 0.20 5.90 5.05 3.90 1.75 Nom 0.75 0.02 0.200 0.25 6.00 5.10 4.00 1.80 0.75 BSC 0.70 REF 0.40 0.45 3000 pieces e 16 15 14 13 12 11 10 9 TDFN MO-229C* E 16 Inches Max 0.80 0.05 0.225 0.30 6.10 5.15 4.10 1.85 Min 0.028 0.000 0.007 0.008 0.232 0.199 0.153 0.012 Nom 0.030 0.001 0.008 0.010 0.236 0.201 0.157 0.016 Max 0.031 0.002 0.009 0.012 0.240 0.203 0.161 0.08 C 0.10 C Pin 1 Marking 12345678 SIDE VIEW 0.020 A1 A A3 0.029 BSC 0.028 REF 0.014 0.016 0.018 BOTTOM VIEW 16X 0.10 M CAB b Controlling dimension: millimeters * This package is compliant with JEDEC standard MO-229C with the exception of the D, D2, E, E2, K and L dimensions as called out in the table above. Pin 1 Locator 1 2 3 4 5 6 7 8 E2 C0.2 GND PAD 16 15 14 13 12 11 10 K 9 D2 L Dimensions for 16-Lead, 0.75mm pitch TDFN package (c) 2008 California Micro Devices Corp. All rights reserved. 4/24/2008 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 9 Issue X-2 CM1234 Tape and Reel Specifications PART NUMBER CM1234 PACKAGE SIZE (mm) 6.00 X 4.00 X 0.75 POCKET SIZE (mm) B0 X A0 X K0 6.30 X 4.30 X 1.10 TAPE WIDTH W 12mm REEL DIAMETER 330mm (13") QTY PER REEL 3000 P0 4mm P1 8mm Po Top Cover Tape 10 Pitches Cumulative Tolerance On Tape 0.2 mm Ao W Bo Ko For tape feeder reference only including draft. Concentric around B. Embossment P1 User Direction of Feed Center Lines of Cavity (c) 2008 California Micro Devices Corp. All rights reserved. 10 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 Tel: 408.263.3214 Fax: 408.263.7846 www.cmd.com 4/24/2008 |
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