PI90LV211/PI90LVT211 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 1:6 Differential Clock Distribution Chip Features Description • • • • The PI90LV211 implements low voltage differential signaling (LVDS) to achieve clocking rates as high as 320 MHz with low skew. The PI90LV211 is a low skew 1:6 fanout device designed explicitly for low skew clock distribution applications. The device features a multiplexed clock input to allow for the distribution of a lower speed scan or test clock with the high-speed system clock. When LOW the SEL pin will select the differential clock input. • • • • • • • • • • • • Meets or Exceeds Requirements of ANSI TIA/EIA-644-1995 Designed for Clocking Rates up to 320MHz Operates from a single 3.3-V Supply Low-Voltage Differential Signaling (LVDS) with Output Voltages of ±350mV into a 100-ohm load Choice between LVDS or TTL clock input Synchronous Enable/Disable Multiplexed clock input – Internal 300 kohm pullup resistor on all control pins – CLK and CLK have 110-ohm termination (PI90LVT211) Common and individual Enable/Disable control 50ps Output-to-Output Skew ±24ps Period Jitter Bus Pins are High Impedance when disabled or with VCC <1.5V TTL Inputs are 5V Tolerant Power Dissipation at 300 MHz P190LV211 is functionally compatible with Motorola’s (PECL) MC 10E211/MC100E211 >12kV ESD Protection Packaging (Pb-free & Green available): - 28-pin TSSOP (L) - 28-pin QSOP (Q) Both a common enable and individual output enables are provided. When asserted the positive output will go LOW on the next negative transition of the CLK (or SCLK) input. The enable function is synchronous so that the outputs will only be enabled/disabled when they are already in the LOW state. This avoids any chance of generating a runt clock pulse when the device is enabled/disabled as can happen with an asynchronous control. The internal flip flop is clocked on the falling edge of the input clock, therefore all associated specification limits are referenced to the negative edge of the clock input. Individual synchronous enable controls and multiplexed clock inputs make this device ideal as the first level distribution unit in a distribution tree. The individual enables could be used to allow for the disabling of individual cards on a backplane in fault tolerant designs. Function Table Block Diagram & Pin Configuration VCC EN1 1 2 28 27 D 26 GND EN2 SCLK CLK 3 25 D 1 24 6 EN3 SEL 7 23 D 0 22 8 9 SEL ENx CEN CLK OUT (±) H/L X ↓ ↓ X H/L ↓ ↓ L H X H L L H L L L L H CLK SCLK Z* Z** * ENx disables individual banks ** CEN disables all six banks ↓ = Negative transition of CLK or SCLK Z = High Impedance CLK2OUT+ CLK2OUT– Q PI90LVT211 Only 110Ω CLK CLK1OUT+ CLK1OUT– SCLK Q 4 5 VCC CLK/CLK CLK3OUT+ CLK3OUT– Q 21 D 20 CLK4OUT+ CLK4OUT– Q EN4 10 19 D EN5 18 11 CLK5OUT+ CLK5OUT– Q EN6 12 17 D 16 CEN GND 13 14 CLK6OUT+ CLK6OUT– Q 15 GND 1 PS8535C 10/04/04 PI90LV211/PI90LVT211 1:6 Differential Clock Distribution Chip 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 Electrical Characteristics over Recommended Operating Conditions (unless otherwise noted). Symbol Parame te r VOD Differential output voltage magnitude ∆VOD Change in differential output voltage magnitude between logic states VOC(SS) Steady- state common- mode output voltage ∆VOC(SS) Change in steady- state common- mode output voltage between logic states VOC(PP) Peak- to- peak common- mode output voltage Te s t Conditions RL = 100Ω See Figures 1 and 2 M in. Typ.(1) M ax. 247 340 454 –50 1.125 See Figure 3 50 1. 3 0 –50 1.60 mV V 50 mV 40 150 Enabled, RL = 100Ω VIN = VCC or GND 27 35 Disabled, VIN = VCC or GND 3.0 3.9 ICC Supply Current IIH High- level input current VIH = 2V 4.8 20 IIL Low- level input current VIL = 0.8V 9 20 IOS Short- circuit output current IOZ High- impedance output current VO = 0V or VCC ±1 Power- off output current VCC = 1.1V, VO = 2.4V ±1 CIN Input capacitance, VI = 0.4 sin (4E6πt) +0.5V 9 CO Output capacitance VI = 0.4 sin (4E6πt) +0.5V, Disabled 10 RTERM Termination Resistor PI90LVT211 IO(OFF) Units ±7 VODOUT+ or VODOUT– = 0V ±4.5 VOD = 0V 2 90 110 mA µA mA µA pF 132 PS8535C Ω 10/04/04 PI90LV211/PI90LVT211 1:6 Differential Clock Distribution Chip 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 Switching Characteristics over Recommended Operating Conditions (unless otherwise noted)(8,9). Characte ris tic Propagation De lay to Output CLK to CLKOUT ± SCLK to CLKOUT ± SEL to CLKOUT ± Dis able Time CLK or SCLK to CLKOUT ± Part-to-Part Ske w CLK (Diff) to Q CLK (SE), SCLK to Q With Device Skew Symbol M in. Typ. M a x. tPLH tPHL 1.5 1.5 1.5 2.7 2.7 2.7 3.4 3.24 3.6 2.2 2.1 3.6 2.8 2.8 2.8 4.8 4.8 tskew –48 +48 Pe riod Jitte r tjit(per) –24 +24 Se tup Time ENx to CLK CEN to CLK ts 200 200 th 600 Figure 6 ps 2 760 VCMR 0.125 1.5 VCC - 0.2 Ris e /Fall Time s 20 – 80% tr, tf 150 400 1200 Duty Cycle Dis tortion Puls e Ske w ( tPLH - tPHL) SCLK to CLKOUT± CLK to CLKOUT± tSK1R tSK1R 140 25 180 60 Channe l-to-Channe l Ske w, s ame e dge tSK2R 30 100 0.800 250 Figure 7 2 0.20 M aximum Ope rating Fre que ncy 1 –100 0 VPP Com. M ode Range (CLK) 2 TBD TBD TBD tjit(cc) M inimum Input Swing (CLK) Condition ns tPHZ tPLZ tPZH tPZL Cycle -to-Cycle Jitte r Hold Time CLK to ENx, CEN Units V ps 3 4 5 6 MHz 7 Notes: 1. Within-Device skew is defined for identical transitions on similar paths through a device. 2. Setup, Hold, and Disable times are all relative to a falling edge on CLK or SCLK. 3. Minimum input swing for which AC parameters are guaranteed. Full DC LVDS output swings will be generated with only 50mV input swings. 4. The range in which the high level of the input swing must fall while meeting the VPP spec. 5. tSKIR is the difference in receiver propagation delay (tPLH-tPHL) of one device, and is the duty cycle distortion of the output at any given temperature and VCC. The propagation delay specification is a device-to-device worst case over process, voltage, and temperature. 6. tSK2R is the difference in receiver propagation delay between channels in the same device of any outputs switching in the same direction. This parameter is guaranteed by design and characterization. 7. Generator input conditions: trtf < 1ns, 50% duty cycle, differential (1.10V to 1.35V peak-peak). Output Criteria: 60%/40% duty cycle, VOL (max) 0-4V, VOH (min) 2.7V, Load - 7pF (stray plus probes). 8. CL includes probe and fixture capacitance. 9. Generator waveform for all tests unless otherwise specified: f = 25 MHz, ZO = 50 ohms, tr = 1ns, tf = 1ns (35%-65%). To ensure fastest propagation delay and minimum skew, clock input edge rates should not be slower than 1ns/V; control signals not slower than 3ns/V. 3 PS8535C 10/04/04 PI90LV211/PI90LVT211 1:6 Differential Clock Distribution Chip 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 Parameter Measurement Information DOUT+ II DIN VI IOY IOZ VOD VODOUT+ VOC VODOUT– DOUT– GND (VODOUT++VODOUT–)/2 Figure 1. Voltage and Current Definitions 3.75kΩ DOUT+ VOD Input 100Ω DOUT– 3.75kΩ ± 0V ≤ VTEST ≤ 2.4V Figure 2. VOD Test Circuit 3V DOUT+ 49.9Ω ±1% (2 places) VI Input DOUT– 0V VOC(PP) VOC(SS) VOC Figure 3. Test Circuit & Definitions for the Driver Common-Mode Output Voltage Note: 1. All input pulses are supplied by a generator having the following characteristics: tr or tf ≤ 1ns, Pulse Repetition Rate (PRR) = 50 Mpps, Pulse width = 10 ±0.2ns. CL includes instrumentation and fixture capacitance within 0.06m of the D.U.T. Themeasurement of VOC(PP) is made on test equipment with a –3dB bandwidth of at least 300MHz. 4 PS8535C 10/04/04 PI90LV211/PI90LVT211 1:6 Differential Clock Distribution Chip 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 Parameter Measurement Information (continued) 32V 1.4V Input 0.8V DOUT+ Input tPLH VOD DOUT– tPHL 100Ω ±1% Output CL= 10pF (2 places) 100% 80% VOD(H) 0V VOD(L) 20% 0% tf tr Figure 4. Test Circuit, Timing, & Voltage Definitions for the Differential Output Signal Note: 1. All input pulses are supplied by a generator having the following characteristics: tr or tf ≤ 1ns, Pulse Repetition Rate (PRR) = 15 Mpps, Pulse width = 10 ±0.2ns. CL includes instrumentation and fixture capacitance within 0.06m of the D.U.T. 49.9Ω ±1% (2 places) DOUT+ 0.8V or 2V DOUT– VODOUT+ VODOUT– + 1.2V – Input 2V 1.4V Input 0.8V tPZH tPHZ ≅1.4V VODOUT+ or VODOUT– 1.3V 1.2V tPZL tPLZ 1.2V VODOUT– 1.1V or VODOUT+ ≅1V Figure 5. Enable & Disable Time Circuit & Definitions Note: 1. All input pulses are supplied by a generator having the following characteristics: tr or tf ≤ 1ns, Pulse Repetition Rate (PRR) = 0.5 Mpps, Pulse width = 500 ±10ns. CL includes instrumentation and fixture capacitance within 0.06m of the D.U.T. 5 PS8535C 10/04/04 PI90LV211/PI90LVT211 1:6 Differential Clock Distribution Chip 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 C L KO U T – C L KO U T + t cycle n t cycle n+1 t jit(cc) = t cycle n - t cycle n+1 Figure 6. Cycle-to-Cycle Jitter C L KO U T – C L KO U T + t cycle n C L KO U T – C L KO U T + 1 fO t jit(per) = t cycle n 1 fO Figure 7. Period Jitter 6 PS8535C 10/04/04 PI90LV211/PI90LVT211 1:6 Differential Clock Distribution Chip 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 General Desciption The PI90LV211 is a 1:6 fanout tree designed explicitly for low-skew, high-speed clock distribution. The device was targeted to work in conjunction with the PI90LV14 device to provide another level of flexibility in the design and implementation of clock distribution trees. The individual synchronous enable controls and multiplexed clock inputs make the device ideal as the first level distribution unit in a distribution tree. The device provides the ability to distribute a lower speed scan or test clock along with the high-speed system clock to ease the design of system diagnostics and self test procedures. The individual enables could be used to allow for the disabling of individual cards on a backplane in fault tolerant designs. is characterized and tested with all of the outputs switching, therefore the numbers in the data book are guaranteed only for this situation. If all of the outputs of the PI90LV211 are not needed and there is a desire to save power, the unused output pairs can be left unterminated. Unterminated outputs can influence the propagation delay on adjacent pins by 15ps–20ps. Therefore, under these conditions, this 15ps–20ps needs to be added to the overall skew of the device. Pins which are separated by a package corner are not considered adjacent pins in the context of propagation delay influence. Therefore if all of the outputs on a single side of the package are terminated, the specification limits in the data sheet will apply. Handling Open Inputs and Outputs Using the Enable Pins With the simultaneous switching characteristics and the tight skew specifications of the P90LV211, the handling of the unused outputs becomes critical. To minimize the noise generated on the die all outputs should be terminated in pairs, i.e. both the true and compliment outputs should be terminated even if only one of the outputs will be used in the system. With both complimentary pairs terminated, the current in the VCC pins will remain essentially constant and thus inductance induced voltage glitches on VCC will not occur. VCC glitches will result in distorted output waveforms and degradations in the skew performance of the device. Both the common enable (CEN) and the individual enables (ENx) are synchronous to the CLK or SCLK input depending on which is selected. The active low signals are clocked into the enable flip flops on the negative edges of the PI90LV211 clock inputs. In this way, the devices will only be disabled when the outputs are already in the LOW state. The internal propagation delays are such that the delay to the output through the distribution buffers is less than that through the enable flip flops. This will ensure that the disabling of the device will not slice any time off the clock pulse. On initial power up, the enable flip flops will randomly attain a stable state; therefore precautions should be taken on initial power up to ensure the PI90LV211 is in the desired state. The package parasitics of the 28-lead package cause the signals on a given pin to be influenced by signals on adjacent pins. PI90LV211 PI90LV14 PI90LV211 BACKPLANE D0 PI90LV14 D5 Figure 8. Standard PI90LV211 LVDS Application 7 PS8535C 10/04/04 PI90LV211/PI90LVT211 1:6 Differential Clock Distribution Chip 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 Packaging Mechanical: 28-Pin TSSOP (L) 28 .169 .177 4.3 4.5 .004 .008 1 .378 .386 9.6 9.8 0.45 0.75 SEATING PLANE .007 .012 0.19 0.30 .002 .006 .018 .030 .252 BSC 6.4 .047 1.20 Max .0256 BSC 0.65 0.09 0.20 X.XX DENOTES CONTROLLING X.XX DIMENSIONS IN MILLIMETERS 0.05 0.15 Packaging Mechanical: 28-Pin QSOP (Q) 28 .008 0.20 MIN. 0.150 0.157 .008 .013 0.20 0.33 3.81 3.99 Guage Plane .010 0.254 1 Detail A .041 1.04 REF .386 9.804 .394 10.009 .033 REF 0.84 0˚-6˚ .016 .035 0.41 0.89 .015 x 45˚ 1.35 .053 1.75 .069 Detail A .007 0.178 .010 0.254 SEATING PLANE .025 BSC 0.635 .008 0.203 .012 0.305 0.41 .016 1.27 .050 .004 0.101 .010 0.254 .228 .244 5.79 6.19 X.XX DENOTES DIMENSIONS X.XX IN MILLIMETERS 8 PS8535C 10/04/04 PI90LV211/PI90LVT211 1:6 Differential Clock Distribution Chip 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 12345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012123456789012 Ordering Information Ordering Code PI90LV211L PI90LV211LE PI90LV211Q PI90LV211QE PI90LVT211L PI90LVT211LE PI90LVT211Q PI90LVT211QE Package Code L L Q Q L L Q Q Package Type 28-pin 173-mil TSSOP Pb-free & Green, 28-pin 173-mil TSSOP 28-pin 150-mil QSOP Pb-free & Green, 28-pin 150-mil QSOP 28-pin 173-mil TSSOP Pb-free & Green, 28-pin 173-mil TSSOP 28-pin 150-mil QSOP Pb-free & Green, 28-pin 150-mil QSOP Notes: 1. Thermal characteristics can be found on the company web site at www.pericom.com/packaging/ 9 PS8535C 10/04/04