8T3910BNLGI8

Crystal or Differential to Differential Clock Fanout Buffer IDT8T3910I PRELIMINARY DATA SHEET General Description Features The IDT8T3910I is a high-performance clock fanout buffer. The input clock can be selected from two differential inputs or one crystal input. The internal oscillator circuit is automatically disabled if the crystal input is not selected. The selected signal is distributed to ten differential outputs which can be configured as LVPECL, LVDS or HSCL outputs. In addition, an LVCMOS output is provided. The user should always turn off this LVCMOS output when (the) clock is over 200MHz. The differential outputs can be disabled into an high-impedance state. The device is designed for signal fanout of high-frequency, low phase-noise clock and data signal. The outputs are at a defined level when inputs are open or shorted. It’s designed to operate from a 3.3V core power supply, and either a 3.3V or 2.5V output operating supply. • • Two differential reference clock input pairs • • • Crystal Oscillator Interface • One single-ended reference output with synchronous enable to avoid clock glitch • Output skew: (Bank A and Bank B at the same output level) 32ps (typical) • • • • Part-to-part skew: 200ps (typical) • • -40°C to 85°C ambient operating temperature Available in lead-free (RoHS 6) package Differential input pairs can accept the following differential input levels: LVPECL, LVDS, HCSL Crystal input frequency range: 10MHz to 40MHz Two banks, each has five differential output pairs that can be configured as LVPECL or LVDS or HCSL Additive RMS phase jitter: 0.22ps (typical) Power supply modes: Output supply voltage modes: VCC/VDDO 3.3V/3.3V 3.3V/2.5V The Preliminary Information presented herein represents a product in pre-production. The noted characteristics are based on initial product characterization and/or qualification. Integrated Device Technology, Incorporated (IDT) reserves the right to change any circuitry or specifications without notice. IDT8T3910BNLI MARCH 23, 2012 1 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Block Diagram SMODEA[1:0] Pulldown REF_SEL[1:0] Pulldown CLK0 Pulldown nCLK0 CLK1 nCLK1 Pullup/Pulldown QA0 nQA0 QA1 nQA1 QA2 nQA2 QA3 nQA3 QA4 nQA4 00 Pulldown Pullup/Pulldown XTAL_IN OSC XTAL_OUT 01 QB0 nQB0 QB1 nQB1 QB2 nQB2 QB3 nQB3 QB4 nQB4 10 or 11 IREF SMODEB[1:0] Pulldown REFOUT OE_SE Pulldown IDT8T3910BNLI MARCH 23, 2012 SYNC 2 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER QB0 nQB0 QB1 nQB1 VDDO QB2 nQB2 VDDO QB3 nQB3 QB4 nQB4 Pin Assignment 36 35 34 33 32 31 30 29 28 27 26 25 GND 37 24 GND IREF 38 23 SMODEB0 SMODEB1 39 22 REF_SEL1 nCLK1 40 CLK1 41 VDD 42 GND 43 REFOUT 44 21 nCLK0 IDT8T3910I 48 Lead VFQFN 7.0mm x 7.0mm x 0.925mm, package body NL Package Top View VDDO 45 19 REF_SEL0 18 GND 17 OSCO 16 OSCI OE_SE 46 15 VDD SMODEA1 47 14 SMODEA0 GND 48 IDT8T3910BNLI MARCH 23, 2012 20 CLK0 5 6 7 8 3 nQA0 QA1 nQA1 VDDO QA2 nQA2 VDDO 9 10 11 12 QA4 4 nQA4 3 nQA3 2 QA3 1 QA0 13 GND ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Table 1. Pin Descriptions Number Name 1, 2 QA0, nQA0 Output Type Description Differential Bank A clock output pair. LVPECL, LVDS or HCSL interface levels. 3, 4 QA1, nQA1 Output Differential Bank A clock output pair. LVPECL, LVDS or HCSL interface levels. 5, 8, 29, 32, 45 VDDO Power Output supply pins. 6, 7 QA2, nQA2 Output Differential Bank A clock output pair. LVPECL, LVDS or HCSL interface levels. 9, 10 QA3, nQA3 Output Differential Bank A clock output pair. LVPECL, LVDS or HCSL interface levels. 11, 12 QA4, nQA4 Output Differential Bank A clock output pair. LVPECL, LVDS or HCSL interface levels. 13, 18, 24, 37, 43, 48 GND Power Power supply ground. 14, 47 SMODEA0, SMODEA1 Input 15, 42 VDD Power 16, 17 XTAL_IN, XTAL_OUT Input 19, 22 REF_SEL0, REF_SEL1 Input Pulldown Input clock selection. LVCMOS/LVTTL interface levels. See Table 3A for function. 20 CLK0 Input Pulldown Non-inverting differential clock. 21 nCLK0 Input Pullup/ Pulldown Inverting differential clock. Internal resistor bias to VDD/2. 23, 39 SMODEB0, SMODEB1 Input Pulldown Output driver select for Bank B outputs. See Table 3D for function. LVCMOS/LVTTL interface levels. 25, 26 nQB4, QB4 Output Differential Bank B clock output pair. LVPECL, LVDS or HCSL interface levels. 27, 28 nQB3, QB3 Output Differential Bank B clock output pair. LVPECL, LVDS or HCSL interface levels. 30, 31 nQB2, QB2 Output Differential Bank B clock output pair. LVPECL, LVDS or HCSL interface levels. 33, 34 nQB1, QB1 Output Differential Bank B clock output pair. LVPECL, LVDS or HCSL interface levels. 35, 36 nQB0, QB0 Output Differential Bank B clock output pair. LVPECL, LVDS or HCSL interface levels. 38 IREF Input An external fixed precision resistor (475) from this pin to ground provides a reference current used for differential current-mode QXx, nQXx clock outputs. 40 nCLK1 Input Pullup/ Pulldown Non-inverting differential clock. Internal resistor bias to VDD/2. 41 CLK1 Input Pulldown Inverting differential clock. 44 REFOUT Output 46 OE_SE Input Pulldown Output driver select for Bank A outputs. See Table 3D for function. LVCMOS/LVTTL interface levels. Power supply pins. Crystal oscillator interface. XTAL_IN is the input, XTAL_OUT is the output. Single-ended reference clock output. LVCMOS/LVTTL interface levels Pulldown Output enable. LVCMOS/LVTTL interface levels. See Table 3B. NOTE: Pulldown and Pullup refer to an internal input resistors. See Table 2, Pin Characteristics, for typical values. IDT8T3910BNLI MARCH 23, 2012 4 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Table 2. Pin Characteristics Symbol Parameter CIN Input Capacitance 4 pF RPULLDOWN Input Pulldown Resistor 51 k RPULLUP Input Pullup Resistor 51 k pF Power Dissipation Capacitance VDDO = 3.3V 10 CPD VDDO = 2.5V 9 pF Output Impedance VDDO = 3.3V 15 ROUT  VDDO = 2.5V 18  IDT8T3910BNLI MARCH 23, 2012 Test Conditions 5 Minimum Typical Maximum Units ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Function Tables Table 3A. REF_SELx Function Table Control Input REF_SEL[1:0] Selected Input Reference Clock 00 (default) CLK0, nCLK0 01 CLK1, nCLK1 10 XTAL 11 XTAL Table 3B. OE_SE Function Table OE_SE REF_OUT 0 (default) High-Impedance 1 Enabled NOTE: Synchronous output enable to avoid clock glitch. IDT8T3910BNLI MARCH 23, 2012 6 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Table 3C. Input/Output Operation Table, OE_SE Input Status Output State OE_SE REF_SEL [1:0] CLKx and nCLKx REFOUT 0 Not care Don’t Care High Impedance 1 10 or 11 Don’t Care Fanout crystal oscillator CLK0 and nCLK0 are both open circuit Logic low CLK0 and nCLK0 are tied to ground Logic low CLK0 is high, nCLK0 is low Logic High CLK0 is low, nCLK0 is high Logic Low CLK1 and nCLK1 are both open circuit Logic low CLK1 and nCLK1 are tied to ground Logic low CLK1 is high, nCLK1 is low Logic High CLK1 is low, nCLK1 is high Logic Low 1 00 1 01 NOTE: The device output should support differential input being driven by a single-ended signal. Table 3D. Input/Output Operation Table, SMODEA Input Status Output State SMODEA[1:0] REF_SEL[1:0] CLKx and nCLKx QA[4:0], nQA[4:0] 11 Not care Don’t Care High Impedance 00,01,or 10 10 or 11 Don’t Care Fanout crystal oscillator CLK0 and nCLK0 are both open circuit QA[4:0]=Low nQA4:0]=High CLK0 and nCLK0 are tied to ground QA[4:0]=Low nQA[4:0]=High CLK0 is high, nCLK0 is low QA[4:0]=High nQA[4:0]=Low CLK0 is low, nCLK0 is high QA[4:0]=Low nQA[4:0]=High CLK1 and nCLK1 are both open circuit QA[4:0]=Low nQA4:0]=High CLK1 and CLK1 are tied to ground. QA[4:0]=Low nQA[4:0]=High CLK1 is high, nCLK1 is low QA[4:0]=High nQA[4:0]=Low CLK1 is low, nCLK1 is high QA[4:0]=Low nQA4:0]=High 00,01,or 10 00,01,or 10 00 01 NOTE: The device output should support differential input being driven by a single-ended signal. IDT8T3910BNLI MARCH 23, 2012 7 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Table 3E. Input/Output Operation Table, SMODEB Input Status Output State SMODEB[1:0] REF_SEL[1:0] CLKx and nCLKx QB[4:0], nQB[4:0] 11 Not care Don’t Care High Impedance 00,01,or 10 10 or 11 Don’t Care Fanout crystal oscillator CLK0 and nCLK0 are both open circuit QB[4:0]=Low nQB4:0]=High CLK0 and nCLK0 are tied to ground QB[4:0]=Low nQB[4:0]=High CLK0 is high, nCLK0 is low QB[4:0]=High nQB[4:0]=Low CLK0 is low, nCLK0 is high QB[4:0]=Low nQB[4:0]=High CLK1 and nCLK1 are both open circuit QB[4:0]=Low nQB[4:0]=High CLK1 and nCLK1 are tied to ground QB[4:0]=Low nQB[4:0]=High CLK1 is high, nCLK1 is low QB[4:0]=High nQB[4:0]=Low CLK1 is low, nCLK1 is high QB[4:0]=Low nQB[4:0]=High 00,01,or 10 00,01,or 10 00 01 NOTE: The device output should support differential input being driven by a single-ended signal. IDT8T3910BNLI MARCH 23, 2012 8 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER 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. Functional 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. Item Rating Supply Voltage, VDD 3.6V Inputs, VI XTAL_IN Other Inputs 0V to VDD -0.5V to VDD + 0.5V Outputs, VO, (HCSL, LVCMOS) -0.5V to VDD + 0.5V Outputs, IO, (LVPECL) Continuous Current Surge Current 50mA 100mA Outputs, IO, (LVDS) Continuous Current Surge Current 10mA 15mA Package Thermal Impedance, JA 29°C/W (0 mps) Storage Temperature, TSTG -65C to 150C DC Electrical Characteristics Table 4A. Power Supply DC Characteristics, VDD = VDDO = 3.3V±5%, GND = 0V, TA = -40°C to 85°C Symbol Parameter VDD Test Conditions Minimum Typical Maximum Units 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 SMODEA/B[1:0] = 01 67 mA IDDO Output Supply Current SMODEA/B[1:0] = 01 264 mA IEE Power Supply Current SMODEA/B[1:0] = 00 (default) 165 mA IDD Power Supply Current SMODEA/B[1:0] = 10 80 mA IDDO Power Supply Current SMODEA/B[1:0] = 10 22 mA Table 4B. Power Supply DC Characteristics, VDD = 3.3V±5%, VDDO = 2.5V±5%, GND = 0V, TA = -40°C to 85°C Symbol Parameter VDD Minimum Typical Maximum Units 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 SMODEA/B[1:0] = 01 67 mA IDDO Output Supply Current SMODEA/B[1:0] = 01 263 mA IEE Power Supply Current SMODEA/B[1:0] = 00 (default) 164 mA IDD Power Supply Current SMODEA/B[1:0] = 10 80 mA IDDO Power Supply Current SMODEA/B[1:0] = 10 18 mA IDT8T3910BNLI MARCH 23, 2012 Test Conditions 9 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Table 4C. LVCMOS/LVTTL DC Characteristics, VDD = 3.3V±5%, VDDO = 3.3V±5% or 2.5V±5%, GND = 0V, TA = -40°C to 85°C Symbol Parameter Test Conditions Minimum VIH Input High Voltage VDD = 3.3V±5% VIL Input Low Voltage VDD = 3.3V±5% IIH Input High Current REF_SEL, SMODEA, SMODEB, OE_SE IIL Input Low Current OE_SE VOH Output High Voltage; NOTE 1 VOL Output Low Voltage; NOTE 1 Typical Maximum Units 2 VDD + 0.3 V -0.3 0.8 V 150 µA VDD = VIN = 3.465V VDD = 3.465V, VIN = 0V -5 µA REFOUT VDDO = 3.3V±5% 2.6 V REFOUT VDDO = 2.5V±5% 1.8 V REFOUT VDDO = 3.3V±5% or 2.5V±5% 0.5 V NOTE 1: Outputs terminated with 50 to VDDO/2. See Parameter Measurement Information, Output Load Test Circuit diagrams. Table 4D. Differential DC Characteristics, VDD = 3.3V±5%, VDDO = 3.3V±5% or 2.5V±5%, GND = 0V, TA = -40°C to 85°C Symbol Parameter Test Conditions IIH Input High Current IIL Input Low Current VPP Peak-to-Peak Input Voltage; NOTE 1 VCMR Common Mode Input Voltage; NOTE 1, 2 Minimum Typical Maximum Units 150 µA CLK[0:1], nCLK[0:1] VDD = VIN = 3.465V CLK[0:1] VDD = 3.465V, VIN = 0V -5 µA nCLK[0:1] VDD = 3.465V, VIN = 0V -150 µA 0.3 1.3 V GND + 0.5 VDD – 0.85 V NOTE 1: VIL should not be less than -0.3V. NOTE 2. Common mode voltage is defined as VIH. Table 4E. LVPECL DC Characteristics, VDD = VDDO = 3.3V±5%, GND = 0V, TA = -40°C to 85°C Symbol Parameter VOH Output High Voltage; NOTE 1 VOL Output Low Voltage; NOTE 1 VSWING Peak-to-Peak Output Voltage Swing Test Conditions Minimum Typical Maximum Units VDDO – 1.4 VDDO – 0.9 V VDDO – 2.0 VDDO – 1.7 V 0.6 1.0 V Maximum Units NOTE 1: Outputs termination with 50 to VDDO – 2V. Table 4F. LVPECL DC Characteristics, VDD = 3.3V±5%, VDDO = 2.5V±5%, GND = 0V, TA = -40°C to 85°C Symbol Parameter Test Conditions Minimum Typical VOH Output High Voltage; NOTE 1 VDDO – 1.4 VDDO – 0.9 V VOL Output Low Voltage; NOTE 1 VDDO – 2.0 VDDO – 1.4 V VSWING Peak-to-Peak Output Voltage Swing 0.4 1.0 V NOTE 1: Outputs termination with 50 to VDDO – 2V. IDT8T3910BNLI MARCH 23, 2012 10 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Table 4G. LVDS DC Characteristics, VDD = VDDO = 3.3V±5%, GND = 0V, TA = -40°C to 85°C Symbol Parameter Test Conditions Minimum Typical Maximum Units VOD Differential Output Voltage 405 mV VOD VOD Magnitude Change 50 mV VOS Offset Voltage 1.26 V VOS VOS Magnitude Change 50 mV Table 4H. LVDS DC Characteristics, VDD = 3.3V±5%, VDDO = 2.5V±5%, GND = 0V, TA = -40°C to 85°C Symbol Parameter Test Conditions Minimum Typical Maximum Units VOD Differential Output Voltage 405 mV VOD VOD Magnitude Change 50 mV VOS Offset Voltage 1.26 V VOS VOS Magnitude Change 50 mV Table 5. Crystal Characteristics Parameter Test Conditions Minimum Maximum Units 40 MHz Equivalent Series Resistance (ESR) 50  Shunt Capacitance 7 pF Mode of Oscillation Fundamental Frequency IDT8T3910BNLI MARCH 23, 2012 Typical 10 11 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER AC Electrical Characteristics Table 6A. AC Characteristics, VDD = VDDO = 3.3V±5%, TA = -40°C to 85°C Symbol fOUT tjit Parameter Output Frequency Additive Phase Jitter:156.25MHz Integration Range 12kHz - 20MHz REF_SEL[1:0] = 00 or 01 tjit RMS Phase Jitter; 25MHz Integration Range: 100Hz - 1MHz tPD Propagation Delay; CLK0, nCLK0 or CLK1, nCLK1 to any Qx, nQx Outputs; NOTE 1 Test Conditions Minimum Using External Crystal 10 LVDS, LVPECL output Typical Maximum Units 40 MHz 500 MHz HCSL output 250 MHz LVCMOS output 200 MHz SMODEA/B[1:0] = 00 0.185 ps SMODEA/B[1:0] = 01 0.20 ps SMODEA/B[1:0] = 10 0.22 ps REF_SEL[1:0] = 10 or 11 0.375 ps SMODEA/B[1:0] = 00 1.72 ns SMODEA/B[1:0] = 01 1.77 ns SMODEA/B[1:0] = 10 2.88 ns tsk(o) Output Skew; NOTE 2, 3 32 ps tsk(pp) Part-to-Part Skew; NOTE 3, 4 200 ps VRB Ring-back Voltage Margin; NOTE 5, 6 HCSL Outputs VMAX Voltage High; NOTE 7, 8 HCSL Outputs VMIN Voltage Low; NOTE 7, 9 HCSL Outputs -300 VCROSS Absolute Crossing Voltage; NOTE 7, 10, 11 HCSL Outputs 250 VCROSS Total Variation of VCROSS over all edges; NOTE 7, 10, 12 HCSL Outputs Rise/Fall Edge Rate; NOTE 7, 13 HCSL Outputs; Measured between 150mV to +150mV t R / tF Output Rise/Fall Time MUX_ISOLATION MUX Isolation -100 100 mV 1150 mV mV 0.6 SMODEA/B[1:0] = 00; 20% to 80% 430 SMODEA/B[1:0] = 01; 20% to 80% 515 156.25MHz 83 550 mV 140 mV 4.0 V/ns ps dB NOTE: Electrical parameters are guaranteed over 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. NOTE 1: Measured from the differential input crossing point to the differential output crossing point. NOTE 2: Defined as skew between outputs at the same supply voltage and with equal load conditions. Measured at the differential cross points. NOTE 3: This parameter is defined in accordance with JEDEC Standard 65. NOTE 4: Defined as skew between outputs on different devices operating at the same supply voltage, same temperature, same frequency and with equal load conditions. Using the same type of inputs on each device, the outputs are measured at the differential cross points. NOTE 5: Measurement taken from differential waveform. NOTE 6: TSTABLE is the time the differential clock must maintain a minimum ± 150mV differential voltage after rising/falling edges before it is allowed to drop back into the VRB ±100mV differential range. NOTE 7: Measurement taken from single-ended waveform. NOTE 8: Defined as the maximum instantaneous voltage including overshoot. See Parameter Measurement Information Section. NOTE 9: Defined as the minimum instantaneous voltage including undershoot. See Parameter Measurement Information Section. NOTE 10: Measured at crossing point where the instantaneous voltage value of the rising edge of Qx equals the falling edge of nQx. Notes continued on next page. IDT8T3910BNLI MARCH 23, 2012 12 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER NOTE 11: Refers to the total variation from the lowest crossing point to the highest, regardless of which edge is crossing. Refers to all crossing points for this measurement. Notes continue on next page. NOTE 12: Defined as the total variation of all crossing voltages of rising Qx and falling nQx, This is the maximum allowed variance in Vcross for any particular system. NOTE 13: Measured from -150mV to +150mV on the differential waveform (Qx minus nQx). The signal must be monotonic through the measurement region for rise and fall time. The 300mV measurement window is centered on the differential zero crossing. Table 6B. AC Characteristics, VDD = 3.3V±5%, VDDO = 2.5V±5%, TA = -40°C to 85°C Symbol fOUT tjit Parameter Output Frequency Additive Phase Jitter: 156.25 MHz Integration Range: 12kHz - 20 MHz REF_SEL[1:0] = 00 or 10 Test Conditions Minimum Using External Crystal 10 LVDS, LVPECL output Typical Maximum Units 40 MHz 500 MHz HCSL output 250 MHz LVCMOS output 200 MHz SMODEA/B[1:0] = 00 0.185 ps SMODEA/B[1:0] = 01 0.20 ps SMODEA/B[1:0] = 10 0.22 ps REF_SEL[1:0] = 10 or 11 0.375 ps SMODEA/B[1:0] = 00 1.72 ns SMODEA/B[1:0] = 01 1.77 ns SMODEA/B[1:0] = 10 tjit RMS Phase Jitter; 25MHz Integration Range: 100Hz - 1MHz tPD Propagation Delay; CLK0, nCLK0 or CLK1, nCLK1 to any Qx, nQx Outputs; NOTE 1 2.88 ns tsk(o) Output Skew; NOTE 2, 3 32 ps tsk(pp) Part-to-Part Skew; NOTE 3, 4 200 ps VRB Ring-back Voltage Margin; NOTE 5, 6 HCSL Outputs VMAX Voltage High; NOTE 7, 8 HCSL Outputs VMIN Voltage Low; NOTE 7, 9 HCSL Outputs -300 VCROSS Absolute Crossing Voltage; NOTE 7, 10, 11 HCSL Outputs 250 VCROSS Total Variation of VCROSS over all edges; NOTE 7, 10, 12 HCSL Outputs Rise/Fall Edge Rate; NOTE 7, 13 t R / tF Output Rise/Fall Time MUX_ISOLATION MUX Isolation HCSL Outputs; Measured between 150mV to +150mV -100 100 mV 1150 mV mV 0.6 SMODEA/B[1:0] = 00; 20% to 80% 430 SMODEA/B[1:0] = 01; 20% to 80% 570 156.25MHz 83 550 mV 140 mV 4.0 V/ns ps dB NOTE: Electrical parameters are guaranteed over 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. NOTE 1: Measured from the differential input crossing point to the differential output crossing point. NOTE 2: Defined as skew between outputs at the same supply voltage and with equal load conditions. Measured at the differential cross points. NOTE 3: This parameter is defined in accordance with JEDEC Standard 65. NOTE 4: Defined as skew between outputs on different devices operating at the same supply voltage, same temperature, same frequency and with equal load conditions. Using the same type of inputs on each device, the outputs are measured at the differential cross points. Notes continued on next page. IDT8T3910BNLI MARCH 23, 2012 13 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER NOTE 5: Measurement taken from differential waveform. NOTE 6: TSTABLE is the time the differential clock must maintain a minimum ± 150mV differential voltage after rising/falling edges before it is allowed to drop back into the VRB ±100mV differential range. NOTE 7: Measurement taken from single-ended waveform. NOTE 8: Defined as the maximum instantaneous voltage including overshoot. See Parameter Measurement Information Section. NOTE 9: Defined as the minimum instantaneous voltage including undershoot. See Parameter Measurement Information Section. NOTE 10: Measured at crossing point where the instantaneous voltage value of the rising edge of Qx equals the falling edge of nQx. NOTE 11: Refers to the total variation from the lowest crossing point to the highest, regardless of which edge is crossing. Refers to all crossing points for this measurement. NOTE 12: Defined as the total variation of all crossing voltages of rising Qx and falling nQx, This is the maximum allowed variance in Vcross for any particular system. NOTE 13: Measured from -150mV to +150mV on the differential waveform (Qx minus nQx). The signal must be monotonic through the measurement region for rise and fall time. The 300mV measurement window is centered on the differential zero crossing. IDT8T3910BNLI MARCH 23, 2012 14 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Additive Phase Jitter (LVPECL) The spectral purity in a band at a specific offset from the fundamental compared to the power of the fundamental is called the dBc Phase Noise. This value is normally expressed using a Phase noise plot and is most often the specified plot in many applications. Phase noise is defined as the ratio of the noise power present in a 1Hz band at a specified offset from the fundamental frequency to the power value of the fundamental. This ratio is expressed in decibels (dBm) or a ratio of the power in the 1Hz band to the power in the fundamental. When the required offset is specified, the phase noise is called a dBc value, which simply means dBm at a specified offset from the fundamental. By investigating jitter in the frequency domain, we get a better understanding of its effects on the desired application over the entire time record of the signal. It is mathematically possible to calculate an expected bit error rate given a phase noise plot. SSB Phase Noise dBc/Hz Additive Phase Jitter @ 156.25MHz 12kHz to 20MHz = 0.185ps (typical) Offset from Carrier Frequency (Hz) As with most timing specifications, phase noise measurements has issues relating to the limitations of the equipment. Often the noise floor of the equipment is higher than the noise floor of the device. The additive phase jitter is dependent on the input source and measurement equipment. IDT8T3910BNLI MARCH 23, 2012 The above plot was measured using a Rohde & Schwarz SMA100A as the input source. 15 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Additive Phase Jitter (HCSL) The spectral purity in a band at a specific offset from the fundamental compared to the power of the fundamental is called the dBc Phase Noise. This value is normally expressed using a Phase noise plot and is most often the specified plot in many applications. Phase noise is defined as the ratio of the noise power present in a 1Hz band at a specified offset from the fundamental frequency to the power value of the fundamental. This ratio is expressed in decibels (dBm) or a ratio of the power in the 1Hz band to the power in the fundamental. When the required offset is specified, the phase noise is called a dBc value, which simply means dBm at a specified offset from the fundamental. By investigating jitter in the frequency domain, we get a better understanding of its effects on the desired application over the entire time record of the signal. It is mathematically possible to calculate an expected bit error rate given a phase noise plot. SSB Phase Noise dBc/Hz Additive Phase Jitter @ 156.25MHz 12kHz to 20MHz = 0.22ps (typical) Offset from Carrier Frequency (Hz) As with most timing specifications, phase noise measurements has issues relating to the limitations of the equipment. Often the noise floor of the equipment is higher than the noise floor of the device. The additive phase jitter is dependent on the input source and measurement equipment. IDT8T3910BNLI MARCH 23, 2012 The above plot was measured using a Rohde & Schwarz SMA100A as the input source. 16 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Additive Phase Jitter (LVDS) The spectral purity in a band at a specific offset from the fundamental compared to the power of the fundamental is called the dBc Phase Noise. This value is normally expressed using a Phase noise plot and is most often the specified plot in many applications. Phase noise is defined as the ratio of the noise power present in a 1Hz band at a specified offset from the fundamental frequency to the power value of the fundamental. This ratio is expressed in decibels (dBm) or a ratio of the power in the 1Hz band to the power in the fundamental. When the required offset is specified, the phase noise is called a dBc value, which simply means dBm at a specified offset from the fundamental. By investigating jitter in the frequency domain, we get a better understanding of its effects on the desired application over the entire time record of the signal. It is mathematically possible to calculate an expected bit error rate given a phase noise plot. SSB Phase Noise dBc/Hz Additive Phase Jitter @ 156.25MHz 12kHz to 20MHz = 0.20ps (typical) Offset from Carrier Frequency (Hz) As with most timing specifications, phase noise measurements has issues relating to the limitations of the equipment. Often the noise floor of the equipment is higher than the noise floor of the device. The additive phase jitter is dependent on the input source and measurement equipment. IDT8T3910BNLI MARCH 23, 2012 The above plot was measured using a Rohde & Schwarz SMA100A as the input source. 17 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Noise Power dBc Hz Typical Phase Noise at 25MHz Integration Range: 100Hz - 1MHz Offset Frequency (Hz) IDT8T3910BNLI MARCH 23, 2012 18 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Parameter Measurement Information 3.3V±5% 3.3V±5% SCOPE SCOPE 50Ω 33Ω VDD, VDDO 49.9Ω 50Ω 33Ω VDD, VDDO 450Ω HCSL 2pF HCSL IREF Qx 50 50 nQx IREF 450Ω GND GND 49.9Ω 2pF 475Ω 475 0V 0V This load condition is used for IDD, tjit, tsk(o) and tsk(pp), tPD measurements. 3.3V Core/3.3V HCSL Output Load AC Test Circuit 3.3V Core/3.3V HCSL Output Load AC Test Circuit 3.3V±5% 3.3V±5% 2.5V±5% 2.5V±5% SCOPE SCOPE 50Ω 33Ω VDD VDDO IREF VDD 450Ω VDDO 49.9Ω 2pF HCSL 50Ω 33Ω Qx 50Ω HCSL nQx 50Ω 450Ω IREF GND 49.9Ω 475Ω GND 2pF 475Ω 0V 0V This load condition is used for IDD, tjit, tsk(o) and tsk(pp), tPD measurements. 3.3V Core/2.5V HCSL Output Load AC Test Circuit 3.3V Core/2.5V HCSL Output Load AC Test Circuit 2V 2.8V±0.04V 2V VDD VDD, Qx SCOPE Qx SCOPE VDDO VDDO LVPECL GND LVPECL nQx nQx GND -0.5V±0.125V -1.3V±0.165V 3.3V Core/2.5V LVPECL Output Load AC Test Circuit 3.3V Core/3.3V LVPECL Output Load AC Test Circuit IDT8T3910BNLI MARCH 23, 2012 19 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Parameter Measurement Information, continued 3.3V 2.5V SCOPE 3.3V±5% POWER SUPPLY + Float GND – VDDO VDD, VDDO ] Qx VDD, LVDS VDD Qx + + VDDO nQx SCOPE nQx – POWER SUPPLY Float GND 2.5V Core/2.5V LVDS Output Load AC Test Circuit 3.3V Core/3.3V LVDS Output Load AC Test Circuit nQXx nQXx QXx QXx nQXy nQXy QXy Par t 1 Par t 2 QXy tsk(o) tsk(pp) Where X = Bank A or Bank B Where X = Bank A or Bank B Output Skew Part-to-Part Skew Spectrum of Output Signal Q MUX selects active input clock signal Amplitude (dB) A0 nCLK[0:1] CLK[0:1] MUX_ISOL = A0 – A1 nQA[0:4], nQB[0:4] MUX selects static input A1 QA[0:4], QB[0:4] ƒ (fundamental) Frequency Propagation Delay MUX Isolation IDT8T3910BNLI MARCH 23, 2012 tPD 20 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Parameter Measurement Information, continued nQA[0:4], nQB[0:4] nQA[0:4], nQB[0:4] 80% 80% 80% 80% VSW I N G QA[0:4], QB[0:4] VOD 20% 20% QA[0:4], QB[0:4] tF tR 20% 20% tF tR LVPECL Output Rise/Fall Time LVDS Output Rise/Fall Time VDD nQA[0:4], nQB[0:4] out t PW t DC Input LVDS ➤ QA[0:4], QB[0:4] PERIOD ➤ odc = t PW out x 100% t PERIOD VOS/Δ VOS ➤ Output Duty Cycle/Pulse Width/Period Offset Voltage Setup VDD VDD ➤ out nCLK[0:1] ➤ DC Input LVDS 100 V VOD/Δ VOD PP Cross Points V CMR CLK[0:1] ➤ out GND Differential Output Voltage Setup IDT8T3910BNLI MARCH 23, 2012 Differential Input Level 21 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Parameter Measurement Information, continued TSTABLE VRB Clock Period (Differential) Positive Duty Cycle (Differential) Negative Duty Cycle (Differential) +150mV VRB = +100mV 0.0V VRB = -100mV -150mV 0.0V Q - nQ VRB Q - nQ TSTABLE Differential Measurement Points for Duty Cycle/Period Differential Measurement Points for Ringback VMAX nQ nQ VCROSS_MAX ΔVCROSS VCROSS_MIN Q Q VMIN Single-ended Measurement Points for Absolute Cross Point/Swing Rise Edge Rate Single-ended Measurement Points for Delta Cross Point Fall Edge Rate +150mV 0.0V -150mV Q - nQ Differential Measurement Points for Rise/Fall Time IDT8T3910BNLI MARCH 23, 2012 22 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Applications Information Recommendations for Unused Input and Output Pins Inputs: Outputs: CLK/nCLK Inputs LVCMOS Outputs For applications not requiring the use of the differential input, both CLK and nCLK can be left floating. Though not required, but for additional protection, a 1k resistor can be tied from CLK to ground. All unused LVCMOS output can be left floating We recommend that there is no trace attached. Differential Outputs Crystal Inputs All unused differential outputs can be left floating. We recommend that there is no trace attached. Both sides of the differential output pair should either be left floating or terminated. For applications not requiring the use of the crystal oscillator input, both XTAL_IN and XTAL_OUT can be left floating. Though not required, but for additional protection, a 1k resistor can be tied from XTAL_IN to ground. LVPECL Outputs All unused LVPECL output pairs can be left floating. We recommend that there is no trace attached. Both sides of the differential output pair should either be left floating or terminated. LVCMOS Control Pins All control pins have internal pulldowns; additional resistance is not required but can be added for additional protection. A 1k resistor can be used. LVDS Outputs All unused LVDS output pairs can be either left floating or terminated with 100 across. If they are left floating, we recommend that there is no trace attached. IDT8T3910BNLI MARCH 23, 2012 23 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Wiring the Differential Input to Accept Single-Ended Levels Figure 1 shows how a differential input can be wired to accept single ended levels. The reference voltage V1= VDD/2 is generated by the bias resistors R1 and R2. The bypass capacitor (C1) is used to help filter noise on the DC bias. This bias circuit should be located as close to the input pin as possible. The ratio of R1 and R2 might need to be adjusted to position the V1in the center of the input voltage swing. For example, if the input clock swing is 2.5V and VDD = 3.3V, R1 and R2 value should be adjusted to set V1 at 1.25V. The values below are for when both the single ended swing and VDD are at the same voltage. This configuration requires that the sum of the output impedance of the driver (Ro) and the series resistance (Rs) equals the transmission line impedance. In addition, matched termination at the input will attenuate the signal in half. This can be done in one of two ways. First, R3 and R4 in parallel should equal the transmission line impedance. For most 50 applications, R3 and R4 can be 100. The values of the resistors can be increased to reduce the loading for slower and weaker LVCMOS driver. When using single-ended signaling, the noise rejection benefits of differential signaling are reduced. Even though the differential input can handle full rail LVCMOS signaling, it is recommended that the amplitude be reduced. The datasheet specifies a lower differential amplitude, however this only applies to differential signals. For single-ended applications, the swing can be larger, however VIL cannot be less than -0.3V and VIH cannot be more than VCC + 0.3V. Though some of the recommended components might not be used, the pads should be placed in the layout. They can be utilized for debugging purposes. The datasheet specifications are characterized and guaranteed by using a differential signal. VCC VCC VCC VCC R3 100 Ro RS R1 1K Zo = 50 Ohm + Driver V1 Ro + Rs = Zo R4 100 Receiv er - C1 0.1uF R2 1K Figure 1. Recommended Schematic for Wiring a Differential Input to Accept Single-ended Levels IDT8T3910BNLI MARCH 23, 2012 24 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Crystal Input Interface The IDT8T3910I has been characterized with 18pF parallel resonant crystals. The capacitor values, C1 and C2, shown in Figure 2 below were determined using an 18pF parallel resonant crystal and were chosen to minimize the ppm error. The optimum C1 and C2 values can be slightly adjusted for different board layouts. XTAL_IN C1 15pF X1 18pF Parallel Crystal XTAL_OUT C2 15pF Figure 2. Crystal Input Interface Overdriving the XTAL Interface The XTAL_IN input can accept a single-ended LVCMOS signal through an AC coupling capacitor. A general interface diagram is shown in Figure 3A. The XTAL_OUT pin can be left floating. The maximum amplitude of the input signal should not exceed 2V and the input edge rate can be as slow as 10ns. This configuration requires that the output impedance of the driver (Ro) plus the series resistance (Rs) equals the transmission line impedance. In addition, VCC 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 applications, R1 and R2 can be 100. This can also be accomplished by removing R1 and making R2 50. By overdriving the crystal oscillator, the device will be functional, but note, the device performance is guaranteed by using a quartz crystal. XTAL_OUT R1 100 Ro Rs C1 Zo = 50 ohms XTAL_IN R2 100 Zo = Ro + Rs .1uf LVCMOS Driver Figure 3A. General Diagram for LVCMOS Driver to XTAL Input Interface XTAL_OUT C2 Zo = 50 ohms XTAL_IN .1uf Zo = 50 ohms LVPECL Driver R1 50 R2 50 R3 50 Figure 3B. General Diagram for LVPECL Driver to XTAL Input Interface IDT8T3910BNLI MARCH 23, 2012 25 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Differential Clock Input Interface The CLK /nCLK accepts LVDS, LVPECL, SSTL, HCSL and other differential signals. Both signals must meet the VPP and VCMR input requirements. Figures 4A to 4E show interface examples for the CLK /nCLK input with built-in 50 terminations driven by the most common driver types. The input interfaces suggested here are examples only. If the driver is from another vendor, use their termination recommendation. Please consult with the vendor of the driver component to confirm the driver termination requirements. 3.3V 3.3V 3.3V 3.3V 3.3V R3 125Ω R4 125Ω Zo = 50Ω CLK Zo = 50Ω CLK Zo = 50Ω nCLK Zo = 50Ω R1 84Ω R1 50Ω Differential Input LVPECL R2 84Ω Differential Input LVPECL nCLK R2 50Ω R2 50Ω Figure 4B. CLK/nCLK Input Driven by a 3.3V LVPECL Driver Figure 4A. CLK/nCLK Input Driven by a 3.3V LVPECL Driver 3.3V 3.3V 3.3V 3.3V *R3 33Ω Zo = 50Ω Zo = 50Ω CLK CLK R1 100Ω Zo = 50Ω nCLK HCSL *R4 33Ω R1 50Ω R2 50Ω Zo = 50Ω Differential Input LVDS nCLK Receiver *Optional – R3 and R4 can be 0Ω Figure 4C. CLK/nCLK Input Driven by a 3.3V HCSL Driver IDT8T3910BNLI MARCH 23, 2012 Figure 4D. CLK/nCLK Input Driven by a 3.3V LVDS Driver 26 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Recommended Termination Figure 5A is the recommended source termination for applications where the driver and receiver will be on a separate PCBs. This termination is the standard for PCI Express™ and HCSL output 0.5" Max Rs types. All traces should be 50Ω impedance single-ended or 100Ω differential. 0.5 - 3.5" 1-14" 0-0.2" 22 to 33 +/-5% L1 L2 L4 L1 L2 L4 L5 L5 PCI Expres s PCI Expres s Connector Driver 0-0.2" L3 L3 PCI Expres s Add-in Card 49.9 +/- 5% Rt Figure 5A. Recommended Source Termination (where the driver and receiver will be on separate PCBs) Figure 5B is the recommended termination for applications where a point-to-point connection can be used. A point-to-point connection contains both the driver and the receiver on the same PCB. With a matched termination at the receiver, transmission-line reflections will 0.5" Max Rs 0 to 33 L1 be minimized. In addition, a series resistor (Rs) at the driver offers flexibility and can help dampen unwanted reflections. The optional resistor can range from 0Ω to 33Ω. All traces should be 50Ω impedance single-ended or 100Ω differential. 0-18" 0-0.2" L2 L3 L2 L3 0 to 33 L1 PCI Expres s Driver 49.9 +/- 5% Rt Figure 5B. Recommended Termination (where a point-to-point connection can be used) IDT8T3910BNLI MARCH 23, 2012 27 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER LVDS Driver Termination A general LVDS interface is shown in Figure 6. Standard termination for LVDS type output structure requires both a 100 parallel resistor at the receiver and a 100 differential transmission line environment. In order to avoid any transmission line reflection issues, the 100 resistor must be placed as close to the receiver as possible. IDT offers a full line of LVDS compliant devices with two types of output structures: current source and voltage source. The standard termination schematic as shown in Figure 6 can be used with either type of output structure. If using a non-standard termination, it is recommended to contact IDT and confirm if the output is a current source or a voltage source type structure. In addition, since these outputs are LVDS compatible, the amplitude and common mode input range of the input receivers should be verified for compatibility with the output. + LVDS Driver LVDS Receiver 100Ω – 100Ω Differential Transmission Line Figure 6. Typical LVDS Driver Termination Termination for 3.3V LVPECL Outputs The clock layout topology shown below is a typical termination for LVPECL outputs. The two different layouts mentioned are recommended only as guidelines. transmission lines. Matched impedance techniques should be used to maximize operating frequency and minimize signal distortion. Figures 7A and 7B show two different layouts which are recommended only as guidelines. Other suitable clock layouts may exist and it would be recommended that the board designers simulate to guarantee compatibility across all printed circuit and clock component process variations. The differential outputs are low impedance follower outputs that generate ECL/LVPECL compatible outputs. Therefore, terminating resistors (DC current path to ground) or current sources must be used for functionality. These outputs are designed to drive 50 R3 125Ω 3.3V 3.3V Zo = 50Ω 3.3V R4 125Ω 3.3V 3.3V + Zo = 50Ω + _ LVPECL Input Zo = 50Ω R1 50Ω _ LVPECL R2 50Ω R1 84Ω VCC - 2V RTT = 1 * Zo ((VOH + VOL) / (VCC – 2)) – 2 R2 84Ω RTT Figure 7A. 3.3V LVPECL Output Termination IDT8T3910BNLI MARCH 23, 2012 Input Zo = 50Ω Figure 7B. 3.3V LVPECL Output Termination 28 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Termination for 2.5V LVPECL Outputs level. The R3 in Figure 8B can be eliminated and the termination is shown in Figure 8C. Figure 8A and Figure 8B show examples of termination for 2.5V LVPECL driver. These terminations are equivalent to terminating 50 to VDD – 2V. For VDDO = 2.5V, the VDDO – 2V is very close to ground 2.5V VCC = 2.5V 2.5V 2.5V VCC = 2.5V R1 250Ω 50Ω R3 250Ω + 50Ω 50Ω + – 50Ω 2.5V LVPECL Driver – R1 50Ω 2.5V LVPECL Driver R2 62.5Ω R2 50Ω R4 62.5Ω R3 18Ω Figure 8A. 2.5V LVPECL Driver Termination Example Figure 8B. 2.5V LVPECL Driver Termination Example 2.5V VCC = 2.5V 50Ω + 50Ω – 2.5V LVPECL Driver R1 50Ω R2 50Ω Figure 8C. 2.5V LVPECL Driver Termination Example IDT8T3910BNLI MARCH 23, 2012 29 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER 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 shown in Figure 9. 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. and dependent upon the package 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 the 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 recommendations are to be used as a guideline 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. While the land pattern on the PCB 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 specific PIN PIN PAD SOLDER EXPOSED HEAT SLUG GROUND PLANE THERMAL VIA SOLDER LAND PATTERN (GROUND PAD) PIN PIN PAD Figure 9. P.C. Assembly for Exposed Pad Thermal Release Path – Side View (drawing not to scale) IDT8T3910BNLI MARCH 23, 2012 30 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Power Considerations This section provides information on power dissipation and junction temperature for the IDT8T39101. Equations and example calculations are also provided. LVPECL Power Considerations 1. Power Dissipation. The total power dissipation for the IDT8T39101 is the sum of the core power plus the power dissipated in the load(s). The following is the power dissipation for VDD = 3.3V+5% = 3.465, which gives worst case results. The Maximum current at 85°C is as follows IEE_MAX = 189mA NOTE: Please refer to Section 3 for details on calculating power dissipated in the load. • Power (core)MAX = IEE_MAX * VDD_MAX = 3.465V * 189mA = 655mW • Power (outputs)MAX = 30.0mW/Loaded Output pair If all outputs are loaded, the total power is 10 * 30.0mW = 300mW LVCMOS Output Power Dissipation • Output Impedance ROUT Power Dissipation due to loading 50 to VDDO/2 Output Current: IOUT = VDDO_MAX / [2 * (RLOAD + ROUT)] = 3.465V / [2 * (50 + 15 ] = 26.654mA • Power Dissipation on ROUT per LVCMOS output: Power (ROUT) = ROUT * IOUT2 = 15 * (26.654mA)2 = 10.656mW • Dynamic Power Dissipation at 200MHz, (REFOUT) • Power (200MHz) = CPD * Frequency * VDDO2 = 10pF * 200MHz * 3.4652 = 24.012mW • Total Power (200MHz) = 24.012mW * 1 = 24.012mW Total Power_Max = 655mW + 300mW + 10.656mW + 24.012mW = 989.67mW 2. Junction Temperature. Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad directly affects the reliability of the device. The maximum recommended junction temperature is 125°C. Limiting the internal transistor junction temperature, Tj, to 125°C ensures that the bond wire and bond pad temperature remains below 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 value is 40.2°C/W per Table 7 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 0.99 W * 29.0°C/W = 113.8°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 48 Lead VQFN, Forced Convection JA by Velocity Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards IDT8T3910BNLI MARCH 23, 2012 0 1 2.5 29.0°C/W 25.4°C/W 22.8°C/W 31 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER 3. Calculations and Equations. The purpose of this section is to calculate the power dissipation for the LVPECL output pair. LVPECL output driver circuit and termination are shown in Figure 10. VCC Q1 VOUT RL 50Ω VCC - 2V Figure 10. LVPECL Driver Circuit and Termination To calculate worst case power dissipation into the load, use the following equations which assume a 50 load, and a termination voltage of VDD – 2V. • For logic high, VOUT = VOH_MAX = VDD_MAX – 0.90V (VDD_MAX – VOH_MAX) = 0.90V • For logic low, VOUT = VOL_MAX = VCC_MAX – 1.7V (VDD_MAX – VOL_MAX) = 1.7V Pd_H is power dissipation when the output drives high. Pd_L is the power dissipation when the output drives low. Pd_H = [(VOH_MAX – (VCC_MAX – 2V))/RL] * (VCC_MAX – VOH_MAX) = [(2V – (VCC_MAX – VOH_MAX))/RL] * (VCC_MAX – VOH_MAX) = [(2V – 0.9V)/50] * 0.9V = 19.8mW Pd_L = [(VOL_MAX – (VCC_MAX – 2V))/RL] * (VCC_MAX – VOL_MAX) = [(2V – (VCC_MAX – VOL_MAX))/RL] * (VCC_MAX – VOL_MAX) = [(2V – 1.7V)/50] * 1.7V = 10.2mW Total Power Dissipation per output pair = Pd_H + Pd_L = 30.mW IDT8T3910BNLI MARCH 23, 2012 32 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Power Considerations This section provides information on power dissipation and junction temperature for the IDT8T39101. Equations and example calculations are also provided. HCSL Power Considerations 1. Power Dissipation. The total power dissipation for the IDT8T39101 is the sum of the core power plus the power dissipated in the load(s). The following is the power dissipation for VDD = 3.3V+5% = 3.465, which gives worst case results. The Maximum current at 85°C is as follows IDD_MAX = 92mA NOTE: Please refer to Section 3 for details on calculating power dissipated in the load. • Power (core)MAX = VDD_MAX * IDD_MAX = 3.465V * 92mA = 319mW • Power (outputs)MAX = 44.5mW/Loaded Output pair If all outputs are loaded, the total power is 10 * 44.5mW = 445mW LVCMOS Output Power Dissipation • Output Impedance ROUT Power Dissipation due to loading 50 to VDDO/2 Output Current: IOUT = VDDO_MAX / [2 * (RLOAD + ROUT)] = 3.465V / [2 * (50 + 15 ] = 26.654mA • Power Dissipation on ROUT per LVCMOS output: Power (ROUT) = ROUT * IOUT2 = 15 * (26.654mA)2 = 10.656mW • Dynamic Power Dissipation at 200MHz, (REFOUT) • Power (200MHz) = CPD * Frequency * VDDO2 = 10pF * 200MHz * 3.4652 = 24.012mW • Total Power (200MHz) = 24.012mW * 1 = 24.012mW • Total Power_Max = 319mW + 445mW + 10.656mW + 24.012mW = 798.67mW 2. Junction Temperature. Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad directly affects the reliability of the device. The maximum recommended junction temperature is 125°C. Limiting the internal transistor junction temperature, Tj, to 125°C ensures that the bond wire and bond pad temperature remains below 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 value is 40.2°C/W per Table 7 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 0.799 W * 29.0°C/W = 108.2°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 8. Thermal Resistance JA for 48 Lead VQFN, Forced Convection JA by Velocity Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards IDT8T3910BNLI MARCH 23, 2012 0 1 2.5 29.0°C/W 25.4°C/W 22.8°C/W 33 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER 3. Calculations and Equations. The purpose of this section is to calculate power dissipation on the IC per HCSL output pair. HCSL output driver circuit and termination are shown in Figure 6. VDDO IOUT = 17mA ➤ VOUT RREF = 475Ω ± 1% RL 50Ω IC Figure 11. HCSL Driver Circuit and Termination HCSL is a current steering output which sources a maximum of 17mA of current per output. To calculate worst case on-chip power dissipation, use the following equations which assume a 50 load to ground. The highest power dissipation occurs when VDDO_MAX. Power = (VDDO_MAX – VOUT) * IOUT, since VOUT – IOUT * RL = (VDDO_MAX – IOUT * RL) * IOUT = (3.465V – 17mA * 50) * 17mA Total Power Dissipation per output pair = 44.5mW IDT8T3910BNLI MARCH 23, 2012 34 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Power Considerations This section provides information on power dissipation and junction temperature for the IDT8T39101. Equations and example calculations are also provided. LVDS Power Considerations 1. Power Dissipation. The total power dissipation for the IDT8T39101 is the sum of the core power plus the power dissipated in the load(s). The following is the power dissipation for VDD = 3.3V+5% = 3.465, which gives worst case results. The Maximum current at 85°C is as follows IDD_MAX = 76mA IDDO_MAX = 303mA Power (core) Max = VDD_MAX *( IDD_MAX + IDDO_MAX) = 3.465 * (76mA + 303mA) = 1313.235mW. LVCMOS Output Power Dissipation • Output Impedance ROUT Power Dissipation due to loading 50 to VDDO/2 Output Current: IOUT = VDDO_MAX / [2 * (RLOAD + ROUT)] = 3.465V / [2 * (50 + 15 ] = 26.654mA • Power Dissipation on ROUT per LVCMOS output: Power (ROUT) = ROUT * IOUT2 = 15 * (26.654mA)2 = 10.656mW • Dynamic Power Dissipation at 200MHz, (REFOUT) • Power (200MHz) = CPD * Frequency * VDDO2 = 10pF * 200MHz * 3.4652 = 24.012mW • Total Power (200MHz) = 24.012mW * 1 = 24.012mW • Total Power_Max = 1313.235mW + 10.656 + 24.012 = 1347.903mW 2. Junction Temperature. Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad directly affects the reliability of the device. The maximum recommended junction temperature is 125°C. Limiting the internal transistor junction temperature, Tj, to 125°C ensures that the bond wire and bond pad temperature remains below 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 value is 40.2°C/W per Table 7 below. Therefore, Tj for an ambient temperature of 85°C with all outputs switching is: 85°C + 1.344W * 29.0°C/W = 124.1°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 9. Thermal Resistance JA for 48 Lead VQFN, Forced Convection JA by Velocity Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards IDT8T3910BNLI MARCH 23, 2012 0 1 2.5 29.0°C/W 25.4°C/W 22.8°C/W 35 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Reliability Information Table10. JA vs. Air Flow Table for a 48 Lead VFQFN JA vs. Air Flow Meters per Second Multi-Layer PCB, JEDEC Standard Test Boards 0 1 2.5 29.0°C/W 25.4°C/W 22.8°C/W Transistor Count The transistor count for IDT8T3910I is: 19,425 IDT8T3910BNLI MARCH 23, 2012 36 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Package Outline and Package Dimensions Package Outline NL Suffix for 48 Lead VFQFN Bottom View w/Type A ID 2 1 CHAMFER 4 N N-1 Bottom View w/Type C ID 2 1 RADIUS 4 N N-1 There are 2 methods of indicating pin 1 corner at the back of the VFQFN package are: 1. Type A: Chamfer on the paddle (near pin 1) 2. Type C: Mouse bite on the paddle (near pin 1) Table 11. Package Dimensions for 48 Lead VFQFN Symbol N A A1 A3 b D&E D1 & E1 D2 & E2 e R ZD & ZE L All Dimensions in Millimeters Minimum Nominal Maximum 48 0.8 0.9 0 0.02 0.05 0.2 Ref. 0.18 0.25 0.30 7.00 Basic 5.50 Basic 5.50 5.65 5.80 0.50 Basic 0.20~0.25 0.75 Basic 0.35 0.40 0.45 Reference Document: IDT Drawing #PSC-420 IDT8T3910BNLI MARCH 23, 2012 37 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER Ordering Information Table 12. Ordering Information Part/Order Number 8T3910BNLGI 8T3910BNLGI8 Marking IDT8T3910BNLGI IDT8T3910BNLGI Package Lead-Free, 48 Lead VFQFN Lead-Free, 48 Lead VFQFN Shipping Packaging Tray 1500 Tape & Reel Temperature -40°C to 85°C -40°C to 85°C NOTE: Parts that are ordered with an "G" suffix to the part number are the Pb-Free configuration and are RoHS compliant. While the information presented herein has been checked for both accuracy and reliability, Integrated Device Technology (IDT) assumes no responsibility for either its use or for the infringement of any patents or other rights of third parties, which would result from its use. No other circuits, patents, or licenses are implied. This product is intended for use in normal commercial and industrial applications. Any other applications, such as those requiring high reliability or other extraordinary environmental requirements are not recommended without additional processing by IDT. IDT reserves the right to change any circuitry or specifications without notice. IDT does not authorize or warrant any IDT product for use in life support devices or critical medical instruments. IDT8T3910BNLI MARCH 23, 2012 38 ©2012 Integrated Device Technology, Inc. IDT8T3910I Preliminary Data Sheet CRYSTAL OR DIFFERNTIAL-TO-DIFFERENTIAL CLOCK FANOUT BUFFER We’ve Got Your Timing Solution 6024 Silver Creek Valley Road San Jose, California 95138 Sales 800-345-7015 (inside USA) +408-284-8200 (outside USA) Fax: 408-284-2775 www.IDT.com/go/contactIDT Technical Support netcom@idt.com +480-763-2056 DISCLAIMER Integrated Device Technology, Inc. (IDT) and its subsidiaries reserve the right to modify the products and/or specifications described herein at any time and at IDT’s sole discretion. All information in this document, including descriptions of product features and performance, is subject to change without notice. Performance specifications and the operating parameters of the described products are determined in the independent state and are not guaranteed to perform the same way when installed in customer products. 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