CDCF5801DBQ

Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 CLOCK MULTIPLIER WITH DELAY CONTROL AND PHASE ALIGNMENT (Not Recommended for New Designs Use CDCF5801A as a Replacement) FEATURES APPLICATIONS • • • • • • • • • • • • • • • • • • Low-Jitter Clock Multiplier: ×1, ×2, ×4, ×8 Programmable Bidirectional Delay Steps of 1.3 mUI Output Frequency Range of 25 MHz to 280 MHz Input Frequency Range of 12.5 MHz to 240 MHz Low Jitter Generation Single-Ended REFCLK Input With Adjustable Trigger Level (Works With LVTTL, HSTL, and LVPECL) Differential/Single-Ended Output Output Can Drive LVPECL, LVDS, and LVTTL Three Power Operating Modes to Minimize Power Low Power Consumption (< 190 mW at 280 MHz/3.3 V) Packaged in a Shrink Small-Outline Package (DBQ) No External Components Required for PLL Spread Spectrum Clock Tracking Ability to Reduce EMI (SSC) Video Graphics Gaming Products Datacom Telecom Noise Cancellation Created by FPGAs DBQ PACKAGE (TOP VIEW) VDDREF REFCLK VDDP GNDP GND LEADLAG DLYCTRL GNDPA VDDPA VDDPD STOPB PWRDNB 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 P0 P1 VDDO GNDO CLKOUT NC CLKOUTB GNDO VDDO MULT0 MULT1 P2 DESCRIPTION The CDCF5801 provides clock multiplication from a reference clock (REFCLK) signal with the unique capability to delay or advance the CLKOUT/CLKOUTB with steps of only 1.3 mUI through a phase aligner. For every rising edge on the DLYCTRL pin the CLKOUT is delayed by a 1.3-mUI step size as long as the LEADLAG input detects a low signal at the time of the DLYCTRL rising edge. Similarly for every rising edge on the DLYCTRL pin the CLKOUT is advanced by a 1.3-mUI step size as long as the LEADLAG pin is high during the transition. This unique capability allows the device to phase align (zero delay) between CLKOUT/CLKOUTB and any one other CLK in the system by feeding the clocks that need to be aligned to the DLYCTRL and the LEADLAG pins. Also it provides the capability to program a fixed delay by providing the proper number of edges on the DLYCTRL pin, while strapping the LEADLAG pin to dc high or low. Further possible applications are: • Aligning the rising edge of the output clock signal to the input clock rising edge • Avoiding PLL instability in applications that require very long PLL feedback lines • Isolation of jitter and digital switching noise • Limitation of jitter in systems with good ppm frequency stability Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2003–2006, Texas Instruments Incorporated Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 The CDCF5801 provides clock multiplication and division from a reference clock (REFCLK) signal. The device is optimized to have extremely low jitter impact from input to output. The predivider pins MULT[0:1] and post-divider pins P[0:2] provide selection for frequency multiplication and division ratios, generating CLKOUT/CLOUTKB frequencies ranging from 25 MHz to 280 MHz with clock input references (REFCLK) ranging from 12.5 MHz to 240 MHz. See Table 1 for detailed frequency support. The selection of pins MULT[0:1] and P[1:2] determines the multiplication value of 1, 2, 4, or 8. The CDCF5801 offers several power-down/ high-impedance modes, selectable by pins P0, STOPB and PWRDN. Another unique capability of the CDCF5801 is the high sensitivity and wide common-mode range of the clock-input pin REFCLK by varying the voltage on the VDDREF pin. The clock signal outputs CLKOUT and CLKOUTB can be used independently to generate single-ended clock signals. The CLKOUT/CLKOUTB outputs can also be combined to generate a differential output signal suitable for LVDS, LVPECL, or HSTL/SSTL signaling. The CDCF5801 is characterized for operation over free-air temperatures of -40°C to 85°C. 2 Submit Documentation Feedback REFCLK VDDREF/2 12.5-240 MHz Control PWRDNB P0 Submit Documentation Feedback div4 div8 div16 00 11 10 MULT[0:1] 2 div2 PLL 01 VDDP GNDP DLY- div8 div4 div2 GNDPA LEADLAG 0-280 MHz VDDPD/2 DLYCTRL 0-240 MHz DLY+ >CLK Delay Phase Aligner VDDPA P[1:2] 2 01 10 11 VDDO 25-280 MHz GNDO STOPB CLKOUTB CLKOUT Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 FUNCTIONAL BLOCK DIAGRAM 3 Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 TERMINAL FUNCTIONS TERMINAL I/O DESCRIPTION NAME NO. CLKOUT CLKOUTB 2018 O Output CLK signal (low-noise CMOS) Complementary output CLK signal (low-noise CMOS) DLYCTRL 7 I Every rising edge on this pin delays/advances the CLKOUT/CLKOUTB signal by 1/768th of the CLKOUT/CLKOUTB period (1.3 mUI). (E.g., for a 90-degree delay or advancement one needs to provide 192 rising edges). See Table 3. GND 5 GND for VDDREF and VDDPD GNDO 17, 21 GND for the output pins (CLKOUT, CLKOUTB) GNDP 4 GNDPA 8 LEADLAG 6 I Controls whether the output CLK is delayed or advanced relative to REFCLK. See Table 3. MULT0 MULT1 15 I PLL multiplication factor select. See Table 1. GND for the PLL GND for phase aligner, digital logic, and inputs P[0:2], MULT[0:1], STOPB, PWRDNB MULT[0:1] = 10: ×16 14 MULT[0:1] = 11: ×8 MULT[0:1] = 00: ×4 MULT[0:1] = 01: ×2 NC 19 P0 24 Not connected; leave pin floating or tied to GND. I Mode control pins (see Table 1) 0 - Normal operation 1 - High-Z outputs and other special settings P1 23 I Post divider control (see Table 1) P[1:2] = 11: div2 P[1:2] = 10: div4 P2 13 PWRDNB 12 P[1:2] = 01: div8 I Active-low power-down state. CLKOUT/CLKOUTB goes low, See Table 2). 0 - IC in power down 1 - Normal operation REFCLK 2 I Reference input clock STOPB 11 I Active low output disabler, PLL and PA still running, CLKOUT and CLKOUTB goes to a dc value as listed in Table 2. 0 - Outputs disabled 1 - Normal operation 4 VDDO 16, 22 VDDP 3 VDD for the output pin (CLKOUT, CLKOUTB) and power down circuit VDD for PLL and input buffer VDDPA 9 VDD for phase aligner, digital logic, and inputs P[0:2], MULT[0:1], and STOPB VDDPD 10 Reference voltage for inputs LEADLAG and DLYCTRL VDDREF 1 Reference voltage for REFCLK Submit Documentation Feedback Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 Table 1. Input-to-Output Settings INPUT-TO-OUTPUT MULTIPLICATION-RATIO 8 4 2 1 INPUT FREQUENCY (MHz) OUTPUT FREQUENCY (MHz) PREDIVIDER FROM TO FROM TO MULT0 MULT1 P1 P2 12.5 35 100 280 1 0 1 1 12.5 39 50 156 1 0 1 0 25 70 100 280 1 1 1 1 12.5 39 25 78 1 0 0 1 25 78 50 156 1 1 1 0 50 140 100 280 0 0 1 1 25 78 25 78 1 1 0 1 50 156 50 156 0 0 1 0 100 240 100 240 0 1 1 1 X X 0 0 X X 0 1 X X 1 X CLKOUT high-impedance CLOUOTB high-impedance CLKOUT = high CLKOUTB = high CLKOUT = P2 CLKOUTB = P2 (1) POST DIVIDER P0 0 1 NOTE Normal operation (1) Special mode of operation There is some overlapping of the input frequency ranges for multiplication ratios of 1, 2, and 4. For example, an input frequency of 30 MHz for a multiplication ratio of four falls within both the 12.5 to 39-MHz range and the 25 to 70-MHz range. For best device operation in a case such as this, always select the input frequency range nearer to the top of the table. PLL DIVIDER/MULITPLIER SELECTION Table 2. Power Down Modes STATE PWRDNB STOPB Power down 0 X CLKOUT and CLKOUTB GNDO Clock stop 1 0 VO, STOP Normal 1 1 See Table 1 Table 3. Programmable Delay and Phase Alignment DLYCTR NOTE LEADLAG Each rising For every 32 edges, there are one or two edges for which the phase aligner does not edge+ update the phase. Therefore, CLKOUT phase is not updated for every 32nd edge. The frequency of the DLYCTRL pin should Each rising always be equal to or less than the edge+ frequency of the LEADLAG pin. CLKOUT and CLKOUTB HI Advanced by one step: step size: 1/768 of the CLKOUT period (1.3 mUI) at P[1:2] = 11 1/1536 of the CLKOUT period (0.65 mUI) at P[1:2] = 10 1/3072 of the CLKOUT period (0.325 mUI) at P[1:2] = 01 LO Delayed by one step: step size: 1/768 of the CLKOUT period (1.3 mUI) at P[1:2] = 11 1/1536 of the CLKOUT period (0.65 mUI) at P[1:2] = 10 1/3072 of the CLKOUT period (0.325 mUI) at P[1:2] = 01 Submit Documentation Feedback 5 Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 ABSOLUTE MAXIMUM RATINGS over operating free-air temperature (unless otherwise noted) (1) VDDx (2) Tstg (1) (2) Supply voltage range -0.5 V to 4 V Voltage range at any output terminal -0.5 V to VDD + 0.5 V Voltage range at any input terminal -0.5 V to VDD + 0.5 V Storage temperature range -65°C to 150°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds 260°C Stresses beyond those listed under,, absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under,, recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltage values are with respect to the GND terminals. POWER DISSIPATION RATING TABLE PACKA GE TA≤ 25°C POWER RATING DERATING FACTOR (1) ABOVE TA = 25°C TA = 85°C POWER RATING 830 mW 8.3 mW/°C 332 mW DBQ (1) This is the inverse of the junction-to-ambient thermal resistance when board-mounted and with no air flow. RECOMMENDED OPERATING CONDITIONS MIN NOM MAX 3 3.3 3.6 UNIT VDDP, VDDPA, VDDO Supply voltage VIH (CMOS) High-level input voltage VIL (CMOS) Low-level input voltage 0.3 VDD V VIL (DLYCTRL, LEADLAG) Input signal low voltage VDDPD
0.2 2 V VIH (DLYCTRL, LEADLAG) Input signal high voltage (VDDPD) Input reference voltage for DLYCNTRL and LEADLAG IOH High-level output current -16 mA IOL Low-level output current 16 mA (VDDREF) (see Application section) Input reference voltage for REFCLK VIL (see Application section) REFCLK input low voltage VIH (see Application section) REFCLK input high voltage TA Operating free-air temperature 0.7 VDD V V VDDPD
0.2 2 V 1.2 VDD 1.2 V VDD V VDDREF
0.2 2 V V VDDREF
0.2 2 -40 85 °C TIMING REQUIREMENTS PARAMETER Fmod MIN Input frequency of modulation, (if driven by SSC CLKIN) 33 Modulation index, nonlinear maximum 0.5% SR UNIT kHz 0.6% Input slew rate 1 4 Input duty cycle on REFCLK 40% 60% Input frequency on REFCLK 12.5 240 MHz 25 280 MHz 240 MHz Output frequency on CLKOUT and CLKOUTB Allowable frequency on DLYCTRL 6 MAX Submit Documentation Feedback V/ns Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 TIMING REQUIREMENTS (continued) PARAMETER MIN MAX UNIT 280 MHz 25% 75% Allowable frequency on LEADLAG Allowable duty cycle on DLYCTRL and LEADLAG pins ELECTRICAL CHARACTERISTICS over recommended operating conditions (unless otherwise noted) TEST CONDITIONS (1) PARAMETER MIN TYP (2) VO(STOP) Output voltage during Clkstop mode See Figure 1 VO(X) Output crossing-point voltage See Figure 1 and Figure 4 VO Output voltage swing (VOH - VOL) See Figure 1 VIK Input clamp voltage VDD = 3 V, II = -18 mA VDD = 3 to 3.6 V, See Figure 1 2 VDD = 3 V, IOH = -16 mA 2.2 VDD = 3 to 3.6 V, See Figure 1 VDD = 3 V, IOH = 16 mA VDD = 3.135 V, VO = 1 V VDD = 3.3 V, VO = 1.65 V VDD = 3.465 V, VO = 3.135 V VDD = 3.135 V, VO = 1.95 V VDD = 3.3 V, VO = 1.65 V VOH High-level output voltage VOL Low-level output voltage IOH High-level output current IOL Low-level output current VDD = 3.465 V, VO = 0.4 V IOZ High-impedance-state output current P0 = 1, P1 = P2 = 0 IOZ(STOP) High-impedance-state output current during Clk Stop Stop = 0, VO = GND or VDD IOZ(PD) High-impedance-state output current in power-down state PWRDNB = 0, VO = GND or VDD IIH High-level input current IIL REFCLK; STOPB; VDD = 3.6 V, PWRDNB; P[0:2]; MULT[0:1]; VDD = 3.6 V, DLYCTRL; LEADLAG MAX UNIT 1.1 2 V VDDO
0.2 2 VDDO
0.2 2 V 1.7 2.9 V -1.2 V 2.5 0.4 V 0.6 0.5 -32 -52 -51 -14.5 43 V mA -21 61.5 65 25.5 -10 VI = VDD VI =0 mA 40 ±10 µA ±100 µA 100 µA 10 µA -10 µA ZO Output impedance (single ended) High state RI at IO-14.5 mA to -16.5 mA 15 35 50 Low state RI at IO 14.5 mA to 16.5 mA 10 17 35 IREF Reference current VDDREF; VDDPD VDD = 3.6 V CI Input capacitance VI = VDD or GND 2 pF CO Output capacitance VO = GND or VDD 3 pF IDD(PD) Supply current in power-down state REFCLK = 0 MHz to 280 MHz; PWRDNB = 0; STOPB = 1 IDD(CLKSTOP) Supply current in CLK stop state IDD(NORMAL) (1) (2) Supply current (normal operation mode) PWRDNB = 0 PWRDNB = 1 Ω 50 µA 0.5 mA 4 mA BUSCLK configured for 280 MHz 44 mA BUSCLK 280 MHz, MULT[0:1] = 10; P[0:2] = 011; Load , See Figure 1 75 mA VDD refers to any of the following; VDDP, VDDREF, VDDO, VDDPD, and VDDPA All typical values are at VDD = 3.3 V, TA = 25°C. Submit Documentation Feedback 7 Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 JITTER SPECIFICATION over recommended free-air temperature range and VCC range (unless otherwise noted) TEST CONDITIONS PARAMETER TYP (ps) MAX (ps) 20 48 Period p-p 120 225 Cycle to cycle + 70 165 Cycle to cycle - 70 165 RMS phase jitter (accumulated, 100 kHz-12.5 MHz) 80 160 7 15 Period p-p 37 75 Cycle to cycle + 27 55 Cycle to cycle - 27 55 27 65 5 14 30 65 24 55 24 55 35 65 4 8 20 40 Cycle to cycle + 17 40 Cycle to cycle - 17 40 RMS phase jitter (accumulated, 100 kHz-40 MHz) 15 35 8 15 38 60 Cycle to cycle + 5 55 Cycle to cycle - 35 55 RMS phase jitter (accumulated, 100 kHz-40 MHz) 30 60 Period rms (1-sigma jitter, full frequency band) Period rms (1-sigma jitter, full frequency band) REFCLK (MHz) CLKOUT (MHz) 25 25 50 50 MULT[0:1] P[0:2] 11 11 001 001 RMS phase jitter (accumulated, 100 kHz-25 MHz) Period rms (1-sigma jitter, full frequency band) 100 100 00 010 Period p-p t(jitter) Cycle to cycle + Cycle to cycle RMS phase jitter (accumulated, 100 kHz-40 MHz) Period rms (1-sigma jitter, full frequency band) 156 156 00 010 Period p-p Period rms (1-sigma jitter, full frequency band) 200 200 01 Period p-p 8 Submit Documentation Feedback NOTES 011 Phase aligner running (CLKOUT tight to LEADLAG; REFCLK tight to DLYCTRL). All typical values are at VDD = 3.3 V, TA = 25°C. Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 JITTER SPECIFICATION (continued) over recommended free-air temperature range and VCC range (unless otherwise noted) TEST CONDITIONS PARAMETER TYP (ps) MAX (ps) 4 11 Period p-p 20 48 Cycle to cycle + 16 45 Cycle to cycle - 16 45 4 11 Period p-p 22 55 Cycle to cycle + 15 45 Cycle to cycle - 15 45 4 11 18 48 15 45 15 45 6 16 34 75 20 65 20 65 3 11 Period p-p 15 44 Cycle to cycle + 13 40 Cycle to cycle - 13 40 6 20 Period p-p 35 80 Cycle to cycle + 25 75 Cycle to cycle - 25 75 REFCLK (MHz) CLKOUT (MHz) 25 200 Period rms (1-sigma jitter, full frequency band) Period rms (1-sigma jitter, full frequency band) 25 Period rms (1-sigma jitter, full frequency band) MULT[0:1] P[0:2] 10 100 70 011 10 280 010 11 011 Period p-p Cycle to cycle + t(jitter) Cycle to cycle Period rms (1-sigma jitter, full frequency band) 25 50 10 001 Period p-p Cycle to cycle + Cycle to cycle Period rms (1-sigma jitter, full frequency band) Period rms (1-sigma jitter, full frequency band) 78 156 62.5 11 125 NOTES Phase aligner not running (LEADLAG = 0, DLYCTRL = 0). All typical values are at VDD = 3.3 V, TA = 25°C. 010 00 011 SWITCHING CHARACTERISTICS over recommended operating free-air temperature range (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX t(DC) Output duty cycle over 1000 cycles See Figure 3 42% tr, tf Output rise and fall times (measured at 20%-80% of output voltage See Figure 5 150 250 350 MIN TYP MAX UNIT 58% ps STATE TRANSITION LATENCY SPECIFICATIONS PARAMETER t(powerup) FROM Delay time, PWRDNB↑ to CLKOUT / CLKOUTB settled Delay time, PWRDNB↑ to internal PLL and clock are on and settled TO TEST CONDITION UNIT 3 Power down Normal Submit Documentation Feedback See Figure 6 ms 3 9 Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 STATE TRANSITION LATENCY SPECIFICATIONS (continued) PARAMETER t(VDDpowerup) FROM Delay time, power up to CLKOUT output settled TO TEST CONDITION MIN TYP MAX UNIT 3 Delay time, power up to internal PLL and clock are on and settled VDD Normal See Figure 6 ms 3 t(MULT) MULT0 and MULT1 change to CLKOUT output resettled Normal Normal See Figure 7 1 ms t(CLKON) STOPB↑ to CLKOUT glitch-free clock edges CLK stop Normal See Figure 8 10 ns t(CLKSETL) STOPB↑ to CLKOUT output settled to within 50 ps of the phase before STOPB was disabled CLK stop Normal See Figure 8 20 cycles t(CLKOFF) STOPB↓ to CLKOUT output disabled Normal CLK stop See Figure 8 5 ns t(powerdown) Delay time, PWRDNB↓ to the device in the power-down mode Normal Power down See Figure 6 1 ms t(STOP) Maximum time in CLKSTOP (STOPB = 0) before reentering normal mode (STOPB = 1) STOPB Normal See Figure 8 100 µs t(ON) Minimum time in normal mode (STOPB = 1) before reentering CLKSTOP (STOPB = 0) Normal CLK stop See Figure 8 100 ms PARAMETER MEASUREMENT INFORMATION TESTING CONDITIONS CLKOUT 50 Ω VCM 50 Ω 10 pF CLKOUTB Figure 1. Test Load and Voltage Definitions VOH, VOL, VO(STOP) CLKOUT CLKOUTB tCYCLE(i) tCYCLE(i+1) Cycle-to-Cycle Jitter (t(jitter)) = | tCYCLE(i) - tCYCLE(i+1) | over 1000 consecutive cycles Figure 2. Cycle-to-Cycle Jitter 10 Submit Documentation Feedback Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 PARAMETER MEASUREMENT INFORMATION (continued) CLKOUT CLKOUTB tPW+ tCYCLE Duty Cycle = (tPW+/tCYCLE) Figure 3. Output Duty Cycle CLKOUT VO(X)+ VO(X), nom VO(X)CLKOUTB Figure 4. Crossing Point Voltage VOH 80% 20% VOL tr tf Figure 5. Voltage Waveforms PWRDNB CLKOUT CLKOUTB















t(powerdown) t(powerup) Figure 6. PWRDNB Transition Timings MULT0 and/or MULT1 CLKOUT CLKOUTB




















t(MULT) Figure 7. MULT Transition Timings Submit Documentation Feedback 11 Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 PARAMETER MEASUREMENT INFORMATION (continued) t(ON) t(STOP) STOPB














t(CLKSETL) t(CLKON) (see Note A) CLKOUT CLKOUTB Output clock not specified glitches ok A. Clock enabled and glitch free Clock output settled within 50 ps of the phase before disabled Vref = VO±200 mV Figure 8. STOPB Transition Timings 12 Submit Documentation Feedback t(CLKOFF) (see Note A) Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 APPLICATION INFORMATION APPLICATION EXAMPLE The following figure shows an example of using the CDCF5801 as a phase aligner de-skewing the unknown buffer delay of the two CDCV304s in the circuit. This circuitry would not be possible with a simple PLL because the feedback of the PLL would have the second CDCV304 in the loop, causing instability of the PLL due to a long delay. Z = 50 Ω; Length = L1 30 Ω 25 MHz CDCV304 Clock Buffer 25 MHz Z = 50 Ω Z = 50 Ω CLK Outputs are Phase Aligned Between the Two Buffers CDCF5801 3.3 V VDDREF P0 P1 REFCLK 3.3 V VDDP VDDO GNDP GNDO GND CLKOUT LEADLAG NC DLYCTRL CLKOUTB GNDPA 3.3 V CDCV304 Clock Buffer 3.3 V 25 MHz 25 MHz Z = 50 Ω 35 Ω CLK GNDO VDDPA VDDO VDDPD MULT0 STOPB MULT1 PWRDNB 3.3 V P2 Z = 50 Ω; Length = L1 Figure 9. Application Example NOTE: If an active element (microcontroller, ASIC, DSP< FPYA, DSP, etc.) is used in the CDCF5801 CLKOUT to DLYCTRL feedback loop, see application report SCAA075. SELECTING VDDREF Generally, VDDREF can be set to any value between 1.2 V and VDD. The setting of VDDREF directly influences the trigger voltage of the input. Special care must be taken when using small signal swings to drive the CVDCF5801 input (e.g., PECL). It is recommended to connect VDDREF directly to VDD, ac-couple the REFCLK input, and rebias the signal. The following circuit is recommended to drive the CDCF5801 from a differential clock signal like PECL. Submit Documentation Feedback 13 Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 APPLICATION INFORMATION (continued) 3.3 V ± 10% 150 Ω R1 100 Ω CDCF5801 VDDREF Z = 50 Ω REFCLK PECL R2 100 Ω GND 150 Ω A. 14 GNDP NOTE: If more signal swing is required and an unterminated transmission is on option, then R1 and R2 can both be replaced with 10-kΩ resistors. Submit Documentation Feedback Not Recommended for New Designs CDCF5801 www.ti.com SCAS698F – SEPTEMBER 2003 – REVISED APRIL 2006 Revision History DATE REV PAGE 29 JUL 05 E 13 SECTION 18 DEC 04 D – – Unknown 17 FEB 04 C – – Unknown 15 OCT 03 B – – Unknown 9 OCT 03 A – – Unknown 16 SEP 03 * – – Original version Application Example DESCRIPTION Changed first paragraph and changed P2 connection in Figure 9 Submit Documentation Feedback 15 PACKAGE OPTION ADDENDUM www.ti.com 13-Jul-2022 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) CDCF5801DBQ NRND SSOP DBQ 24 50 RoHS & Green NIPDAU Level-2-260C-1 YEAR -40 to 85 CDCF5801 CDCF5801DBQR NRND SSOP DBQ 24 2500 RoHS & Green NIPDAU Level-2-260C-1 YEAR -40 to 85 CDCF5801 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of