Advance Information Advance Information VT98501 VT98501 3.3VLow LowPhase PhaseNoise NoiseClock ClockMultiplier Multiplier Applications •= •= Oscillator Replacement LCD monitor clock source General Description The VT98501 is a 3.3V CMOS, clock multiplier integrated circuit. The device provides an excellent quality high frequency output clock from a lower frequency crystal or clock input. Tri-level selection inputs S0 and S1 are used to select any one of nine multipliers, stored in the on-board ROM, and apply it to the input to produce the desired output. The resulting output includes many commonly used frequencies up to 160 MHz. Phase Locked Loop (PLL) technology allows the device to use an input signal from an inexpensive crystal. When Output Enable (OE) is low, the clock output is in high impedance state. The VT98501, when used with an inexpensive crystal, provides a cost-effective clock source for most electronic systems. Features •= Low phase noise •= Exceptionally low jitter: 25 ps one sigma •= Zero ppm multiplication error •= Fully Compatible with all popular CPUs •= Input clock frequency 2 - 50 MHz. •= Duty Cycle of 45/55 up to 160 MHz. •= Input crystal frequency 5 – 27 MHz •= 25mA drive capability at TTL levels •= Output clock frequencies up to 160 MHz. •= High-Z output for board level testing •= 5V tolerant inputs and output Figure 2. Pin Assignment Figure 1. Functional Block Diagram VDD GND 8-pin SOIC S0 S1 Clock or Xtal X1/ICLK input Xtal. Osc. PLL Clock Multiplier & ROM Output Buffer CLK X2 Optional caps 2001-03-05 X1/ICLK 1 8 X2 VDD 2 7 OE GND 3 6 S0 S1 4 5 CLK Output Enable Page 1 MDST-0009-00 Vaishali Semiconductor 1300 White Oaks Road, Ste. 200 Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063 VT98501 Advance Information Table 1. Clock Output Table S1 0 0 0 M M M 1 1 1 S0 0 M 1 0 M 1 0 M 1 CLK 4 x input 5.3125 x input 5 x input 6.25 x input 2 x input 3.125 x input 6 x input 3 x input 8 x input Minimum Input See table 7 20 MHz See table 7 4 MHz See table 7 8 MHz See table 7 See table 7 See table 7 0 = Connect to ground. 1 = Connect directly to VDD M = Leave unconnected (floating) Table 2. Examples of Common Output Frequencies. Output Input Selection (S1,S0) 20 10 M,M Output Input Selection (S1,S0) 50 16.66 1,M Output Input Selection (S1,S0) 83.33 16.66 0,1 24 12 M,M 30 10 1,M 32 16 M,M 33.33 16.66 M,M 37.5 12 M,1 40 10 0,0 48 12 0,0 60 10 1,0 62.5 20 M,1 64 16 0,0 66.66 16.66 0,0 72 12 1,0 75 12 M,0 80 10 1,1 90 15 1,0 100 20 0,1 106.25 20 0,M 120 15 1,1 125 20 M,0 155.52 19.44 1,1 Table 3. Pin Description No. 1 2 3 4 5 6 7 8 Name X1/ICLK VDD GND S1 CLK S0 OE X2 Type I P P TI O TI I O Description Xtal connection or clock input. Connect to +3.3V Connect to ground. Select 1 for output clock. Connect to ground or VDD or float Clock output per table 2. Select 0 for output clock. Connect to ground or VDD or float. Output Enable. Tri- states CLK output when low. Xtal connection. Leave unconnected for clock input. Legend: I = Input TI = Tri-level Input O = Output P = Power supply connection 2001-03-05 Page 2 MDST-0009-00 Vaishali Semiconductor 1300 White Oaks Road, Ste 200 Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063 VT98501 Advance Information Table 4. Absolute Maximum Ratings Parameter Conditions Supply voltage, VDD Referenced to GND Inputs and Clock Outputs Referenced to GND Soldering Temperature Max of 10 seconds Min Typ -0.5 Storage temperature -65 Max Units 4.6 V 4.6 V 260 °C 150 °C Table 5. Operating Conditions Parameter Min Typ Max Units Ambient Operating Temperature 0 70 °C Operating Voltage, VDD 3 3.6 V Input High Voltage, VIH, X1 pin only 2.5 1.65 Input Low Voltage, VIL, X1 pin only 1.65 Input High Voltage, VIH, OE pin 0.5 V 2 V Input Low Voltage, VIL, OE pin Input High Voltage, VIH, trinary inputs V 0.8 V VDD-0.5 V Input Low Voltage, VIL, trinary inputs 0.5 V DC Characteristics Table 6. DC Characteristics VDD = 3V to 3.6V Parameter Condition Output High Voltage, VOH IOH=-25mA Output Low Voltage, VOL IOL=25mA Operating Supply Current, IDD (20 MHz Xtal) No Load, 100MHz Short Circuit Current Input Capacitance Typ Max 2.4 Units V 0.4 V 25 mA CLK output ±100 mA S0, S1, OE 4 pF Frequency synthesis error 2001-03-05 Min 0 Page 3 ppm MDST-0009-00 Vaishali Semiconductor 1300 White Oaks Road, Ste 200 Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063 VT98501 Advance Information AC Characteristics Table 7. AC Characteristics VDD = 3V to 3.6V over the operating temperature range Max Units fosc Symbol Input Crystal Frequency Parameter Condition Min 5 27 MHz fin Input clock frequency 2 50 MHz fout Output Frequency, 14 160 MHz tr Output Clock Rise Time 0.8 to 2.0V 1 ns tf Output Clock Fall Time 2.0 to 0.8V 1 ns tod Output Clock Duty Cycle 1.5 V, up to 160 MHz PLL Bandwidth 45 Typ 49 to 51 55 10 % kHz TPZH, TPZL Output Enable Time, OE high to output on 50 ns TPHZ, TPLZ Output Disable time, OE low to Tri-state 50 ns tjit (abs) Absolute Clock period Jitter tjit (sigma) One Sigma Clock Period Jitter Deviation from mean 70 ps 25 ps Note: External Crystal Connection. The external crystal should be connected in as close physical proximity to the VT98501 as possible. The crystal should be a fundamental mode, parallel resonant. Do not use third overtone. Decoupling capacitors of 0.01 µF and 0.1 µF should be connected between VDD and Ground. Capacitors should be mounted as close to the chip as possible. A 33Ω termination resistor may be mounted in series with the clock output in order to minimize ringing and reflections. Precision tuning of the crystal can be achieved by connecting a capacitor from pin X1 to ground and another from pin X2 to ground. The value of these capacitors is determined by the crystal load capacitance. The value can be determined using the following equation, where CL is the crystal load capacitance. Crystal capacitors (pf) = (CL - 5) x 2. For example, a crystal with a load capacitance of 16 pF should have 22 pF tuning capacitors. Figure 3. External Crystal Connection Block Diagram X2 Crystal XTAL OSC X1 CX2 C 33pF X1 CX1 CLK3 CLK 106.25MHz PLL CLOCK GEN. GEN External Crystal Load Capacitors OE Ordering Information Part Number VT98501S1 VT98501S1X VT98501/D 2001-03-05 Marking VT98501S1 VT98501S1 Shipping/Packaging Tubes Tape & Reel Page 4 No. of Pins 8 8 Package SOIC SOIC Temperature o o 0 C to +70 C o o 0 C to +70 C o o 0 C to +70 C MDST-0009-00 Vaishali Semiconductor 1300 White Oaks Road, Ste 200 Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063