Preliminary VT73127 27 MHz 3.3V VCXO with Output Enable Applications •= Crystal-driven clock source General Description The Vaishali VT73127 is a single-chip, low-jitter Voltage-Controlled-Crystal-Oscillator. The device accepts a 27 MHz, 20 pF crystal input, and produces a low jitter output at the same frequency. The output is enabled when OE is logic HIGH and goes into high impedance state when OE is logic LOW. A 0 to 3.0V control signal is used to fine tune the output clock frequency in the ±100ppm range. Features •= 3.3V operating voltage •= On-chip oscillator with 200 ppm pull range (±100 ppm) •= Uses inexpensive pullable crystals •= Active High output enable •= 12mA drive capability at TTL levels •= Die only Figure 1. Functional Block Diagram VDD1 VDD2 Load Cap Control VIN X2 Output Buffer 27 MHz Pullable Crystal Load Caps CLK Oscillator OE X1 GND GND Page 1 MDST-0012-02 www.vaishali.com Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063 2001-08-06 VT73127 Preliminary Figure 2. Pad Configuration VT73127/D X1 X2 1 9 VDD1 2 8 GND VIN 3 7 VDD2 GND 4 6 OE 5 CLK Table 1. Pad Description Pad Type X1 Name 1 Xi Crystal connection. Connect to a 27 MHz pullable crystal Description VDD1 2 P Core VDD. Connect to 3.3V VIN 3 I Tuning control input. Zero to 3.3V signal controls the frequency of the VCXO. GND 4 P Connect to ground. CLK 5 O Clock output OE 6 I Active HIGH output enable. When LOW, the output is held in a tri-state condition VDD2 7 P Output buffer VDD . Connect to 3.3V GND 8 P Connect to ground. X2 9 Xi Crystal connection. Connect to a 27 MHz pullable crystal. Legend: I = Input O = Output P = Power supply connection Xi = Crystal connections. Table 2. Absolute Maximum Ratings Parameter Conditions Supply voltage, VDD Referenced to GND Inputs and Clock Outputs Referenced to GND Soldering Temperature Max of 10 seconds Storage temperature Min Typ -0.5 -65 Max Units 7 V VDD+0.5 V 260 °C 150 °C Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. These ratings are stress specifications only and correct functional operation of the device at these or any other conditions above those listed in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect product reliability. Table 3. Operating Conditions Parameter Conditions Min Operating Voltage, VDD 3.0 Input High Voltage, VIH, X1 pin only 2.5 Input Low Voltage, VIL, X1 pin only Operating Temperature Input crystal accuracy 0 Typ 3.3 Max 3.6 Units V V 0.4 V 70 °C ±30 ppm Page 2 MDST-0012-02 www.vaishali.com Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063 2001-08-06 VT73127 VCXO control voltage, VIN Preliminary 0 3.3 V Page 3 MDST-0012-02 www.vaishali.com Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063 2001-08-06 VT73127 Preliminary Table 4. DC Electrical Characteristics TA = 0°C to +70°C, VDD = 3.0 V to 3.6 V Parameter Condition (1) Min Typ Max 2.4 Units Output High Voltage, VOH IOH=-12mA V Output Low Voltage, VOL IOL=12mA Operating Supply Current, IDD No Load 25 mA Short Circuit Current Each output ±85 mA 7 pF 0.4 Input Capacitance V Note: 1. Typical values are at VDD = 3.3V and 25°C Table 5. AC Electrical Characteristics TA = 0°C to +70°C, VDD = 3.0 V to 3.6 V Symbol Parameter Condition Min Typ Max 27 Units fosc Input Crystal Frequency tr Output Clock Rise Time 0.8 to 2.0V 1.5 ns tf Output Clock Fall Time 2.0 to 0.8V 1.5 ns tPZL Output Enable Time 6.5 ns tPZH (OE to CLK) tPLZ Output Disable Time 6.5 ns tPHZ (OE to CLK) tod Output Clock Duty Cycle 60 % tjit (pk – pk) Maximum Absolute Jitter 150 ps At VDD/2 40 MHz (Peak to Peak) 0V ≤VIN ≤ 3.3V Output pullability ±100 ppm Note: 1. Typical values are at VDD = 3.3V and 25°C Table 6 Pullable Crystal Specifications Parameter Correlation (Load) Capacitance Capacitance Ratio Symbol CL CO/C1 Value 20pF 240 max ESR 50 Ω max Initial Accuracy ±30ppm Temperature and Aging Stability ±50ppm Ordering Information VT73127 Part Number VT73127/D VT73127/DW Marking Shipping/Packaging Dice in waffle-pack Dice in wafer form No. of Pads Package Temperature o o 0 C to +70 C o o 0 C to +70 C Page 4 MDST-0012-02 www.vaishali.com Vaishali Semiconductor 747 Camden Avenue, Suite C Campbell CA 95008 Ph. 408.377.6060 Fax 408.377.6063 2001-08-06