PRELIMINARY DS76KHz 76.8 kHz TCXO www.dalsemi.com FEATURES PIN ASSIGNMENT A Accurate to ±7.5 ppm (-40°C to +85°C) Accurate to ±2 ppm (0°C to 40°C) Battery back up for continuous output VBAT operating voltage 2.7 to 5.5 volts (with VCC grounded) VCC operating voltage 4.5 to 5.5 volts Operating temperature range: COM: 0°C to 70°C IND: -40°C to +85°C No calibration required Low power consumption Surface mountable VCC: VBAT: 76KHz: GND: B C D 1 2 3 4 5 6 7 8 9 DS76KHz 36-Pin SMD (TOP VIEW) C2, C3, D2, D3 A4, A5, B4, B5 C4, C5, D4, D5 All Remaining Balls DESCRIPTION The DS76KHz is a temperature-compensated crystal oscillator (TCXO) with an output frequency of 76.8 kHz. This device is available in commercial and industrial temperature versions, DS76KHz and DS76KHz-N respectively. The DS76KHz requires four pins for operation: VCC, GND, VBAT and 76KHz OUT. See Figures 1, 2 and 3 for connection schemes. Power is applied via VCC and GND, while VBAT is used to maintain the 76KHz output in the absence of power. The output is accurate to ±7.5 ppm from -40°C to +85°C and ±2 ppm from 0°C to 40°C. The DS76KHz is packaged in a small 36-pin SMD, utilizing Ball Grid Array (BGA) technology, with dimensions 0.400 inches wide, 0.450 inches long, and 0.180 inches high. The recommended land pattern layout is shown on page 5. The additional board space required is negligible in most applications and therefore the recommended land pattern layout should be implemented on all new designs and future board revisions to satisfy applications requiring better accuracy. 1 of 5 050599 DS76KHz DELTA FREQUENCY vs TEMPERATURE POWER SUPPLY CONNECTIONS Figure 1.0 Figure 2.0 Figure 1.0 shows how the DS76KHz should be connected when using two power supplies. VCC should be between 4.5 and 5.5 volts while VBAT should be between 2.7 and 3.3 volts. Figure 2.0 shows how the DS76KHz can be used when only a single supply is available. VCC should be grounded and VBAT should then be held between 2.7 and 5.5 volts. The VBAT pin should be connected directly to a battery using no external components. Figure 2.0 illustrates how the DS76KHz can be used in a single supply system. DS76KHz CONNECTIONS VCC Figure 3.0 2 of 5 DS76KHz ABSOLUTE MAXIMUM RATINGS* Voltage on Any Pin Relative to Ground Operating Temperature Storage Temperature Soldering Temperature ∗ -3.0V to +7.0V 0°C to 70°C - Commercial -40°C to +85°C - Industrial -40°C to +85°C +260°C for 10 seconds (2 times max.) This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. The Dallas Semiconductor DS76KHz is built to the highest quality standards and manufactured for long term reliability. All Dallas Semiconductor devices are made using the same quality materials and manufacturing methods. However, the DS76KHz is not exposed to environmental stresses, such as burn-in, that some industrial applications require. For specific reliability information on this product, please contact the factory in Dallas at (972) 371-4448. RECOMMENDED DC OPERATING CONDITIONS PARAMETER Power Supply Voltage Battery Voltage SYMBOL VCC VBAT MIN 4.5 2.7 DC ELECTRICAL CHARACTERISTICS PARAMETER Active Supply Current Active Battery Current (VCC =0V, VBAT =3.3V) High Output Voltage IOH=-1.0 mA) Low Output Voltage (IOL =2.1 mA) Battery Switch Voltage SYMBOL ICC IBAT MIN VOH 2.4 TYP 150 1 VBAT UNITS V V NOTES 1 1, 7 UNITS µA µA NOTES 2, 8 3, 8 V 6 V 6 V (VCC =4.5V to 5.5V; -40°C to +85°C) MIN ∆f/V TW/T tCYC tH/tL tR tF tOSC MAX 180 4 0.4 VSW SYMBOL fOUT ∆f/fO MAX 5.5 3.3, 5.5 (VCC =4.5V to 5.5V; -40°C to +85°C) VOL AC TIMING CHARACTERISTICS PARAMETER Output Frequency Frequency Stability vs Temp (0°C to 40°C) (-40°C to +85°C) Frequency Stability vs Operating Voltage Duty Cycle Cycle Time High/Low Time Rise Time Fall Time Oscillator Start-Up Time TYP 5.0 3.0 (-40°C to +85°C) TYP 76.8 ±2.0 ±7.5 MAX ±7.5 ±1.0 45 3 of 5 50 13.021 6.31 325 75 150 UNITS kHz PPM NOTES ppm/V 55 % µs µs ns ns ms 4 4 4 4 4 DS76KHz NOTES: 1. All voltages are referenced to ground. 2. Typical values are at +25°C and nominal supplies. 3. This current is the active mode current sourced from the backup supply/battery. 4. These parameters are measured using a 15 pF load. 5. DS76KHz-N is tested over the industrial temperature range to meet the specifications above. 6. These parameters are measured with VCC on under nominal operating conditions. 7. When VCC is grounded VBAT can operate from 2.7V to 5.5V. Freq. stability will be affected in this operation, typically 1PPM/Volt above or below 3.0V. 8. These parameters are measured under no load conditions. The difference between ICC and IBAT is due to power switching circuitry. 9. Typical crystal aging is ±1 ppm/yr after reflow. 76KHz OUTPUT WAVEFORM MECHANICAL DIMENSIONS 4 of 5 DS76KHz RECOMMENDED LAND PATTERN LAYOUT (36-Pin BGA) 5 of 5