CDP6872
January 1996
Low Power Crystal Oscillator
Description
The CDP6872 is a very low power crystal-controlled oscillators that can be externally programmed to operate between 10kHz and 10MHz. For normal operation it requires only the addition of a crystal. The part exhibits very high stability over a wide operating voltage and temperature range. The CDP6872 also features a disable mode that switches the output to a high impedance state. This feature is useful for minimizing power dissipation during standby and when multiple oscillator circuits are employed.
Features
• Single Supply Operation at 32kHz . . . . . . . 2.0V to 7.0V • Operating Frequency Range. . . . . . . . 10kHz to 10MHz • Supply Current at 32kHz . . . . . . . . . . . . . . . . . . . . . .5µA • Supply Current at 1MHz . . . . . . . . . . . . . . . . . . . .130µA • Drives 2 CMOS Loads • Only Requires an External Crystal for Operation
Applications
• Battery Powered Circuits • Remote Metering • Embedded Microprocessors
Ordering Information
PART NUMBER TEMPERATURE RANGE -40oC to +85oC -40oC to +85oC -40oC to +85oC PACKAGE 8 Lead Plastic DIP 8 Lead Plastic SOIC (N) DIE
CDP6872E • Palm Top/Notebook PC CDP6872M CDP6872H
Pinout
CDP6872 (PDIP, SOIC) TOP VIEW
Typical Application Circuit
VDD 0.1µf
VDD OSC IN OSC OUT VSS
1 2 3 4
8 7 6 5
ENABLE FREQ 2 FREQ 1 OUTPUT 32.768kHz CRYSTAL
1 2 CDP6872 3 4
8 7 6 5 32.768kHz CLOCK
32.768kHz MICROPOWER CLOCK OSCILLATOR
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. http://www.intersil.com or 407-727-9207 | Copyright © Intersil Corporation 1999
File Number
4069
1
CDP6872 Simplified Block Diagram
1 8 ENABLE EXTERNAL CRYSTAL VDD (NOTE 1)
OSC IN 2
RF
3 OSC OUT
VDD
15pF S1b VDD S1c
15pF VDD
VDD
VDD - 1.4V VDD - 2.2V VDD - 3.0V
S1a S2 S3 S4 VRN + -
OUTPUT LEVEL SHIFTER VRN 4 VSS 5 BUFFER
VDD - 3.8V IBIAS 1 OF 4 DECODE
BUFFER AMP
VDD P 6 FREQ 1 VDD (NOTE 1) 7 FREQ 2 RF (NOTE 1) IN P N
VDD
OUT
VRN OSCILLATOR
FREQUENCY SELECTION TRUTH TABLE ENABLE 1 1 1 1 0 NOTE: 1. Logic input pull-up resistors are constant current source of 0.4µA. FREQ 1 1 1 0 0 X FREQ 2 1 0 1 0 X SWITCH S1a, b, c S2 S3 S4 X OUTPUT RANGE 10kHz - 100kHz 100kHz - 1MHz 1MHz - 5MHz 5MHz - 10MHz+ High Impedance
2
Specifications CDP6872
Absolute Maximum Ratings
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.0V Voltage (any pin). . . . . . . . . . . . . . . . . . . . . . .VSS-0.3V to VDD+0.3V Junction Temperature (Plastic Package) . . . . . . . . . . . . . . . +150oC ESD Rating (Note 2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . >4000V Lead Temperature (Soldering 10s) . . . . . . . . . . . . . . . . . . . . +300oC (SOIC - Lead Tip Only)
Operating Conditions
Operating Temperature (Note 3) . . . . . . . . . . . . . . . . -40oC to +85oC Storage Temperature Range. . . . . . . . . . . . . . . . . . -65oC to +150oC
Thermal Information (Typical)
Thermal Resistance (oC/W) 8 Lead Plastic DIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Lead Plastic SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . θJA 125 170
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Electrical Specifications
VSS = GND, TA = +25oC, Unless Otherwise Specified VDD = 5V VDD = 3V MAX 7 MIN TYP MAX UNITS V
PARAMETER VDD Supply Range (fOSC = 32kHz) IDD Supply Current fOSC = 32kHz, EN = 0 Standby fOSC = 32kHz, CL = 10pF (Note 1), EN = 1, Freq1 = 1, Freq2 = 1 fOSC = 32kHz, CL = 40pF, EN = 1, Freq1 = 1, Freq2 = 1 fOSC = 1MHz, CL = 10pF (Note 1), EN = 1, Freq1 = 0, Freq2 = 1 fOSC = 1MHz, CL = 40pF, EN = 1, Freq1 = 0, Freq2 = 1 VOH Output High Voltage (IOUT = -1mA) VOL Output Low Voltage (IOUT = 1mA) IOH Output High Current (VOUT ≥ 4V) IOL Output Low Current (VOUT ≤ 0.4V) Three-State Leakage Current (VOUT = 0V, 5V, TA = 25oC, -40oC) (VOUT = 0V, 5V, TA = 85oC) IIN Enable, Freq1, Freq2 Input Current (VIN = VSS to VDD) VIH Input High Voltage Enable, Freq1, Freq2 VIL Input Low Voltage Enable, Freq1, Freq2 Enable Time (CL = 18pF, RL = 1kΩ) Disable Time (CL = 18pF, RL = 1kΩ) tR Output Rise Time (10% - 90%, fOSC = 32kHz, CL = 40pF) tF Output Fall Time (10% - 90%, fOSC = 32kHz, CL = 40pF) Duty Cycle (CL = 40pF) fOSC = 1MHz, Packaged Part Only (Note 4) Duty Cycle (CL = 40pF) fOSC = 32kHz, (See Typical Curves) Frequency Stability vs. Supply Voltage (fOSC = 32kHz, VDD = 5V, CL=10pF) Frequency Stability vs. Temperature (fOSC = 32kHz, VDD = 5V, CL=10pF) Frequency Stability vs. Load (fOSC = 32kHz, VDD = 5V, CL=10pF) NOTES: 1. 2. 3. 4.
MIN 2
TYP 5
4.0 5.0
5.0 5.2 10 130 270 4.9 0.07 -10 10.0
9.0 10.2 15 200 350 0.4 -5 -
-
3.6 6.5 90 180 2.8 0.1 -
6.1 9 180 270 -
µA µA µA µA µA V V mA mA
2.0 40 -
0.1 10 0.4 800 90 12 12 54 41 1 0.1 0.01
1.0 0.8 25 25 60 -
-
12 14 44 -
-
nA nA µA V V ns ns ns ns % % ppm/V ppm/oC ppm/pF
Calculated using the equation IDD = IDD (No Load) + (VDD) (fOSC)(CL) Human body model. This product is production tested at +25oC only. Duty cycle will vary with supply voltage, oscillation frequency, and parasitic capacitance on the crystal pins.
3
CDP6872 Test Circuits
0.1µF +5V
1VP-P
1 2
8 ENABLE 7 FREQ 2 CDP6872 6 FREQ 1 5 CL VOUT 18pF
section of the circuit. The use of a current source in the reference string allows for wide supply variation with minimal effect on performance. The reduced operating voltage of the oscillator section reduces power consumption and limits transconductance and bandwidth to the frequency range selected. For frequencies at the edge of a range, the higher range may provide better performance. The OSC OUT waveform on pin 3 is squared up through a series of inverters to the output drive stage. The Enable function is implemented with a NAND gate in the inverter string, gating the signal to the level shifter and output stage. Also during Disable the output is set to a high impedance state useful for minimizing power during standby and when multiple oscillators are OR'd to a single node.
50Ω
1000pF
3 4
FIGURE 1.
Design Considerations
The low power CMOS transistors are designed to consume power mostly during transitions. Keeping these transitions short requires a good decoupling capacitor as close as possible to the supply pins 1 and 4. A ceramic 0.1µF is recommended. Additional supply decoupling on the circuit board with 1µF to 10µF will further reduce overshoot, ringing and power consumption. The CDP6872, when compared to a crystal and inverter alone, will speed clock transition times, reducing power consumption of all CMOS circuitry run from that clock. Power consumption may be further reduced by minimizing the capacitance on moving nodes. The majority of the power will be used in the output stage driving the load. Minimizing the load and parasitic capacitance on the output, pin 5, will play the major role in minimizing supply current. A secondary source of wasted supply current is parasitic or crystal load capacitance on pins 2 and 3. The CDP6872 is designed to work with most available crystals in its frequency range with no external components required. Two 15pF capacitors are internally switched onto crystal pins 2 and 3 to compensate the oscillator in the 10kHz to 100kHz frequency range. The supply current of the CDP6872 may be approximately calculated from the equation: IDD = IDD(Disabled) + VDD × FOSC × CL where: IDD = Total supply current VDD = Total voltage from VDD (pin1) to VSS (pin4) FOSC = Frequency of Oscillation CL = Output (pin5) load capacitance
In production the CDP6872 is tested with a 32kHz and a 1MHz crystal. However for characterization purposes data was taken using a sinewave generator as the frequency determining element, as shown in Figure 1. The 1VP-P input is a smaller amplitude than what a typical crystal would generate so the transitions are slower. In general the Generator data will show a “worst case” number for IDD, duty cycle, and rise/fall time. The Generator test method is useful for testing a variety of frequencies quickly and provides curves which can be used for understanding performance trends. Data for the CDP6872 using crystals has also been taken. This data has been overlaid onto the generator data to provide a reference for comparison.
Theory of Operation
The CDP6872 is a Pierce Oscillator optimized for low power consumption, requiring no external components except for a bypass capacitor and a Parallel Mode Crystal. The Simplified Block Diagram shows the Crystal attached to pins 2 and 3, the Oscillator input and output. The crystal drive circuitry is detailed showing the simple CMOS inverter stage and the P-channel device being used as biasing resistor RF . The inverter will operate mostly in its linear region increasing the amplitude of the oscillation until limited by its transconductance and voltage rails, VDD and VRN. The inverter is self biasing using RF to center the oscillating waveform at the input threshold. Do not interfere with this bias function with external loads or excessive leakage on pin 2. Nominal value for RF is 17MΩ in the lowest frequency range to 7MΩ in the highest frequency range. The CDP6872 optimizes its power for 4 frequency ranges selected by digital inputs Freq1 and Freq2 as shown in the Block Diagram. Internal pull up resistors (constant current 0.4µA) on Enable, Freq1 and Freq2 allow the user simply to leave one or all digital inputs not connected for a corresponding “1” state. All digital inputs may be left open for 10kHz to 100kHz operation. A current source develops 4 selectable reference voltages through series resistors. The selected voltage, VRN, is buffered and used as the negative supply rail for the oscillator
Example #1: VDD = 5V, FOSC = 100kHz, CL = 30pF IDD(Disabled) = 4.5µA (Figure 10) IDD = 4.5µA + (5V)(100kHz)(30pF) = 19.5µA Measured IDD = 20.3µA Example #2: VDD = 5V, FOSC = 5MHz, CL = 30pF IDD(Disabled) = 75µA (Figure 9) IDD = 75µA + (5V)(5MHz)(30pF) = 825µA Measured IDD = 809µA
4
CDP6872 Crystal Selection
For general purpose applications, a Parallel Mode Crystal is a good choice for use with the CDP6872. However for applications where a precision frequency is required, the designer needs to consider other factors. Crystals are available in two types or modes of oscillation, Series and Parallel. Series Mode crystals are manufactured to operate at a specified frequency with zero load capacitance and appear as a near resistive impedance when oscillating. Parallel Mode crystals are manufactured to operate with a specific capacitive load in series, causing the crystal to operate at a more inductive impedance to cancel the load capacitor. Loading a crystal with a different capacitance will “pull” the frequency off its value. The CDP6872 has 4 operating frequency ranges. The higher three ranges do not add any loading capacitance to the oscillator circuit. The lowest range, 10kHz to 100kHz, automatically switches in two 15pF capacitors onto OSC IN and OSC OUT to eliminate potential start-up problems. These capacitors create an effective crystal loading capacitor equal to the series combination of these two capacitors. For the CDP6872, in the lowest range, the effective loading capacitance is 7.5pF. Therefore the choice for a crystal, in this range, should be a Parallel Mode crystal that requires a 7.5pF load. In the higher 3 frequency ranges, the capacitance on OSC IN and OSC OUT will be determined by package and layout parasitics, typically 4 to 5pF. Ideally the choice for crystal should be a Parallel Mode set for 2.5pF load. A crystal manufactured for a different load will be “pulled” from its nominal frequency (see Crystal Pullability).
+5V
Frequency Fine Tuning
Two Methods will be discussed for fine adjustment of the crystal frequency. The first and preferred method (Figure 2), provides better frequency accuracy and oscillator stability than method two (Figure 3). Method one also eliminates start-up problems sometimes encountered with 32kHz tuning fork crystals. For best oscillator performance, two conditions must be met: the capacitive load must be matched to both the inverter and crystal to provide ideal conditions for oscillation, and the frequency of the oscillator must be adjustable to the desired frequency. In Method two these two goals can be at odds with each other; either the oscillator is trimmed to frequency by de-tuning the load circuit, or stability is increased at the expense of absolute frequency accuracy. Method one allows these two conditions to be met independently. The two fixed capacitors, C1 and C2, provide the optimum load to the oscillator and crystal. C3 adjusts the frequency at which the circuit oscillates without appreciably changing the load (and thus the stability) of the system. Once a value for C3 has been determined for the particular type of crystal being used, it could be replaced with a fixed capacitor. For the most precise control over oscillator frequency, C3 should remain adjustable. This three capacitor tuning method will be more accurate and stable than method two and is recommended for 32kHz tuning fork crystals; without it they may leap into an overtone mode when power is initially applied. Method two has been used for many years and may be preferred in applications where cost or space is critical. Note that in both cases the crystal loading capacitors are connected between the oscillator and VDD; do not use VSS as an AC ground. The Simplified Block Diagram shows that the oscillating inverter does not directly connect to VSS but is referenced to VDD and VRN. Therefore VDD is the best AC ground available.
+5V
C1
C2
XTAL 2 OSC IN
C3 3 OSC OUT 1 VDD C1 + CDP6872 VREG XTAL 2 OSC IN 3 OSC OUT 1 VDD + CDP6872 C2
FIGURE 2.
VREG
FIGURE 3.
5
CDP6872
Typical values of the capacitors in Figure 2 are shown below. Some trial and error may be required before the best combination is determined. The values listed are total capacitance including parasitic or other sources. Remember that in the 10kHz to 100kHz frequency range setting the CDP6872 switches in two internal 15pF capacitors.
CRYSTAL FREQUENCY 32kHz 1MHz 2MHz 4MHz LOAD CAPS C1, C2 33pF 33pF 25pF 22pF TRIMMER CAP C3 5-50pF 5-50pF 5-50pF 5-100pF
Layout Considerations
Due to the extremely low current (and therefore high impedance) the circuit board layout of the CDP6872 must be given special attention. Stray capacitance should be minimized. Keep the oscillator traces on a single layer of the PCB. Avoid putting a ground plane above or below this layer. The traces between the crystal, the capacitors, and the OSC pins should be as short as possible. Completely surround the oscillator components with a thick trace of VDD to minimize coupling with any digital signals. The final assembly must be free from contaminants such as solder flux, moisture, or any other potential source of leakage. A good solder mask will help keep the traces free of moisture and contamination over time.
Further Reading
Al Little “HA7210 Low Power Oscillator: Micropower Clock Oscillator and Op Amps Provide System Shutdown for Battery Circuits”. Intersil Application Note AN9317. Robert Rood “Improving Start-Up Time at 32KHz for the HA7210 Low Power Crystal Oscillator”. Intersil Application Note AN9334. S. S. Eaton “Timekeeping Advances Through COS/MOS Technology”. Intersil Application Note ICAN-6086. E. A. Vittoz et. al. “High-Performance Crystal Oscillator circuits: Theory and Application”. IEEE Journal of Solid-State Circuits, Vol. 23, No3, June 1988, pp774-783.
Crystal Pullability
Figure 4 shows the basic equivalent circuit for a crystal and its loading circuit.
VDD C2 CM LM RM
C1
C0 2 OSC IN 3 OSC OUT
M. A. Unkrich et. al. “Conditions for Start-Up in Crystal Oscillators”. IEEE Journal of Solid-State Circuits, Vol. 17, No1, Feb. 1982, pp87-90. Marvin E. Frerking “Crystal Oscillator Design and Temperature Compensation”. New York: Van Nostrand-Reinhold, 1978. Pierce Oscillators Discussed pp56-75.
FIGURE 4.
Where:
CM = Motional Capacitance LM = Motional Inductance RM = Motional Resistance C0 = Shunt Capacitance 1 = ---------------------------- = Equivalent Crystal Load C CL 1 1 ------- + ------- C C 1 2
If loading capacitance is connected to a Series Mode Crystal, the new Parallel Mode frequency of resonance may be calculated with the following equation: F =F C M 1 + -----------------------------------C +C 2 CL 0
P
S
Where:
FP = Parallel Mode Resonant Frequency FS = Series Mode Resonant Frequency
In a similar way, the Series Mode resonant frequency may be calculated from a Parallel Mode crystal and then you may calculate how much the frequency will “pull” with a new load.
6
CDP6872 Die Characteristics
DIE DIMENSIONS: 68 x 64 x 14 ± 1mils METALLIZATION: Type: Si - Al Thickness: 10kÅ ± 1kÅ GLASSIVATION: Type: Nitride (Si3N4) Over Silox (SiO2, 3% Phos) Silox Thickness: 7kÅ ± 1kÅ Nitride Thickness: 8kÅ ± 1kÅ DIE ATTACH: Material: Silver Epoxy - Plastic DIP and SOIC SUBSTRATE POTENTIAL: VSS
Metallization Mask Layout
CDP6872
(8) ENABLE
(1) VDD
(7) FREQ 2
CRYSTAL (2)
CRYSTAL (3)
(6) FREQ 1
VSS (4)
7
OUTPUT (5)
CDP6872 Typical Performance Curves
CL = 40pF, FOSC = 5MHz, VDD = 5V, VSS = GND CL = 18pF, FOSC = 5MHz, VDD = 5V, VSS = GND
1.0V/DIV.
20.0ns/DIV.
1.0V/DIV.
20.0ns/DIV.
FIGURE 5. OUTPUT WAVEFORM (CL = 40pF)
1050 FIN = 5MHz, EN = 1, F1 = 0, F2 = 0, CL = 30pF, VCC = 5V 1000 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 25 24 26
FIGURE 6. OUTPUT WAVEFORM (CL = 18pF)
EN = 1, F1 = 1, F2 = 1, FIN = 100kHz, CL = 30pF, VCC = 5V
950 GENERATOR† (1VP-P) 900
GENERATOR† (1VP-P) 23 22 21 20 XTAL AT +25oC 19 18 -100
850 XTAL AT 800 +25oC
750 -100
-50
0
50
100
150
-50
0
50 (oC)
100
150
TEMPERATURE (oC)
TEMPERATURE
FIGURE 7. SUPPLY CURRENT vs TEMPERATURE
350 FIN = 5MHz, EN = 0, F1 = 0, F2 = 0, VCC = 5V 300 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 250 GENERATOR† (1VP-P) 200 150 100 50 0 -100 XTAL AT +25oC
FIGURE 8. SUPPLY CURRENT vs TEMPERATURE
7.5 EN = 0, F1 = 1, F2 = 1, FIN = 100kHz, VCC = 5V 7 6.5 6 5.5 5 XTAL AT +25oC 4.5 4 -100
GENERATOR† (1VP-P)
-50
0
50
o
100
150
-50
0
50
100
150
TEMPERATURE ( C)
TEMPERATURE (oC)
FIGURE 9. DISABLE SUPPLY CURRENT vs TEMPERATURE
FIGURE 10. DISABLE SUPPLY CURRENT vs TEMPERATURE
† Refer to Test Circuit (Figure 1).
8
CDP6872 Typical Performance Curves
3000 EN = 1, F1 = 0, F2 = 0, CL = 18pF, GENERATOR† (1VP-P) 2500 SUPPLY CURRENT (µA) VCC = +8V 2000 SUPPLY CURRENT (µA) 1200 VCC = +8V 1000 800 600 VCC = +3V 400 200 0 4 5 6 7 8 9 10 11 0 1 2 3 4 5 6 FREQUENCY (MHz) FREQUENCY (MHz)
(Continued)
1400 EN = 1, F1 = 0, F2 =1, CL = 18pF, GENERATOR† (1VP-P)
1500 VCC = +5V
VCC = +5V
1000
500 0
FIGURE 11. SUPPLY CURRENT vs FREQUENCY
300 EN = 1, F1 = 1, F2 = 0, CL = 18pF, GENERATOR† (1VP-P) 250 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) VCC = +8V 200 VCC = +5V 150 40 50
FIGURE 12. SUPPLY CURRENT vs FREQUENCY
EN = 1, F1 = 0, F2 =1, CL = 18pF, GENERATOR† (1VP-P)
VCC = +8V 30
20
VCC = +5V
100 VCC = +3V 50 0 0 100 200 300 400 500 600 700 800 900 1000 1100 FREQUENCY (kHz)
10 VCC = +3V 0
0
10
20
30
40
50
60
70
80
90
100
110
FREQUENCY (kHz)
FIGURE 13. SUPPLY CURRENT vs FREQUENCY
EN = 0, F1 = 0, F2 = 0, CL = 18pF, GENERATOR† (1VP-P) 250 VCC = +8V SUPPLY CURRENT (µA) 200 VCC = +5V 150 SUPPLY CURRENT (µA) 120 110 100 90 80 70 60 50 40 30 4 5 6 7 8 9 10 11 FREQUENCY (MHz)
FIGURE 14. SUPPLY CURRENT vs FREQUENCY
EN = 0, F1 = 0, F2 = 1, CL = 18pF, GENERATOR† (1VP-P) VCC = +8V
VCC = +5V
100
50 VCC = +3V 0
VCC = +3V
0
1
2
3
4
5
6
FREQUENCY (MHz)
FIGURE 15. DISABLED SUPPLY CURRENT vs FREQUENCY
FIGURE 16. DISABLE SUPPLY CURRENT vs FREQUENCY
† Refer to Test Circuit (Figure 1).
9
CDP6872 Typical Performance Curves
35 VCC = +8V SUPPLY CURRENT (µA) 30 VCC = +5V 25 20 15 10 3 5 0 100 200 300 400 500 600 700 800 900 1000 1100 FREQUENCY (kHz) 2 0 10 20 30 40 50 60 70 80 90 100 110 FREQUENCY (kHz) SUPPLY CURRENT (µA) 9 8 7 6 5 4 VCC = +3V VCC = +5V
(Continued)
EN = 0, F1 = 1, F2 = 1, CL = 18pF, GENERATOR† (1VP-P) 11 10 VCC = +8V
EN = 0, F1 = 1, F2 = 0, CL = 18pF, GENERATOR† (1VP-P)
VCC = +3V
FIGURE 17. DISABLE SUPPLY CURRENT vs FREQUENCY
EN = 1, F1 = 0, F2 = 0, VCC = +5V, GENERATOR† (1VP-P)
FIGURE 18. DISABLE SUPPLY CURRENT vs FREQUENCY
EN = 1, F1 = 0, F2 = 1, VCC = +5V, GENERATOR† (1VP-P) 1400 CL = 40pF 1200 SUPPLY CURRENT (µA) 1000 800 600 400 200 CL = 18pF
3000
CL = 40pF 2500 SUPPLY CURRENT (µA)
2000
1500 CL = 18pF 1000
500
0 4 5 6 7 8 9 10 11 0 1 2 3 4 5 6 FREQUENCY (MHz) FREQUENCY (MHz)
FIGURE 19. SUPPLY CURRENT vs FREQUENCY
EN = 1, F1 = 1, F2 = 0, VCC = +5V, GENERATOR† (1VP-P) 300 CL = 40pF SUPPLY CURRENT (µA) 250 SUPPLY CURRENT (µA)
FIGURE 20. SUPPLY CURRENT vs FREQUENCY
EN = 1, F1 = 1, F2 = 1, VCC = +5V, GENERATOR† (1VP-P) 35 CL = 40pF 30 25 20 15 10 5 0 0 10 20 30 40 50 60 70 80 FREQUENCY (kHz) 90 100 110 CL = 18pF
200
150 CL = 18pF 100
50 0 0 100 200 300 400 500 600 700 800 900 1000 1100 FREQUENCY (kHz)
FIGURE 21. SUPPLY CURRENT vs FREQUENCY
FIGURE 22. SUPPLY CURRENT vs FREQUENCY
† Refer to Test Circuit (Figure 1).
10
CDP6872 Typical Performance Curves
60
(Continued)
FIN = 100kHz, F1 = 1, F2 = 1, CL = 30pF, VCC = 5V 70 GENERATOR† (1VP-P)
FIN = 5MHz, F1 = 0, F2 = 0, CL = 30pF, VCC = 5V
55 DUTY CYCLE (%) DUTY CYCLE (%) XTAL AT +25oC 50
60 XTAL AT +25oC
50
45
40
40 GENERATOR† (1VP-P) 35 30 -100
30
20 10 -100
-50
0
50
100
150
-50
0
50
100
150
TEMPERATURE (oC)
TEMPERATURE (oC)
FIGURE 23. DUTY CYCLE vs TEMPERATURE
F1 = F2 = 0, VDD = 5V, CL = 18pF, C1 = C2 = 0 DATA COLLECTED USING CRYSTALS AT EACH FREQUENCY 65 60
FIGURE 24. DUTY CYCLE vs TEMPERATURE
F1 = 0, F2 = 1, VDD = 5V, CL = 18pF, C1 = C2 = 0 DATA COLLECTED USING CRYSTALS AT EACH FREQUENCY
70
70
65 DUTY CYCLE (%) DUTY CYCLE (%) F1 = 0, F2 = 0 RECOMMENDED FOR 5MHz TO 10MHz RANGE 45 0 5 10 FREQUENCY (MHz) 15 20
60
55
55
50 45 F1 = 0, F2 = 1 RECOMMENDED FOR 1MHz TO 5MHz RANGE 40 0 1 2 3 4 5 6 FREQUENCY (MHz) 7 8 9
50
FIGURE 25. DUTY CYCLE vs FREQUENCY
F1 = 1, F2 = 0, VDD = 5V, CL = 18pF, C1 = C2 = 0 65 DATA COLLECTED USING CRYSTALS AT EACH FREQUENCY DUTY CYCLE (%)
FIGURE 26. DUTY CYCLE vs FREQUENCY
F1 = F2 = 1, VDD = 5V, CL = 18pF, C1 = C2 = 0 DATA COLLECTED USING CRYSTALS AT EACH FREQUENCY
47 46 45 44 43 42
DUTY CYCLE (%)
60
55
50
45 41 F1 = 1, F2 = 0 RECOMMENDED FOR 100kHz TO 1MHz RANGE 40 0 500 1000 1500 2000 2500 3000 3500 FREQUENCY (kHz) 40 0 50 100 FREQUENCY (kHz) 150 200 F1 = 1, F2 = 1 RECOMMENDED FOR 10kHz TO 100kHz RANGE
FIGURE 27. DUTY CYCLE vs FREQUENCY
FIGURE 28. DUTY CYCLE vs FREQUENCY
† Refer to Test Circuit (Figure 1).
11
CDP6872 Typical Performance Curves
30 25 FREQUENCY CHANGE (PPM) 20 15 10 5 0 -5 -10 -15 -20 2 DEVIATION FROM 5.0V FREQUENCY 4 VDD SUPPLY VOLTAGE (V) 6 0 -100 -50 0 50 TEMPERATURE (oC) 100 150 32kHz 1MHz 5MHz 10MHz
(Continued)
VCC = 5V, CL = 30pF, GENERATOR† (1VP-P) 6
EDGE JITTER (% OF PERIOD)
5
4
FIN = 5MHz, F1 = 0, F2 = 0
3
2
1
FIN = 100kHz, F1 = 1, F2 = 1
FIGURE 29. FREQUENCY CHANGE vs VDD
FIN = 5MHz, F1 = 0, F2 = 0, CL = 30pF, VCC = 5V 13 12 11 RISE/FALL TIME (ns) 10 9 8 7 6 5 4 3 2 -100 -50 0 50 (oC) 100 150 Tr GENERATOR† (1VP-P) Tf XTAL AT +25oC Tr XTAL AT +25oC RISE/FALL TIME (ns) Tf GENERATOR† (1VP-P) 12 11 10 9
FIGURE 30. EDGE JITTER vs TEMPERATURE
FIN = 100kHz, F1 = 1, F2 = 1, CL = 30pF, VCC = 5V Tf GENERATOR† (1VP-P)
8 Tr GENERATOR† (1VP-P) 7 6 5 4 3 2 -100 -50 0 50
Tf XTAL AT +25oC
Tr XTAL AT +25oC
100
150
TEMPERATURE
TEMPERATURE (oC)
FIGURE 31. RISE/FALL TIME vs TEMPERATURE
VCC = 5V, GENERATOR† (1VP-P) 30 Tf (FIN = 100kHz) RISE/FALL TIME (ns) RISE/FALL TIME (ns) 25 Tf (FIN = 5MHz) 20 Tr (FIN = 5MHz) Tr (FIN = 100kHz) 15 15 14 13 12 11 10 9 8 7 10 5 10 6 5 20 30 40 50 60 CL (pF) 70 80 90 100 110 4
FIGURE 32. RISE/FALL TIME vs TEMPERATURE
CL = 18pF, GENERATOR† (1VP-P) Tf (FIN = 5MHz) Tf (FIN = 100kHz) Tr (FIN = 5MHz) Tr (FIN = 100kHz)
2
3
4
5
6
7
8
9
VCC (+VOLTS)
FIGURE 33. RISE/FALL TIME vs CL
FIGURE 34. RISE/FALL TIME vs VCC
† Refer to Test Circuit (Figure 1).
12
CDP6872 Typical Performance Curves
VDD = 5V, VSS = GND 620 580 TRANSCONDUCTANCE (µA/V) 540 500 460 420 380 340 300 260 10K 2 50Ω 3 CDP6872 100Ω 1000pF 1µF 178o PHASE (DEGREES) 180 170 160 150 140 10M 436.5µA/V F1 = 0, F2 = 0 TRANSCONDUCTANCE (µA/V)
(Continued)
VDD = 5V, VSS = GND F1 = 0, F2 = 1
500 460 420 380 340
311.6µA/V
260 1000pF 2 50Ω
1µF 3
177o 100Ω
170 160 150 140 130 10M
CDP6872
100K 1M FREQUENCY (Hz)
10K
100K 1M FREQUENCY (Hz)
FIGURE 35. TRANSCONDUCTANCE vs FREQUENCY
FIGURE 36. TRANSCONDUCTANCE vs FREQUENCY
240 220 TRANSCONDUCTANCE (µA/V) 200 180 160
VDD = 5V, VSS = GND F1 = 1, F2 = 0 TRANSCONDUCTANCE (µA/V)
VDD = 5V, VSS = GND 20 15 10 5 0 166o 1µF 3 100Ω CDP6872 130 120 110 1M 180 PHASE (DEGREES) 170 160 1000pF 2 50Ω 150 140 F1 = 1, F2 = 1 6.56µA/V
156.7µA/V
120 100
1000pF 2 50Ω 3
1µF 100Ω
170 160 150 140 130 10M
CDP6872
PHASE (DEGREES)
140
176.6o
180
10K
100K 1M FREQUENCY (Hz)
10K
100K FREQUENCY (Hz)
FIGURE 37. TRANSCONDUCTANCE vs FREQUENCY
FIGURE 38. TRANSCONDUCTANCE vs FREQUENCY
F1 = F2 = 1, VDD = 5V, CL = 18pF, TA = 25oC, FOSC = 32.768kHz 60
55 DUTY CYCLE (%)
EPSON PART # C-001R32.768K-A
50 XTAL 45 NDK PART # MX-38 2 OSC IN RS 3 OSC OUT CDP6872 35 0 20 40 60 RS (kΩ) 80 100 120
40
FIGURE 39. DUTY CYCLE vs RS at 32kHz NOTE: Figure 39 (Duty Cycle vs RS at 32kHz) should only be used for 32kHz crystals. RS may be used at other frequencies to adjust Duty Cycle but experimentation will be required to find an appropriate value. The RS value will be proportional to the effective series resistance of the crystal being used.
13
PHASE (DEGREES)
300
180
CDP6872 Dual-In-Line Plastic Packages (PDIP)
E8.3 (JEDEC MS-001-BA ISSUE D)
N E1 INDEX AREA 12 3 N/2 -B-AD BASE PLANE SEATING PLANE D1 B1 B 0.010 (0.25) M D1 A1 A2 L A C L E
8 LEAD DUAL-IN-LINE PLASTIC PACKAGE INCHES SYMBOL A A1 A2 B B1 C D D1 E E1
C
MILLIMETERS MIN 0.39 2.93 0.356 1.15 0.204 9.01 0.13 7.62 6.10 MAX 5.33 4.95 0.558 1.77 0.355 10.16 8.25 7.11 NOTES 4 4 8, 10 5 5 6 5 6 7 4 9 Rev. 0 12/93
MIN 0.015 0.115 0.014 0.045 0.008 0.355 0.005 0.300 0.240
MAX 0.210 0.195 0.022 0.070 0.014 0.400 0.325 0.280
-C-
eA eC eB
e
C A BS
NOTES: 1. Controlling Dimensions: INCH. In case of conflict between English and Metric dimensions, the inch dimensions control. 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. 3. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of Publication No. 95. 4. Dimensions A, A1 and L are measured with the package seated in JEDEC seating plane gauge GS-3. 5. D, D1, and E1 dimensions do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010 inch (0.25mm). 6. E and eA are measured with the leads constrained to be perpendicular to datum -C- . 7. eB and eC are measured at the lead tips with the leads unconstrained. eC must be zero or greater. 8. B1 maximum dimensions do not include dambar protrusions. Dambar protrusions shall not exceed 0.010 inch (0.25mm). 9. N is the maximum number of terminal positions. 10. Corner leads (1, N, N/2 and N/2 + 1) for E8.3, E16.3, E18.3, E28.3, E42.6 will have a B1 dimension of 0.030 - 0.045 inch (0.76 - 1.14mm).
e eA eB L N
0.100 BSC 0.300 BSC 0.115 8 0.430 0.150 -
2.54 BSC 7.62 BSC 10.92 3.81 8
2.93
14
CDP6872 Small Outline Plastic Packages (SOIC)
N INDEX AREA E -B1 2 3 SEATING PLANE -AD -CA h x 45o H 0.25(0.010) M BM
M8.15 (JEDEC MS-012-AA ISSUE C) 8 LEAD NARROW BODY SMALL OUTLINE PLASTIC PACKAGE
INCHES SYMBOL A A1
L
MILLIMETERS MIN 1.35 0.10 0.33 0.19 4.80 3.80 MAX 1.75 0.25 0.51 0.25 5.00 4.00 NOTES 9 3 4 5 6 7 8o Rev. 0 12/93
MIN 0.0532 0.0040 0.013 0.0075 0.1890 0.1497
MAX 0.0688 0.0098 0.020 0.0098 0.1968 0.1574
B C D E
α
A1 0.10(0.004) C
e H h L N
0.050 BSC 0.2284 0.0099 0.016 8 0o 8o 0.2440 0.0196 0.050
1.27 BSC 5.80 0.25 0.40 8 0o 6.20 0.50 1.27
e
B 0.25(0.010) M C AM BS
NOTES: 1. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of Publication Number 95. 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. 3. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006 inch) per side. 4. Dimension “E” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm (0.010 inch) per side. 5. The chamfer on the body is optional. If it is not present, a visual index feature must be located within the crosshatched area. 6. “L” is the length of terminal for soldering to a substrate. 7. “N” is the number of terminal positions. 8. Terminal numbers are shown for reference only. 9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater above the seating plane, shall not exceed a maximum value of 0.61mm (0.024 inch). 10. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact.
α
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Spec Number 15