LTC6990 Linear Technology, LTC6990 Datasheet
LTC6990
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LTC6990 Summary of contents
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... It can be used as a fi xed-frequency or voltage-controlled oscillator (VCO). The LTC6990 is part of the TimerBlox™ family of versatile silicon timing devices. A single resistor, R nal master oscillator frequency. The output frequency ...
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... Specifi ed Temperature Range (Note 3) LTC6990C ................................................ 0°C to 70°C + ≤ 0.3V) LTC6990I .............................................–40°C to 85°C PIN LTC6990H .......................................... –40°C to 125°C Junction Temperature ........................................... 150°C Storage Temperature Range .................. –65°C to 150°C Lead Temperature (Soldering, 10sec) ................... 300°C 6 OUT 5 GND ...
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... DIV SET + V = 2.25V + R = ∞ 128 50k V = 5.5V L DIV SET + V = 2.25V + R = ∞ 128 800k V = 5.5V L DIV SET + V = 2.25V www.DataSheet4U.com LTC6990 + = 2.25V to 5.5V DIVCODE = MIN TYP MAX 0.488 1000 0.488 2000 ±0.8 ±1.5 l ±2.2 ±2.4 l ±3.2 l ±0.005 l 0.23 0.55 l 0.06 0.16 0.38 0.22 0.027 0.022 0.004 l ...
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... Note 2: The LTC6990C is guaranteed functional over the operating temperature range of –40°C to 85°C. Note 3: The LTC6990C is guaranteed to meet specifi ed performance from 0°C to 70°C. The LTC6990C is designed, characterized and expected to meet specifi ed performance from –40°C to 85°C but it is not tested or QA sampled at these temperatures. The LTC6990I is guaranteed to meet specifi ...
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... 50k, ÷1 SET 200 R SET 150 R = 50k, ÷128 SET 100 R = 800k, ÷1 SET 800k, ÷128 SET SUPPLY VOLTAGE (V) www.DataSheet4U.com LTC6990 + V = 3.3V, unless otherwise noted. Frequency Error vs Temperature 1 3.3V DIVCODE = 4 1.0 0.5 R SET 0.0 –0.5 R –1.0 –1.5 6 –50 – TEMPERATURE (°C) ...
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... LTC6990 TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Frequency, 5V 400 RECOMMENDED RANGE EXTENDED RANGE 350 300 250 200 ÷128 150 100 FREQUENCY (kHz) Supply Current vs OE Pin Voltage 200 T = 25° 800k SET 175 DIVCODE = 7 5V, OE FALLING 150 3.3V, OE FALLING 125 ...
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... G18 Frequency Modulation V CTRL 2V/DIV OUT 2V/DIV f OUT 50kHz/DIV 6990 G20 + V = 3.3V, DIVCODE = 200k, R SET f = 175kHz to 350kHz OUT www.DataSheet4U.com LTC6990 T = 25° 5pF LOAD SUPPLY VOLTAGE (V) 6990 G17 6990 G19 20μs/DIV 6990 G21 20μs/DIV = 464k VCO 6990p 7 ...
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... OUT (Pin 6/Pin 6): Oscillator Output. The OUT pin swings + from GND to V with an output resistance of approximately 30Ω. When driving an LED or other low-impedance load a series output resistor should be used to limit source/sink current to 20mA. www.DataSheet4U.com voltage. OE OUT LTC6990 + V + GND 0.1μF SET DIV ...
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... DIGITAL FILTER MASTER OSCILLATOR V 1μs SET t • MCLK MASTER 50k I SET < 500nA SET I SET + – SET 3 SET R SET www.DataSheet4U.com LTC6990 OE 1 Hi-Z BIT Hi-Z WHEN DISABLED OUT PROGRAMMABLE DIVIDER 6 ÷ 16, 32, 64, 128 t OUT Hi-Z OUTPUT UNTIL SETTLED POR 6990 BD 6990p 9 ...
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... LTC6990 OPERATION The LTC6990 is built around a master oscillator with a 1MHz maximum frequency. The oscillator is controlled by the SET pin current (I ) and voltage (V SET 1MHz • 50k conversion factor that is accurate to ±0.8% under typical conditions 1MHz • 50k • MASTER t MASTER A feedback loop maintains ± ...
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... Hi-Z BIT = 0.5•V INCREASING V DIV Figure 2. Frequency Range and Hi-Z Bit vs DIVCODE www.DataSheet4U.com LTC6990 R2 ( DIV Short ≤ 0.03125 ±0.015 102 0.09375 ±0.015 182 0.15625 ±0.015 280 0.21875 ±0.015 392 0.28125 ±0.015 523 0.34375 ± ...
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... Less than 100pF will not affect performance. Output Enable The OE pin controls the state of the LTC6990’s output as seen on the OUT pin. Pulling the OE pin high enables the oscillator output. Pulling it low disables the output. When ...
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... SET Figure 5. DIVCODE Change from Start-Up Time When power is fi rst applied to the LTC6990 the power-on reset (POR) circuit will initiate the start-up time, t The OUT pin is fl oated (high-impedance) during this time. The typical value for t depending on the master oscillator frequency (indepen- ...
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... LTC6990 APPLICATIONS INFORMATION OE OUT Figure 7. Start-Up Timing Diagram ( OUT Figure 8. Start-Up Timing Diagram ( OUT Figure 9. Start-Up Timing Diagram ( OUT Figure 10. Start-Up Timing Diagram ( Hi-Z 1/2 t OUT t t START OUT DIV OE Hi START MASTER OUT DIV OE Hi-Z t ENABLE ...
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... Hi-Z bit = 0, or simply remain fl oating if Hi Basic Fixed Frequency Operation The simplest and most accurate method to program the LTC6990 for fi xed frequency operation is to use a single resistor between the SET and GND pins. The design SET procedure is a simple two step process ...
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... LTC6990 APPLICATIONS INFORMATION Equation (2) can be re-written as shown below, where f is the output frequency when V CTRL frequency gain. Note that the gain is negative (the output frequency decreases as V increases). CTRL – K • V OUT (0V) VCO CTRL 1MHz • 50k (0V) N • ...
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... In this design example, with its wide 10:1 frequency range, the potential output frequency error due ranges from less than ±1% when ±36% when V 6990 F12 must be accounted for in the system design. www.DataSheet4U.com LTC6990 = 100kHz CTRL(MIN) = 10kHz CTRL(MAX) Value ...
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... VCO SET Figure 13 shows a design similar to the previous design example where the V 0.4V. This satisfi es the V and the design assures that the output frequency error due to V SET 10kHz TO 100kHz 3V OE OUT LTC6990 + GND V V SET SET DIV 3V 6990 F13 R + VCO ...
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... Figure 14. Digitally Controlled Oscillator with V The oscillator will still function with reduced accuracy in its extended range (see the Electrical Characteristics section). voltage, the The LTC6990 is designed to function normally for I CTRL and using low as 1.25μA. At approximately 500nA, the oscillator SET output will be frozen in its current state. For N variation and OUT will halt in a low state ...
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... The LTC6990 will respond to changes in I bandwidth of 0.4 • f (see Figure 15). This makes it easy OUT to stabilize a feedback loop around the LTC6990, since it does not introduce a low-frequency pole. Settling time depends on the master oscillator frequency. Following 0.5x step change in I frequency takes approximately six master clock cycles (6 • ...
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... APPLICATIONS INFORMATION SUPPLY BYPASSING AND PCB LAYOUT GUIDELINES The LTC6990 is a 2.2% accurate silicon oscillator when used in the appropriate manner. The part is simple to use and by following a few rules, the expected performance is easily achieved. The most important use issues involve adequate supply bypassing and proper PCB layout. ...
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... VCO2 26.1k OE OUT LTC6990 5V GND V D1 IN4148 – LT1490 SET DIV + 6990 TA03 R SET 826k Setting (Positive Frequency Control, f DIV OUT 10k LTC6990 5V GND V – R VCO 53.6k LT1490 SET DIV + 6990 TA04 R SET1 412k R SET2 412k www.DataSheet4U.com DIVCODE DAC CODE ...
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... R B 6990 TA06 392k 523k (Maximum Annoyance for Best Effect 10k OE OUT OFF LTC6990 + GND V 1M SET DIV 6990 TA07 392k 523k www.DataSheet4U.com LTC6990 5V 8Ω IN4004 2N2222 50k 5V PIEZO ALARM 4kHz 5V MURATA PKM29-3A0 PIEZO ALARM MURATA 5V PKM29-340 f = 4kHz 6990p 23 ...
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... COSINE 2.5V N S1A BP LP LTC1059 OR – + 1/2 LTC1060 – 2.5V 2k LT1004 1M 5V –2. – OUT LTC1440 REF + HYST 0.1μF 4.12k 1M www.DataSheet4U.com to 60kHz 3.3V MOC207M f OUT 412Ω CLOCK 5V OUT OE LTC6990 + V GND R1 R VCO 1M 267k FREQ DIV SET ADJ R2 R 6990 TA09 SET 280k 49.9k 6990p ...
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... THERMISTOR: VISHAY NTHS120601N2202J ≈ –1.4kHz per Microampere of Photo Diode Current, I OUT 1000pF 5V OE 24.9k LTC6990 GND 5V – 222k LT1677 SET SFH213 + 619k www.DataSheet4U.com LTC6990 ≈ 25kHz) OUT 5V f OUT OUT + DIV 6990 TA11 681k PD f OUT OUT + V 5V ...
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... LTC6990 PACKAGE DESCRIPTION 1.65 0.05 3.55 0.05 (2 SIDES) 2.15 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS PIN 1 BAR TOP MARK (SEE NOTE 6) 0.200 REF 26 DCB Package 6-Lead Plastic DFN (2mm × 3mm) (Reference LTC DWG # 05-08-1715) 0.70 0.05 PACKAGE OUTLINE 0.25 0.05 0.50 BSC 1.35 0.05 (2 SIDES 0.115 2.00 0.10 (2 SIDES 0.05 TYP 3.00 0.10 1.65 0.10 (2 SIDES) (2 SIDES) 0.75 0.05 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD NOTE: 1 ...
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... S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636) 1.22 REF 1.50 – 1.75 2.80 BSC 1.4 MIN (NOTE 4) 0.95 BSC 0.80 – 0.90 1.00 MAX 0.09 – 0.20 (NOTE 3) www.DataSheet4U.com LTC6990 2.90 BSC (NOTE 4) PIN ONE ID 0.30 – 0.45 6 PLCS (NOTE 3) 0.01 – 0.10 1.90 BSC S6 TSOT-23 0302 REV B 27 6990p ...
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... LTC6906/LTC6907 10kHz to 1MHz or 40kHz ThinSOT Silicon Oscillator LTC6930 Fixed Frequency Oscillator, 32.768kHz to 8.192MHz 28 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● Ultrasonic Frequency Sweep Generator f = 500kHz TO 31.25kHz OUT OE OUT LTC6990 + GND V C1 0.1μF SET DIV R 6990 TA13 SET1 74HC125 49. ...