Datasheet LTC6991 (Analog Devices) - 4

link to page 2 link to page 9 link to page 10 link to page 10 LTC6991
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. Test conditions are V+ = 2.25V to 5.5V, RST = 0V, DIVCODE = 0 to 15 (NDIV = 1 to 221), RSET = 50k to 800k, RLOAD =
∞
, CLOAD = 5pF unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Digital I/O
RST Pin Input Capacitance 2.5 pF RST Pin Input Current RST = 0V to V+ ±10 nA VIH High Level RST Pin Input Voltage (Note 6) l 0.7 • V+ V VIL Low Level RST Pin Input Voltage (Note 6) l 0.3 • V+ V IOUT(MAX) Output Current V+ = 2.7V to 5.5V ±20 mA VOH High Level Output Voltage (Note 7) V+ = 5.5V IOUT = –1mA l 5.45 5.48 V IOUT = –16mA l 4.84 5.15 V V+ = 3.3V IOUT = –1mA l 3.24 3.27 V IOUT = –10mA l 2.75 2.99 V V+ = 2.25V IOUT = –1mA l 2.17 2.21 V IOUT = –8mA l 1.58 1.88 V VOL Low Level Output Voltage (Note 7) V+ = 5.5V IOUT = 1mA l 0.02 0.04 V IOUT = 16mA l 0.26 0.54 V V+ = 3.3V IOUT = 1mA l 0.03 0.05 V IOUT = 10mA l 0.22 0.46 V V+ = 2.25V IOUT = 1mA l 0.03 0.07 V IOUT = 8mA l 0.26 0.54 V tRST Reset Propagation Delay V+ = 5.5V 16 ns V+ = 3.3V 24 ns V+ = 2.25V 40 ns tWIDTH Minimum Input Pulse Width V+ = 3.3V 5 ns tr Output Rise Time (Note 8) V+ = 5.5V 1.1 ns V+ = 3.3V 1.7 ns V+ = 2.25V 2.7 ns tf Output Fall Time (Note 8) V+ = 5.5V 1.0 ns V+ = 3.3V 1.6 ns V+ = 2.25V 2.4 ns
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 7:
To conform to the Logic IC Standard, current out of a pin is may cause permanent damage to the device. Exposure to any Absolute arbitrarily given a negative value. Maximum Rating condition for extended periods may affect device
Note 8:
Output rise and fall times are measured between the 10% and the reliability and lifetime. 90% power supply levels with 5pF output load. These specifications are
Note 2:
The LTC6991C is guaranteed functional over the operating based on characterization. temperature range of –40°C to 85°C.
Note 9:
Settling time is the amount of time required for the output to settle
Note 3:
The LTC6991C is guaranteed to meet specified performance from within ±1% of the final frequency after a 0.5× or 2× change in ISET . 0°C to 70°C. The LTC6991C is designed, characterized and expected to
Note 10:
Jitter is the ratio of the deviation of the period to the mean of the meet specified performance from –40°C to 85°C but it is not tested or period. This specification is based on characterization and is not 100% QA sampled at these temperatures. The LTC6991I is guaranteed to meet tested. specified performance from –40°C to 85°C. The LTC6991H is guaranteed
Note 11:
Long-term drift of silicon oscillators is primarily due to the to meet specified performance from –40°C to 125°C. The LTC6991MP is movement of ions and impurities within the silicon and is tested at 30°C guaranteed to meet specified performance from –55°C to 125°C. under otherwise nominal operating conditions. Long-term drift is specified
Note 4:
Frequency accuracy is defined as the deviation from the fOUT as ppm/√kHr due to the typically nonlinear nature of the drift. To calculate equation, assuming RSET is used to program the frequency. drift for a set time period, translate that time into thousands of hours, take
Note 5:
See Operation section, Table 1 and Figure 2 for a full explanation the square root and multiply by the typical drift number. For instance, a of how the DIV pin voltage selects the value of DIVCODE. year is 8.77kHr and would yield a drift of 266ppm at 90ppm/√kHr. Drift
Note 6:
The RST pin has hysteresis to accommodate slow rising or falling without power applied to the device may be approximated as 1/10th of the signals. The threshold voltages are proportional to V+. Typical values can drift with power, or 9ppm/√kHr for a 90ppm/√kHr device. be estimated at any supply voltage using VRST(RISING) ≈ 0.55 • V+ + 185mV and VRST(FALLING) ≈ 0.48 • V+ – 155mV. Rev. D 4 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts