Datasheet LT6657 (Analog Devices) - 4

LT6657
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. The test conditions are VIN = VOUT  + 0.5V, VSHDN = 1.6V, IOUT = 0, CIN = 0.1µF, COUT = 1µF. For LT6657-1.25 VSHDN = 1.45V, CIN = 1µF, COUT = 2.7µF, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
Shutdown Pin (SHDN) All, Except LT6657-1.25 Logic High Input Voltage l 1.6 V Logic High Input Current, SHDN = 1.6V l 0.7 2 µV Logic Low Input Voltage l 0.8 V Logic Low Input Current, SHDN = 0.8V l 0.2 1 µV LT6657-1.25V Logic High Input Voltage l 1.45 V Logic High Input Current, SHDN = 1.45V l 0.5 2 µV Logic Low Input Voltage l 0.8 V Logic Low Input Current, SHDN = 0.8V l 0.05 1 µV Supply Current in Shutdown SHDN = 0.4V l 0.01 4 µA SHDN = 0.8V l 2.0 20 µA Supply Current No Load 1.2 1.8 mA l 2.3 mA Output Short-Circuit Current Short VOUT to GND 15 mA Short VOUT to VIN 16 mA Output Voltage Noise (Note 6) 0.1Hz ≤ f ≤ 10Hz 0.5 ppmP-P 10Hz ≤ f ≤ 1kHz 0.8 ppmRMS Turn-On Time 0.1% Settling, COUT = 1µF 180 µsec Long-Term Drift of Output Voltage (Note 7) 30 ppm/√kHr Hysteresis (Note 8) ΔT = 0°C to 50°C 20 ppm ΔT = 0°C to 70°C 24 ppm ΔT = –40°C to 85°C 30 ppm ΔT = –40°C to 125°C 35 ppm ΔT = –55°C to 125°C 40 ppm
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings statistical theory. In general, typical values are considered to be those for may cause permanent damage to the device. Exposure to any Absolute which at least 50% of the units may be expected to perform similarly or Maximum Rating condition for extended periods may affect device better. For the 1000 interval test, a typical unit will exhibit noise that is reliability and lifetime. less than the typical value listed in the Electrical Characteristics table in
Note 2:
With V more than 50% of its measurement intervals. See Application Note 124 for IN at 40V, VOUT may not be pulled below 0V. The total VIN to V noise testing details. RMS noise is measured with a spectrum analyzer in a OUT differential voltage must not exceed ±40V.
Note 3:
The stated temperature is typical for soldering of the leads during shielded environment. manual rework. For detailed IR reflow recommendations, refer to the
Note 7:
Long term stability typically has a logarithmic characteristic Application information section. and therefore change after 1000 hours tend to be much smaller than
Note 4:
Temperature coefficient is measured by dividing the maximum before that time. Total drift in the second thousand hours is normally change in output voltage by the specified temperature range. less than one third of the first thousand hours with a continuing trend toward reduced drift with time. Long-term stability will also be affected by
Note 5:
Line and load regulation are measured on a pulse basis for differential stresses between the IC and the board material created during specified input voltage or load current ranges. Output voltage change due board assembly. to die temperature change must be taken into account separately.
Note 8 :
Hysteresis in output voltage is created by mechanical stress that
Note 6:
Peak-to-peak noise is measured with a 2-pole highpass filter at depends on whether the IC was previously at a different temperature. 0.1Hz and 3-pole lowpass filter at 10Hz. The unit is enclosed in a still-air Output voltage is always measured at 25°C, but the IC is cycled 25°C to environment to eliminate thermocouple effects on the leads, and the cold to 25°C, or 25°C to hot to 25°C before successive measurements. test time is 10 seconds. Due to the statistical nature of noise, repeating Hysteresis measures the maximum output change for the averages of noise measurements will yield larger and smaller peak values in a given three hot or cold temperature cycles, preconditioned by one cold and one measurement interval. By repeating the measurement for 1000 intervals, hot cycles. For instruments that are stored at well controlled temperatures each 10 seconds long, it is shown that there are time intervals during (within 30 degrees of the operational temperature), hysteresis is usually which the noise is higher than in a typical single interval, as predicted by not a significant error source. 6657fd 4 For more information www.linear.com/LT6657