LM12454, LM12458, LM12H458
SNAS079A – MAY 2004 – REVISED FEBRUARY 2006
Internal Reference Characteristics
The following specifications apply to the LM12454, LM12458, and LM12H458 for VA+ = VD+ = 5V unless otherwise specified.
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C.
Internal Reference Output Voltage
Internal Reference Temperature
Sourcing (0 < IL ≤ +4 mA)
Internal Reference Load Regulation
−1 ≤ IIL < 0 mA)
≤ VA+ ≤ 5.5V
Internal Reference Short Circuit Current
VREFOUT = 0V
Long Term Stability
VA+ = VD+ = 0V →
Internal Reference Start-Up Time
5V, CL = 100 μF
Two on-chip diodes are tied to each analog input through a series resistor, as shown below. Input voltage magnitude up to 5V above
VA+ or 5V below GND will not damage the LM12454 or the LM12(H)458. However, errors in the A/D conversion can occur if these
diodes are forward biased by more than 100 mV. As an example, if VA+ is 4.5 VDC, full-scale input voltage must be ≤4.6 VDC to ensure
VA+ and VD+ must be connected together to the same power supply voltage and bypassed with separate capacitors at each V
+ pin to
assure conversion/comparison accuracy.
Typical figures are at TA = 25°C and represent most likely parametric norm.
Limits are to AOQL (Average Output Quality Level).
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Product Folder Links: LM12454 LM12458 LM12H458