T

V

V

REF_MIN

=

Minimum

output

voltage

over

operating

temperature range

V

REF_MAX

= Maximum output voltage over operating

temperature range

∆T = Operating temperature range.

The LM4132 features a low temperature drift of 10ppm

(max) to 30ppm (max), depending on the grade.

LONG TERM STABILITY

Long-term stability refers to the fluctuation in output voltage

over a long period of time (1000 hours). The LM4132 fea-

tures a typical long-term stability of 50ppm over 1000 hours.

The measurements are made using 5 units of each voltage

option, at a nominal input voltage (5V), with no load, at room

temperature.

EXPRESSION OF ELECTRICAL CHARACTERISTICS

Electrical characteristics are typically expressed in mV, ppm,

or a percentage of the nominal value. Depending on the

application, one expression may be more useful than the

other. To convert one quantity to the other one may apply the

following:

ppm to mV error in output voltage:

Where:

V

Bit error (1 bit) to voltage error (mV):

V

number of bits.

mV to ppm error in output voltage:

Where:

V

Voltage error (mV) to percentage error (percent):

Where:

V

PRINTED CIRCUIT BOARD and LAYOUT

CONSIDERATIONS

References in SOT packages are generally less prone to PC

board mounting than devices in Small Outline (SOIC) pack-

ages. To minimize the mechanical stress due to PC board

mounting that can cause the output voltage to shift from its

initial value, mount the reference on a low flex area of the PC

board, such as near the edge or a corner.

The part may be isolated mechanically by cutting a U shape

slot on the PCB for mounting the device. This approach also

provides some thermal isolation from the rest of the circuit.

Bypass capacitors must be mounted close to the part.

Mounting bypass capacitors close to the part will reduce the

parasitic trace components thereby improving performance.

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