TLE2074ACDWR datasheet(47/83 Pages) TI

47 / 83 page

TLE207x, TLE207xA

EXCALIBUR LOW NOISE HIGHSPEED

JFET INPUT OPERATIONAL AMPLIFIERS

SLOS181B − FEBRUARY 1997 − REVISED APRIL 2004

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

PARAMETER MEASUREMENT INFORMATION

−

2 k

Ω

VCC +

VCC −

Ground Shield

Picoammeters

Figure 3. Noise-Voltage Test Circuit

Figure 4. Input-Bias and Offset-

Current Test Circuit

−

VCC +

VCC −

IN −

IN +

Cic

Cid

Figure 5. Internal Input Capacitance

typical values

Typical values presented in this data sheet represent the median (50% point) of device parametric performance.

input bias and offset current

At the picoampere bias current level typical of the TLE207x and TLE207xA, accurate measurement of the bias

current becomes difficult. Not only does this measurement require a picoammeter but test socket leakages can

easily exceed the actual device bias currents. To accurately measure these small currents, Texas Instruments

uses a two-step process. The socket leakage is measured using picoammeters with bias voltages applied but

with no device in the socket. The device is then inserted in the socket and a second test is performed that

measures both the socket leakage and the device input bias current. The two measurements are then

subtracted algebraically to determine the bias current of the device.

TLE2074ACDWR Datasheet(PDF) 47 Page - Texas Instruments