SLVSJ15 Data sheet | 德州仪器 TI.com.cn

SLVSJ15 June 2026 LMP8601 , LMP8602 , LMP8603

PRODUCTION DATA

封装选项

机械数据 (封装 | 引脚)

D|8
- MSOI002K

散热焊盘机械数据 (封装 | 引脚)

订购信息

6.4.1.2 Increasing Gain

Figure 6-3 shows the configuration that can be used to increase the gain of the LMP8601.

NOTE: K2 = 2 for LMP8601; 5 for LMP8602; or 10 for LMP8603.

Figure 6-3 Increase Gain

R_i creates positive feedback from the output pin to the input of the buffer amplifier. The positive feedback increases the gain. The increased gain G_i for the LMP8601 becomes:

Equation 27.

G_{i} = \frac{{20 R}_{i}}{R_{i} + 100 k Ω}

For the LMP8602:

Equation 28.

G_{i} = \frac{{50 R}_{i}}{R_{i} + 400 k Ω}

And for the LMP8603:

Equation 29.

G_{i} = \frac{{100 R}_{i}}{R_{i} + 900 k Ω}

From this equation, for a desired value of the gain, the LMP8601 required value of R_i is calculated with:

Equation 30.

R_{i} = 100 k Ω \times \frac{G_{i}}{G_{i} - 20}

For the LMP8602:

Equation 31.

R_{i} = 400 k Ω \times \frac{G_{i}}{G_{i} - 50}

And for the LMP8603 with:

Equation 32.

R_{i} = 900 k Ω \times \frac{G_{i}}{G_{i} - 100}

Note that from the equation for the gain G_i, for large gains, R_i approaches 100kΩ. In this case, the denominator in the equation becomes close to zero. In practice, for large gains, the denominator is determined by tolerances in the value of the external resistor R_i and the internal 100kΩ resistor. In this case, the gain becomes very inaccurate. If the denominator becomes equal to zero, the system becomes unstable. TI recommends to limit the application of this technique to gain values of 50 or smaller.