SLVSKC6 Data sheet | 德州仪器 TI.com.cn

SLVSKC6 December 2025 RES31A

PRODUCTION DATA

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机械数据 (封装 | 引脚)

DDF|8
- MPDS569D

散热焊盘机械数据 (封装 | 引脚)

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8.1.2.2 Voltage-Divider Circuit Drift

As discussed in Section 8.1.2, the voltage-divider circuit error t_VDx of the RES31A is related to the gain-circuit error t_Dx by one of the two following expressions (depending on the placement of R_G and R_IN):

Equation 31.

G_{V D x} = \frac{R_{IN x}}{R_{I N x} + R_{G x}} = G_{{V D}_{n o m}} (1 + t_{V D x}) \to t_{V D x} = \frac{{- G}_{nom} \times t_{D x}}{G_{n o m} \times t_{D x} + G_{n o m} + 1}

Equation 32.

G_{V D x} = \frac{R_{G x}}{R_{I N x} + R_{G x}} = G_{{V D}_{n o m}} (1 + t_{V D x}) \to t_{V D x} = \frac{t_{D x}}{G_{n o m} \times t_{D x} + G_{n o m} + 1}

Therefore, the change in the voltage divider transfer function G_VDx with temperature is a direct function of the change in t_Dx with temperature. Multiplying the temperature coefficient TCR_ratio by the change in ambient temperature gives the change in t_Dx, which is in turn substituted in the appropriate equation above to calculate the change in t_VDx. The change in t_VDx directly describes the change in G_VDx.

As an example, consider a RES31A40 with G_nom = 4 and a circuit configuration as shown in Figure 8-4, with R_X = R_G1 and R_Y = R_IN1. Assume t_D1 is initially 85ppm and increases by 5ppm due to a 25°C increase in ambient temperature. The initial value of t_VD1, before the temperature change, is calculated as:

Equation 33.

t_{V D 1} = \frac{{- G}_{nom} \times t_{D 1}}{G_{n o m} \times t_{D 1} + G_{n o m} + 1} = \frac{–4 \times 0.000085}{4 \times 0.000085 + 4 + 1} = –0.000068 = –68 ppm

The new value of t_VD1 after the temperature change is calculated as:

Equation 34.

t_{V D 1} = \frac{{- G}_{nom} \times t_{D 1}}{G_{n o m} \times t_{D 1} + G_{n o m} + 1} = \frac{–4 \times 0.000090}{4 \times 0.000090 + 4 + 1} = –0.000072 = –72 ppm

In this first scenario, the shift in t_D1 of 5ppm causes a shift in t_VD1 of –4ppm.

If the circuit configuration is inverted so that R_X = R_IN1 and R_Y = R_G1, then the initial value of t_VD1 is calculated as:

Equation 35.

t_{V D 1} = \frac{t_{D 1}}{G_{n o m} \times t_{D 1} + G_{n o m} + 1} = \frac{0.000085}{4 \times 0.000085 + 4 + 1} = 0.000017 = 17 ppm

The new value of t_VD1 after the temperature change is calculated as:

Equation 36.

t_{V D 1} = \frac{t_{D 1}}{G_{n o m} \times t_{D 1} + G_{n o m} + 1} = \frac{0.000090}{4 \times 0.000090 + 4 + 1} = 0.000018 = 18 ppm

In this second scenario, the shift in t_D1 of 5ppm causes a shift in t_VD1 of only 1ppm.