米6体育平台手机版

ZHCSJJ4A march 2019 – august 2021 TL7700-SEP

PRODUCTION DATA

封装选项

机械数据 (封装 | 引脚)

PW|8
- MPDS568

散热焊盘机械数据 (封装 | 引脚)

订购信息

9.2.2 Detailed Design Procedure

The SENSE terminal input voltage, V_s, for TL7700-SEP is typically 500 mV. By using two external resistors, any sense voltage over 500 mV can be sensed.

Resistor R1 should be selected first to set the desired hysteresis. Section 8.3.2 provides detailed information on how to set the hysteresis. For this application, a 240-kΩ resistor is selected.

Equation 4.

V_{h y s} = I_{s} \times R 1

Equation 5.

V_{h y s} = 2.5 µ A \times 240 k Ω = 0.6 V

Resistor R2 should then be selected based on the R1 value and the desired sense voltage (V_s'). Section 8.3.1 describes how to set V_s' and provides and equation. In this example, V_s' is set to 4.5 V by using the value of R1 selected earlier and using a 30-kΩ resistor for R2.

Equation 6.

V_{s'} = V_{s} \times \frac{(R 1 + R 2)}{R 2}

Equation 7.

V_{s'} = 0.5 V \times \frac{(240 k Ω + 30 k Ω)}{30 k Ω} = 4.5 V

Finally, the output pulse duration (t_PO) is set using the equation found in Section 8.3.3.

Equation 8.

t_{p o} = C_{T} \frac{{Δ V}_{C T}}{I_{C T}}

Equation 9.

t_{p o} = 510 p F \frac{1.5 V}{15 µ A} = 51 µ s