ZHCSEI2B January 2016 – June 2021 TPS7A84
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Pin Configurations and Functions
- 6 Specifications
- 7 Detailed Description
-
8 Application and Implementation
- 8.1
Application Information
- 8.1.1 Recommended Capacitor Types
- 8.1.2 Input and Output Capacitor Requirements (CIN and COUT)
- 8.1.3 Noise-Reduction and Soft-Start Capacitor (CNR/SS)
- 8.1.4 Feed-Forward Capacitor (CFF)
- 8.1.5 Soft-Start and In-Rush Current
- 8.1.6 Optimizing Noise and PSRR
- 8.1.7 Charge Pump Noise
- 8.1.8 ANY-OUT Programmable Output Voltage
- 8.1.9 ANY-OUT Operation
- 8.1.10 Increasing ANY-OUT Resolution for LILO Conditions
- 8.1.11 Current Sharing
- 8.1.12 Adjustable Operation
- 8.1.13 Sequencing Requirements
- 8.1.14 Power-Good Operation
- 8.1.15 Undervoltage Lockout (UVLO) Operation
- 8.1.16 Dropout Voltage (VDO)
- 8.1.17 Behavior when Transitioning from Dropout into Regulation
- 8.1.18 Load Transient Response
- 8.1.19 Negatively-Biased Output
- 8.1.20 Reverse Current Protection
- 8.1.21 Power Dissipation (PD)
- 8.1.22 Estimating Junction Temperature
- 8.1.23 Recommended Area for Continuous Operation (RACO)
- 8.2 Typical Applications
- 8.1
Application Information
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
8.1.12 Adjustable Operation
The TPS7A84 can be used either with the internal ANY-OUT network or by using external resistors. Using the ANY-OUT network allows the TPS7A84 to be programmed from 0.8 V to 3.95 V. To extend this output voltage range to 5.0 V, external resistors must be used. This configuration is referred to as the adjustable configuration of the TPS7A84 throughout this document. Regardless whether the internal resistor network or whether external resistors are used, the output voltage is set by two resistors, as shown in Figure 8-4. Using the internal resistor ensures a 1% accuracy and minimizes the number of external components.
Figure 8-4 Adjustable OperationR1 and R2 can be calculated for any output voltage range using Equation 8. This resistive network must provide a current equal to or greater than 5 μA for dc accuracy. Using an R1 of 12.1 kΩ is recommended to optimize the noise and PSRR.
Table 8-5 shows the resistor combinations required to achieve several common rails using standard 1%-tolerance resistors.
| TARGETED OUTPUT VOLTAGE (V) | FEEDBACK RESISTOR VALUES | CALCULATED OUTPUT VOLTAGE (V) | |
|---|---|---|---|
| R1 (kΩ) | R2 (kΩ) | ||
| 0.9 | 12.4 | 100 | 0.899 |
| 0.95 | 12.4 | 66.5 | 0.949 |
| 1.00 | 12.4 | 49.9 | 0.999 |
| 1.10 | 12.4 | 33.2 | 1.099 |
| 1.20 | 12.4 | 24.9 | 1.198 |
| 1.50 | 12.4 | 14.3 | 1.494 |
| 1.80 | 12.4 | 10 | 1.798 |
| 1.90 | 12.1 | 8.87 | 1.89 |
| 2.50 | 12.4 | 5.9 | 2.48 |
| 2.85 | 12.1 | 4.75 | 2.838 |
| 3.00 | 12.1 | 4.42 | 2.990 |
| 3.30 | 11.8 | 3.74 | 3.324 |
| 3.60 | 12.1 | 3.48 | 3.582 |
| 4.5 | 11.8 | 2.55 | 4.502 |
| 5.00 | 12.4 | 2.37 | 4.985 |