ZHCSHR1A September 2017 – February 2018 TPS7A54-Q1
PRODUCTION DATA.
- 1 特性
- 2 應用
- 3 說明
- 4 修訂歷史記錄
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Detailed Description
-
8 Application and Implementation
- 8.1
Application Information
- 8.1.1 Recommended Capacitor Types
- 8.1.2 Soft Start and Inrush Current
- 8.1.3 Optimizing Noise and PSRR
- 8.1.4 Charge Pump Noise
- 8.1.5 Current Sharing
- 8.1.6 Adjustable Operation
- 8.1.7 Power-Good Operation
- 8.1.8 Undervoltage Lockout (UVLO) Operation
- 8.1.9 Dropout Voltage (VDO)
- 8.1.10 Device Behavior During Transition From Dropout Into Regulation
- 8.1.11 Load Transient Response
- 8.1.12 Reverse Current Protection Considerations
- 8.1.13 Power Dissipation (PD)
- 8.1.14 Estimating Junction Temperature
- 8.2 Typical Application
- 8.1
Application Information
- 9 Power Supply Recommendations
- 10Layout
- 11器件和文檔支持
- 12機械、封裝和可訂購信息
7.3.2.2 Internal Sequencing
Controlling when a single power supply turns on can be difficult in a power distribution network (PDN) because of the high power levels inherent in a PDN, and the variations between all of the supplies. As shown in Figure 41 and Table 2, the LDO turnon and turnoff time is set by the enable circuit (EN) and undervoltage lockout circuits (UVLO1,2(IN) and UVLOBIAS).
Figure 41. Simplified Turnon Control
Table 2. Internal Sequencing Functionality Table
| INPUT VOLTAGE | BIAS VOLTAGE | ENABLE STATUS | LDO STATUS | ACTIVE DISCHARGE | POWER GOOD |
|---|---|---|---|---|---|
| VIN ≥ VUVLO_1,2(IN) | VBIAS ≥ VUVLO(BIAS) | EN = 1 | On | Off | PG = 1 when VOUT ≥ VIT(PG) |
| EN = 0 | Off | On | PG = 0 | ||
| VBIAS< VUVLO(BIAS) + VHYS(BIAS) | EN = don't care | Off | On(1) | ||
| VIN< VUVLO_1,2(IN) – VHYS1,2(IN) | BIAS = don't care | Off | |||
| IN = don't care | VBIAS ≥ VUVLO(BIAS) | Off |
(1) The active discharge remains on as long as VIN or VBIAS provide enough headroom for the discharge circuit to function.