ZHCSH35B November 2017 – May 2021 LM73605-Q1 , LM73606-Q1
PRODUCTION DATA
- 1 特性
- 2 应用
- 3 说明
- 4 Revision History
- 5 Device Comparison
- 6 Pin Configuration and Functions
- 7 Specifications
-
8 Detailed Description
- 8.1 Overview
- 8.2 Functional Block Diagram
- 8.3
Feature Description
- 8.3.1 Synchronous Step-Down Regulator
- 8.3.2 Auto Mode and FPWM Mode
- 8.3.3 Fixed-Frequency Peak Current-Mode Control
- 8.3.4 Adjustable Output Voltage
- 8.3.5 Enable and UVLO
- 8.3.6 Internal LDO, VCC_UVLO, and BIAS Input
- 8.3.7 Soft Start and Voltage Tracking
- 8.3.8 Adjustable Switching Frequency
- 8.3.9 Frequency Synchronization and Mode Setting
- 8.3.10 Internal Compensation and CFF
- 8.3.11 Bootstrap Capacitor and VBOOT-UVLO
- 8.3.12 Power-Good and Overvoltage Protection
- 8.3.13 Overcurrent and Short-Circuit Protection
- 8.3.14 Thermal Shutdown
- 8.4 Device Functional Modes
- 9 Layout
- 10Device and Documentation Support
9.2 Typical Application
The LM73605-Q1/6-Q1 only a few external components to perform high-efficiency power conversion, as shown in Figure 9-1.
Figure 9-1 LM73605-Q1/6-Q1 Basic SchematicThe LM73605-Q1/6-Q1 also many practical features to meet a wide range of system design requirements and optimization, such as UVLO, programmable soft-start time, start-up tracking, programmable switching frequency, clock synchronization, and a power-good flag. Note that for ease of use, the feature pins do not require an additional component when not in use. They can be either left floating or shorted to ground. Please refer to the Section 6 for details.
A comprehensive schematic with all features utilized is shown in Figure 9-2.
Figure 9-2 LM73605-Q1/6-Q1 Comprehensive Schematic with All Features UtilizedThe external components must fulfill not only the needs of the power conversion, but also the stability criteria of the control loop. The LM73605-Q1/6-Q1 optimized to work with a range of external components. For quick component selection, Table 9-1 can be used.
| fSW (kHz) | VOUT (V) | L (µH) | COUT (µF)(1) | RFBT (kΩ) | RFBB (kΩ) | RT (kΩ) |
| 350 | 1 | 2.2 | 500 | 100 | OPEN | 115 |
| 500 | 1 | 1.5 | 400 | 100 | OPEN | 78.7 or open |
| 1000 | 1 | 0.68 | 200 | 100 | OPEN | 39.2 |
| 2200 | 1 | 0.47 | 100 | 100 | OPEN | 17.4 |
| 350 | 3.3 | 4.7 | 200 | 100 | 43.5 | 115 |
| 500 | 3.3 | 3.3 | 150 | 100 | 43.5 | 78.7 or open |
| 1000 | 3.3 | 1.8 | 88 | 100 | 43.5 | 39.2 |
| 2200 | 3.3 | 1.2 | 44 | 100 | 43.5 | 17.4 |
| 350 | 5 | 6.8 | 120 | 100 | 25 | 115 |
| 500 | 5 | 4.7 | 88 | 100 | 25 | 78.7 or open |
| 1000 | 5 | 3.3 | 66 | 100 | 25 | 39.2 |
| 2200 | 5 | 2.2 | 44 | 100 | 25 | 17.4 |
| 350 | 12 | 15 | 66 | 100 | 9.1 | 115 |
| 500 | 12 | 10 | 44 | 100 | 9.1 | 78.7 or open |
| 1000 | 12 | 6.8 | 22 | 100 | 9.1 | 39.2 |
| 350 | 24 | 22 | 40 | 100 | 4.3 | 115 |
| 500 | 24 | 15 | 30 | 100 | 4.3 | 78.7 or open |