ZHCSDB0 February   2015 LP8728B-Q1

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  4. 4 修订历史记录
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 System Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Buck Information
        1. 7.3.1.1 Features
      2. 7.3.2 Thermal Shutdown (TSD)
      3. 7.3.3 Undervoltage Lockout (UVLO)
      4. 7.3.4 Overvoltage Protection (OVP)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode
      2. 7.4.2 Active Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Inductor
        2. 8.2.2.2 Input and Output Capacitors
      3. 8.2.3 Application Performance Plots
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11器件和文档支持
    1. 11.1 器件支持
      1. 11.1.1 第三方产品免责声明
    2. 11.2 相关文档　
    3. 11.3 商标
    4. 11.4 静电放电警告
    5. 11.5 术语表
  12. 12机械封装和可订购信息

5 Pin Configuration and Functions

WQFN (RSG) Package
28 Pins
LP8728B-Q1 Pin_Ass_snvs972.gif

Pin Functions

PIN TYPE(1) DESCRIPTION
NUMBER NAME
1 EN_B1 D/I Enable Buck 1
2 VIN_B1 P Positive power supply input for Buck 1
3 SW_B1 P Switch node for Buck 1
4 GND_B1 G Power ground for Buck 1
5 GND_B2 G Power ground for Buck 2
6 SW_B2 P Switch node for Buck 2
7 VIN_B2 P Positive power supply input for Buck 2
8 FB_B2 A Feedback pin for Buck 2. Referenced against AGND.
9 EN_B2 D/I Enable Buck 2
10 PG_B2 D/O Open-drain Power Good output for Buck 2
11 DEFSEL D/I Buck 3 output voltage selection pin
12 PG_B3 D/O Open-drain Power Good output for Buck 3
13 EN_B3 D/I Enable Buck 3
14 FB_B3 A Feedback pin for Buck 3. Referenced against AGND.
15 VIN_B3 P Positive power supply input for Buck 3
16 SW_B3 P Switch node for Buck 3
17 GND_B3 G Power ground for Buck 3
18 GND_B4 G Power ground for Buck 4
19 SW_B4 P Switch node for Buck 4
20 VIN_B4 P Positive power supply input for Buck 4
21 EN_B4 D/I Enable Buck 4
22 FB_B4 A Feedback pin for Buck 4. Referenced against AGND.
23 PG_B4 D/O Open-drain Power Good output for Buck 4
24 AGND G Analog ground
25 BYP A Internal 1.8-V supply voltage capacitor pin. A ceramic low-ESR 1-μF capacitor should be connected from this pin to AGND. The BYP voltage is generated internally, do not supply or load this pin externally.
26 AVDD P Analog positive power supply pin (VIN level)
27 PG_B1 D/O Open-drain Power Good output for Buck 1
28 FB_B1 A Feedback pin for Buck 1. Referenced against AGND.
DAP Die Attachment Pad Exposed die attachment pad should to be connected to GND plane with thermal vias to improve the thermal performance of the system.
(1) A: Analog Pin, G: Ground Pin, P: Power Pin, O: Output Pin, D/I: Digital Input, D/O: Digital Output.