ZHCSK35C March 2019 – March 2021 TPS92682-Q1
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3
Feature Description
- 7.3.1 Device Enable
- 7.3.2 Internal Regulator and Undervoltage Lockout (UVLO)
- 7.3.3 Oscillator
- 7.3.4 Spread Spectrum Function
- 7.3.5 Gate Driver
- 7.3.6 Rail-to-Rail Current Sense Amplifier
- 7.3.7 Transconductance Error Amplifier
- 7.3.8 Switch Current Sense
- 7.3.9 Slope Compensation
- 7.3.10 ILED Setting in CC Mode
- 7.3.11 Output Voltage Setting in CV Mode
- 7.3.12 PWM Dimming
- 7.3.13 P-Channel FET Gate Driver Output
- 7.3.14 Soft Start
- 7.3.15 Two-Phase Operation
- 7.3.16 Faults and Diagnostics
- 7.4 Device Functional Modes
- 7.5 Programming
- 7.6
TPS92682 Registers
- 7.6.1 EN Register
- 7.6.2 CFG1 Register
- 7.6.3 CFG2 Register
- 7.6.4 SWDIV Register
- 7.6.5 ISLOPE Register
- 7.6.6 FM Register
- 7.6.7 SOFTSTART Register
- 7.6.8 CH1IADJ Register
- 7.6.9 CH2IADJ Register
- 7.6.10 PWMDIV Register
- 7.6.11 CH1PWML Register
- 7.6.12 CH1PWMH Register
- 7.6.13 CH2PWML Register
- 7.6.14 CH2PWMH Register
- 7.6.15 ILIM Register
- 7.6.16 IFT Register
- 7.6.17 MFT Register
- 7.6.18 FLT1 Register (read only)
- 7.6.19 FLT2 Register (read only)
- 7.6.20 FEN1 Register
- 7.6.21 FEN2 Register
- 7.6.22 FLATEN Register
- 7.6.23 OV Register
- 7.6.24 LHCFG Register
- 7.6.25 LHCH1IADJ Register
- 7.6.26 LHCH2IADJ Register
- 7.6.27 LHCH1PWML Register
- 7.6.28 LHCH1PWMH Register
- 7.6.29 LHCH2PWML Register
- 7.6.30 LHCH2PWMH Register
- 7.6.31 LHILIM Register
- 7.6.32 LHIFT Register
- 7.6.33 LHMFT Register
- 7.6.34 LHFEN1 Register
- 7.6.35 LHFEN2 Register
- 7.6.36 LHFLATEN Register
- 7.6.37 LHOV Register
- 7.6.38 CAL Register
- 7.6.39 RESET Register
-
8 Application and Implementation
- 8.1 Application Information General Design Considerations
- 8.2 Application Information CC Mode
- 8.3 Typical Application CV Mode
- 8.4
Typical Application CC Mode
- 8.4.1 CC Boost Design Requirements
- 8.4.2
CC Boost Detailed Design Procedure
- 8.4.2.1 Calculating Duty Cycle
- 8.4.2.2 Setting Switching Frequency
- 8.4.2.3 Setting Dither Modulation Frequency
- 8.4.2.4 Inductor Selection
- 8.4.2.5 Output Capacitor Selection
- 8.4.2.6 Input Capacitor Selection
- 8.4.2.7 Main N-Channel MOSFET Selection
- 8.4.2.8 Rectifier Diode Selection
- 8.4.2.9 Setting ILED and Selecting RCS
- 8.4.2.10 Setting Switch Current Limit
- 8.4.2.11 Slope Compensation
- 8.4.2.12 Compensator Parameters
- 8.4.2.13 Overvoltage Protection
- 8.4.2.14 Series P-Channel MOSFET Selection
- 8.4.3 CC Buck-Boost Design Requirements
- 8.4.4
CC Buck-Boost Detailed Design Procedure
- 8.4.4.1 Calculating Duty Cycle
- 8.4.4.2 Setting Switching Frequency
- 8.4.4.3 Setting Dither Modulation Frequency
- 8.4.4.4 Inductor Selection
- 8.4.4.5 Output Capacitor Selection
- 8.4.4.6 Input Capacitor Selection
- 8.4.4.7 Main N-Channel MOSFET Selection
- 8.4.4.8 Rectifier Diode Selection
- 8.4.4.9 Setting ILED and Selecting RCS
- 8.4.4.10 Setting Switch Current Limit
- 8.4.4.11 Slope Compensation
- 8.4.4.12 Compensator Parameters
- 8.4.4.13 Overvoltage Protection
- 8.4.5 PWM Dimming Consideration
- 8.4.6 Application Curves
- 8.5
Typical Application CV Mode
- 8.5.1 CV Design Requirements
- 8.5.2
Detailed Design Procedure
- 8.5.2.1 Calculating Duty Cycle
- 8.5.2.2 Setting Switching Frequency
- 8.5.2.3 Setting Dither Modulation Frequency
- 8.5.2.4 Inductor Selection
- 8.5.2.5 Output Capacitor Selection
- 8.5.2.6 Input Capacitor Selection
- 8.5.2.7 Main N-Channel MOSFET Selection
- 8.5.2.8 Rectifier Diode Selection
- 8.5.2.9 Programming VOUT
- 8.5.2.10 Setting Switch Current Limit
- 8.5.2.11 Slope Compensation
- 8.5.2.12 Compensator Parameters
- 8.5.2.13 Overvoltage Protection
- 8.5.3 Application Curves
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
封裝選項
機械數據 (封裝 | 引腳)
散熱焊盤機械數據 (封裝 | 引腳)
訂購信息
8.2.5 Feedback Compensation
The loop gain T(s) is the product of the converter transfer function Givc(s) (Equation 28) and the feedback transfer function Gc(s).
Using a first-order approximation, the converter transfer function can be modeled as a single pole created by the output capacitor and the LED string dynamic resistance, rD. In the boost and buck-boost topologies, the transfer function has a right half-plane zero created by the inductor, and the DC output current ILED. The ESR of the output capacitor is neglected in this analysis.
Table 8-1 summarizes the expression for the small-signal model parameters.
| DC GAIN (G0) | POLE FREQUENCY (ωP) | ZERO FREQUENCY (ωZ) | |
|---|---|---|---|
| Boost |  |  |  |
| Buck-Boost |  |  |  |
The feedback transfer function includes the current sense resistor and the loop compensation of the transconductance amplifier. A compensation network at the output of the error amplifier is used to configure loop gain and phase characteristics. A simple capacitor, CCOMP, from COMPx to GND (as shown in Figure 8-4) provides integral compensation and creates a pole at the origin. Alternatively, a network of RCOMP, CCOMP, and CHF, shown in Figure 8-5, can be used to implement Proportional-Integral (PI) compensation to create a pole at the origin, a low-frequency zero, and a high-frequency pole.
The feedback transfer function is defined as follows.
Feedback transfer function with integral compensation:
Feedback transfer function with proportional integral compensation:
Figure 8-4 Integral Compensator
Figure 8-5 Proportional Integral CompensatorThe pole at the origin minimizes output steady-state error. High bandwidth is achieved with the PI compensator by introducing a phase lead using a low-frequency zero. Use the following expressions to calculate the compensation network.
- BOOST and BUCK-BOOST with an Integral Compensator:
Equation 31.
- BOOST and BUCK-BOOST with a Proportional-Integral Compensator:
Equation 32.
Equation 33.
Equation 34.
The above compensation values are calculated to provide reasonable phase margin (> 45°) and bandwidth. In practice, the above values can be modified for desired dynamic performance (for example: PWM dimming rise/fall-time or overshoot/undershoot).