ZHCSPA9A november   2021  – may 2023 TPS62441 , TPS62442

PRODUCTION DATA  

  1.   1
  2. 1 特性
  3. 2 应用
  4. 3 说明
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  9. 8 Parameter Measurement Information
    1. 8.1 Schematic
  10. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Precise Enable (EN)
      2. 9.3.2 COMP/FSET
      3. 9.3.3 MODE/SYNC
      4. 9.3.4 Undervoltage Lockout (UVLO)
      5. 9.3.5 Power-Good Output (PG)
      6. 9.3.6 Thermal Shutdown
    4. 9.4 Device Functional Modes
      1. 9.4.1 Pulse Width Modulation (PWM) Operation
      2. 9.4.2 Power Save Mode Operation (PWM/PFM)
      3. 9.4.3 100% Duty-Cycle Operation
      4. 9.4.4 Current Limit and Short-Circuit Protection
      5. 9.4.5 Output Discharge
      6. 9.4.6 Soft Start
  11. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Programming the Output Voltage
      2. 10.1.2 External Component Selection
        1. 10.1.2.1 Inductor Selection
        2. 10.1.2.2 Capacitor Selection
          1. 10.1.2.2.1 Input Capacitor
          2. 10.1.2.2.2 Output Capacitor
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curves
    3. 10.3 Power Supply Recommendations
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 第三方产品免责声明
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 接收文档更新通知
    4. 11.4 支持资源
    5. 11.5 Trademarks
    6. 11.6 静电放电警告
    7. 11.7 术语表
  13. 12Mechanical, Packaging, and Orderable Information

封装选项

机械数据 (封装 | 引脚)
散热焊盘机械数据 (封装 | 引脚)
订购信息

9.3.2 COMP/FSET

This pin allows to set three different parameters:

  • Internal compensation settings for the control loop (two settings available)
  • The switching frequency in PWM mode from 1.8 MHz to 4 MHz
  • Enable/ disable spread spectrum clocking (SSC)
A resistor from COMP/FSET to GND changes the compensation as well as the switching frequency. The change in compensation allows the user to adopt the device to different values of output capacitance. The resistor must be placed close to the pin to keep the parasitic capacitance on the pin to a minimum. The compensation setting is sampled at start-up of the converter, so a change in the resistor during operation only has an effect on the switching frequency but not on the compensation.

To save external components, the pin can also be directly tied to VIN or GND to set a pre-defined setting. Do not leave the pin floating.

The switching frequency has to be selected based on the input voltage and the output voltage to meet the specifications for the minimum on time and minimum off time.

Example:

V I N = 5.5 V ;   V O U T = 1   ⇒ D u t y   C y c l e = 1 V 5.5 V = 0.2
t o n , m i n = 1 f s × 0.2
f s w , m a x = 1 t o n , m i n × 0.2 = 1 0.075 μ s × 0.2 = 2.67 M H z

The compensation range has to be chosen based on the minimum capacitance used. The capacitance can be increased from the minimum value as given in Table 9-1, up to the maximum of 200-µF effective capacitance in both compensation ranges. If the capacitance of an output changes during operation, for example, when load switches are used to connect or disconnect parts of the circuitry, the compensation has to be chosen for the minimum capacitance on the output. With large output capacitance, the compensation must be done based on that large capacitance to get the best load transient response. Compensating for large output capacitance but placing less capacitance on the output can lead to instability.

The switching frequency for the different compensation setting is determined by the following equations.

For compensation (comp) setting 1 with spread spectrum clocking (SSC) disabled:

Equation 1. R C F k Ω = 18   M H z   × k Ω f s ( M H z ) - 0.18 k

For compensation (comp) setting 1 with spread spectrum clocking (SSC) enabled:

Equation 2. R C F k Ω = 60   M H z   × k Ω f s ( M H z ) - 0.6 k

For compensation (comp) setting 2 with spread spectrum clocking (SSC) disabled:

Equation 3. R C F k Ω = 180   M H z   × k Ω f s ( M H z ) - 1.8 k
Table 9-1 Switching Frequency, Compensation, and Spread Spectrum Clocking
RCF COMPENSATION SWITCHING FREQUENCY MINIMUM OUTPUT CAPACITANCE
FOR VOUT < 1 V		 MINIMUM OUTPUT CAPACITANCE
FOR 1 V ≤ VOUT < 3.3 V		 MINIMUM OUTPUT CAPACITANCE
FOR VOUT ≥ 3.3 V

10

kΩ .. 4.5 kΩ		 for smallest output capacitance
(comp setting 1)
SSC disabled		 1.8 MHz (10 kΩ) .. 4 MHz (4.5 kΩ)
according to Equation 1		 11 µF 7 µF 5 µF
33 kΩ .. 18 kΩ for smallest output capacitance
(comp setting 1)
SSC enabled		 1.8 MHz (33 kΩ) .. 4 MHz (18 kΩ)
according to Equation 2		 11 µF 7 µF 5 µF

100

kΩ .. 45 kΩ		 for best transient response (larger output capacitance)
(comp setting 2)
SSC disabled		 1.8 MHz (100 kΩ) ..4 MHz (45 kΩ)
according to Equation 3		 30 µF 18 µF 15 µF
tied to GND for smallest output capacitance
(comp setting 1)
SSC disabled		 internally fixed 2.25 MHz 11 µF 7 µF 5 µF
tied to VIN for best transient response (larger output capacitance)
(comp setting 2)
SSC enabled		 internally fixed 2.25 MHz 30 µF 18 µF 15 µF

Refer to Section 10.1.2.2.2 for further details on the output capacitance required depending on the output voltage.

A too-high resistor value for RCF is decoded as "tied to VIN", a value below the lowest range as "tied to GND". The minimum output capacitance in Table 9-1 is for capacitors close to the output of the device. If the capacitance is distributed, a lower compensation setting can be required.