SLVSDU1H August   2018  – April 2021 TPS62810-Q1 , TPS62811-Q1 , TPS62812-Q1 , TPS62813-Q1

PRODUCTION DATA  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  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 Typical Characteristics
  8. Parameter Measurement Information
    1. 8.1 Schematic
  9. Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Precise Enable
      2. 9.3.2 COMP/FSET
      3. 9.3.3 MODE / SYNC
      4. 9.3.4 Spread Spectrum Clocking (SSC)
      5. 9.3.5 Undervoltage Lockout (UVLO)
      6. 9.3.6 Power Good Output (PG)
      7. 9.3.7 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 Foldback Current Limit and Short Circuit Protection
      6. 9.4.6 Output Discharge
      7. 9.4.7 Soft Start / Tracking (SS/TR)
  10. 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
      3. 10.1.3 Capacitor Selection
        1. 10.1.3.1 Input Capacitor
        2. 10.1.3.2 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 System Examples
      1. 10.3.1 Fixed Output Voltage Versions
      2. 10.3.2 Voltage Tracking
      3. 10.3.3 Synchronizing to an External Clock
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

COMP/FSET

This pin allows to set two different parameters independently:

  • Internal compensation settings for the control loop
  • The switching frequency in PWM mode from 1.8 MHz to 4 MHz

A resistor from COMP/FSET to GND changes the compensation as well as the switching frequency. The change in compensation allows you to adapt 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 switching frequency / compensation. 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.

For example: VIN = 5 V, VOUT = 1 V --> duty cycle (DC) = 1 V / 5 V = 0.2

  • with ton = DC × T --> ton,min = 1 / fs,max × DC
  • --> fs,max = 1 / ton,min × DC = 1 / 0.075 µs · 0.2 = 2.67 MHz

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 and Table 9-2, up to the maximum of 470 µF in all of the three 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:

Equation 1. GUID-BCB54321-0F7C-4FA0-913F-C10F445F419D-low.gif

For compensation (comp) setting 2:

Equation 2. GUID-F83636F8-6FA0-4941-A99C-CF71CDFDB227-low.gif

For compensation (comp) setting 3:

Equation 3. GUID-BBFBC723-54CC-4762-B3DD-CA2F4F88958A-low.gif
Table 9-1 Switching Frequency and Compensation for TPS62810-Q1 (4 A) and TPS62813-Q1 (3 A)
COMPENSATIONRCFSWITCHING FREQUENCYMINIMUM OUTPUT
CAPACITANCE
FOR VOUT < 1 V
MINIMUM OUTPUT
CAPACITANCE
FOR 1 V ≤ VOUT < 3.3 V
MINIMUM OUTPUT
CAPACITANCE
FOR VOUT ≥ 3.3 V
for smallest output capacitance
(comp setting 1)
10 kΩ ... 4.5 kΩ1.8 MHz (10 kΩ) ... 4 MHz (4.5 kΩ)
according to Equation 1
53 µF32 µF27 µF
for medium output capacitance
(comp setting 2)
33 kΩ ... 15 kΩ1.8 MHz (33 kΩ) ... 4 MHz (15 kΩ)
according to Equation 2
100 µF60 µF50 µF
for large output capacitance
(comp setting 3)
100 kΩ ... 45 kΩ1.8 MHz (100 kΩ) ... 4 MHz (45 kΩ)
according to Equation 3
200 µF120 µF100 µF
for smallest output capacitance
(comp setting 1)
tied to GNDinternally fixed 2.25 MHz53 µF32 µF27 µF
for large output capacitance
(comp setting 3)
tied to VINinternally fixed 2.25 MHz200 µF120 µF100 µF
Table 9-2 Switching Frequency and Compensation for TPS62812-Q1 (2 A) and TPS62811-Q1 (1 A)
COMPENSATIONRCFSWITCHING FREQUENCYMINIMUM OUTPUT CAPACITANCE
FOR VOUT < 1 V
MINIMUM OUTPUT CAPACITANCE
FOR 1 V ≤ VOUT < 3.3 V
MINIMUM OUTPUT CAPACITANCE
FOR VOUT ≥ 3.3 V
for smallest output capacitance
(comp setting 1)
10 kΩ ... 4.5 kΩ1.8 MHz (10 kΩ) ... 4 MHz (4.5 kΩ)
according to Equation 1
30 µF18 µF15 µF
for medium output capacitance
(comp setting 2)
33 kΩ ... 15 kΩ1.8 MHz (33 kΩ) ... 4 MHz (15 kΩ)
according to Equation 2
60 µF36 µF30 µF
for large output capacitance
(comp setting 3)
100 kΩ ... 45 kΩ1.8MHz (100 kΩ) ...4 MHz (45 kΩ)
according to Equation 3
130 µF80 µF68 µF
for smallest output capacitance
(comp setting 1)
tied to GNDinternally fixed 2.25 MHz30 µF18 µF15 µF
for large output capacitance
(comp setting 3)
tied to VINinternally fixed 2.25 MHz130 µF80 µF68 µF

Refer to Section 10.1.3.2 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 is decoded as "tied to GND". The minimum output capacitance in Table 9-1 and Table 9-2 is for capacitors close to the output of the device. If the capacitance is distributed, a lower compensation setting can be required. All values are effective capacitance, including all tolerances, aging, dc bias effect, and so forth.