SLVS631C December   2005  – May 2015 TPS51117


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Recommended Operating Conditions
    3. 6.3 Electrical Characteristics
    4. 6.4 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  PWM Frequency and Adaptive On-Time Control
      2. 7.3.2  Low-Side Driver
      3. 7.3.3  High-Side Driver
      4. 7.3.4  Soft-Start
      5. 7.3.5  Powergood
      6. 7.3.6  Output Discharge Control (Soft-Stop)
      7. 7.3.7  Overcurrent Limit
      8. 7.3.8  Negative Overcurrent Limit (PWM-Only Mode)
      9. 7.3.9  Overvoltage Protection
      10. 7.3.10 Undervoltage Protection
      11. 7.3.11 Start-Up Sequence
      12. 7.3.12 UVLO Protection
      13. 7.3.13 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 PWM Operation
      2. 7.4.2 Light-Load Condition With Auto-Skip Function
  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. D-CAP Mode Operation
      3. 8.2.3 Application Curves
    3. 8.3 System Examples
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • RGY|14
  • PW|14
Thermal pad, mechanical data (Package|Pins)
Orderable Information

5 Pin Configuration and Functions

RGY Package
14-Pin VQFN
Bottom View
TPS51117 po_rgy_lvs631.gif
PW Package
14-Pin TSSOP
Top View
TPS51117 po_lvs631.gif

Pin Functions

DRVH 13 O High-side NFET gate driver output. Source 5 Ω, sink 1.5-Ω LL-node referenced driver. Drive voltage corresponds to VBST to LL voltage.
DRVL 9 O Rectifying (low-side) NFET gate driver output. Source 5 Ω, sink 1.5-Ω PGND referenced driver. Drive voltage is V5DRV voltage.
EN_PSV 1 I Enable / power save pin. Connect to ground to disable SMPS. Connect to 3.3 V or 5 V to turn on SMPS and activate skip mode. Float to turn on SMPS but disable skip mode (forced continuous conduction mode).
GND 7 I Signal ground pin.
LL 12 I/O High-side NFET gate driver return. Also serves as anode of overcurrent comparator.
PGND 8 I/O Ground return for rectifying NFET gate driver. Also cathode of overcurrent protection and source node of the output discharge switch.
PGOOD 6 O Powergood window comparator, open-drain, output. Pull up to 5-V rail with a pullup resistor. Current capability is 7.5 mA.
TON 2 I On-time / frequency adjustment pin. Connect to LL with 100-kΩ to 600-kΩ resistor.
TRIP 11 I Overcurrent trip point set input. Connect resistor from this pin to signal ground to set threshold for both overcurrent and negative overcurrent limit.
VBST 14 I Supply input for high-side NFET gate driver (boost terminal). Connect capacitor from this pin to LL-node. An internal PN diode is connected between V5DRV to this pin. Designer can add external Schottky diode if forward drop is critical to drive the power NFET.
VFB 5 I SMPS voltage feedback input. Connect the resistor divider here for adjustable output.
VOUT 3 I Connect to SMPS output. This terminal serves two functions: output voltage monitor for on-time adjustment, and input for the output discharge switch.
V5DRV 10 I 5-V Power supply input for FET gate drivers. Internally connected to VBST by a PN diode. Connect 1 μF or more between this pin and PGND to support instantaneous current for gate drivers.
V5FILT 4 I 5-V Power supply input for all the control circuitry except gate drivers. Supply 5-V ramp rate should be 17 mV/μs or less and Tj < 85°C to secure safe start-up of the internal reference circuit. Apply RC filter consists of 300 Ω + 1 μF or 100 Ω + 4.7 μF at the pin input.