SLUSFS4A September 2025 – September 2025 UCC27734-Q1 , UCC27735-Q1
PRODUCTION DATA
- 1
- 1 Features
- 2 Applications
- 3 Description
- 4 Pin Configuration and Functions
- 5 Specifications
-
6 Detailed Description
- 6.1 Overview
- 6.2 Functional Block Diagram
- 6.3
Feature Description
- 6.3.1 Input Stages and Interlock
- 6.3.2 Enable Function (UCC277x5-Q1 Only)
- 6.3.3 Undervoltage Lockout (UVLO)
- 6.3.4 Level Shifter
- 6.3.5 Output Stage
- 6.3.6 Low Propagation Delays and Tightly Matched Outputs
- 6.3.7 HS Node dV/dt
- 6.3.8 Split Grounds (COM and VSS)
- 6.3.9 Operation Under Negative HS Voltage Condition
- 6.4 Device Functional Modes
-
7 Application and Implementation
- 7.1 Application Information
- 7.2
Typical Application
- 7.2.1 Design Requirements
- 7.2.2
Detailed Design Procedure
- 7.2.2.1 Selecting HI and LI Low Pass Filter Components (RHI, RLI, CHI, CLI)
- 7.2.2.2 Selecting Bootstrap Capacitor (CBOOT)
- 7.2.2.3 Selecting VDD Bypass Capacitor (CVDD)
- 7.2.2.4 Selecting Bootstrap Resistor (RBOOT)
- 7.2.2.5 Selecting Gate Resistor RHO/RLO
- 7.2.2.6 Selecting Bootstrap Diode
- 7.2.2.7 Estimate the UCC2773x-Q1 Power Losses
- 7.2.2.8 Application Example Schematic Note
- 7.2.3 Application Curves
- 7.3 Power Supply Recommendations
- 7.4 Layout
- 8 Device and Documentation Support
- 9 Revision History
- 10Mechanical, Packaging, and Orderable Information
6.3.5 Output Stage
The UCC2773x-Q1 device output stage features a unique architecture on the pull up structure which delivers the highest peak-source current when it is most needed during the Miller plateau region of the power-switch turn on transition (when the power switch drain or collector voltage experiences dV/dt). The output stage pull-up structure features a P-Channel MOSFET and an additional N-Channel MOSFET in parallel. The function of the N-Channel MOSFET is to provide a brief boost in the peak sourcing current enabling fast turn on. This is accomplished by briefly turning-on the N-Channel MOSFET during a narrow instant when the output is changing state from low to high.
The ROH parameter (see Figure 5-12) is a DC measurement and it is representative of the on-resistance of the P-Channel device only. This is because the N-Channel device is held in the off state in DC condition and is turned on only for a narrow instant when output changes state from low to high.
The effective resistance of the UCC2773x-Q1 pull-up stage during the turn-on instant is much lower than what is represented by ROH parameter.
The pull-down structure in the UCC2773x-Q1 is simply composed of a N-Channel MOSFET. The ROL parameter (see Figure 5-13), which is also a DC measurement, is representative of the impedance of the pull-down stage in the device.
Each output stage in the UCC2773x-Q1 is capable of supplying 3.5A peak source and 4A peak sink current pulses. The output voltage swings between (VDD and COM) and (HB and HS) providing rail-to-rail operation.
Figure 6-4 Output
Stage Structure