Datasheet

CYCLE BY CYCLE

CLIM

FAULT - CBC

FAULT MODULE

FAULT IN

FAULT FLAG

MAX COUNT

FAULT EN

DPWM EN

UCD3138

SLUSAP2F –MARCH 2012 –REVISED NOVEMBER 2013

www.ti.com

The Fault Mux Module provides a multitude of fault protection functions within the UCD3138 high-speed

loop (Front End Control, Filter, DPWM and Loop Mux modules). The Fault Mux Module allows highly

configurable fault generation based on digital comparators, high-speed analog comparators and external

fault pins. Each of the fault inputs to the DPWM modules can be configured to one or any combination of

the fault events provided in the Fault Mux Module.

Each one of the DPWM engines has four fault modules. The modules are called CBC fault module, AB

fault module, A fault module and B fault module.

The internal circuitry in all the four fault modules is identical, and the difference between the modules is

limited to the way the modules are attached to the DPWMs.

All fault modules provide immediate fault detection but only once per DPWM switching cycle. Each one of

the fault modules own a separate max_count and the fault flag will be set only if sequential cycle-by-cycle

faults count exceeds max_count.

Once the fault flag is set DPWMs need to be disabled by DPWM_EN going low in order to clear the fault

flags. Please note, all four Fault Modules share the same DPWM_EN control, all fault flags (output of Fault

Modules) will be cleared simultaneously.

All four Fault Modules share the same global FAULT_EN as well. Therefore a specific Fault Module

cannot be enabled/ disabled separately.

Unlike Fault Modules, only one Cycle by Cycle block is available in each DPWM module.

The Cycle by Cycle block works in conjunction with CBC Fault Module and enables DPWM reaction to

signals arriving from Analog Peak current mode (PCM) module.

The Fault Mux Module supports the following basic functions:

• 4 digital comparators with programmable thresholds and fault generation

• Configuration for 7 high speed analog comparators with programmable thresholds and fault generation

• External GPIO detection control with programmable fault generation

• Configurable DPWM fault generation for DPWM Current Limit Fault, DPWM Over-Voltage Detection

Fault, DPWM A External Fault, DPWM B External Fault and DPWM IDE Flag

• Clock Failure Detection for High and Low Frequency Oscillator blocks

• Discontinuous Conduction Mode Detection

Submit Documentation Feedback

Product Folder Links: UCD3138