1FEATURES

2? Internal Start-up Bias Regulator

? Programmable Line Under-Voltage Lockout

(UVLO) with Adjustable Hysteresis

? Current Mode Control

? Internal Error Amplifier with Reference

? Cycle-by-cycle Over-Current Protection

? Leading Edge Blanking

? Programmable Push-Pull Overlap or Dead

Time

? Internal 1.5A Push-Pull Gate Drivers

? Programmable Soft-Start

? Programmable Oscillator with Sync Capability

? Precision Reference

? Thermal Shutdown

APPLICATIONS

? Telecommunication Power Converters

? Industrial Power Converters

? Multi-Output Power Converters

PACKAGES

? TSSOP-16

? WSON-16 (5x5 mm) Thermally Enhanced

DESCRIPTION

The LM5041B PWM controller contains all of the

features necessary to implement either current-fed or

voltage-fed push-pull or bridge power converters.

These “Cascaded” topologies are well suited for

multiple output and higher power applications. The

LM5041B includes these four control outputs: the

buck stage controls (HD and LD) and the push-pull

control outputs (PUSH and PULL). Push-pull outputs

are driven at 50% nominal duty cycle at one half of

the switching frequency of the buck stage and can be

configured for either a specified overlap time (for

current-fed applications) or a specified non-overlap

time (for voltage-fed applications). Push-pull stage

MOSFETs can be driven directly from the internal

gate drivers while the buck stage requires an external

driver such as the LM5102. The LM5041B includes a high-voltage start-up regulator that operates over a

wide input range of 15V to 100V. The PWM controller

is designed for high-speed capability including an

oscillator frequency range up to 1 MHz and total

propagation delays of less than 100 ns. Additional features include line Under-Voltage Lock-Out

(UVLO), Soft-Start, an error amplifier, precision

voltage reference, and thermal shutdown.

The differences between LM5041, LM5041A and

LM5041B are as follows: In the LM5041A and the

LM5041B version, the hiccup mode over-current

protection is not employed and the VCC bias regulator is not disabled by a low state at the SS pin.

In the LM5041B version, both the high and low side

buck stage gate drivers are forced to a low state

when the controller is disabled. In the LM5041 and

the LM5041B version, the buck stage controller is

disabled by either a low state at the UVLO pin or a

low state at the SS pin. Also in the LM5041B version,

the REF pin 5V regulator is not disabled by a UVLO

pin low state.