The LM5041A 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 LM5041A’s four control outputs
include: 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 an overlap time (for current-fed applications) or a
both-off 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
LM5041A 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 100ns. Additional features include:
line Under-Voltage Lockout (UVLO), soft-start, an error amplifier, precision voltage reference, and
thermal shutdown.
The two differences between the LM5041 and the LM5041A are: No second level current limit
in the 'A' version No softstart (SS) shutdown comparator in the 'A' version.
- 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
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| Topology | Push pull |
| Control mode | Current |
| Duty cycle (max) (%) | 50 |
| Switching frequency (max) (kHz) | 1000 |
| Features | Current limiting, Programmable soft start, Synchronization pin |
| UVLO thresholds on/off (V) | Programmable/2.5V |
| Operating temperature range (°C) | -40 to 125 |
| Rating | Catalog |
| Gate drive (typ) (A) | 1.5 |
| Vin (max) (V) | 15 |