SNVSBV6B December 2020 – January 2023 LM25149-Q1
PRODUCTION DATA
The LM25149-Q1 has a high-gain transconductance amplifier that generates an error current proportional to the difference between the feedback voltage and an internal precision reference (0.8 V). The control loop compensation is configured two ways. The first is using the internal compensation amplifier, which has a transconductance of 30 µS. Internal compensation is configured by connecting the EXTCOMP pin through a 10-kΩ resistance to VDDA. If a 10-kΩ resistor is not detected, the LM25149-Q1 defaults to the external loop compensation network. The transconductance of the amplifier for external compensation is 1200 µS. This is latched and cannot be reconfigured after programmed unless power to the device is recycled. Use an external compensation network if higher performance is required to meet a stringent transient response specification. To reconfigure the compensation (internal or external), remove power and allow VCC to drop below its VCCUVLO threshold, which is 3.3 V typical.
A type-II compensation network is generally recommended for peak current-mode control.