JAJSOR9 September 2024 LM70660 , LM706A0
PRODUCTION DATA
The LM706x0 has a high-gain transconductance amplifier that generates an error current proportional to the difference between the feedback voltage and an internal precision reference (0.8V). The control loop compensation can be configured in two ways. The first is using the internal compensation amplifier, which has a gain of 30µS. To use the internal compensation network connect the EXTCOMP through a 100kΩ resistor to the VDDA pin. If a 100kΩ resistor is not detected, the LM706x0 defaults to the external loop compensation network. The external loop compensation network is latched and cannot be re-configured easily. When using the external compensation network, the gain of the transconductance amplifier is 1200µS. Typically if higher performance is required to meet a stringent transient response requirement, TI advises to use external compensation configuration. To re-configure the compensation (internal or external) power must be recycled and VCC must be allowed to drop below the VCCUVLO threshold.
TI generally recommends a type-II compensation network for peak current-mode control. If no external compensation impedance is detected on power up, the fixed internal compensation network is used.