Question:
RESET pin of MAX22513 has dual function of reset input and POK output. How should we use this pin?
Answer:
The new RESET Pin has the following functions
>Power OK Function
•RESET/POK is an open-drain logic output/input that needs a pull-up resistor to VL or VCCB to operate as POK
•RESET/POK is low when the DC/DC and V5 supplies are low
>Note that the VL supply must be present for MAX22513 to be able to actively pull RESET/POK low
•RESET/POK goes high with a delay of 3.3ms/4.4ms after the DC/DC and V5 are in normal operating range 95% of set DC/DC voltage)
>RESET Function
•RESET/POK is also a (active low) RESET input
•When RESET/POK is pulled low, the Registers are reset to default value
•When RESET/POK is driven low, the C/Q and DO drivers are tri-stated
•When RESET/POK is high, both drivers will be operational
>If the DC/DC is not used, then the FB pin must be connected to VCC, so the chip thinks the DC/DC power is OK