This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM5066I: and LM5069 Built-in Reverse Protection Diode

Part Number: LM5066I
Other Parts Discussed in Thread: LM5069, LM5066

Hello TI,

I have two equivalent designs using LM5066 and LM5069. While testing for reverse input voltage behaviour, I discovered that these 2 parts have internal diode voltage when measured from GND to each pin. However, the internal diodes are not illustrated in the component block diagram.

Can you help to confirm the presence of the internal diode, its type and purpose?

LM5066 and LM5069 datasheet recommends output schottky diode for inductive loads, but only LM5066 datasheet suggests zener diode at the input (Figure 36)

LM5066

Measurements taken on LM5066 component removed from PCB

Pin # Pin GND-Pin (V) Pin # Pin GND-Pin (V)
1 OUT 0.679 15 VREF 0.569
2 GATE 0.616 16 DIODE 0.574
3 SENSE 0.630 17 VAUX 0.574
4 VIN_K 0.604 18 ADR2 0.573
5 VIN 0.604 19 ADR1 0.574
6 NC OL 20 ADR0 0.574
7 UVLO/EN 0.668 21 VDD 0.498
8 OVLO 0.165 22 CL 0.618
9 AGND 0.000 23 FB 0.680
10 GND 0.000 24 RETRY~ 0.661
11 SDAI 0.572 25 TIMER 0.616
12 SDAO 0.572 26 PWR 0.608
13 SCL 0.574 27 NC OL
14 SMBA~ 0.757 28 PGD 0.637

LM5069

Measurements taken on LM5066 component removed from PCB

Pin # Pin GND-Pin (V)
1 SENSE 0.711
2 VIN 0.608
3 UVLO 0.675
4 OVLO 0.661
5 GND 0.000
6 TIMER 0.658
7 PWR 0.650
8 PGD 0.635
9 OUT 0.685
10 GATE 0.612