Li-ion charger modeled after schematic on datasheet page 35.
Design specs
DCIN 22 - 24V
Vbat 12.3V
Max charge current 20A.
How it works
With the battery at 6.3V, DCIN = 24V/3A from bench supply, Green LED comes on
INTVcc = 5.01V
FB = 1.42V
Enab = 1.49V
LB = 1.22V
SW:
Scope says it's 917kHz, with 232K on RT. (in-circuit with power off and caps drained it measures 146K.)
TG:
BG:
A DVM with a current shunt says there's no charging current.
The bench supply says it's supplying .011A
(With DCIN turned off, and an auto headlamp on the battery, the DVM says it draws 6.6A, so it can measure current.)
What do I need to look at to get it charging?