liuyonggen_1
Full Member level 4
could someone help me?
tha attachment is the structure of bandgap voltage reference. the simulation result showed that the output is about 1.12v with 10ppm.
but when I measured it after taped out, the output voltage is about 0.7v.
the following will show you the performance of the elements.
the threshold voltage of the BJT is about 0.8v. its current gain is about 10 (very small). maybe, the matching between the resistance is bad.
could you explain it for me ? thanks a lot!
tha attachment is the structure of bandgap voltage reference. the simulation result showed that the output is about 1.12v with 10ppm.
but when I measured it after taped out, the output voltage is about 0.7v.
the following will show you the performance of the elements.
the threshold voltage of the BJT is about 0.8v. its current gain is about 10 (very small). maybe, the matching between the resistance is bad.
could you explain it for me ? thanks a lot!