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module information
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measure_fuse: measure the resistor of fuse (rfuse) with LZB source. When rfuse<300 ohm, fuse_meas =0, else fuse_meas=1.
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check_fuse_connection: check the fuse_meas, when some fuses always open(fuse_meas==1), fuse_connection=1.
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get_value_no_trim: test the parameter before trimming (value_bf_trim), and seek the trim table(p_fuse_cond) with fuse_meas , when the fuse_meas accord to the trim table, record the row number(cond_no) of the trim table.
Value_no_trim=value_bf_trim /(1+ p_fuse_cond[cond_no].average_pct)
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get_trim_flag: get the target adjustment,
adj_value= (target_value - value_no_trim) / value_no_trim ,
and seek the trim table to get the condition number(cond_no) when the adjust_target is closest to adj_value. Then get the trim_flag from this condition row.
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store_adj: store value_bf_trim , fuse_meas, value_af_trim, cond_no to tr_adj_store.
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update_adj: update the actual adjustment (Actual_adj) which recorded at the previous test to the relevant condition row of the trim table.
Actual_adj = (value_af_trim-value_bf_trim)/ value_bf_trim *100
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Dynamic Adjustment effection( MTM vs. CTM , A0175A051 as example)
Before trimming
A0175A051-29116690w014
Trim with CTM
A0175A051-29116690w014 (CPK:1.0)
Trim with MTM
A0175A051-29116690w020(CPK:1.4)
A0175A051-29104370_1w021 (CPK:1.0)
Trim with MTM
A0175A051-29116690w021 CPK:1.4)
Conclusion: CPK increase when trim with MTM.
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Re-trim effection (uu002 as example)
Before trimming
Trim with CTM (target value:3.30V)
Re-trim with MTM (change target value from 3.3V to 3.5V according to the requests of customer)
Conclusion: Yield after re-trim: 52% (limitation: 3.41V~3.59V), low yield because the fine regulation of UU002 can’t re-trimming after the first trimming and the precision of coarse regulation is low ( about 5%) .
2009-5-27
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