Common issues in BJT diff pair

BJT diff pair

Routing

(by TA)

1. unfinished routing

2. one stage diff pair 是沒有 miller 電容 cc

miller 電容在 stage 2 

Parameter Optimization

 (by TA)

1. SA 是無效的    

檢查sa 效能 

2. 檢查是否合規 

gain 47.6 db 不夠

PM 0 很危險，不穩定

GBW 太大

設計目標 (3.3V):

Ad ≥ 50 dB  |  CMRR ≥ 80 dB

GBW ≥ 100 MHz  |  PM 55°–75°

Vos ≤ 1 mV  |  Pd ≤ 20 mW

Poly R: 250 Ω/sq (±20%)

MIM C: 1 fF/μm² (±15%)

refer to sample