有人care過bandgap可能存在不止1個degenerate points(stable points)嗎？

hi.china59

有人care過bandgap可能存在不止1個degenerate points(stable points)嗎？
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The degenerate point of Bandgap reference circuit
Q:有人care過bandgap可能存在不止1個degenerate points(stable points)嗎？
3 k3 u( o) h$ {2 n  ZA: We do care the degenerate points of a bandgap reference circuit. The bandgap reference circuit needs a more effective startup circuit than those usually adopted. The crossing (degenerate) points are much less defined. Please read the attached bandgap degenerate points.pdf

0 e& G" k0 a# f) ^============================================================
' R% q3 Q9 b7 A$ G  l3 {8 N' LLow Voltage Bandgap Reference Circuit
, e0 p5 |2 D7 w, _Patent number: 6489835
  R) O. y- V) n9 }1 m0 N) z% P' aFiling date: Aug 28, 2001
( ^9 Z) u) v& y3 T+ N7 q/ v" vIssue date: Dec 3, 2002
Inventors: Quan Yu, Edwin Chan
5 n' u2 ~7 K/ K5 AAssignee: Lattice Semiconductor Corporation

Banba et al, in "A CMOS Bandgap Reference Circuit with Sub-1-V Opeation", discloses a bandgap reference circuit that can operate at supply voltage down to about 1V.  This configuration needs two additional resistors, RA and RB, to generate CTAT currents.  However, these two resistors will result in more than one opeating point, especially when the drain voltages of PMOS transistors, drops below ΔVbe(i.e., when the two bipolar devices are turns off).  Existence of more than one opeating point makes the start-up circuit very complex, or requires an additional circuit to gurantee achievement of a proper operating point.  Without such a circuit, the risk of having an undesired operating point is high.
This configuration differs from Banba's circuit in several ways.
5 u# p# B  |/ U: n5 A, g: l' y1. Only one resistor, RC, is added to provide an CTAT current, rather than need two such resistors.
2. Only one non-zero initial current, and this system will move to this point after power-up.
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6 }) ^* z/ ?# Q4 |  f" R( KLow_voltage_bandgap_reference_circuit.pdf

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a1654812398

這是個很重要的問題~之前有遇過
謝謝樓主的分享~

suz

xiexie！thanks for share！

pooq2597

感謝大大分享
8 Z$ Z9 M' s- ^9 F) L% @. V  a學習學習

何建頫@FB

從來沒有想過這問題
感謝大大的提點

李柏毅@FB

good!!! good!!!, ^+ a8 N9 [( d3 s2 T % e% t' p6 H% T" I' Fthanks for sharing!!!

f4612

這是個很重要的問題
謝謝樓主的分享~

tfkc1744990

最近遇到,來參考一下

感謝大大分享

LiYingLi@FB

好像沒考慮過這個問題!!!

grant7163

Thx for share ! It is very useful !

engineer

Of course, it may stuck at the initial state.  That's why a startup circuit is required to bring the BG out of the initial state to the operating point.

spreecat

剛進入LDO,BG設計研究，感謝分享資料。

abner2

It's so helpful.
- z2 _) T  {8 `6 l. gThanks for sharing!!!!!

xtcel246

thanks for sharing, good topic !

bomora

回復 1# hi.china59
/ c" w$ s, x" D7 r6 d' E
: b: E. m% b% t6 a
( D9 O) X! u/ d; A* ^+ ^' rgood!!
thanks for sharing.......

yuri

Thank you! It's good information for me 'cause I'm struggling with this.

game750219

Thx for share ! It is very useful !

pocket112

只考慮過一個的，再多了也不會了

xyzw

衝一下人氣喔
衝一下人氣喔
衝一下人氣喔

alibiwei

good question!
thanks for your sharing.