vbe curvature
Hi,
Curvature compensation try to cancel the nonlinear component of the base-emitter voltage Vbe.
Generaly, Vbe(T)=Vgo - B*T - C*f(T) ,
where Vgo, B, C - temperature-independent constants.
1-st order references sum a positive linear T-dependent voltage to a Vbe to cancel the effect of constant B.
2-order BG reference sum a T-dependent voltage exhibiting both a positive linear and positive nonlinear T-dependence, i.e.
Vref=Vbe(T)+Vx(T)=Vbe(T)+D*T+E*f2(T)=Vgo.
The most common technique used to generate E*f2(T) is the squared PTAT compensation scheme.
Pls reference to
G.A.Rincon-Mora, Voltage references.
regards,
Uladz55