VRE210

VRE210DS

3

P r o d u c t I n n o v a t i o n F r o m

VRE210C

VRE210CA

QUIESCENT CURRENT VS. TEMP

JUNCTION TEMP. RISE VS. OUTPUT CURRENT

Output Current (mA)

PSRR VS. FREQUENCY

Frequency (Hz)

VRE210M

VRE210MA

0.8

-0.8

-0.6

0.6

-1.2

1.2

-1.0

1.0

2. TYPICAL PERFORMANCE CURVES

3. THEORY OF OPERATION

The following discussion refers to the block diagram in Figure 1. In operation, approximately 6.3 volts is applied to

the noninverting input of the op amp. The voltage is amplified by the op amp to produce a 10 V output. The gain is

determined by the networks R1 and R2: G=1 + R2/R1. The 6.3V zener diode is used because it is the most stable

diode over time and temperature.

The zener operating current is derived from the regulated output voltage through R3. This feedback arrangement

provides a closely regulated zener current. This current determines the slope of the references’ voltage vs. tempera-

ture function. By trimming the zener current a lower drift over temperature can be achieved. But since the voltage

vs. temperature function is nonlinear this compensation technique is not well suited for wide temperature ranges.

A nonlinear compensation network of thermistors and resistors that is used in the VRE series voltage references.

This proprietary network eliminates most of the nonlinearity in the voltage vs. temperature function. By then adjust-

ing the slope, Thaler Corporation produces a very stable voltage over wide temperature ranges. This network is less

than 2% of the overall network resistance so it has a negligible effect on long term stability. By using highly stable

resistors in our network, we produce a voltage reference that also has very good long term stability.