VRE104

4

VRE104DS

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

4. APPLICATION INFORMATION

The proper connection of the VRE104 series voltage references is shown below with the optional trim resistors. Pay

careful attention to the circuit layout to avoid noise pickup and voltage drops in the lines.

The VRE104 series voltage references have the ground terminal brought out on two pins (pin 6 and pin 7) which

are connected together internally. This allows the user to achieve greater accuracy when using a socket. Voltage

references have a voltage drop across their power supply ground pin due to quiescent current flowing through the

contact resistance. If the contact resistance was constant with time and temperature, this voltage drop could be

trimmed out. When the reference is plugged into a socket, this source of error can be as high as 20 ppm. By con-

necting pin 7 to the power supply ground and pin 6 to a high impedance ground point in the measurement circuit,

the error due to the contact resistance can be eliminated. If the unit is soldered into place, the contact resistance is

sufficiently small that it does not effect performance.

VRE104 Used With Crystal Semiconductor ADC

Suggested Reading: Crystal Semiconductor Application Note -

“Voltage References for the CS501X/CS25IIX Series of A/D Converters"

EXTERNAL CONNECTIONS

PIN CONFIGURATION

1. Optional Fine Adjust for approximately ±10mV.

TOP VIEW

VRE104

+PS

NC

NC

NC

GND

REF. GND

NC

NC

NC

NC

NC

FINE ADJ.

FINE ADJ.

+4.5V