VRE3025AS Cirrus Logic Inc, VRE3025AS Datasheet - Page 5

• Manufacturer Part Number: VRE3025AS
• Description: IC VOLT REF PREC 2.5V 8-SMD
• Manufacturer: Cirrus Logic Inc

Specifications of VRE3025AS

• Reference Type: Series
• Voltage - Output: 2.5V
• Tolerance: ±0.25mV
• Temperature Coefficient: 0.6ppm/°C
• Voltage - Input: 8 ~ 36 V
• Number Of Channels: 1
• Current - Quiescent: 4mA
• Current - Output: 15mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SMD
• Product: Voltage References
• Topology: Series References
• Output Voltage: 2.5 V
• Average Temperature Coefficient (typ): 0.6 PPM / C
• Series Vref - Input Voltage (max): 40 V
• Shunt Current (max): 15 mA
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Cathode: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 598-1773

EXTERNAL CONNECTIONS
PIN DESCRIPTIONS
4. BASIC CIRCUIT CONNECTION
To achieve the specified performance, pay careful attention to the layout. A low resistance star configuration will
reduce voltage errors, noise pickup, and noise coupled from the power supply. Commons should be connected to
a single point to minimize interconnect resistances.
5. TEMPERATURE PERFORMANCE
The VRE3025 is designed for applications where the initial error at room temperature and drift over temperature are
important to the user. For many instrument manufacturers, a voltage reference with a temperature coefficient less
than 1 ppm/°C makes it possible to not have to perform a system temperature calibration, a slow and costly process.
Of the three TC specification methods (slope, butterfly, and box), the box method is used commonly used. A box
is formed by the min/max limits for the nominal output voltage over the operating temperature range. The equation
follows:
This method corresponds more accurately to the method of test and provides a closer estimate of actual error than
the other methods. The box method guarantees limits for the temperature error but does not specify the exact shape
and slope of the device under test.
A designer who needs a 14-bit accurate data acquisition system over the industrial temperature range (-40°C to
+85°C), will need a voltage reference with a temperature coefficient (TC) of 1.0 ppm/°C if the reference is allowed
to contribute an error equivalent to 1LSB. For 1/2LSB equivalent error from the reference you would need a volt-
age reference with a temperature coefficient of 0.5 ppm/°C. Figure 4 shows the required reference TC vs. delta T
change from 25°C for resolution ranging from 8 bits to 20 bits.
VRE3025DS
Optional Noise
1, 3, 7
Reduction
2
4
5
6
8
Capacitor
C
N
1µF
T.C. =
N. C.
V
GND
TRIM
OUT
NR
IN
V
NOMINAL
P r o d u c t T e c h n o l o g y F r o m
8
V
Internally connected. Do not use
Positive power supply input
Ground
External trim input. Leave open if not
used.
Voltage reference output
Noise Reduction
VRE3025
MAX
x (T
+ V
– V
2
4
IN
MAX
MIN
– T
6
5
MIN
)
x 10
10kΩ
+ V
Optional Fine
Trim Adjustment
6
OUT
VRE3025
5