14 vref, Vref, Table 110: vref performance specifications – Rainbow Electronics 71M6542G User Manual
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© 2008–2011 Teridian Semiconductor Corporation
v1.1
6.4.14 VREF
shows the performance specifications for the ADC reference voltage (VREF).
Table 109: VREF Performance Specifications
Parameter
Condition
Min
Typ
Max
Unit
VREF output voltage,
VREF(22)
T
A
= 22 ºC
1.193
1.195
1.197
V
VREF output voltage,
VREF(22)
PLL_FAST=0
1.195
V
VREF output impedance
VREF_CAL = 1,
I
LOAD
= 10 µA, -10 µA
3.2
kΩ
VREF power supply sensitivity
ΔVREF / ΔV3P3A
V3P3A = 3.0 to 3.6 V
-1.5
1.5
mV/V
VREF input impedance
VREF_DIS = 1,
VREF = 1.3 V to 1.7 V
100
kΩ
VREF chop step, trimmed
VREF(CHOP=01)
−
VREF(CHOP=10)
-10
0
10
mV
VNOM definition (see note 2)
2
)
22
(
1
)
22
(
)
22
(
)
(
2
TC
T
TC
T
VREF
T
VNOM
−
+
−
+
=
V
VNOM temperature
coefficients:
TC1 =
TC2 =
TRIMT
⋅
− 95
.
4
275
TRIMT
⋅
+
−
00028
.
0
557
.
0
µV/°C
µV/°C
2
VREF(T) deviation from
VNOM(T) (see note 1):
62
10
)
(
)
(
)
(
6
T
VNOM
T
VNOM
T
VREF
−
-40
+40
ppm/°C
VREF aging
±25
ppm/
year
Notes:
1. Guaranteed by design; not production tested.
2. This relationship describes the nominal behavior of VREF at different temperatures, as
governed by a second order polynomial of 1
st
and 2
nd
order coefficients TC1 and TC2.
3. For the parameters in this table, unless otherwise specified, VREF_DIS = 0, PLL_FAST=1