Datasheet

71M6541D/F/G and 71M6542F/G Data Sheet
Rev 4 149
6.4.14 VREF
Table 109 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,
ILOAD = 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
TCT
TC
TVREFTVNOM −+
−
+=
V
VNOM temperature
coefficients:
TC1 =
TC2 =
TRIMT⋅− 95.4275
TRIMT⋅−− 00028.0557.0
µV/°C
µV/°C
2
VREF(T) deviation from
VNOM(T) (see note 1):
62
10
)(
)()(
6
TVNOM
TVNOMTVREF −
-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.