Datasheet

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SLAS361D − JANUARY 2002 − REVISED AUGUST 2004
26
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature (unless otherwise
noted) (continued)
10-bit ADC, built-in reference
PARAMETER TEST CONDITIONS MIN NOM MAX UNIT
Positive built-in reference
REF2_5V = 1 for 2.5 V
I
VREF+
≤ I
VREF+
max
V
CC
= 3 V 2.35 2.5 2.65
V
REF+
Positive built-in reference
voltage output
REF2_5V = 0 for 1.5 V
I
VREF+
≤ I
VREF+
max
V
CC
=
2.2 V/3 V
1.41 1.5 1.59
V
REF2_5V = 0, I
VREF+
≤ 1mA 2.2
V
CC(min)
V
CC
minimum voltage,
Positive built-in reference
REF2_5V = 1, I
VREF+
≤ 0.5mA V
REF+
+ 0.15
VV
CC(min)
Positive built-in reference
active
REF2_5V = 1, I
VREF+
≤ 1mA V
REF+
+ 0.15
V
Load current out of V
REF+
V
CC
= 2.2 V ±0.5
I
VREF+
Load current out of V
REF+
terminal
V
CC
= 3 V ±1
mA
I
VREF+
= 500 µA +/− 100 µA
V
CC
= 2.2 V ±2
Load-current regulation
Analog input voltage ~0.75 V;
REF2_5V = 0
V
CC
= 3 V ±2
LSB
I
L(VREF)+
†
Load-current regulation
V
REF+
terminal
I
VREF+
= 500 µA ± 100 µA
Analog input voltage ~1.25 V;
REF2_5V = 1
V
CC
= 3 V ±2 LSB
Load current regulation
I
VREF+
=100 µA → 900 µA,
ADC10SR = 0 400
t
DL(VREF) +
‡
Load current regulation
V
REF+
terminal
V
CC
=3 V, Ax ~0.5 x V
REF+
Error of conversion result ≤ 1 LSB
ADC10SR = 1 2000
ns
C
VREF+
Capacitance at pin V
REF+
(see Note 1)
REFON =1, I
VREF+
≤±1 mA
V
CC
=
2.2 V/3 V
100 pF
T
REF+
†
Temperature coefficient of
built-in reference
I
VREF+
is a constant in the range of
0 mA ≤ I
VREF+
≤ 1 mA
V
CC
=
2.2 V/3 V
±100 ppm/°C
Settle time of internal
I
VREF+
= 0.5 mA,V
REF+
= 1.5 V, V
CC
= 3.6 V,
REFON = 0 → 1
30
t
REFON
†
reference voltage and
V
REF+
I
VREF+
= 0.5 mA, V
REF+
= 1.5 V,
ADC10SR = 0 0.8
µs
V
REF+
(see Note 2)
I
VREF+
= 0.5 mA, V
REF+
= 1.5 V,
V
CC
= 2.2 V, REFON = 1
ADC10SR = 1 2.5
†
Not production tested, limits characterized
‡
Not production tested, limits verified by design
NOTES: 1. The capacitance applied to the internal buffer operational amplifier, if switched to terminal P2.4/TA2/A4/V
REF+
/V
eREF+
(REFOUT=1),
must be limited; the reference buffer may become unstable otherwise.
2. The condition is that the error in a conversion started after t
REFON
is less than ±0.5 LSB.