Maxim-integrated MAXQ7666 Manual de usuario Pagina 113

  • Descarga
  • Añadir a mis manuales
  • Imprimir
  • Pagina
    / 386
  • Tabla de contenidos
  • MARCADORES
  • Valorado. / 5. Basado en revisión del cliente
Vista de pagina 112
MAXQ7665/MAXQ7666 Users Guide
3-23
Table 3-5 shows the input range for various PGA settings (PGG2:PGG0) in unipolar mode. When the PGA is used (gain > 1), the dif-
ferential input range at the analog multiplexer input is reduced by the gain factor. The maximum PGA output value is limited to 3.2V.
For gain > 1, differential input range x PGA gain 3.2V and the ADC output code range is limited to 0–2621 (decimal).
Table 3-5. Unipolar Input Scaling
The MAXQ7665/MAXQ7666 ADC output is two’s complement in bipolar mode. Figure 3-6 shows the MAXQ7665/MAXQ7666 ADC bipo-
lar transfer function for PGA gain = 1. Table 3-6 shows the bipolar relationship between the differential analog input voltage and the
digital output code for PGA gain = 1. In bipolar mode, the inputs are measured in a truly differential fashion where either input can
exceed the other by up to REFADC/2 (for gain = 1, but limited for gain > 1).
PGG2 PGG1 PGG0
GAIN
FACTOR
DIFFERENTIAL INPUT
RANGE AT MUX
INPUTS
DIFFERENTIAL INPUT
RANGE WITH 5.0V
EXTERNAL REFERENCE
LSB SIZE WITH 5.0V
EXTERNAL
REFERENCE
OUTPUT CODE RANGE
(DECIMAL)
0 0 0 x1 0 to +REFADC 0 to 4.99878V 1.22mV 0–4095
0 0 1 x2
0 to +REFADC/2
(1.6V max)
0 to 1.6V
610.35V
0 1 0 x4
0 to +REFADC/4
(0.8V max)
0 to 0.8V
305.18V
0 1 1 x8
0 to +REFADC/8
(0.4V max)
0 to 0.4V
152.59V
1 0 0 x16
0 to +REFADC/16
(0.2V max)
0 to 0.2V
76.29V
1 0 1 x32
0 to +REFADC/32
(0.1V max)
0 to 0.1V
38.15V
0–2621
(REFADC = +5V)
Figure 3-6. Bipolar Transfer Function (PGA Gain = 1)
800
801
FFE
001
000
FFF
7FE
7FF
-FS
0
+FS
OUTPUT CODE (hex)
DIFFERENTIAL INPUT VOLTAGE (LSB)
+FS - 1.5 LSB
FULL-SCALE
TRANSITION
+FS = REFADC / 2
ZS = 0
-FS = -REFADC / 2
1 LSB = REFADC / 4096
-FS + 0.5 LSB
Maxim Integrated
Vista de pagina 112
1 2 ... 108 109 110 111 112 113 114 115 116 117 118 ... 385 386

Comentarios a estos manuales

Sin comentarios