MAX148BMJP Maxim Integrated, MAX148BMJP Datasheet - Page 19

• Manufacturer Part Number: MAX148BMJP
• Description: Analog to Digital Converters - ADC
• Manufacturer: Maxim Integrated

Specifications of MAX148BMJP

• Number Of Channels: 8/4
• Architecture: SAR
• Conversion Rate: 133 KSPs
• Resolution: 10 bit
• Input Type: Single-Ended/Differential
• Snr: Yes
• Interface Type: 4-Wire, Microwire, QSPI, Serial, SPI
• Operating Supply Voltage: 2.7 V to 5.25 V
• Maximum Operating Temperature: + 125 C
• Package / Case: CDIP N
• Maximum Power Dissipation: 640 mW
• Minimum Operating Temperature: - 55 C
• Number Of Converters: 1
• Voltage Reference: External

Table 7. Full Scale and Zero Scale
Figure 18. Bipolar Transfer Function, Full Scale (V
+ V
deliver up to 350FA DC load current and have 10I or
less output impedance. If the reference has a higher
output impedance or is noisy, bypass it close to the V
pin with a 4.7FF capacitor.
Using the REFADJ input makes buffering the external
reference unnecessary. To use the direct V
disable the internal buffer by tying REFADJ to V
In power-down, the input bias current to REFADJ is
typically 25FA (MAX149) with REFADJ tied to V
REFADJ to AGND to minimize the input bias current in
power-down.
*V
COM
COM
011 . . . 111
011 . . . 110
000 . . . 010
000 . . . 001
000 . . . 000
111 . . . 111
111 . . . 110
111 . . . 101
100 . . . 001
100 . . . 000
V
REF
, Zero Scale (ZS) = COM
Full Scale
≥ V
OUTPUT CODE
REF
+ V
/2
COM
-V
V
1 LSB =
- FS
FS
UNIPOLAR MODE
ZS = COM
FS
=
=
-V
+2.7V to +5.25V, Low-Power, 8-Channel,
V
REF
REF
2
2
V
1024
REF
+ V
+ V
COM
COM
INPUT VOLTAGE (LSB)
Zero Scale
COM*
V
COM
FS
+FS - 1 LSB
REF
) = V
DD
input,
REF
. Pull
Positive Full Scale
REF
V
DD
REF
/2
.
/2 + V
Figure 19. Power-Supply Grounding Connection
Table 7 shows the full-scale voltage ranges for unipolar
and bipolar modes.
The external reference must have a temperature coef-
ficient of 20ppm/NC or less to achieve accuracy to within
1 LSB over the 0NC to +70NC commercial temperature
range.
Figure 17 depicts the nominal, unipolar input/output
(I/O) transfer function, and Figure 18 shows the bipolar
input/output transfer function. Code transitions occur
halfway between successive-integer LSB values. Output
coding is binary, with 1 LSB = 2.44mV (2.500V/1024)
for unipolar operation, and 1 LSB = 2.44mV [(2.500V/2 -
-2.500V/2)/1024] for bipolar operation.
COM
R* = 10Ω
*OPTIONAL
V
+3V
DD
Serial 10-Bit ADCs
BIPOLAR MODE
Zero Scale
V
AGND
COM
MAX148
MAX149
SUPPLIES
COM
Transfer Function
DGND
Negative Full Scale
- V
REF
/2 + V
+3V
+3V
CIRCUITRY
DIGITAL
COM
DGND
GND
19