MAX126BC/D Maxim Integrated, MAX126BC/D Datasheet - Page 11

• Manufacturer Part Number: MAX126BC/D
• Description: Analog to Digital Converters - ADC NULL
• Manufacturer: Maxim Integrated

Specifications of MAX126BC/D

• Number Of Channels: 8
• Architecture: SAR
• Conversion Rate: 250 KSPs
• Resolution: 14 bit
• Input Type: Single-Ended
• Interface Type: Parallel
• Operating Supply Voltage: +/- 2.5 V
• Maximum Power Dissipation: 941 mW
• Number Of Converters: 1
• Voltage Reference: 2.5 V

The minimum output voltage is within millivolts of
ground for single-supply operation where the load is
referenced to ground (V
voltage range and output voltage swing of a MAX4131
connected as a voltage follower. With a +3V supply
and the load tied to ground, the output swings from
0.00V to 2.90V. The maximum output voltage swing
depends on the load, but will be within 150mV of a +3V
supply, even with the maximum load (500Ω to ground).
Figure 3. Rail-to-Rail Input/Output Voltage Range
Figure 5. MAX4131 Small-Signal Transient Response with
Capacitive Load
Single/Dual/Quad, Wide-Bandwidth, Low-Power,
OUT
OUT
IN
IN
V
CC
______________________________________________________________________________________
= 3V, R
Single-Supply, Rail-to-Rail I/O Op Amps
Rail-to-Rail Output Stage
L
TIME (200ns/div)
TIME (1µs/div)
EE
= 10kΩ to V
). Figure 3 shows the input
EE
V
R
C
CC
L
L
= 130pF
= 10kΩ
= 5V
Driving a capacitive load can cause instability in most
high-speed op amps, especially those with low quies-
cent current. The MAX4130–MAX4134 have a high tol-
erance for capacitive loads. They are stable with
capacitive loads up to 160pF. Figure 4 gives the stable
operating region for capacitive loads. Figures 5 and 6
show the response with capacitive loads and the
results of adding an isolation resistor in series with the
output (Figure 7). The resistor improves the circuit’s
phase margin by isolating the load capacitor from the
op amp’s output.
Figure 4. Capacitive-Load Stability
Figure 6. MAX4131 Transient Response to Capacitive Load
with Isolation Resistor
500
450
400
350
300
250
200
150
100
50
OUT
0
IN
0.1
R
V
OUT
L
TO V
= V
EE
CC
LOAD RESISTANCE (kΩ)
/2
1
TIME (500ns/div)
OPERATING
UNSTABLE
REGION
OPERATING
V
C
R
STABLE
REGION
CC
L
S
10
= 1000pF
= 39Ω
= 5V
100
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