MAX120/MAX122
500ksps, 12-Bit ADCs with Track/Hold
and Reference
General Description
The MAX120/MAX122 complete, BiCMOS, sampling 12-bit
analog-to-digital converters (ADCs) combine an on-chip
track/hold (T/H) and a low-drift voltage reference with fast
conversion speeds and low-power consumption. The T/H’s
350ns acquisition time combined with the MAX120’s 1.6µs
conversion time results in throughput rates as high as 500k
samples per second (ksps). Throughput rates of 333ksps
are possible with the 2.6µs conversion time of the MAX122.
The MAX120/MAX122 accept analog input voltages from
-5V to +5V. The only external components needed are
decoupling capacitors for the power-supply and reference voltages. The MAX120 operates with clocks in the
0.1MHz to 8MHz frequency range. The MAX122 accepts
0.1MHz to 5MHz clock frequencies.
The MAX120/MAX122 employ a standard microprocessor
(µP) interface. Three-state data outputs are configured
to operate with 12-bit data buses. Data-access and busrelease timing specifications are compatible with most
popular µPs without resorting to wait states. In addition,
the MAX120/MAX122 can interface directly to a first-in,
first-out (FIFO) buffer, virtually eliminating µP interrupt
overhead. All logic inputs and outputs are TTL/CMOS
compatible. For applications requiring a serial interface,
refer to the MAX121.
Applications
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Digital-Signal Processing
Audio and Telecom Processing
Speech Recognition and Synthesis
High-Speed Data Acquisition
Spectrum Analysis
Data Logging Systems
Pin Configuration
TOP VIEW
1
+
MODE
RD
24
2
VSS MAX122 CS
23
3
VDD
INT/BUSY
22
4
AIN
CLKIN
21
5
VREF
CONVST
20
6
AGND
D0
19
7
D11
D1
18
8
D10
D2
17
9
D9
D3
16
10
D8
D4
15
11
D7
D5
14
12
DGND
D6
13
MAX120
PDIP/SO/SSOP
19-0030; Rev 1; 3/12
Features
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12-Bit Resolution
No Missing Codes Over Temperature
20ppm/°C -5V Internal Reference
1.6µs Conversion Time/500ksps Throughput
(MAX120)
2.6µs Conversion Time/333ksps Throughput
(MAX122)
Low Noise and Distortion:
• 70dB (min) SINAD
• -77dB (max) THD (MAX122)
Low Power Dissipation: 210mW
Separate Track/Hold Control Input
Continuous-Conversion Mode Available
±5V Input Range, Overvoltage Tolerant to ±15V
24-Pin Narrow DIP, Wide SO, and SSOP Packages
Ordering Information
PART
TEMP RANGE
PINPACKAGE
INL
(LSB)
MAX120CNG+
0°C to +70°C
24 PDIP
±1
MAX120CWG+
0°C to +70°C
24 Wide SO
±1
MAX120CAG+
0°C to +70°C
24 SSOP
±1
MAX120ENG+
-40°C to +85°C
24 PDIP
±1
MAX120EWG+
-40°C to +85°C
24 Wide SO
±1
+Denotes a lead(Pb)-free/RoHS-compliant package.
Functional Diagram
