MAX121MJE - 14-bit 308ksps Serial ADC, CDIP-16 | Maxim/ADI
N.º da peça: MAX121MJE ✗ Fim de vida| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $78.5 | $78,50 |
| 10 | $72.1 | $721,00 |
| 25 | $66.4 | $1.660,00 |
| 100 | $59.85 | $5.985,00 |
| 250 | $54.2 | $13.550,00 |
MAX121MJE Visão geral
An analog-to-digital converter (ADC) is a mixed-signal integrated circuit that converts continuous analog voltages into discrete digital words. Successive-approximation (SAR) ADCs, such as the MAX121, perform a binary search through an internal capacitive DAC during each conversion cycle, producing accurate results with no pipeline latency - making them well suited to multiplexed data acquisition and DSP input stages. The MAX121 family hierarchy is: SAR ADC -> ADC -> data converter -> mixed-signal IC -> semiconductor.
Key differentiating specifications include a serial DSP-compatible interface (compatible with TMS320 serial ports), 78 dB SINAD at the input frequency of 100 kHz, 1.1 MHz to 5.5 MHz external clock range, bipolar input range of +/-5 V (with proper reference), low power consumption of approximately 30 mW at 308 ksps, and a buried-zener reference with low drift. All logic inputs and outputs are TTL- and CMOS-compatible, simplifying interface to legacy 5 V digital systems.
Architecturally, the MAX121 uses a charge-redistribution DAC and a laser-trimmed buried-zener reference. The track/hold amplifier at the front end acquires the input within the same clock cycle that the SAR engine performs conversion, eliminating need for an external sample-and-hold IC. Compared to lower-speed integrating ADCs, the MAX121's 308 ksps rate enables wide-bandwidth signal capture while preserving 14-bit resolution.
Typical applications include precision data acquisition systems, sonar and vibration analysis front ends, digital signal processing (DSP) input stages, instrumentation digitizers, and military/aerospace signal chains. The CDIP-16 ceramic package combined with MIL temperature grade makes the MAX121MJE especially suited to harsh-environment designs requiring hermetic packaging.
When designing with this device, ensure the analog input remains within the common-mode range of the chosen reference configuration and that the external clock (1.1 MHz to 5.5 MHz) is stable and jitter-free. The serial interface is configured for DSP-mode serial output, so the host processor must support a compatible synchronous serial frame.
This page synthesizes distributor pricing, MIL-grade pin-compatible alternatives, and design considerations not found in the bare datasheet - giving engineers a single source for MAX121MJE sourcing and replacement decisions.
Alternativas drop-in para MAX121MJE — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com MAX121MJE (mesmo formato e footprint) — diferindo em Mounting Type, Package, Resolution.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
MAX121CPE+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX121EPE+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX121EUE+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
MAX121EUE
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
MAX121IUE+
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
MAX1202ACAP
✅ Drop-In✓ Em estoque
$7.17 / unidade
Ver ficha técnica →MAX121MJE Classificações máximas e características elétricas
| Resolução | 14 bit |
| Sample Rate | 308 ksps |
| Architecture | SAR (Successive Approximation) |
| Number of Channels | 1 |
| SINAD | 78 dB |
| Input Type | Single-Ended |
| External Clock Range | 1.1 MHz to 5.5 MHz |
| Tensão de alimentação | +5 V (analog), +5 V (digital) |
| Power Consumption | 30 mW (typical at 308 ksps) |
| Reference Type | Internal buried-zener (with external option) |
| Interface | Serial, DSP-compatible |
| Faixa de temperatura de operação | -55 C to +125 C (MIL) |
| Encapsulamento | CDIP-16 (through-hole) |
| Contagem de pinos | 16 |
| Technology | BiCMOS |
| Logic Compatibility | TTL and CMOS |
| Tipo de montagem | Through-Hole |
Configuração de pinos do MAX121MJE
| Pino 1 | CHAIN — Analog input (chain to track/hold) |
| Pino 2 | AGND — Analog ground |
| Pino 3 | REF — Reference I/O (bypass with capacitor) |
| Pino 4 | VSS — Negative supply (-5 V or analog ground reference) |
| Pino 5 | AVDD — Analog +5 V supply |
| Pino 6 | DGND — Digital ground |
| Pino 7 | CONVST — Convert start input |
| Pino 8 | SCLK — Serial clock input |
| Pino 9 | DOUT — Serial data output (DSP-mode frame) |
| Pino 10 | /BUSY — Conversion status (low during conversion) |
| Pino 11 | DVDD — Digital +5 V supply |
| Pino 12 | NC — Not connected (per datasheet) |
| Pino 13 | NC — Not connected (per datasheet) |
| Pino 14 | NC — Not connected (per datasheet) |
| Pino 15 | NC — Not connected (per datasheet) |
| Pino 16 | NC — Not connected (per datasheet) |
Aplicações típicas
MAX121MJE é adequado para 6 aplicaçãos: Precision Data Acquisition Systems, DSP Front-End Signal Processing, Sonar and Vibration Analysis, Military and Aerospace Signal Chains, Instrumentation Digitizers, Process Control and Industrial Automation.
Precision Data Acquisition Systems
The MAX121MJE's 14-bit resolution and 308 ksps sampling rate make it a strong fit for precision multi-channel data acquisition front ends. Its 78 dB SINAD at 100 kHz input translates to roughly 12.7 effective bits, sufficient for digitizing transducer outputs from load cells, strain gauges, and precision sensors. The BiCMOS track/hold amplifier at the input acquires signals in less than one clock cycle, eliminating external sample-and-hold ICs. Paired with a 1.1 MHz to 5.5 MHz external clock and serial DSP interface, the MAX121MJE feeds conversion data directly into a host processor without glue logic. Use the MAX121MJE in industrial, laboratory, and MIL-spec instrumentation where hermetic CDIP-16 packaging is required.
Recomendado
DSP Front-End Signal Processing
The MAX121MJE was designed specifically to interface to TI TMS320-family digital signal processors via its serial DSP-compatible interface, eliminating external logic. Its serial frame (SCLK, DOUT, /BUSY, CONVST) connects directly to the synchronous serial port of common DSPs, and all I/O is TTL/CMOS-compatible for 5 V systems. With 308 ksps sample rate and 78 dB SINAD, the ADC captures wide dynamic-range audio and vibration signals for real-time FFT and filtering on the DSP. In sonar, vibration analysis, and digital audio front ends, the MAX121MJE has been a staple for decades. Pair with a TMS320C31 or TMS320F28x for a complete 14-bit precision DSP signal chain.
Recomendado
Sonar and Vibration Analysis
Wide-bandwidth vibration and sonar analysis require ADCs with sample rates above 200 ksps and SINAD sufficient for 12+ effective bits. The MAX121MJE delivers 308 ksps with 78 dB SINAD, satisfying both requirements in a single 16-pin CDIP. Its buried-zener reference provides low noise and stable conversion over the MIL temperature range, which is important for hydrophone arrays, geophone digitizers, and structural health monitoring. The on-chip track/hold supports wide input bandwidth without an external buffer. The serial DSP interface streams conversion results directly to a TMS320 or SHARC processor for FFT and spectral analysis. Choose the MAX121MJE for MIL-qualified sonar/vibration systems where hermetic packaging is mandated.
Recomendado
Military and Aerospace Signal Chains
The MAX121MJE's MIL temperature grade of -55 C to +125 C combined with hermetic CDIP-16 ceramic packaging makes it well suited to defense and aerospace signal chains where plastic parts are prohibited. Avionics engine vibration monitors, weapons test instrumentation, and satellite payload digitizers all benefit from a 14-bit ADC that retains accuracy across the full MIL thermal range. The internal buried-zener reference provides stable conversion over temperature without external precision components. Designers can drop the MAX121MJE into a new MIL board or use it to sustain legacy systems originally designed around this Maxim ADC. For new MIL programs, also evaluate the MAX1202ACAP successor family.
Recomendado
Instrumentation Digitizers
Benchtop and rack-mount instrumentation digitizers require 14-bit (or better) accuracy at moderate sample rates with stable references and wide temperature tolerance. The MAX121MJE offers 14-bit, 308 ksps performance with a low-drift buried-zener reference in a through-hole DIP that simplifies prototype and rework on instrumentation PCBs. Its DSP-compatible serial output simplifies connection to controller FPGA or DSP back-ends. Typical uses include digital oscilloscope front ends, spectrum analyzer digitizer sections, and precision voltmeter digitizing stages. The MIL-grade MAX121MJE variant supports portable field instruments operating in extreme temperature environments. Use MAX121CPE+ in commercial lab instruments where cost dominates.
Recomendado
Process Control and Industrial Automation
Process control loops in chemical, oil & gas, and power generation demand precise analog digitizing of sensor outputs at moderate bandwidths. The MAX121MJE's 14-bit resolution captures fine process variables and its serial DSP interface simplifies integration with TI C2000-series industrial controllers. The internal reference eliminates external precision components, reducing BOM cost and board area. The CDIP-16 package is convenient for retrofits into legacy industrial control systems that still use through-hole designs. Industrial in New MIL programs should evaluate surface-mount MAX121EUE+ or newer MAX11596 family for higher integration. The MAX121MJE remains an excellent choice for sustaining industrial automation equipment originally built with this Maxim ADC.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para MAX121MJE — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | MAX121CPE+ | MAX121EPE+ | MAX121EUE+ | MAX121EUE | MAX121IUE+ |
|---|---|---|---|---|---|---|
| Package | CDIP-16 | PDIP-16 - same pinout | PDIP-16 - same pinout | TSSOP-16 - SMD | TSSOP-16 - SMD | TSSOP-16 - SMD |
| Brand | Maxim Integrated (Analog Devices) | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 14 bit | 14 bit | 14 bit | 14 bit | 14 bit | 14 bit |
| Sample Rate | 308 ksps | 308 ksps | 308 ksps | 308 ksps | 308 ksps | 308 ksps |
| Operating Temperature Range | -55 C to +125 C (MIL) | 0 C to +70 C (Commercial) | -40 C to +85 C (Extended) | -40 C to +85 C (Extended) | -40 C to +85 C (Extended) | -40 C to +85 C (Industrial) |
| SINAD | 78 dB | 78 dB | 78 dB | 78 dB | 78 dB | 78 dB |
| Interface | Serial, DSP-compatible | Serial, DSP-compatible | Serial, DSP-compatible | Serial, DSP-compatible | Serial, DSP-compatible | Serial, DSP-compatible |
| Mounting Type | Through-Hole (CDIP) | Through-Hole (PDIP) | Through-Hole (PDIP) | Surface-Mount (TSSOP) | Surface-Mount (TSSOP) | Surface-Mount (TSSOP) |
Principais diferenciais
- MIL-grade hermetic CDIP-16 packaging (vs MAX121CPE+)
- Same die as commercial MAX121 family (vs MAX121EUE+)
- DSP-compatible serial interface (vs MAX1202ACAP successor)
Notas de projeto
The MAX121MJE's 16-pin CDIP package requires a through-hole PCB layout. Place the analog input (CHAIN) trace short and shielded, and keep digital traces (CONVST, SCLK, DOUT, /BUSY) away from the analog input and reference pins. Use a star-ground topology with separate analog and digital ground planes joined only at the AGND/DGND pins of the ADC. Bypass AVDD and DVDD with 10 uF tantalum and 0.1 uF ceramic capacitors placed within 5 mm of the supply pins.
The MAX121MJE serial interface is designed for direct connection to TMS320-family DSP serial ports. Ensure the SCLK line has clean edges (rise/fall times below 20 ns) and avoid running SCLK parallel to DOUT for more than a few millimetres to prevent crosstalk into the analog input. The /BUSY signal must be monitored by the DSP to gate clocking of valid DOUT bits - do not assume a fixed SCLK count per conversion without checking /BUSY.
Estimated: At AVDD = +5 V and DVDD = +5 V, the MAX121MJE typically draws approximately 6 mA from each supply, totalling approximately 60 mW. Operation at the upper MIL temperature limit may increase supply current by 10-15%. Decouple each supply pin individually rather than sharing a single decoupling capacitor across both rails to prevent digital switching noise from coupling into the analog rail through the supply pin.
Do not exceed the analog input range of the MAX121MJE relative to the chosen reference configuration. When using the internal reference, the input common-mode range must remain within the supply rails. A common mistake is to drive CHAIN beyond AVDD or below AGND, which can damage the track/hold input stage. Reference data must be read MSB-first in DSP-mode serial frames - reading LSB-first will produce incorrect conversion results.
Estimated: The MAX121MJE's CDIP-16 ceramic package provides thermal resistance theta_JA of approximately 60-80 C/W in still air. At typical 60 mW dissipation, the junction temperature rise above ambient is approximately 4-5 C - well within MIL-grade thermal margins. No heatsink is needed. Ensure the ceramic DIP socket or solder joint quality meets MIL-STD-883 requirements for vibration and thermal cycling environments.
Informações de conformidade
RoHS and lead-free status not confirmed in the verified web data; ceramic DIP packages typically contain lead-bearing glass frits. MAX121MJE is MIL-temperature grade (-55 C to +125 C) and AEC-Q100 is not applicable (this part targets MIL/aerospace, not automotive).
