MAX1238KEEE+T - 12-Bit, 12-Channel SAR ADC | Maxim Integrated
Teilenummer: MAX1238KEEE+T ✓ Aktiv| Menge | Stückpreis | Gesamt |
|---|---|---|
| 1 | $8.46 | $8,46 |
| 10 | $7.61 | $76,10 |
| 100 | $6.77 | $677,00 |
| 500 | $6.09 | $3.045,00 |
| 1.000 | $5.42 | $5.420,00 |
| 2.500 | $4.91 | $12.275,00 |
MAX1238KEEE+T Übersicht
A SAR ADC (Successive Approximation Register ADC) is a type of analog-to-digital converter that uses a binary search through an internal DAC to resolve an analog input into a digital code, one bit per conversion clock cycle. The SAR ADC family sits within the broader hierarchy of ADCs -> data converters -> mixed-signal ICs -> integrated circuits, and it is widely used when designers need a deterministic acquisition time, low latency, and moderate resolution (typically 8 to 18 bits) at sample rates up to a few MSPS.
Key features include 12-bit resolution with no missing codes, software-configurable unipolar/bipolar input ranges, an internal 2.5V reference (4.096V in the MAX1239 variant), single-ended or pseudo-differential channel configurations, and an I2C-compatible serial interface supporting both 400 kHz Fast Mode and 1.7 MHz High-Speed Mode. The 16-pin QSOP package measures approximately 3.9 mm wide, suiting compact PCB layouts where multiple analog sensors must be digitized close to the controller.
The architecture combines a capacitive DAC, a high-bandwidth track/hold front end, and an on-chip oscillator, eliminating the need for external precision components. An integrated sequencer can automatically scan all configured channels in one I2C transaction, reducing host firmware overhead in multi-sensor data acquisition loops.
Typical applications include battery monitoring in portable medical and industrial equipment, multi-cell battery pack voltage sensing in power tools and e-bikes, front-end digitizing for PLC analog input modules, temperature/pressure transducer arrays in process control, and general-purpose sensor multiplexing in 4 mA to 20 mA loop replacement designs.
When designing with this ADC, place the 0.1 µF supply bypass capacitor as close to pin 16 (VDD) and pin 1 (GND) as possible. Because the reference is internal, supply noise above 100 kHz couples directly into the conversion result; a ferrite bead or pi-filter on AVDD/REF is recommended when the part shares a rail with noisy digital or switching loads.
This page synthesizes distributor pricing from DigiKey and Mouser, pin-compatible same-family drop-in alternatives, and PCB-level design notes that are not duplicated in the manufacturer datasheet.
Drop-in-Alternativen für MAX1238KEEE+T – gleiches Gehäuse, Pin-kompatibel. Bauteile mit anderem Gehäuse, die eine PCB-Überarbeitung erfordern, sind ausgeschlossen.
Varianten dieser Serie
Modelle derselben Serie, die drop-in-kompatibel sind mit MAX1238KEEE+T (gleiche Bauform und Footprint) – abweichend in Resolution, Architecture, Package, Interface, Internal Reference Voltage.
Schnellvergleichstool – Wählen Sie Alternativbauteile für den Direktvergleich:
MAX1238EEE+
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
MAX1238KEEE+
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
MAX1239EEE+
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
MAX1239KEEE+T
✅ Drop-In📋 Referenzalternative (nicht im Katalog)
MAX1139MEEE+T
✅ Drop-In✓ Auf Lager
$3.9 / Stück
Datenblatt ansehen →MAX1139KEEE+
✅ Drop-In✓ Auf Lager
$4.45 / Stück
Datenblatt ansehen →MAX1238KEEE+T Grenzwerte & elektrische Eigenschaften
| Auflösung | 12 bit |
| Number of Analog Input Channels | 12 (single-ended) / 6 (pseudo-differential) |
| Architecture | SAR (Successive Approximation Register) |
| Input Type | Single-Ended, Pseudo-Differential |
| Supply Voltage - 3.3V Mode | 2.7 V to 3.6 V |
| Supply Voltage - 5V Mode | 4.5 V to 5.5 V |
| Supply Current at Max Throughput | 670 uA |
| Shutdown Supply Current | 1 uA |
| Internal Reference Voltage | 2.5 V |
| Digital Interface | I2C-compatible 2-wire serial (Fast Mode 400 kHz, High-Speed Mode 1.7 MHz) |
| Betriebstemperaturbereich | -40 C to +85 C (extended) |
| Gehäuse | 16-QSOP (0.154 inch / 3.90 mm width) |
| Montageart | Surface Mount |
| Sampling Architecture | Internal Track/Hold with on-chip oscillator |
| RoHS-Status | Compliant |
| Terminal Form | GULL WING |
| Temperature Grade | INDUSTRIAL |
MAX1238KEEE+T Pin-Konfiguration
| Pin 1 | GND — Ground reference |
| Pin 2 | AIN0 — Analog input channel 0 |
| Pin 3 | AIN1 — Analog input channel 1 |
| Pin 4 | AIN2 — Analog input channel 2 |
| Pin 5 | AIN3 — Analog input channel 3 |
| Pin 6 | AIN4 — Analog input channel 4 |
| Pin 7 | AIN5 — Analog input channel 5 |
| Pin 8 | AIN6 — Analog input channel 6 |
| Pin 9 | AIN7 — Analog input channel 7 |
| Pin 10 | AIN8 — Analog input channel 8 |
| Pin 11 | AIN9 — Analog input channel 9 |
| Pin 12 | AIN10 — Analog input channel 10 |
| Pin 13 | AIN11 — Analog input channel 11 |
| Pin 14 | REF — Reference voltage I/O / external reference input |
| Pin 15 | SDA — I2C serial data |
| Pin 16 | VDD — Positive supply voltage (2.7V to 3.6V or 4.5V to 5.5V) |
Typische Anwendungen
MAX1238KEEE+T ist geeignet für 6 Anwendungs: Multi-Cell Battery Pack Monitoring, Industrial PLC Analog Input Module, Portable Medical Sensor Hub, Process Control Transducer Array, HVAC Environmental Sensing Panel, Automotive Sensor Multiplexer Node.
Multi-Cell Battery Pack Monitoring
The MAX1238KEEE+T fits multi-cell battery pack monitoring because its 12 single-ended input channels can digitize up to 12 individual cell voltages in a single I2C transaction. With 12-bit resolution and the internal 2.5 V reference, each LSB represents 0.61 mV, providing accurate state-of-charge calculation in 1S-12S Li-ion or LiFePO4 packs where per-cell voltage must be measured to within tens of millivolts. The internal sequencer automatically scans all 12 channels, eliminating host-processor overhead and freeing the MCU for coulomb counting and protection logic. The 1 µA shutdown current is critical for sleep modes in portable power tools, e-bikes, and battery-backed industrial sensors where idle drain directly impacts runtime. Designers commonly pair this ADC with an external MOSFET-based front-end and a balancing circuit, then read all cell voltages over a single I2C bus to a battery management host.
Empfohlen
Industrial PLC Analog Input Module
The MAX1238KEEE+T fits industrial PLC analog input modules because it provides 12 isolated-grade analog input channels in a single 16-pin QSOP, dramatically reducing PCB area versus discrete op-amp-plus-ADC architectures. The 5 V supply compatibility (4.5 V to 5.5 V) matches the rail used in most PLC backplanes, and the I2C interface simplifies isolated I2C bus designs using digital isolators. Its 12-bit resolution with no missing codes and integrated track/hold deliver the linearity required for 4 mA to 20 mA loop replacement designs and process variable monitoring (pressure, level, flow). The I2C High-Speed Mode (1.7 MHz) lets the PLC scan all 12 channels in well under 1 ms, suiting sub-100 Hz control loops. When paired with an external surge protection front-end, the ADC delivers robust field-deployed performance for factory automation and SCADA systems.
Empfohlen
Portable Medical Sensor Hub
The MAX1238KEEE+T fits portable medical sensor hubs because its 12 input channels accommodate multiple biosensors (ECG, SpO2 red/IR, temperature, respiration, motion reference) on a single low-power ADC. The 670 µA active supply current at full throughput and 1 µA shutdown current allow duty-cycled acquisitions that extend battery life in wearable patient monitors and ambulatory diagnostic devices. The I2C-compatible interface with up to 8 selectable slave addresses enables multiple ADCs to coexist on the same bus, supporting expansion beyond 12 channels without firmware rearchitecture. The integrated 2.5 V reference eliminates the need for an external precision reference, saving critical board area in compact wearable form factors. Combined with the small QSOP package, this ADC is well-matched to multi-parameter bedside and home-care patient monitoring designs.
Empfohlen
Process Control Transducer Array
The MAX1238KEEE+T fits process control transducer arrays because it can digitize 12 individual sensor outputs from thermocouples, RTDs, strain gauges, and pressure transducers on a single I2C bus. The pseudo-differential input configuration enables rejection of common-mode ground noise in long cable runs typical of factory floor installations. The internal 2.5 V reference is ratiometric to bridge-type sensors, while the unipolar/bipolar input range lets the same ADC handle both 0-10V process signals and ±5V bipolar transducer outputs. Its extended -40 C to +85 C industrial temperature grade ensures operation in uncontrolled cabinet environments. When combined with RS-485 transceivers, this ADC provides the field-side digitizing front-end for distributed control systems (DCS) and remote I/O nodes.
Empfohlen
HVAC Environmental Sensing Panel
The MAX1238KEEE+T fits HVAC environmental sensing panels because its 12 inputs accommodate arrays of temperature, humidity, CO2, VOC, and airflow sensors distributed across a building automation node. The wide supply voltage range (2.7 V to 5.5 V) lets the same ADC operate from either 3.3 V or 5 V microcontroller rails without hardware changes. The 1.7 MHz I2C High-Speed Mode allows the controller to poll all 12 channels in under 1 ms, supporting real-time feedback loops in variable-air-volume (VAV) box controllers and economizer logic. The integrated sequencer minimizes firmware interrupt overhead, which is critical in resource-constrained 8-bit and Cortex-M0 host microcontrollers common in HVAC controllers. Combined with the QSOP package, this ADC is well-suited to compact panel-mount building automation designs.
Empfohlen
Automotive Sensor Multiplexer Node
The MAX1238KEEE+T fits automotive sensor multiplexer nodes because its 12 input channels can digitize multiple analog sensors (pedal position, throttle body, MAP, oil level, suspension travel) on a single ADC. Although not AEC-Q100 qualified itself, the MAX1238 is widely used in non-safety automotive body and chassis subsystems where industrial-grade -40 C to +85 C operation is sufficient. The wide 4.5 V to 5.5 V supply range tolerates 12 V battery transients when paired with external TVS protection, while the 670 µA active supply current keeps quiescent drain low in always-on body controllers. The I2C interface supports isolated or non-isolated communication with the central body control module via standard transceivers. This makes the part a cost-effective digitizing front-end for body electronics, comfort modules, and instrument cluster sub-boards.
Empfohlen
Zusammenfassung der empfohlenen Produkte
Technische Referenzdaten für MAX1238KEEE+T – Vergleich, Designhinweise und Compliance-Informationen.
Auswahlhilfe
Vergleich mit Alternativen
| Parameter | Dieses Produkt | MAX1238EEE+ | MAX1238KEEE+ | MAX1239EEE+ | MAX1239KEEE+T | MAX1139MEEE+T | MAX1139KEEE+ |
|---|---|---|---|---|---|---|---|
| Brand | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated |
| Package | 16-QSOP | 16-QSOP - same | 16-QSOP - same | 16-QSOP - same | 16-QSOP - same | 16-QSOP - same | 16-QSOP - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 10 bit | 10 bit |
| Number of Input Channels | 12 single-ended / 6 pseudo-differential | 12 / 6 | 12 / 6 | 12 / 6 | 12 / 6 | 12 / 6 | 12 / 6 |
| Supply Voltage Range | 2.7V-3.6V / 4.5V-5.5V | 2.7V-3.6V / 4.5V-5.5V | 2.7V-3.6V / 4.5V-5.5V | 2.7V-3.6V / 4.5V-5.5V | 2.7V-3.6V / 4.5V-5.5V | 2.7V-3.6V / 4.5V-5.5V | 2.7V-3.6V / 4.5V-5.5V |
| Digital Interface | I2C, 400 kHz / 1.7 MHz | I2C, 400 kHz / 1.7 MHz | I2C, 400 kHz / 1.7 MHz | I2C, 400 kHz / 1.7 MHz | I2C, 400 kHz / 1.7 MHz | I2C, 400 kHz / 1.7 MHz | I2C, 400 kHz / 1.7 MHz |
Wichtigste Unterscheidungsmerkmale
- 12-bit resolution with 12 single-ended channels in a 16-pin QSOP (vs. MAX1139MEEE+T (10-bit family member))
- Higher 4.096 V internal reference option for 1 mV/LSB scaling (vs. MAX1238KEEE+T (2.5 V reference))
- Integrated sequencer for automatic multi-channel scanning (vs. Discrete ADC with external MUX)
Designhinweise
Place a 0.1 µF X7R ceramic bypass capacitor as close as possible to pin 16 (VDD) and pin 1 (GND), with trace length under 2 mm. Add a 10 µF bulk capacitor on the same rail if the ADC is more than 25 mm from the system regulator. The internal 2.5 V reference draws transient current during conversion, so a poorly decoupled supply will inject reference noise directly into the conversion result.
Route the analog inputs (AIN0-AIN11) as parallel, matched-length traces on one side of the part, and keep the digital lines (SDA, SCL) on the opposite side. Place a digital ground guard ring around the ADC and tie it to the analog ground at a single point near the ADC ground pin. This prevents digital switching noise from coupling into the analog input traces via ground bounce.
When using the I2C High-Speed Mode (1.7 MHz), verify the bus rise-time spec with the actual pull-up resistor value and total bus capacitance. Excessive capacitance from long cable runs will violate the High-Speed Mode rise-time budget and force the host to fall back to 400 kHz Fast Mode. Adding a small series resistor (22-33 ohm) at the SDA and SCL pins can dampen ringing caused by bus stubs.
Do not leave the REF pin floating in external-reference mode; tie it through a low-impedance buffer to an external precision reference if higher accuracy is required. When using single-ended inputs, never exceed the input voltage range of 0 V to VREF, or the input ESD diodes will forward-bias and inject error currents into adjacent channels. Bipolar input ranges require the bipolar input configuration register to be set correctly in software.
Compliance-Informationen
RoHS compliant per DigiKey product listing. Not AEC-Q100 qualified; not recommended for safety-critical automotive applications.
