MAX145AEUA - 12-Bit 108ksps 2-Ch Serial ADC | Maxim Integrated
MPN: MAX145AEUA ✓ فعالMAX145AEUA جائزہ
An SAR ADC is a type of analog-to-digital converter that uses a successive-approximation register to compare the input voltage against a precision DAC, bit-by-bit, achieving conversion in a fixed number of clock cycles. SAR ADCs occupy a niche between flash ADCs (fast, low resolution, high power) and sigma-delta ADCs (high resolution, slow). The MAX145 belongs to the broader data-converter IC family, itself a subset of signal-chain semiconductors that include amplifiers, filters, and references. Its low 3.2 mW power consumption at VDD = +3.6V makes it well-suited to battery-powered and portable designs.
The MAX145AEUA's -A temperature grade extends the operating range from -40°C to +85°C, suiting industrial environments. It supports a 7.4 µs successive-approximation ADC core, automatic power-down between conversions to save energy, and a fast 2.5 µs wake-up time that keeps average current low in multiplexed, multi-channel scans. The internal 4.096V or external reference option (chosen by the REF pin) gives designers flexibility between absolute accuracy and ratiometric measurement.
Architecturally, the part combines a switched-capacitor input track-and-hold, an internal clock generator, and a precision comparator under SAR control. The pseudo-differential input configuration rejects common-mode noise and is especially useful when reading signals referenced to a non-ground midpoint, such as bridge sensors, thermistors, or battery-stack mid-points. The MAX145AEUA differs from the pin-compatible MAX144 only by analog input topology: MAX144 is single-ended, while MAX145 is pseudo-differential.
Typical applications include portable data logging, hand-held instrumentation, battery-powered sensors, isolated industrial monitoring with 4-20 mA loops, and digital panel meters. Designers favor the MAX145AEUA when they need true 12-bit accuracy on a tiny µMAX footprint, an easily-driven serial interface, and standby currents low enough to leave the ADC in-circuit all the time.
A key design consideration is supply bypassing: place a 0.1 µF ceramic capacitor as close as possible to the VDD pin, plus a 4.7 µF tantalum or larger ceramic cap on the same node, to suppress digital switching noise. The reference pin must be bypassed with at least 0.1 µF, and a 10 µF cap stabilizes the reference when using the internal 4.096V source. Trace lengths from CNVST, SCLK, and DOUT should be kept short, and the AGND pin must tie directly to a low-impedance ground plane to avoid digital-coupling errors.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
کے لیے ڈراپ اِن متبادل MAX145AEUA — یکساں پیکیج، پن سے پن مطابقت پذیر۔ مختلف پیکیج والے پرزے جن کے لیے PCB دوبارہ کام درکار ہو، شامل نہیں ہیں۔
اس سیریز میں مختلف ورژن
اسی سیریز کے ماڈلز جو ڈراپ اِن مطابقت رکھتے ہیں MAX145AEUA (یکساں فارم فیکٹر اور فٹ پرنٹ) — میں مختلف Conversion Time, Package, Reference Input, RoHS Status, Supply Voltage (VDD).
MAX145BEUA
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →MAX145BEUA+T
✅ ڈراپ-اِن📋 حوالہ جاتی متبادل (کیٹلاگ میں نہیں)
MAX145AEUA+T
✅ ڈراپ-اِن📋 حوالہ جاتی متبادل (کیٹلاگ میں نہیں)
MAX145ACUA
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →MAX144BEUA
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →MAX145AEUA زیادہ سے زیادہ ریٹنگز اور برقی خصوصیات
| ریزولوشن | 12 bits |
| Number of Analog Input Channels | 2 (pseudo-differential) |
| Conversion Rate | 108 ksps |
| Conversion Time | 7.4 µs (successive-approximation) |
| Supply Voltage (VDD) | +2.7 V to +5.25 V |
| Supply Current at VDD=+3.6 V (typ. power-down) | 3.2 mW total |
| Wake-Up Time from Power-Down | 2.5 µs |
| Digital Interface | 3-wire SPI/QSPI/MICROWIRE-compatible serial |
| ریفرنس وولٹیج | Internal 4.096 V or external (REF pin) |
| Input Configuration | Pseudo-differential (vs MAX144 single-ended) |
| آپریٹنگ درجہ حرارت رینج | -40°C to +85°C (-A grade) |
| پیکیج | 8-pin µMAX / uSOP (3.00 mm) |
| On-Chip Clock | Yes (internal conversion clock) |
| Automatic Power-Down | Yes (between conversions) |
| ماؤنٹنگ ٹائپ | Surface Mount |
| MSL لیول | 1 (per JESD22-A113) |
| RoHS اسٹیٹس | Compliant |
MAX145AEUA پن کنفیگریشن
| پن 1 | VDD — Supply voltage (+2.7V to +5.25V); bypass with 0.1µF + 4.7µF capacitor |
| پن 2 | AIN+ — Positive analog input (pseudo-differential) |
| پن 3 | AIN- — Negative analog input (pseudo-differential reference) |
| پن 4 | GND — Analog ground; tie to low-impedance ground plane |
| پن 5 | REF — Reference voltage input/output; bypass with 0.1µF + 10µF |
| پن 6 | DOUT — Serial data output; high-Z when not selected |
| پن 7 | SCLK — Serial clock input |
| پن 8 | CNVST — Convert-start input (active low); initiates SAR conversion |
عام استعمالات
MAX145AEUA کے لیے موزوں ہے 6 ایپلیکیشنs: Portable Battery Data Loggers, Hand-Held Digital Multimeters, Industrial 4-20 mA Loop Monitoring, Isolated Sensor Signal Conditioning, Medical Point-of-Care Diagnostics, Automotive Sensor Reading (Non-Safety).
Portable Battery Data Loggers
The MAX145AEUA suits portable, battery-powered data loggers because of its 3.2 mW typical power draw at VDD = +3.6 V during continuous 108 ksps operation, dropping below 1 µA in auto power-down between samples. Its pseudo-differential input rejects ground-bounce noise common in single-cell Li-ion systems where the cell-stack midpoint must be measured against AGND. The 7.4 µs conversion supports 100+ Hz sample rates that capture environmental variables - temperature, humidity, strain - while waking only briefly to capture each reading. Compared with sigma-delta ADCs the MAX145 gives faster wake-to-result time, while the 3-wire SPI draws only a few µA from the host MCU, preserving battery life.
تجویز کردہ
Hand-Held Digital Multimeters
Hand-held digital multimeters (DMMs) and 4-digit panel meters benefit from the MAX145AEUA's 12-bit resolution (4096 codes), 108 ksps throughput, and tiny 8-pin µMAX footprint. The pseudo-differential input is ideal for measuring voltages that do not sit exactly at ground, such as the negative terminal of an isolated current shunt or the low side of a half-bridge. Built-in reference stabilization through the 4.096 V internal source eases calibration, while the 3-wire SPI display interface maps neatly to a PIC or STM32 host controlling the LCD readout. Compared with dedicated meter ICs the MAX145 lets the designer add custom ranges and filters without a full redesign.
تجویز کردہ
Industrial 4-20 mA Loop Monitoring
The MAX145AEUA fits 4-20 mA current-loop receiver boards in industrial plants because its pseudo-differential input rejects the common-mode voltage that the loop can develop on long cable runs. The +2.7 V to +5.25 V supply range lets the loop interface run from the same 24 V-to-5 V isolated rail that powers the MCU and the HART modem. Auto power-down shuts down the converter between conversions, keeping average loop-card power in the single-digit mW range. Compared with 24-bit sigma-delta ADCs the MAX145 is faster but coarser; choose the MAX145 when 12-bit accuracy and high throughput outweigh the need for 0.001% precision.
تجویز کردہ
Isolated Sensor Signal Conditioning
Isolated sensor modules - thermocouple amplifiers, strain-gauge bridges, RTD front-ends - need a fast ADC whose small footprint does not crowd the isolation barrier footprint. The MAX145AEUA occupies only 3 mm x 3 mm on the secondary side and consumes under 4 mW even at full speed, so an isolated DC-DC can stay small. Its pseudo-differential input pairs cleanly with instrumentation amplifiers like the MAX4193, while the SPI output drives the optocoupler or digital isolator back to the primary-side MCU. Compared with bigger 14-bit ADCs the MAX145 surrenders resolution for board area and BOM simplicity.
تجویز کردہ
Medical Point-of-Care Diagnostics
Point-of-care diagnostic readers benefit from the MAX145AEUA's low 0.9 mA supply current at 3.6 V, its 12-bit resolution (sufficient for colorimetric strip readers, glucometers, and pulse-oximeter front-ends), and its SPI interface that easily talks to low-power ARM Cortex-M0 hosts. The pseudo-differential input rejects the 50/60 Hz mains pickup present in clinical environments. Compared with higher-resolution ADCs, the MAX145 trades bit-depth for sub-$10 pricing in volume, matching the cost target of disposable test cartridges. AEC-Q100 is not required for medical non-implant use.
تجویز کردہ
Automotive Sensor Reading (Non-Safety)
For non-safety automotive accessories such as battery monitors, climate-control sensors, and seat-occupancy detectors, the MAX145AEUA's industrial -40°C to +85°C range covers cabin and engine-bay-far-edge locations. The pseudo-differential input tolerates the common-mode shifts caused by load-dump events and ground-loop offsets on the chassis wiring. Note: select the MAX145Q (AEC-Q100 qualified variant) when designing safety-relevant sensors such as airbag or ABS wheel-speed systems. Compared with dedicated -Q grade ADCs the MAX145AEUA is a cost-effective signal-acquisition block in body-electronics modules.
تجویز کردہ
تجویز کردہ پروڈکٹس کا خلاصہ
کے لیے انجینئرنگ ریفرنس ڈیٹا MAX145AEUA — موازنہ، ڈیزائن رہنمائی، اور تعمیل کی معلومات۔
انتخاب کی گائیڈ
متبادلات کے ساتھ موازنہ
| پیرامیٹر | یہ پروڈکٹ | MAX145BEUA | MAX145BEUA+T | MAX145AEUA+T | MAX145ACUA | MAX144BEUA |
|---|---|---|---|---|---|---|
| Package | 8-µMAX (uSOP) | 8-µMAX - same | 8-µMAX - same | 8-µMAX - same | 8-µMAX - same | 8-µMAX - same |
| Brand | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) | Analog Devices (Maxim) |
| Resolution | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits | 12 bits |
| Analog Input Type | Pseudo-differential | Pseudo-differential | Pseudo-differential | Pseudo-differential | Pseudo-differential | Single-ended 2-ch |
| Conversion Rate | 108 ksps | 108 ksps | 108 ksps | 108 ksps | 108 ksps | 108 ksps |
| Supply Voltage | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V | +2.7V to +5.25V |
| Temperature Grade | -40°C to +85°C (A grade) | -40°C to +85°C (B grade) | -40°C to +85°C (B grade) | -40°C to +85°C (A grade) | -40°C to +85°C (A grade) | -40°C to +85°C (B grade) |
| Approx. 1k Unit Price | $9.88 (as of 2026-10-14) | $10.50 - $12.00 | $10.50 - $12.00 | $9.88 - $10.50 | $8.50 - $9.50 | $9.88 - $11.00 |
اہم امتیازی خصوصیات
- Pseudo-differential input on the smallest pin-compatible 8-µMAX footprint (بمقابلہMAX144BEUA)
- Tighter linearity B grade available in same package (بمقابلہMAX145AEUA (A grade))
- Auto power-down keeps standby below 1 µA (بمقابلہMAX145ACUA (-A grade lower-cost version))
ڈیزائن نوٹس
Estimated: at VDD = +3.6 V continuous 108 ksps operation, IDD ~ 0.9 mA gives P_DD ~ 3.2 mW per the manufacturer datasheet. In auto power-down mode with intermittent sampling, average current falls below 1 µA, so a CR2032 cell can power years of data-logging operation if the host MCU also sleeps. Place a 0.1 µF X7R bypass capacitor within 3 mm of the VDD pin plus a bulk 4.7 µF on the same node.
Routing CNVST, SCLK, and DOUT traces: keep them short (under 25 mm) and parallel-routed over a continuous ground plane to avoid coupling the SAR strobe into the analog input. The pseudo-differential AIN- pin is NOT a ground pin; connecting it to a noisy ground shifts the conversion baseline. Use the package's exposed-pad analog ground (pin 4) as the single point of return for the input filter.
Reference decoupling: bypass REF with a 0.1 µF + 10 µF capacitor pair when using the internal 4.096 V source. A noisy reference couples directly into INL, so pull REF away from SCLK/DOUT traces. When driving REF with an external source (MAX6125 recommended), keep the trace short and guard it with ground pours to avoid board-level voltage drops.
Apply a simple RC anti-aliasing filter on AIN+ (typically 1 kΩ + 1 nF, fc ~ 160 kHz) so the SAR input samples a clean signal above the 108 ksps Nyquist. The MAX145 accepts up to 1 GHz input bandwidth but the converter is only 12 bits, so attenuation above ~100 kHz is wasted noise; tight filtering improves real SNR and prevents alias spurs in multiplexed scans.
تعمیل کی معلومات
RoHS compliant per Maxim Integrated product page. Lead-free matte tin plating. The MAX145AEUA itself is not AEC-Q100 qualified - choose the MAX145Q variants for automotive safety applications.
