MAX182BCPI - 12-Bit 4-Ch SAR ADC w/ T/H and Reference | Maxim
MPN: MAX182BCPI ✗ پایان تولیدMAX182BCPI نمای کلی
An ADC (analog-to-digital converter) is a data-conversion integrated circuit that transforms continuous analog voltage signals at its inputs into discrete digital codes at its output, enabling microcontrollers, DSPs, or FPGAs to process real-world sensor signals. Successive-approximation-register (SAR) ADCs use a binary-search algorithm with an internal DAC and comparator to resolve N bits in N clock cycles, trading conversion speed for excellent DC accuracy, low latency, and very low power consumption - making SAR ADCs the dominant topology for industrial process control, instrumentation, and multichannel data-acquisition systems.
Key features of the MAX182BCPI include an internal 2.5 V bandgap reference (with a REFADJ pin for external trim), a track-and-hold with 1.5 MHz full-power bandwidth, a parallel microprocessor interface, hard-wired channel sequencing or software-programmable channel selection, and single +5 V supply operation. The part draws approximately 4 mA active supply current and powers down to microamp-level standby between conversions, simplifying battery and portable designs. Internal autocalibration of linearity and offset runs at power-up and on demand via the CAL pin, eliminating periodic user adjustment.
Typical applications include multichannel process-control data acquisition boards, portable or rack-mounted industrial instrumentation, sensor-signal conditioning front-ends, and embedded microprocessor analog I/O modules where the integrated reference and track-and-hold reduce external bill-of-materials cost and PCB area compared with discrete ADC + reference designs.
When designing with this device, place 0.1 uF ceramic bypass capacitors close to the supply and reference pins, drive analog inputs through low-impedance buffers, and avoid routing digital lines under the analog input traces to preserve 12-bit noise performance.
جایگزین‌های drop-in برای MAX182BCPI — همان پکیج، سازگار پین‌به‌پین. قطعات با پکیج متفاوت که نیاز به تغییر PCB دارند مستثنی هستند.
MAX182BCPI+
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
MAX182ACPI+
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
MAX182AEPI+
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
MAX174ACPI+
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
MAX174BCPI+
✅ جایگزین مستقیم📋 جایگزین مرجع (خارج از کاتالوگ)
MAX182BCPI حداکثر مقادیر مجاز و مشخصات الکتریکی
| رزولوشن | 12 bit |
| Number of Input Channels | 4 single-ended / 2 differential (configurable) |
| Architecture | SAR (Successive Approximation Register) |
| Conversion Rate | 17 ksps |
| Input Type | Single-Ended, Pseudo-Differential |
| Data Interface | Parallel |
| Reference Type | Internal 2.5 V bandgap (REFADJ pin for external trim) |
| ولتاژ تغذیه | +5 V single supply |
| Track-and-Hold Bandwidth | 1.5 MHz (full-power) |
| دمای کاری | 0C to +70C (C grade) |
| بسته‌بندی | 28-pin PDIP (0.600", 15.24 mm) |
| نوع نصب | Through-Hole |
| Channel Sequencing | Hardware sequential or software programmable |
| Calibration | Internal on-power-up + on-demand via CAL pin |
پیکربندی پین MAX182BCPI
| پین 1 | CH0 — Analog input channel 0 |
| پین 2 | CH1 — Analog input channel 1 |
| پین 3 | CH2 — Analog input channel 2 |
| پین 4 | CH3 — Analog input channel 3 |
| پین 5 | AGND — Analog ground |
| پین 6 | REF — Reference voltage output (2.5 V internal) |
| پین 7 | REFADJ — Reference adjust input (external trim) |
| پین 8 | VDD — +5 V analog supply |
| پین 9 | DGND — Digital ground |
| پین 10 | D0 — Data bit 0 (LSB) |
| پین 11 | D1 — Data bit 1 |
| پین 12 | D2 — Data bit 2 |
| پین 13 | D3 — Data bit 3 |
| پین 14 | D4 — Data bit 4 |
| پین 15 | D5 — Data bit 5 |
| پین 16 | D6 — Data bit 6 |
| پین 17 | D7 — Data bit 7 |
| پین 18 | D8 — Data bit 8 |
| پین 19 | D9 — Data bit 9 |
| پین 20 | D10 — Data bit 10 |
| پین 21 | D11 — Data bit 11 (MSB) |
| پین 22 | CS — Chip select (active low) |
| پین 23 | RD — Read strobe (active low) |
| پین 24 | WR — Write / convert start (active low) |
| پین 25 | INT — Interrupt / end-of-conversion output |
| پین 26 | CAL — Calibration start (active low) |
| پین 27 | MODE — Channel sequencing mode select |
| پین 28 | VLOGIC — Logic supply voltage (+5 V) |
کاربردهای معمول
MAX182BCPI مناسب است برای 6 کاربردs: Multichannel Industrial Process Control DAQ, Portable Battery-Powered Instrumentation, Embedded Microprocessor Analog I/O Modules, Sensor Signal Conditioning Front-End, Automated Test Equipment (ATE) Channels, Legacy System Repair and Obsolete-Part Replacement.
Multichannel Industrial Process Control DAQ
The MAX182BCPI's 4 single-ended / 2 differential input channels and 17 ksps throughput make it a strong fit for multichannel industrial process-control data-acquisition boards where multiple sensor signals (temperature, pressure, flow) must be digitized for a PLC or microcontroller. The integrated 2.5 V reference and on-chip track-and-hold eliminate the need for an external reference IC and reduce BOM cost, while internal autocalibration maintains 12-bit linearity without periodic user adjustment. Placed at the analog front-end between sensor signal conditioners and the MCU's parallel bus, the MAX182BCPI delivers low-latency conversions on each channel, making it suitable for closed-loop control loops where conversion delay affects response time. Designers should still add anti-alias filtering on each analog input to preserve 12-bit SNR.
پیشنهادی
Portable Battery-Powered Instrumentation
The MAX182BCPI's single +5 V supply operation and low active supply current (approximately 4 mA typical) make it suitable for portable or handheld instrumentation such as field meters, data loggers, and battery-powered test equipment. The integrated track-and-hold allows the analog input to settle during acquisition without external buffer amplifiers, simplifying the analog front-end and reducing PCB area. Power-down mode between conversions drops consumption to microamp levels, extending battery life in duty-cycled measurement scenarios. Place 0.1 uF ceramic bypass close to VDD and reference pins, and route analog input traces away from digital lines to preserve noise performance on the 12-bit output.
پیشنهادی
Embedded Microprocessor Analog I/O Modules
The MAX182BCPI's parallel microprocessor interface (D0-D11 plus CS, RD, WR, INT) makes it a natural fit for embedded analog I/O modules built around 8-bit and 16-bit microprocessors or low-end DSPs. With its hardware-sequential or software-programmable channel selection, a single MAX182BCPI can digitize up to 4 sensor inputs and present them on a single bus to the host processor, eliminating an external analog multiplexer. Internal autocalibration on power-up and on demand via the CAL pin removes the need for software trim loops, simplifying host firmware. Designers should confirm bus-timing compatibility with the host microprocessor and add a latch if required for demultiplexed lower-byte / upper-byte read cycles.
پیشنهادی
Sensor Signal Conditioning Front-End
The MAX182BCPI's on-chip 2.5 V reference and 1.5 MHz full-power-bandwidth track-and-hold make it suitable as the analog-to-digital front-end for sensor signal-conditioning boards digitizing strain-gauge bridges, thermocouple amplifiers, or transducer outputs. The internal reference provides the low-noise excitation reference for ratiometric measurements, while the track-and-hold allows a wide range of source impedances to settle within the acquisition window. Use it in 4-wire ratiometric measurements where ADC reference and bridge excitation share the same 2.5 V to cancel drift. Consider adding an input buffer amplifier (e.g., MAX4250) if source impedance exceeds the MAX182's recommended maximum.
پیشنهادی
Automated Test Equipment (ATE) Channels
The MAX182BCPI's 17 ksps sample rate and integrated calibration make it well-suited for low-channel-count automated test equipment, where multiple DUT (device-under-test) analog signals must be digitized for pass/fail comparison. The hardware-sequential channel mode simplifies scanning through multiple test points, while software-programmable mode allows non-sequential measurements on demand. Place the MAX182BCPI on a separate analog ground island connected to the digital ground at a single point near the ADC, and use guard traces around analog inputs to reject digital switching noise from the parallel bus.
پیشنهادی
Legacy System Repair and Obsolete-Part Replacement
The MAX182BCPI is the designated ADC for many legacy industrial control boards, medical instruments, and laboratory equipment manufactured between the early 1990s and mid-2000s. For service and repair of these systems, the MAX182BCPI+ lead-free variant is the direct replacement with identical pinout and electrical behavior. The same-brand MAX182AEPI+ (extended temperature) or MAX182ACPI+ (commercial + lead-free) variants can also substitute directly when the original part is out of stock. Because all variants share the same 28-pin PDIP footprint, board-level replacement requires no PCB modification - simply desolder the original part and solder in the replacement.
پیشنهادی
خلاصه محصولات پیشنهادی
داده‌های مرجع مهندسی برای MAX182BCPI — مقایسه، راهنمای طراحی و اطلاعات انطباق.
راهنمای انتخاب
مقایسه با جایگزین‌ها
| پارامتر | این محصول | MAX182BCPI+ | MAX182ACPI+ | MAX182AEPI+ | MAX174ACPI+ | MAX174BCPI+ |
|---|---|---|---|---|---|---|
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 28-PDIP | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Input Channels | 4 SE / 2 DIFF | 4 SE / 2 DIFF | 4 SE / 2 DIFF | 4 SE / 2 DIFF | 8 SE / 4 DIFF | 8 SE / 4 DIFF |
| Operating Temperature | 0C to +70C (C grade) | 0C to +70C | 0C to +70C | -40C to +85C (extended) | 0C to +70C | 0C to +70C |
| Internal Reference | Yes (2.5 V bandgap) | Yes (2.5 V) | Yes (2.5 V) | Yes (2.5 V) | Yes | Yes |
| Lead-Free / RoHS | No (original C grade) | Yes (lead-free) | Yes (lead-free) | Yes (lead-free) | Yes (lead-free) | Yes (lead-free) |
تفاوت‌های کلیدی
- Same-brand direct drop-in upgrade with extended temperature range (در مقابلMAX182AEPI+)
- Higher channel count in same 28-PDIP package (در مقابلMAX174ACPI+)
- Lead-free RoHS compliance variant available with identical die (در مقابلMAX182BCPI+)
یادداشت‌های طراحی
The MAX182BCPI operates from a single +5 V analog supply on VDD plus a +5 V logic supply on VLOGIC. Place a 0.1 uF ceramic bypass capacitor as close as possible to the VDD pin and a 10 uF bulk tantalum or ceramic capacitor at the supply entry point. Add a ferrite bead or 10 ohm resistor in series with VDD to isolate the ADC's analog supply from digital switching noise on the +5 V rail. A separate VLOGIC pin allows the parallel interface to run at a different logic level if needed, but for typical 5 V microprocessors it is tied directly to VDD.
Use a partitioned ground plane with separate analog and digital ground islands joined at a single point near the MAX182BCPI's AGND/DGND pins. Route analog input traces (CH0-CH3) directly to the ADC input pins without crossing digital traces; use guard traces tied to analog ground around sensitive analog input lines. Place the reference bypass capacitor (typically 10 uF) directly between REF and AGND to filter reference noise. Estimated: with the recommended layout, the ADC typically achieves the datasheet 12-bit SNR; poor layout can degrade SNR by 3-6 dB.
Do not exceed the absolute maximum analog input voltage of VDD + 0.3 V on any CH0-CH3 input - the MAX182BCPI inputs are not overvoltage protected and can be damaged by signals beyond the supply rail. Do not omit the 0.1 uF VDD bypass capacitor, or reference noise will couple into the conversions. Avoid driving the parallel data bus with the host microprocessor before the MAX182BCPI has completed its power-up calibration cycle; check the INT pin before reading the first conversion. Do not float the MODE pin - tie it high or low to select the desired channel-sequencing mode.
اطلاعات انطباق
MAX182BCPI (without + suffix) is the original commercial-temperature, lead-bearing variant; RoHS compliance requires the MAX182BCPI+ lead-free version. AEC-Q100 qualification is not applicable for this through-hole PDIP commercial-grade ADC.
