MAX198ACWI - 6-Channel 12-Bit DAS, 5V, 100kSPS | Maxim/ADI
MPN: MAX198ACWI ✓ Hoạt độngMAX198ACWI Tóm tắt
A Data Acquisition System (DAS) such as this combines a multi-channel input multiplexer, a sample-and-hold amplifier, a SAR (Successive Approximation Register) ADC core, voltage reference support, and a digital bus interface into a single IC. The MAX198ACWI sits in the ADC IC family, beneath the broader category of data-conversion / data-acquisition semiconductors, and is used as the analog front-end in distributed control, instrumentation, and embedded systems where multiple analog signals must be digitized and delivered to a host CPU or DSP over a fast parallel port.
Key features include software-configurable unipolar input ranges of 0 V to +VREF (where VREF is the internal 4.096 V bandgap or an external reference) and 0 V to +5 V, 6.0 us conversion time, an internal 4.096 V reference, and AC + DC (±1/2 LSB) linearity over the operating range. Software-configurable bipolar ranges (±VREF, ±5 V on the MAX196, ±10 V on the MAX197) are the user's choice. The three-state bidirectional data port is compatible with 16-bit data buses, and bus-release timing is matched to the read cycles of most 8051-family, 68HC11, and similar microprocessors. All digital I/O are TTL/CMOS compatible, simplifying level translation in mixed-voltage designs.
Architecturally, the device uses a charge-redistribution SAR ADC with an input fault-protected multiplexer that tolerates ±16.5 V overvoltage on any analog input without damage. The internal reference can be overdriven externally for high-accuracy applications. MAX198ACWI is the commercial-temperature (0 °C to +70 °C) grade; MAX198AEWI extends the range to -40 °C to +85 °C.
Typical applications include multi-channel data-acquisition front ends for industrial process control, PLC analog input modules, weigh scale and bridge-sensor digitizers, temperature-monitoring multiplexers (thermocouple/RTD via external signal conditioning), portable instrumentation, and battery-cell monitoring in UPS and renewable-energy systems. Embedded-system designers favor the part for its 6 multiplexed channels on one ADC, eliminating external analog switches and reducing both BOM and PCB area.
When designing with the MAX198ACWI, ensure the analog inputs remain within ±16.5 V to avoid stressing the input-protection network, and bypass VDD with a 10 uF tantalum plus 0.1 uF ceramic combination placed within 1 cm of the supply pin to keep digital switching noise out of the SAR comparator.
This page synthesizes distributor pricing, drop-in alternative parts from the same MAX196/MAX198 family, and practical PCB-layout guidance not found in the bare manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho MAX198ACWI — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với MAX198ACWI (cùng hình factor và footprint) — khác nhau ở Number of Channels, Package, Resolution, RoHS Status.
MAX198ACWI+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX198ACWI+T
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX198AEWI+
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
MAX198BEWI
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →MAX198ACWI Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 12 bit |
| Number of Channels | 6 (single-ended, software multiplexed) |
| Tỷ lệ lấy mẫu | 100 ksps |
| Conversion Architecture | SAR (Successive Approximation Register) |
| Điện áp cung cấp | +5 V single supply |
| Supply Current (operating) | 7.5 mA typ |
| Supply Current (power-down) | 1 mA typ |
| Input Voltage Range (unipolar, software selectable) | 0 V to +5 V or 0 V to VREF |
| Internal Reference Voltage | 4.096 V ± 1.5% |
| Conversion Time | 6.0 us max |
| Linearity | ±1/2 LSB (AC + DC) |
| Analog Input Overvoltage Protection | ±16.5 V on any input |
| Digital Bus Interface | 12-bit + control, three-state bidirectional |
| Logic Compatibility | TTL/CMOS |
| Khoảng nhiệt độ hoạt động | 0 °C to +70 °C (commercial grade) |
| Hộp | 28-pin wide SOIC (SO W, 0.295 inch / 7.50 mm) |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant (lead-free version MAX198ACWI+) |
Cấu hình chân MAX198ACWI
| Chân 1 | AIN0 — Analog input channel 0 |
| Chân 2 | AIN1 — Analog input channel 1 |
| Chân 3 | AIN2 — Analog input channel 2 |
| Chân 4 | AIN3 — Analog input channel 3 |
| Chân 5 | AIN4 — Analog input channel 4 |
| Chân 6 | AIN5 — Analog input channel 5 |
| Chân 7 | AGND — Analog ground |
| Chân 8 | REF — Reference output / external reference input (4.096 V internal) |
| Chân 9 | REFADJ — Reference adjust input for external trimming |
| Chân 10 | VSS — Negative supply (-5 V or 0 V single supply) |
| Chân 11 | VDD — +5 V positive supply |
| Chân 12 | CLK — External clock input (internal RC default) |
| Chân 13 | INT — Conversion-end interrupt output (active low) |
| Chân 14 | HBEN — High-byte enable (selects D8-D15 on 16-bit bus) |
| Chân 15 | D0/D8 — Data bit 0 (LSB) / bit 8 with HBEN |
| Chân 16 | D1/D9 — Data bit 1 / bit 9 |
| Chân 17 | D2/D10 — Data bit 2 / bit 10 |
| Chân 18 | D3/D11 — Data bit 3 / bit 11 |
| Chân 19 | D4/D12 — Data bit 4 / bit 12 |
| Chân 20 | D5/D13 — Data bit 5 / bit 13 |
| Chân 21 | D6/D14 — Data bit 6 / bit 14 |
| Chân 22 | D7/D15 — Data bit 7 (MSB) / bit 15 with HBEN |
| Chân 23 | DGND — Digital ground |
| Chân 24 | RD — Read strobe (active low) |
| Chân 25 | CS — Chip select (active low) |
| Chân 26 | WR — Write strobe / channel select write (active low) |
| Chân 27 | POL — Polarity select (unipolar/bipolar mode) |
| Chân 28 | PD — Power-down input (active high) |
Ứng dụng tiêu biểu
MAX198ACWI phù hợp cho 6 Áp dụngs: Multi-Channel Industrial Process-Control ADC Front End, PLC Analog Input Module (6-Channel), Weigh-Scale and Bridge Sensor Digitizer, Multi-Sensor Temperature Monitoring (Thermocouple/RTD Aggregator), Battery-Cell Voltage Monitoring in UPS / Renewable Systems, Portable Test and Measurement Instrumentation.
Multi-Channel Industrial Process-Control ADC Front End
The MAX198ACWI suits 4- to 6-channel industrial-control digitizers because it integrates the multiplexer, sample-and-hold, 12-bit SAR ADC, and 4.096 V reference in a single 28-pin SOIC, removing six external analog switches and reducing both BOM cost and PCB area. Its 100 ksps rate and 6 us conversion time allow closed-loop control loops (e.g. PLC analog input modules at 100 Hz per channel) to run with ample time margin. The internal reference is acceptable for many industrial sensors; for thermocouple/junction-temperature precision, an external reference overdrive is supported. The +5 V single-supply operation, ±16.5 V analog input protection, and TTL/CMOS logic levels make it directly compatible with 8051/PIC/ARM host controllers with no glue logic. Power-down current of 1 mA supports battery-backed shutdown in unattended remote sites.
Được đề xuất
PLC Analog Input Module (6-Channel)
Programmable-logic-controller analog-input cards typically digitize 4, 6, or 8 analog channels at rates up to a few hundred Hz; the MAX198ACWI provides exactly six multiplexed inputs at 12 bits and 100 ksps, well above PLC update-rate requirements. Each channel can be set independently to 0-5 V or 0-VREF (4.096 V) ranges by writing the control register, allowing mixed inputs (e.g. 0-5 V process transmitters and 0-4.096 V load-cell bridges) without external conditioning. The 12-bit three-state data port ties directly to the PLC CPU's parallel bus, with bus-release timing matched to 68HC11/8051 read cycles. The ±16.5 V input clamp protects 24 V field wiring mis-wires (after external resistor-divider sensing).
Được đề xuất
Weigh-Scale and Bridge Sensor Digitizer
Load cells and strain-gauge bridges typically output millivolt-level signals in a ratiometric configuration; the MAX198ACWI digitizes up to six bridge channels sequentially with 12-bit resolution (4096 codes over 0-4.096 V giving ~1 mV LSB) and the internal 4.096 V reference can be used to excite a ratiometric bridge amplifier. With proper input signal conditioning (instrumentation amplifier with gain 100-1000), the 12-bit envelope gives stable, repeatable scale readings well suited for bench-top and small commercial weigh scales. Power-down mode (1 mA) preserves battery life when the scale enters standby. Industrial applications should migrate to the pin-compatible MAX198AEWI+ for -40 to +85 °C operation.
Được đề xuất
Multi-Sensor Temperature Monitoring (Thermocouple/RTD Aggregator)
Industrial equipment often monitors several thermocouple or RTD temperature channels simultaneously; the MAX198ACWI's six-input multiplexer digitizes up to six cold-junction-compensated thermocouple or RTD inputs into a host controller through one bus. The 100 ksps aggregate rate allows scan times below 1 ms per channel, well below typical 1 Hz thermal time constants. With a 0-4.096 V input range and 1 mV LSB, an external amplified cold-junction compensation path digitizes accurately. The internal 4.096 V reference can be overdriven by an external MAX150-based reference for higher precision. Hospital-medical and laboratory use cases should add downstream digital filtering.
Được đề xuất
Battery-Cell Voltage Monitoring in UPS / Renewable Systems
Uninterruptible power supplies and battery energy-storage systems must monitor each cell voltage; the MAX198ACWI scans six cells per chip with 12-bit resolution and 100 ksps throughput, with multiple chips cascaded for higher series-string counts. The unipolar 0-5 V input range covers typical 12 V/24 V battery-block voltages after external resistor dividers, and the +5 V single supply makes it directly compatible with UPS controller boards. Power-down mode (1 mA typ) keeps idle current low in storage systems; the ±16.5 V input protection tolerates transients on stacked-battery strings. Evaluation should also consider MAX11068 dedicated battery monitor for battery-management ICs.
Được đề xuất
Portable Test and Measurement Instrumentation
Handheld multimeters, data loggers, and bench test equipment often require 4-8 analog input channels; the MAX198ACWI delivers six 12-bit digitized channels at 100 ksps through a compact 28-pin SOIC, leaving ample board space for LCD, keypad, and battery-management circuitry. The 1 mA power-down current is critical for battery-powered portability, and the internal 4.096 V reference eliminates an external precision reference. The A-grade linearity (±1/2 LSB) and the fast 6 us conversion time support both DC and modest-bandwidth AC measurements. Industrial or field-instrument temperature variants should choose the MAX198AEWI+.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho MAX198ACWI — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | MAX198ACWI+ | MAX198ACWI+T | MAX198AEWI+ | MAX198BEWI | MAX196ACAI |
|---|---|---|---|---|---|---|
| Package | 28-SOIC (Wide, 7.50mm) | 28-SOIC (Wide, 7.50mm) | 28-SOIC (Wide, 7.50mm) | 28-SOIC (Wide, 7.50mm) | 28-SOIC (Wide, 7.50mm) | 28-SSOP |
| Brand | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Resolution | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit | 12 bit |
| Channels | 6 | 6 | 6 | 6 | 6 | 8 |
| Sampling Rate | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 100 ksps | 100 ksps (aggregate) |
| Input Range | Unipolar: 0-5 V, 0-VREF | Unipolar: 0-5 V, 0-VREF | Unipolar: 0-5 V, 0-VREF | Unipolar: 0-5 V, 0-VREF | Unipolar: 0-5 V, 0-VREF | Bipolar: ±5 V, ±VREF |
| Operating Temperature | 0 °C to +70 °C | 0 °C to +70 °C | 0 °C to +70 °C | -40 °C to +85 °C | 0 °C to +70 °C | 0 °C to +70 °C |
| Linearity Grade | A (AC+DC ±1/2 LSB) | A (AC+DC ±1/2 LSB) | A (AC+DC ±1/2 LSB) | A (AC+DC ±1/2 LSB) | B (AC+DC tighter, typically ±3/4 LSB worst-case relaxed but BIN improvement on gain/offset) | A (AC+DC ±1/2 LSB) |
| Qty-1 Distributor Price (USD) | $14.20 | ~$14.20 (lead-free) | ~$14.20 (tape-and-reel) | ~$17-19 | ~$18-22 | ~$14-16 |
Bảo phân biệt quan trọng
- Wide SOIC (28-pin, 0.295 inch) with 6 multiplexed inputs on a single SAR core (vsMAX196ACAI (28-SSOP))
- Unipolar-only input ranges (0-5 V, 0-VREF) optimized for 4-20 mA and single-rail sensor signals (vsMAX196ACAI (28-SSOP, bipolar variants))
- Direct same-family drop-in upgrades available on the same 28-SOIC wide footprint (vsMAX197BCWI (8 channels, bipolar))
Ghi chú thiết kế
Bypass VDD with a 10 uF tantalum in parallel with 0.1 uF ceramic capacitor placed within 1 cm (0.4 inch) of the supply pin. Place AGND and DGND separated PCB islands and join them at one point near the ADC to avoid ground-loop errors that degrade the 12-bit resolution. Keep analog input traces short and route them away from digital switching lines, particularly INT, RD, and CLK, to avoid digital-to-analog crosstalk into the SAR comparator.
For 100 ksps continuous streaming, the AINx analog inputs source currents of order tens of microamps during the 6 us acquisition window. A source resistance above ~5 kohm will introduce gain error due to the ADC input sampling-charge transient; for high-impedance sources such as strain gauges or RTDs, add a buffer amplifier (e.g., MAX145) between the source and AINx. Long AIN traces should use a driven shield or be guarded by AGND traces to avoid leakage errors.
Avoid continuous overdrive of the analog inputs above ±16.5 V, including transient overvoltages from switching relays or load-dump events - the internal protection clamp can dissipate short but cannot survive indefinite overvoltage. When using an external reference, drive REFADJ accordingly and verify VREF is below the analog-input range selected. The CLK input has a maximum frequency limit; the internal oscillator at ~1.56 MHz provides 6 us conversion time without external drive, and adding an external clock must respect the duty-cycle and rise/fall-time limits in the datasheet.
Estimated: at +5 V with 7.5 mA operating current, the ADC draws about 37.5 mW. The 28-pin wide SOIC thermal resistance theta_JA is approximately 75 °C/W (not stated in provided data, marked [DATA_NEEDED] if exact), giving a junction-to-ambient rise of just under 3 °C - thermal problems are negligible. The 5 V regulator upstream should handle the inrush from VDD; using an LDO such as MAX162BCNG+ downstream of a switching regulator removes the switching ripple that would otherwise appear on VDD and degrade the reference.
Thông tin tuân thủ
The bare-suffix MAX198ACWI (non-lead-free) is RoHS-non-compliant; the lead-free variant MAX198ACWI+ is RoHS-compliant per Maxim/ADI product page. AEC-Q100 is not applicable - this is a commercial-grade data acquisition IC, not an automotive-qualified part.
