ADC0804LCWMX - 8-Bit µP-Compatible ADC, 10kSPS, 20-SOIC | TI
料号： ADC0804LCWMX ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.12 | $31.20 |
| 100 | $2.74 | $274.00 |
| 500 | $2.38 | $1,190.00 |
| 1,000 | $2.05 | $2,050.00 |
ADC0804LCWMX 概述
An SAR (successive-approximation-register) ADC is a sampled-data converter that compares the input voltage against an internal DAC using a binary-search algorithm, producing one conversion result per N clock cycles for N bits of resolution. SAR ADCs sit in the converter hierarchy between flash ADCs (faster, more power, expensive) and sigma-delta ADCs (slower, higher resolution, integrated digital filtering); they are favored when low latency, no pipeline delay, moderate resolution (8-16 bit), and simple microprocessor interfacing are required. The ADC0804 family is a benchmark of legacy microprocessor-compatible data acquisition.
Key features of the ADC0804LCWMX include 1 LSB integral nonlinearity (linearity error), a 135 ns memory access time, a built-in clock generator (RC-timed), and continuous or triggered conversion modes. Differential analog voltage inputs improve common-mode noise rejection. The wide-body SOIC footprint and operating range of 0 °C to +70 °C suit legacy industrial control, instrumentation, and embedded designs. According to TI datasheet SNAS538, the device can be used as a stand-alone ADC or with a microprocessor data bus.
Typical applications include legacy 8-bit microprocessor analog front ends (8080, 8051, NSC800), industrial process controllers, battery chargers, panel meters, and any design requiring ratiometric A/D conversion with simple parallel readout. The differential inputs allow direct connection to bridge sensors, thermocouple amplifiers, or ground-referenced signals using a mid-supply reference.
When designing with the ADC0804LCWMX, select an external resistor-capacitor pair (RCLK, CCLK) to set the conversion clock between 100 kHz and 1.46 MHz; the internal state machine derives the SAR clock from this master. Add 0.1 µF decoupling on VCC and ensure the reference ladder is bypassed at the REF pin for stable conversions. This device is pin-compatible with the broader ADC0801/0802/0803/0805 family.
This page synthesizes distributor stock, drop-in alternatives, and design considerations for the ADC0804LCWMX not consolidated in the TI datasheet, helping procurement and engineering teams select with full context.
直接替换替代料： ADC0804LCWMX ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： ADC0804LCWMX （相同外形与封装尺寸） ——差异在于 Architecture, Package, Operating Temperature, Conversion Time, RoHS Status.
快速对比工具——选择替代料号进行并排对比：
ADC0804LCWMX/NOPB
✅ 直接替换📋 参考替代料（不在目录中）
ADC0803LCWMX/NOPB
✅ 直接替换📋 参考替代料（不在目录中）
ADC0802LCWMX/NOPB
✅ 直接替换✓ 有现货
$5.44 / 个
查看数据手册 →ADC0801LCWMX/NOPB
✅ 直接替换📋 参考替代料（不在目录中）
ADC0805LCWMX/NOPB
✅ 直接替换📋 参考替代料（不在目录中）
ADC0804LCWMX 最大额定值与电气特性
| Number of Bits | 8 |
| Number of Inputs | 1 (differential) |
| Converter Type | SAR (Successive Approximation) |
| 采样率 | 10 kSPS |
| Data Interface | Parallel |
| Input Type | Differential (pseudo-bipolar) |
| Architecture | Differential potentiometric ladder (256R type) |
| Integral Nonlinearity (INL) | 1 LSB (max) |
| Supply Voltage (VCC) | +4.5 V to +6.5 V (typical +5 V) |
| Negative Reference (V-) | -5 V nominal |
| Analog Input Range | 0 V to +5 V (with VREF adjusted) or ratiometric with VCC |
| Memory Access Time | 135 ns |
| Conversion Time | Approx. 100 µs at 640 kHz clock |
| Internal Clock Generator | Yes (RC-timed via RCLK, CCLK pins) |
| 工作温度 | 0 °C to +70 °C |
| 封装 | 20-SOIC (0.295 inch / 7.50 mm wide-body) |
| 安装类型 | Surface Mount |
| RoHS 状态 | Depends on suffix - /NOPB variant is RoHS compliant |
| Lead-Free / Pb-Free | Yes (suffix /NOPB) |
ADC0804LCWMX 引脚配置
| 引脚 1 | VREF/2 — Optional reference input / 2.5 V reference output (depends on mode) |
| 引脚 2 | GND — Digital ground |
| 引脚 3 | /WR — Write/Start conversion (active-low input) |
| 引脚 4 | /RD — Read enable (active-low input) |
| 引脚 5 | /INTR — Interrupt output (active-low, signals end-of-conversion) |
| 引脚 6 | VIN+ — Differential analog input, positive |
| 引脚 7 | VIN- — Differential analog input, negative |
| 引脚 8 | AGND — Analog ground |
| 引脚 9 | VREF — Reference voltage (typically VCC or external) |
| 引脚 10 | DGND — Digital ground (often tied to AGND) |
| 引脚 11 | DB7 — Data bit 7 (MSB), three-state output |
| 引脚 12 | DB6 — Data bit 6, three-state output |
| 引脚 13 | DB5 — Data bit 5, three-state output |
| 引脚 14 | DB4 — Data bit 4, three-state output |
| 引脚 15 | DB3 — Data bit 3, three-state output |
| 引脚 16 | DB2 — Data bit 2, three-state output |
| 引脚 17 | DB1 — Data bit 1, three-state output |
| 引脚 18 | DB0 — Data bit 0 (LSB), three-state output |
| 引脚 19 | CCLK — Clock capacitor pin (sets internal clock frequency with RCLK) |
| 引脚 20 | VCC — +5 V analog/digital supply |
典型应用
ADC0804LCWMX 适用于 6 应用s: Legacy 8-bit Microprocessor Data Acquisition, Industrial Process Control Panels, Battery Monitoring and Charger Control, Digital Panel Meters and Instrumentation, Sensor Signal Conditioning Front End, Embedded Control and Robotics.
Legacy 8-bit Microprocessor Data Acquisition
The ADC0804LCWMX is purpose-built for 8080/8051/NSC800 8-bit microprocessor systems where a parallel-bus ADC is required. Its three-state output latches drive the data bus directly, eliminating external glue logic, and the 135 ns memory-access time fits the 8080A read cycle with no wait states. Per TI datasheet timing diagrams, a /WR pulse initiates a conversion and /INTR signals completion, letting the CPU poll or interrupt on conversion end. This makes the part ideal for retrofit boards adding analog inputs to legacy SBCs.
推荐
Industrial Process Control Panels
The differential analog inputs (VIN+ and VIN-) of the ADC0804LCWMX reject common-mode noise present in industrial environments with long sensor cables, motors, and relays. Ratiometric conversion with the +5 V supply removes reference-drift errors when measuring potentiometric or bridge-type sensors. At 10 kSPS the device easily handles thermocouple-derived millivolt signals after amplification, panel-meter inputs, and 4-20 mA loop converters. The wide-body 20-SOIC package tolerates the conformal coating and thermal cycling typical of factory-floor equipment.
推荐
Battery Monitoring and Charger Control
The ratiometric conversion principle of the ADC0804LCWMX is a natural fit for battery voltage monitoring, where the +5 V rail (often derived from the battery via a regulator) serves as the reference. A simple resistor divider scales the battery voltage to the ADC's 0-5 V input range, and any drift in VCC cancels out because both reference and input scale together. The differential input handles the ground-shift issues common in charger circuits with isolated or high-side current-sense paths. A 10 kSPS rate is more than enough for cell-balancing and end-of-charge detection.
推荐
Digital Panel Meters and Instrumentation
Digital panel meters, multimeters, and lab instrumentation benefit from the ADC0804LCWMX's differential inputs, low power, and direct 7-segment display driver compatibility (with external latch/decoder). The 1 LSB INL is sufficient for 3-digit panel meters, and the internal RC clock generator eliminates the need for a precision external oscillator. Stand-alone operation (no microprocessor required) is supported by tying /WR and /INTR together for free-running conversions, making it suitable for cost-sensitive measurement products.
推荐
Sensor Signal Conditioning Front End
Bridge sensors (load cells, pressure transducers) and thermocouples produce low-level differential signals that the ADC0804LCWMX can digitize directly when paired with an instrumentation amplifier. The differential input structure rejects common-mode thermocouple noise and bridge-excitation ground loops. The 8-bit resolution provides 256-step quantization, sufficient for setpoint control, threshold detection, and trend logging in HVAC, weigh scales, and environmental monitoring. Internal ladder reference allows ratiometric reading of bridge outputs.
推荐
Embedded Control and Robotics
The ADC0804LCWMX is widely used in hobbyist, educational, and small-robotics platforms that still rely on 5 V microcontrollers such as the 8051, BASIC Stamp, or Arduino Uno. Its simple /WR-start, /INTR-done handshake maps directly to digital GPIO pins without requiring hardware SPI or I²C peripherals. The 20-SOIC wide-body package is breadboard-friendly with a SOIC-to-DIP adapter, and the differential inputs are useful for current-sense resistors in motor drivers. This makes the part a teaching staple for ADC fundamentals.
推荐
推荐产品汇总
工程参考数据： ADC0804LCWMX ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | ADC0804LCWMX/NOPB | ADC0803LCWMX/NOPB | ADC0802LCWMX/NOPB | ADC0801LCWMX/NOPB | ADC0805LCWMX/NOPB |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 20-SOIC (0.295 inch / 7.50 mm wide-body) | 20-SOIC (0.295 inch / 7.50 mm wide-body) - same | 20-SOIC (0.295 inch / 7.50 mm wide-body) - same | 20-SOIC (0.295 inch / 7.50 mm wide-body) - same | 20-SOIC (0.295 inch / 7.50 mm wide-body) - same | 20-SOIC (0.295 inch / 7.50 mm wide-body) - same |
| Resolution | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit | 8 bit |
| Sampling Rate | 10 kSPS | 10 kSPS | 10 kSPS | 10 kSPS | 10 kSPS | 10 kSPS |
| Integral Nonlinearity (INL) | ±1 LSB | ±1 LSB | ±½ LSB (better) | ±¼ LSB (best) | ±¼ LSB (best) | ±1 LSB |
| Memory Access Time | 135 ns | 135 ns | 135 ns | 135 ns | 135 ns | 135 ns |
| Supply Voltage | +5 V (with -5 V optional) | +5 V (with -5 V optional) | +5 V (with -5 V optional) | +5 V (with -5 V optional) | +5 V (with -5 V optional) | +5 V only (no -5 V needed) |
| RoHS / Lead-Free | Non-RoHS (base), /NOPB variant is Pb-free | Pb-free RoHS compliant | Pb-free RoHS compliant | Pb-free RoHS compliant | Pb-free RoHS compliant | Pb-free RoHS compliant |
| Approx. Unit Price (qty-1, as of 2026-10-06) | $3.45 | $3.65 | $3.85 | $4.10 | $4.30 | $3.55 |
关键差异点
- True differential analog inputs (VIN+ and VIN-) improve common-mode noise rejection （对比 ADC0805LCWMX/NOPB)
- Standard ±1 LSB INL at lowest cost in the family （对比 ADC0801LCWMX/NOPB)
- Direct 8080-bus interface with no external glue logic （对比 ADC0820CCM+ (different family, NOT pin-compatible))
设计说明
Estimated: the ADC0804LCWMX draws typically 1.5 mA quiescent and 3 mA during active conversion at +5 V. Add a 0.1 µF ceramic decoupling capacitor as close as possible to the VCC pin (pin 20), with a 10 µF tantalum or aluminum bulk cap on the supply rail. If using the optional -5 V reference (V-), bypass it with another 0.1 µF cap at the entry point. Reference-noise on VCC directly couples into conversion results in ratiometric mode, so keep VCC clean.
Do not leave the analog input (VIN+ or VIN-) floating - any undefined voltage between AGND and VCC can inject noise and cause erratic LSB toggling. Always tie unused analog inputs to AGND via a 10 kΩ resistor. Also, the internal clock requires an external RC network on pins CCLK (19) and RCLK: a typical 10 pF capacitor and 100 kΩ resistor yields ~640 kHz, but consult the datasheet formula for non-standard clock rates. Mis-sizing these components is the #1 reason for failed first-prototype conversions.
Keep analog and digital grounds separate and join them at a single point near the ADC0804LCWMX AGND pin (pin 8). Place the VCC decoupling capacitor within 3 mm of pin 20, and route analog input traces differentially (VIN+ and VIN- parallel, equal length) to avoid common-mode pickup. Per TI datasheet figure on PCB layout, the SOIC-20 wide-body allows easy manual rework but the exposed lead frame under the part has no thermal pad - thermal dissipation is primarily through the leads, so use wider copper pours on the supply pins.
合规信息
Base ADC0804LCWMX (without /NOPB suffix) is non-RoHS / contains lead. The ADC0804LCWMX/NOPB variant is RoHS compliant and Pb-free. AEC-Q100 not qualified - this is a commercial-grade (0 to +70 C) part. For RoHS-compliant designs, always specify the /NOPB suffix variant.
