ADC0820BCV - 8-Bit 666kSPS Half-Flash ADC w/ T/H | Texas Instruments
N.º de pieza: ADC0820BCV ✗ Fin de vida| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $6.5 | $6,50 |
| 10 | $5.85 | $58,50 |
| 100 | $5.2 | $520,00 |
| 500 | $4.55 | $2.275,00 |
| 1.000 | $3.9 | $3.900,00 |
ADC0820BCV Descripción general
A half-flash (or sub-ranging) ADC is an architecture that splits a full flash converter into two lower-resolution flash blocks (typically 4-bit MSB plus 4-bit LSB) and combines them sequentially to halve the comparator count versus a true flash, while still achieving sub-microsecond conversion times. The ADC0820BCV uses 31 comparators, a 4-bit MSB flash, and a 4-bit LSB flash with internal DAC and track-and-hold. It belongs to the converter -> ADC -> successive-approximation/half-flash ADC -> data-acquisition IC hierarchy.
Key features include latched three-state outputs that map directly to a microprocessor data bus, no external zero/full-scale adjustment, an overflow bit (OF) for cascading, and an operating temperature range of 0°C to +70°C (commercial grade). The PLCC-20 footprint supports 0.3" standard-width 20-pin DIP-style PCB layouts via J-lead castellated edges.
Typical applications include digital voltmeters, portable instrumentation, process-control front ends, disk-drive read channels, and embedded microprocessor data-acquisition boards where parallel bus speed and simple interface logic are critical.
When designing with the ADC0820BCV, treat the analog input as a switched-capacitor node and place a low-impedance buffer ahead of VIN to avoid dynamic errors. Use a clean 5V analog supply with local decoupling (0.1 µF ceramic in parallel with 10 µF tantalum) and route digital ground returns separately from analog grounds to keep digital switching noise out of the converter's reference ladder.
This page consolidates pricing tiers, drop-in alternatives, and application-level design notes that go beyond the manufacturer datasheet's parametric tables.
Alternativas directas para ADC0820BCV — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con ADC0820BCV (mismo factor de forma y huella) — difiere en Operating Temperature, Supply Voltage, Mounting Type, Data Interface, Architecture.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
ADC0820BCN
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ADC0820BCV Valores máximos y características eléctricas
| Number of Bits | 8 |
| Sampling Rate (Per Second) | 667 kSPS |
| Number of Inputs | 1 |
| Input Type | Single-Ended (Pseudo-Differential option per datasheet) |
| Data Interface | Parallel |
| Architecture | Half-Flash (Sub-Ranging) with Track-and-Hold |
| Analog Input Range | 0 V to 5 V |
| Conversion Time | 1.5 µs typical |
| Number of Comparators (internal) | 31 |
| Voltage Supply | 4.5 V to 5.5 V (single 5 V) |
| Power Dissipation | 75 mW max |
| Temperatura de funcionamiento | 0 °C to +70 °C |
| Encapsulado | 20-PLCC (J-Lead, 9x9 mm) |
| Tipo de montaje | Surface Mount |
| Tipo de salida | Three-State Latched Parallel |
| Overflow Output | Yes (cascadable for higher resolution) |
| Zero/Full-Scale Adjust | Not required |
Configuración de pines de ADC0820BCV
| Pin 1 | VIN+ — Analog input (non-inverting) |
| Pin 2 | VIN- — Analog input (inverting / GND for single-ended) |
| Pin 3 | VREF — Voltage reference input (ratiometric) |
| Pin 4 | GND — Ground |
| Pin 5 | OF — Overflow output (high when input overranges) |
| Pin 6 | DB0 — Data bit 0 (LSB, three-state) |
| Pin 7 | DB1 — Data bit 1 (three-state) |
| Pin 8 | DB2 — Data bit 2 (three-state) |
| Pin 9 | DB3 — Data bit 3 (three-state) |
| Pin 10 | DB4 — Data bit 4 (three-state) |
| Pin 11 | DB5 — Data bit 5 (three-state) |
| Pin 12 | DB6 — Data bit 6 (three-state) |
| Pin 13 | DB7 — Data bit 7 (MSB, three-state) |
| Pin 14 | RD — Read strobe (active low) |
| Pin 15 | WR/RDY — Write / mode select / ready |
| Pin 16 | CS — Chip select (active low) |
| Pin 17 | MODE — Mode select (RD/WR vs. RDY) |
| Pin 18 | INT — Interrupt / conversion complete |
| Pin 19 | VCC — +5V supply |
| Pin 20 | VCC — +5V supply (tied to pin 19) |
Aplicaciones típicas
ADC0820BCV es adecuado para 7 aplicacións: Digital Voltmeter / Panel Meter, Embedded Microprocessor Data Acquisition, Process Control / Sensor Front End, Disk Drive / Servo Read Channel, Portable Instrumentation / Handheld Meter, Legacy Industrial PLC Analog Input Module, Audio-Bandwidth Signal Digitizer (Legacy).
Digital Voltmeter / Panel Meter
The ADC0820BCV fits 8-bit panel-meter designs because its 1.5 µs conversion time provides >500 readings per second - more than enough for a 3-1/2 digit display update rate while leaving headroom for averaging. The half-flash architecture eliminates external sample-and-hold complexity, and the 0V-5V input maps directly to most voltage-divider front ends. A typical implementation uses an op-amp input buffer, 2.5V or 5V reference, and direct parallel connection to an LCD driver. Compared to modern SAR ADCs, the ADC0820BCV's 75 mW power is acceptable for mains-powered instruments but high for battery use.
Recomendado
Embedded Microprocessor Data Acquisition
The ADC0820BCV connects to an 8080, 8051, or Z80 microprocessor without external glue logic because its latched three-state outputs appear as a memory-mapped I/O port. The RD and WR control inputs tie directly to the processor bus, while the 8-bit data bus requires no extra latches. With 666 kSPS throughput, the ADC0820BCV samples audio-bandwidth signals (up to ~330 kHz Nyquist) in low-cost SBC designs. Compared to serial-output SAR ADCs, the parallel interface simplifies timing but consumes more GPIO pins on modern microcontrollers.
Recomendado
Process Control / Sensor Front End
The ADC0820BCV suits 4-20 mA loop and thermocouple front ends where 8-bit resolution (1 part in 256) is sufficient for setpoint monitoring rather than precision measurement. Its ratiometric operation cancels reference drift when the sensor excitation is used as VREF - critical for bridge sensors and RTD conditioning. A typical front end uses an instrumentation amp (e.g., AD620 family) feeding the 0-5V input. The PLCC-20 footprint and 0-70°C operating range target industrial cabinet environments, not harsh field mounting.
Recomendado
Disk Drive / Servo Read Channel
Historically the ADC0820BCV was specified into floppy-disk and early hard-disk servo-loop designs because its 1.5 µs conversion time supports the servo-sampling rate of legacy spindle motors. The on-chip track-and-hold captures fast position-error signals without external S/H, simplifying the analog signal chain. Although obsolete for new storage products, the ADC0820BCV remains in repair-channel demand for legacy industrial equipment. Modern replacements include 10-12 bit pipelined ADCs but require complete analog-front-end redesign.
Recomendado
Portable Instrumentation / Handheld Meter
The ADC0820BCV can serve low-speed handheld instruments - multimeters, thermometers, light meters - where 8-bit resolution (0.4% FS) is acceptable. Although its 75 mW dissipation is high for battery operation, the part fits wall-powered or line-rechargeable designs well. The PLCC-20 package is larger than modern QFN alternatives, so handheld enclosures must accommodate the 9x9 mm body. For new handheld designs, choose a modern 8-bit SAR in MSOP/QFN; the ADC0820BCV is reserved for repairing legacy units.
Recomendado
Legacy Industrial PLC Analog Input Module
The ADC0820BCV was a standard analog-input building block in 1980s-1990s PLC modules where its parallel interface simplified backplane bus arbitration. Many of those PLCs are still in service in factories, water-treatment plants, and power substations - keeping the ADC0820BCV in active repair demand. With 0-70°C operating range and 8-bit resolution, the part handles setpoint and alarm monitoring rather than closed-loop PID measurement. For new PLC modules, modern isolated sigma-delta ADCs like AD7738 or AD7708 replace the ADC0820BCV with much higher noise immunity.
Recomendado
Audio-Bandwidth Signal Digitizer (Legacy)
The ADC0820BCV's 666 kSPS throughput yields a Nyquist bandwidth of ~333 kHz - well above the 20 kHz audio band - making it usable for low-cost digital audio effects processors, spectrum analyzers, and graphic equalizers from the early 1990s. Its 8-bit resolution (48 dB SNR ideal) is below modern audio requirements (16-bit/96 dB) but acceptable for toys, karaoke machines, and toys. The on-chip track-and-hold avoids external S/H complexity when digitizing multiplexed audio channels. For modern audio, use a 16+ bit sigma-delta codec like PCM1794A.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para ADC0820BCV — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | ADC0820BCN |
|---|---|---|
| Brand | Texas Instruments | Texas Instruments |
| Package | 20-PLCC (J-Lead, 9x9 mm) | 20-PDIP (thru-hole, NOT same footprint) |
| Resolution | 8 bit | 8 bit |
| Sampling Rate | 666 kSPS | 666 kSPS |
| Architecture | Half-Flash | Half-Flash |
| Analog Input Range | 0 V to 5 V | 0 V to 5 V |
| Power Dissipation | 75 mW max | 75 mW max |
| Operating Temperature | 0 °C to +70 °C | 0 °C to +70 °C |
| Lifecycle Status | Obsolete | Obsolete |
| RoHS | Non-compliant (legacy SnPb) | Non-compliant |
Diferenciadores clave
- On-chip track-and-hold eliminates external S/H (frente a TI ADC0804 (successive-approximation 8-bit))
- Half-flash 1.5 µs conversion time (frente a TI ADC0804 (SAR, ~110 µs conversion))
- Overflow output enables cascadable 9-bit extension (frente a Basic 8-bit flash ADCs without OF)
Notas de diseño
Estimated: at VCC = 5 V and IDD = 15 mA typical, the ADC0820BCV dissipates approximately 75 mW. Place a 0.1 µF ceramic capacitor in parallel with a 10 µF tantalum directly at pins 19/20 (VCC) and pin 4 (GND), within 5 mm of the package. Use a star-ground topology with the ADC ground tied to the analog ground plane near the reference bypass; route digital return currents away from the analog ground island to avoid digital switching noise coupling into the reference ladder.
The PLCC-20 socket requires a 20-pin PLCC through-hole footprint with castellated J-lead pads. If designing for hand-soldered prototypes, use a machine-pin PLCC socket rather than direct soldering because the J-leads are difficult to reflow without hot air. Keep the analog input trace short and guarded with a ground trace; the ADC0820BCV's switched-capacitor input structure draws transient currents during the acquisition phase that inject crosstalk into adjacent traces.
Common pitfalls include: (1) treating VIN as a high-impedance node - it is not; the half-flash architecture draws burst currents during conversion, so always buffer with a low-impedance op-amp (e.g., TL081, LF351, or modern equivalent). (2) Forgetting that MODE pin selection changes the RD/WR timing protocol; mode 0 (RD/WR strobe) differs from mode 1 (RDY handshake) - misconfiguring this yields non-functional reads. (3) Driving VREF above VCC violates absolute-max ratings and latches up the ESD structure.
Información de cumplimiento
Pre-RoHS design (released 1988-1990s era) with SnPb PLCC-20 terminations. Not AEC-Q100 qualified; commercial temperature grade (0 to +70 °C). RoHS-compliant variants may exist in the ADC0820 family - confirm with the manufacturer's ordering information.
