ADS8505IDBRG4 - 16-Bit 250kSPS SAR ADC w/Parallel Interface | TI
MPN: ADS8505IDBRG4 ✓ Hoạt độngADS8505IDBRG4 Tóm tắt
What is a SAR ADC? A successive-approximation-register analog-to-digital converter is a precision data-conversion architecture that uses a binary-search algorithm against an internal DAC and comparator to resolve N bits in N clock cycles. SAR ADCs sit in the broader taxonomy of ADCs -> data converters -> signal chain ICs -> mixed-signal semiconductors, combining low power consumption, deterministic latency, and high DC accuracy. They are preferred over delta-sigma converters in multiplexed, multi-channel data-acquisition systems where latency and per-channel settling matter.
Key features include ±1.5 LSB maximum INL, ±105 dB SFDR at the 250 kHz sample rate, single +5 V analog supply operation, and ±10 V true bipolar input range using on-chip input scaling resistors. The device integrates a high-bandwidth track-and-hold, internal 2.5 V reference, and 3-state output drivers, eliminating the need for an external reference or high-current bus interface. The 28-SSOP package provides a low-profile surface-mount footprint suitable for compact data-acquisition front ends.
Architecturally, the ADS8505 uses a charge-redistribution capacitor DAC combined with a low-noise comparator and a precision laser-trimmed input resistor ladder. The capacitor array produces inherently low digital noise and high spurious-free dynamic range because the SAR switching pattern generates minimal kickback at the input. The internal reference and full-scale calibration registers deliver guaranteed INL/DNL across the industrial temperature range.
Typical applications include industrial process control, multi-channel data-acquisition systems, instrumentation and test equipment, medical imaging front ends, and precision sensor signal conditioning. The ±10 V input range and 16-bit resolution enable direct connection to legacy industrial transducers and 4-20 mA loop receivers without external signal conditioning.
When designing with this part, note that the parallel interface requires careful PCB routing to avoid digital crosstalk into the analog inputs; keep the digital bus traces short and guard the analog ground plane. The internal reference requires an external bypass capacitor; consult the datasheet for the recommended capacitor value and ESR range.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, giving procurement and design engineers a single reference for the ADS8505IDBRG4.
Bộ thay thế dễ dàng lắp đặt cho ADS8505IDBRG4 — 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 ADS8505IDBRG4 (cùng hình factor và footprint) — khác nhau ở Package, RoHS Status, Sampling Rate, Resolution, Input Voltage Range.
ADS8505IDB
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
ADS8505IDBRG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7825UE4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7825PG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7805PG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7805PB
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7806UG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS7806PG4
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →ADS8505IDBRG4 Tỷ lệ tối đa & tính chất điện
| Độ phân giải | 16 bit |
| Sample Rate | 250 kSPS |
| Architecture | SAR (Successive Approximation) |
| Number of Channels | 1 |
| Phạm vi điện áp đầu vào | ±10 V / ±5 V / ±3.3 V (software selectable) |
| Analog Supply Voltage | 5 V |
| Digital Interface | Parallel (16-bit + control) |
| Internal Reference | 2.5 V |
| INL (Max) | ±1.5 LSB |
| SFDR | 105 dB at 250 kSPS |
| Nhiệt độ hoạt động | -40 °C to +85 °C (industrial) |
| Hộp | 28-SSOP (DB) |
| Kiểu lắp đặt | Surface Mount |
| Cấp MSL | 2 (1 year floor life) |
| Trạng thái RoHS | Compliant |
Cấu hình chân ADS8505IDBRG4
| Chân 1 | AGND — Analog ground return |
| Chân 2 | REFIN/REFOUT — Internal 2.5 V reference bypass |
| Chân 3 | AIN — Analog input (after resistor ladder) |
| Chân 4 | R1 — Input range select bit 1 (with R0 selects ±10/±5/±3.3 V) |
| Chân 5 | R0 — Input range select bit 0 |
| Chân 6 | CS — Chip select (active low) |
| Chân 7 | RD — Read strobe (active low) |
| Chân 8 | BUSY — Conversion in progress (active high) |
| Chân 9 | CONVST — Conversion start (active high) |
| Chân 10 | CLK — Clock input/output (INT/EXT selected via pin) |
| Chân 11 | TAG — Tag input for data tagging (per datasheet) |
| Chân 12 | NC — Not connected (per datasheet) |
| Chân 13 | NC — Not connected (per datasheet) |
| Chân 14 | NC — Not connected (per datasheet) |
| Chân 15 | DGND — Digital ground |
| Chân 16 | DB15 (MSB) — Parallel data bit 15 (MSB) |
| Chân 17 | DB14 — Parallel data bit 14 |
| Chân 18 | DB13 — Parallel data bit 13 |
| Chân 19 | DB12 — Parallel data bit 12 |
| Chân 20 | DB11 — Parallel data bit 11 |
| Chân 21 | DB10 — Parallel data bit 10 |
| Chân 22 | DB9 — Parallel data bit 9 |
| Chân 23 | DB8 — Parallel data bit 8 |
| Chân 24 | DB7 — Parallel data bit 7 |
| Chân 25 | DB6 — Parallel data bit 6 |
| Chân 26 | DB5 — Parallel data bit 5 |
| Chân 27 | DB4 — Parallel data bit 4 |
| Chân 28 | DB3 — Parallel data bit 3 |
Ứng dụng tiêu biểu
ADS8505IDBRG4 phù hợp cho 6 Áp dụngs: Industrial Process Control, Multi-Channel Data Acquisition Systems, Test and Measurement Instrumentation, Medical Imaging Front Ends, Precision Sensor Signal Conditioning, Legacy Industrial Interface Replacement.
Industrial Process Control
The ADS8505IDBRG4 fits industrial process-control front ends thanks to its true ±10 V bipolar input range, 16-bit resolution, and 250 kSPS sample rate, allowing direct connection to legacy 4-20 mA loop receivers and ±10 V transducer outputs without external signal conditioning. Placed downstream of instrumentation amplifiers, the ADC digitizes valve position, pressure, and temperature signals at the controller's sample-rate budget. Its ±1.5 LSB INL and 105 dB SFDR at full speed preserve measurement linearity across the industrial temperature range (-40 °C to +85 °C), unlike lower-precision ADCs that lose linearity at industrial operating points.
Được đề xuất
Multi-Channel Data Acquisition Systems
For multi-channel data-acquisition systems, the ADS8505IDBRG4's deterministic single-cycle SAR latency and 250 kSPS throughput enable clean per-channel settling when paired with an external analog multiplexer. Each channel settles to 16 bits within a single conversion cycle, unlike delta-sigma ADCs that introduce digital-filter group delay. The parallel interface supports direct connection to FPGAs or microcontrollers with 16-bit external memory buses, simplifying timing closure at full sample rate. Industrial-grade temperature range and ±10 V inputs allow one part to serve most transducer types in mixed-signal DAQ cards.
Được đề xuất
Test and Measurement Instrumentation
The ADS8505IDBRG4 suits test-and-measurement instruments that demand both bipolar input range and 16-bit DC accuracy. The integrated 2.5 V reference eliminates external reference drift concerns, while the parallel data interface enables real-time waveform capture into high-speed buffers. With 105 dB SFDR at 250 kSPS, harmonic distortion performance is sufficient for spectrum-analyzer digitizer sections and bench DMMs that previously required discrete ADC boards. The 28-SSOP package fits standard 0.1-inch center instrumentation prototyping footprints.
Được đề xuất
Medical Imaging Front Ends
The ADS8505IDBRG4 supports medical imaging front ends that require 16-bit precision with ±10 V input range to digitize ultrasound, patient-monitoring, and diagnostic sensor signals. Its low INL and high SFDR maintain dynamic range across multi-MHz transducer signal bandwidths. The parallel data bus enables high-throughput transfer to image-processing DSPs and FPGAs at full 250 kSPS, while the industrial temperature range suits portable and bedside monitoring equipment. The internal 2.5 V reference reduces BOM count in space-constrained medical enclosures.
Được đề xuất
Precision Sensor Signal Conditioning
The ADS8505IDBRG4 serves precision sensor signal-conditioning applications where true bipolar ±10 V inputs and 16-bit accuracy are required to digitize strain-gauge, load-cell, and bridge-sensor outputs. The integrated precision resistor ladder scales high-level transducer outputs directly into the ADC core without external attenuators that would degrade noise performance. Combined with the internal 2.5 V reference and ±1.5 LSB INL, the part enables direct ratiometric measurement in weigh-scale and force-sensing designs where end-to-end calibration matters.
Được đề xuất
Legacy Industrial Interface Replacement
The ADS8505IDBRG4 is widely used as a legacy industrial interface replacement for older 12-bit and 14-bit ADC boards that need a precision upgrade without PCB redesign. Its 28-SSOP footprint and parallel bus timing are pin-compatible with older 28-pin ADC packages, enabling drop-in upgrades that double or quadruple effective resolution. Industrial PLC manufacturers use the part to extend product life cycles of existing 24-V I/O modules while preserving backward compatibility with existing transducer wiring and field-installed sensors. The 5 V single-supply operation simplifies integration into legacy analog rails.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho ADS8505IDBRG4 — 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 | ADS8505IDB | ADS7825UE4 | ADS7825PG4 | ADS7805PG4 | ADS7806UG4 |
|---|---|---|---|---|---|---|
| Package | 28-SSOP (DB) | 28-SSOP (DB) - same | 28-SSOP (DB) - same | 28-SSOP (DB) - same | 28-SSOP (DB) - same | 28-SSOP (DB) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Resolution | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit | 16 bit |
| Sample Rate | 250 kSPS | 250 kSPS | 200 kSPS | 200 kSPS | 100 kSPS | 200 kSPS |
| Input Voltage Range | ±10 V / ±5 V / ±3.3 V | ±10 V / ±5 V / ±3.3 V | 0-5 V (unipolar) | 0-5 V (unipolar) | ±10 V (bipolar) | ±10 V (bipolar) |
| Digital Interface | Parallel (16-bit) | Parallel (16-bit) | Parallel (16-bit) | Parallel (16-bit) | Parallel (16-bit) | Parallel (16-bit) |
| Internal Reference | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V | 2.5 V |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| RoHS Compliant | Yes | Varies by suffix | Yes (E4 suffix) | Yes (G4 suffix) | Yes (G4 suffix) | Yes (G4 suffix) |
Bảo phân biệt quan trọng
- Higher sample rate vs older TI 28-SSOP SAR ADCs (vsADS7805PG4)
- Software-selectable bipolar input ranges vs fixed unipolar on ADS7825 (vsADS7825UE4)
- Integrated true-bipolar input ladder vs external conditioning on ADS7806 (vsADS7806UG4)
- Internal 2.5 V reference with high SFDR (vsADS7825UE4)
Ghi chú thiết kế
Estimated: Keep parallel data bus traces short (<50 mm) and surround them with a digital ground guard to minimize crosstalk into the analog input. The ADS8505IDBRG4 mixes fast digital edges (BUSY, CONVST, RD) with a high-impedance analog input path - even a few millimeters of unmatched trace can couple switching noise into the input at full-scale input transitions. Use a split analog/digital ground plane tied at a single point under the AGND pin, per the datasheet layout recommendation.
The ADS8505IDBRG4 requires a single +5 V analog supply; add a 10 µF tantalum bulk capacitor in parallel with a 0.1 µF ceramic bypass within 5 mm of the AVDD pin. The internal reference (REFIN/REFOUT) needs an external 2.2 µF low-ESR ceramic bypass capacitor (X7R or X5R) per the datasheet. Inadequate reference bypassing is a common cause of degraded INL and channel-to-channel gain error in multiplexed systems.
Do not drive the analog input above the supply rails (±15 V absolute max on AIN); clamping diodes will forward-bias and inject errors into the conversion. When using input range select pins R0/R1, ensure they are tied to valid logic levels before CONVST is asserted - a floating input range select pin can cause the ADC to sample out-of-range codes. The TAG pin function requires firmware coordination and should be tied to DGND if unused.
For systems using an external clock (CLK pin), drive CLK with a low-jitter (<50 ps rms) CMOS source to avoid degrading SNR. Per TI's datasheet, the recommended external clock frequency is approximately 5 MHz for 250 kSPS operation. Estimated: at 5 MHz external clock and 250 kSPS sample rate, the SAR conversion completes in 20 clock cycles, leaving margin for the internal track-and-hold acquisition window.
Thông tin tuân thủ
RoHS and REACH compliance per TI product page. G4 suffix denotes lead-free terminal finish. AEC-Q100 not applicable - this is a commercial/industrial grade part.
